ECOLOGIA BALKANICA2020 Vol 12 Issue 1 June 2020 pp 41-56

Assessment of Trees Vitality inUrban Landscape of Steppe Zone

Svitlana O Volodarets1 Iryna O Zaytseva2Olexander Z Gluchov3 Anna S Maslak1

1 - Dnipropetrovsk State Medical Academy Department of Biochemistry and MedicalChemistry Soborna Sq 4 Dnipro 49027 49027 UKRAINE

2 - Oles Honchar National University Faculty of Biology and Ecology Department of PlantsPhysiology and Introduction Kazakova Str 24 Dnipro 49107 UKRAINE

3 - The National Academy of Sciences of Ukraine Department of General Biology specialityBiological and Landscape Diversity Volodymyrska Str 54 Kiev 010300 UKRAINE

Corresponding author svetlanavolodaretsgmailcom

Abstract During planning of green planting in cities vital status of plants which make up thegroups is taken into account first The methods of assessment of morphological and physiologicalparameters of the vital status are the most widely used ones In the process of work the vitality ofwoody plants was evaluated under the impact of anthropogenic pressure in the framework of thephysiological state which is determined to a great extent by the content of chlorophylls in theleaves of trees The content of green and yellow pigments was studied in the drought conditions ofvegetative period for 8 species of trees which are common in green planting of cities in the South-East of Ukraine Stable species (Populus simonii Carrieacuter Populus times canadensis Moench) respond byincrease in the content of chlorophylls at maximum air temperatures during the growing seasonNonsufficient-stable species show significant effect of the amount of rainfall on the changes inchlorophyll content in leaves which is the evidence of their adaptive capacity Deterioration of thefunctional state of trees in street and park planting compared to suburban territories was revealedconfirmed by reduced chlorophyll content and increase in carotenoids For the further introductionin the urban greening of industrial cities of steppe zone the models of influence of themeteorological factors on the content of green pigments in the leaves of Polulus simonii and Acerpseudoplatanus L are proposed Key words trees urban environment total chlorophylls carotenoids meteorological factorsexhaust gases

IntroductionTrees as a part of urban plantation

perform a number of functions theydecontaminate the air absorb CO2 enrichthe atmosphere with oxygen etc Howeverin the conditions of big industrial cities trees

are affected by environmental pollutantsThe air pollution of the territories ofindustrial-urban centres has on a complexcharacter In the residential areas of the citythe main source of pollution are motor carsin the industrial zones - the enterprises of

copy Ecologia Balkanicahttpebbiouni-plovdivbg

Union of Scientists in Bulgaria ndash PlovdivUniversity of Plovdiv Publishing House

Assessment of Trees Vitality in the Urban Landscape of Steppe Zone

thermal power metallurgical chemicalprocessing and mining industry The resultof car enginesrsquo running is the release ofexhaust gases CO2 NxOy SO2 hydrocarbonsaldehydes soot and benzo(a)pyrene (Hopke2009) Among industrial pollutants sulfurdioxide and nitrogen oxides represent thegravest hazard for plants Premature fall ofleaves and needles occurs in woody plantsaffected by sulfur dioxide (Palau et all2009) The action of nitrogen oxides leads tochloroses of various types brownish-blacksections appear on the top and at the edgesof leaves (Spellberg 1998) The level ofpollution of a certain territory of the city isdetermined by the distance from the mainsources of contamination the majordirections of the wind rose the topographicfeatures and the city planning situation(Korshikov et al 2005)

Specific conditions of the southeasternsteppe with high temperatures in summerand low temperatures in winter seasonsstrong winds and low rainfall areexacerbated in the urban areas Almost allenvironmental components in the big city ndashatmosphere flora soil relief hydrographicnetwork groundwaters ndash undergo changesAnthropogenic factors affect the indicatorsof temperature humidity the formation ofair masses and light conditions which ingeneral leads to the emergence of peculiarmicroclimate Thermal chemical radiationelectromagnetic light sound vibrationfactors etc are the main negative urbanfactors In the cities they often actsimultaneously particularly with regard tothe motorways with heavy traffic (Zhang etal 2007 Nowak et al 2006 Morgenroth ampOumlstberg Iqbal et al 2015)

In Ukraine the large number of majorcities with powerful enterprises are situatedon the southeast It should be noted thatspecific conditions of the southeastern partof steppe zone of Ukraine with hightemperatures in summer and lowtemperatures in winter seasons strongwinds and low rainfall and drought areadditional stressed factors for plants at

urban territories In these settings thedurability and efficiency of urban treeplantations are diminished that has negativeenvironmental and economic impacts(Korshikov amp Vinogradova 2005) In thisconnection the urgent task of ecologicalresearch is to monitor and diagnose theliving condition of urban-steppe landscapesplantations of the steppe zone with thecomplex influencing negative anthropogenicand natural and climatic factors

In order to determine the vitality oftrees different approaches are used(Johnstone et al 2013) ndash from ocularestimate method of the general conditions ofthe individual on point scales (Suslova et al2013) biomorphological assessments ofgrowth development phenorhythm typesand reproductive ability (Korshikov ampKrasnoshtan 2012) to physiological andbiochemical indicators of the activity ofmetabolic processes and concentration offunctionally important compounds andmetabolites in the leaves - plastid pigmentstotal nitrogen soluble proteins non-structural pigments starch lipids etc(Glibovytska et al 2017) A wide range ofthese methods is able to give definitelycomprehensive assessment of the vital stateof plants At the same time in ecologicalinvestigations preferences are disposed tothe separate test-parameters and express-methods which characterize the mostadequately the state of plants under specificconditions depends on the performancetargets

Besides this the parameter ofphotosynthetic pigment concentration iswidely used in the conditions of industrialcontamination of the functional state of thewoody plants The similar studies areconducted to determine the droughtresistance of plants thereby the plantreaction to the pollution is the same as thereaction of dehydration factor Photosystemsof chloroplast especially photosystem II thatcontains light harvesting complexes ofphotosynthetic pigments are too sensitivesystems of deferential mesophyll cells and

42

Volodarets et al

their adaptability ensures the preservation ofthe photosynthetic apparatus and itsrestoration in case of damage (Morgenroth ampOumlstberg 2017) According to Bessonova et al(2015) sum of chlorophylls is reduced by theaction of car exhausts Changes of theconcentration of chlorophylls andcarotenoids indicate the decrease in theplantsrsquo metabolic processes under stress(Uhrin amp Supuka 2016) For quantityassessment of plants gas resistance has beensuggested air pollution tolerance index forthe calculation of which in addition to theleaf water content indexes pH of leaf tissueextract the parameter of chlorophyllconcentration is used (Tripathi et al 2009)

The physiological aspects of vital status ofwoody plants under the stressed hydrothermalurban conditions during the vegetative periodare not yet fully understood The easternmostcontinental area of the steppe zone of Ukraine ndashDonetsk city draws the biggest attention fromthis side A full-scale study of the viability ofthe urban tree plantations was conducted hereifn through inventory using the ocular estimatemethod (Suslova 2013) In some works thephysiological indicators of treesrsquo vitality in thecities of southeastern Ukraine were determinedFor example the vitality for certain species ofthe Acer genus was determined with the use ofchlorophyll concentration without taking intoaccount meteorological factors of the periodunder study (Korshikov amp Vinogradova 2005)Therefore the study of the impact of the urbanenvironment on the functional state of trees andprediction of its subsequent changes is relevantfor the proper management and planning ofgreen building in the steppe zone

The goal of the work was the assessmentof the vitality of trees in urban and industrialterritories in the conditions of continentaldrought climate of the steppe zone dependingon the dynamics of changes and quantitativedetermination of plastid pigments

Materials and MethodsResearch was conducted during two

years (2012 2013) in one of the largestindustrial cities of southeastern Ukraine ndash

Donetsk The city is located between 48deg 02rsquonorth latitude and 37deg 48rsquo east longitudeMonitoring sites 1 and 2 (ms 1 ms 2) aresituated in the residential area of the citywith inherent level of air pollution which isformed by the fumes from miningprocessing and metallurgical enterprises butthey differ in the content of individualingredients

Ms 1 is located on the Kyivskyi avenuewith intensive with heavy traffic and higherpollution ms 2 ndash in the large green area of theRecreation and Entertainment Park with less levelof pollution According to the Sectoral StateArchive of the Hydro-meteorological Service ofUkraine (Ukrainian hydrometeorological center)the total average daily concentration of SO2 NO2dust CO formaldehyde at ms 1 was 2175 and2102 mgm3 in the years of research whereasmt2 ndash 1712 and 2006 mgm3 It should be notedthat the level of SO2 content at the monitoringpoints in both years was within 02 MPC

Higher total level of pollution on ms 1 wasachieved due to the increased content of thebasic ingredients of exhaust gases in both yearsof research СО - 16925 and 16515 mgm3 andparticularly NO2 - 01771 and 01731 mgm3which was 443 and 433 MPC respectively Atms 2 the CO content was 12451 and 15234mgm3 NO2 - 00967 and 01575 mgm3 (242and 394 MPC) Besides this at ms 1 it wasestablished increased average dailyconcentrations of ammonia - 00730 mgm3 (182MPC) phenol mgm3 - 00036 (120 MPC) Allthis testifies to a higher level of air pollution onthe ms 1 - the central city highway comparedto the city park area (ms 2)

Control monitoring site (ms 3) isplaced at a distance of 15 km from thetown in the village of Tonenke There areno urban and industrial impacts on theenvironment and it is characterized by asmall (background to this region) contentof ingredients such as SO2 (00050 and00100 mgm3) and NO2 (0093 and 01060mgm3)

Species widely used in greening of thecity were studied during the growing seasonin 2012 and 2013 (from May to October)

43

Assessment of Trees Vitality in the Urban Landscape of Steppe Zone

which differ on the hydrothermal conditionsAs illustrated in Fig1 the first year wasprosperous for plants due to the temperatureregime and falls amount except of thedrought autumn period which was nottypical for the steppe zone The second yearwas characterized by the droughts in springand summer which is common for theclimate of the South-East of Ukraine and lesssuitable for normal growth and developmentof trees Monthly average temperatures airhumidity and rainfall were taken from thereports of the National Hydro-meteorological Center of Ukraine (Ukrainianhydrometeorological center)

a

b

Fig1 Hydrothermal conditions in the yearsof research in Donetsk a ndash 2012 b ndash 2013

- drought periods- dynamic of temperature during the year- dynamic of falls during the year

Eight tree species of the AceraceaSalicaceae Fabacea Malvaceae and Oleaceaegenera were studied at three monitoring sitesin different types of plantations in the linearstreet plantations on the Kyivskyi avenue (ms1) in the massive plantations in the Recreationand Entertainment Park (ms 2) plots in thefield shelter belts and village plantations ofvTonenke at control site (ms 3) We selected

7-8 even-aged model trees of each specieswith the most typical vital status for theplantations of monitoring sites

General vitality of the plants wasestablished under the ocular 8-point scaleby Savelieva (1975) which is commonlyused in the investigated area (Suslova et al2013 Polyakov et al 2012) The scale isbased on the criteria of the trunk and crowndamages inhibition of apical and lateralgrowths drying of branches dry tops thepresence of adventitious shoots vegetativeshoots on the trunk coppice shootsdevelopment on the trunk of trees fungiWe evaluated the absence of these criteriain plants as 8points Their appearance andimpact on the trees reduces the vitality ofthe plant from 7 to 1 point complete dryingof the whole tree and root system theabsence of shoots from the stump wasassessed as 0 point

We collected plants materials monthlyin sunny windless weather from May toOctober With the purpose of obtaining theaverage sample leaves were sampled from7-8 trees

Chlorophylls and carotenoids wereextracted in 80 acetone in triplicaterepetition We determined solutionabsorbency (D) by spectrophotometer ULAB108UV under the different wave length 663nm 646 nm and 470 nm Concentration ofpigments of the extract (mgl) wascalculated by the Lichtenthaler equations(Shlyk 1975) with the special extractioncoefficient for each component

Сchla = 1221 D663 ndash 281 D646Сchlb = 2013 D646 ndash 503 D663

Сcar = (1000 D470 ndash 327 Сchla ndash 100 Сchlb)229

We calculated quantity content of thechlorophyls a (chl a) chlorophyls b (chl b)and carotenoids (car) of plants material withcounting of obtained concentration ofpigments in the extract under volume of theextract (25 ml) and weighted amount ofplant material (01-02) g The result wasshown in mgg of wet weight

44

Volodarets et al

Mathematical data processing wasperformed using one-way analysis of variance(ANOVA) with the Tukeyrsquos a posterior analysisunder Levenersquos test The relationship betweenmonthly average meteo-indicators and pigmentconcentrations was determined by multipleregression analysis followed by the calculationof Durbin-Watson statistics and serialcorrelation in the program Statistica 100(StatSoft Inc 2011)

Results At the beginning of the experiment the

observation of planting conditions in the citywere conducted Taking into account the lack ofsensitivity of the method of visual estimation thegeneral vital status of the even-aged trees of eachspecies was determined on ms 1 and ms 2 Thefollowing groups were identified among theplant species under study the first group (8points) ndash the stable species Robinia pseudoacaciaL Populus simonii Carrieacuter the second group (6-7 points) medium-stable species Acer platanoidesL Populus timescanadensis Moench Syringa vulgarisL the third group (4-5 points) nonsufficientstable - Acer pseudoplatanus L Acer negundo LTilia cordata Mill

In order to determine the physiologicalaspects of the plantrsquos vitality due to thedifferent hydrothermal conditions of thevegetation period of two years of research weanalyzed the pigment content in the leaves ofthe investigated species in the control withoutinfluence of urban factors High level ofchlorophyls sum was established in theconditions of July and September 2012 whichwere prosperous to the plants mainly owing tochlorophyll a (Fig 2a) This reaction isprincipally shown in the species of the thirdgroup - Acer pseudoplatanus L Acer negundo LSyringa vulgaris L as well as in the trees of thesecond group - Acer platanoides L Amount ofrainfall in these months exceeds the limit by 74 in July and 189 in August of 2012 Itshould be noted that the concentration of greenpigments of these species under the conditionsof severe drought in September decreasesextremely except for Syringa vulgaris L thatcharacterizes with increasing of chl a and chl b

amount It is evidenced about the adaptationpotential of Syringa vulgaris The highchlorophyll concentration in more stable to theurban conditions species of the first and secondgroups were estimated on the start ofvegetation in the May-June under the lack ofhumidifying

It is found out the dynamic ofchlorophyll concentration of two speciesPopulus simonii and Acer pseudoplatanus thatrepresent the groups with the most and leaststable species under the influence of stresshydrothermal conditions in the growingseason 2013 (Fig2b)

As a result of multiple regression analysisthe rainfall and air humidity are determined asthe main factors influencing the content ofgreen pigments in the leaves of species from thesecond and third groups in the controlconditions (Table 1a) However chl a+b ofspecies where the maximum content of greenpigments is observed in drought periods of theyear depends on the air temperature Forexample for Populus simonii (stable species)correlation with air temperature is establishedin the same way as for the medium-stablespecies Syringa vulgaris (R2=081)

Sum of chlorophylls for the leaves ofSyringa vulgaris in 2012 is described by linearequation

y = 131192+00356x1-04561x2

where y ndash sum of chlorophylls (mgg)x1 ndash amount of rainfall (mm) x2 ndashtemperature (ordmС)

Content of carotenoids in all investigatedspecies in the control increases from May toOctober however the rate of its growth varies(Fig 3) The most significant difference betweencarotenoids content at the beginning and theend of vegetation is established for Acer platanoides (4 times in October comparedto May figure) Increase in the content of yellowpigments at the end of vegetation relates to thepreparation of plants for winter and destructionof green pigments The negative significantinfluence of temperature was revealed for thisspecies (Table 3)

45

Assessment of Trees Vitality in the Urban Landscape of Steppe Zone

Fig 2a The chlorophyll concentration (total chl a and chl b) in leaves of theinvestigated species from May to October at monitoring site 3 (Tonenke) ndash 2012

46

Volodarets et al

Fig 2b The chlorophyll concentration (total chl a and chl b) in leaves of theinvestigated species from May to October at monitoring site 3 (Tonenke) ndash 2013

47

Assessment of Trees Vitality in the Urban Landscape of Steppe Zone

Populus simonii and Populus timesсanadensis are characterized by the absenceof the autumn leaf color at the end ofvegetation unlike the other tree species Inconnection with this the content ofcarotenoids in the leaves of this species inOctober remains unchanged compared toMay (Fig 3) It should be noted that in Juneduring the drought the content ofcarotenoids in P simonii increases indicatingthe protective role of carotenoids

For stable species Populus simonii andnonsufficient stable species Acerpseudoplatanus (Fig2b) it is found that thedynamics of chlorophyll content differs fromyear to year but air temperature remains themain factor (Table 2)

The tendency of the pigment contentchanges during the growing season at ms 1and ms 2 corresponds to the dynamics incontrol (ms 3) so the results are presentedfor one month of each season (Table 4) Insummer and autumn June and October areselected as the drought periods withunfavorable conditions for the growth anddevelopment of trees (Table 4)

Analysis of obtained results (Table 4)shows that reduction of chlorophyll content isobserved in the leaves of species under studyin street and park plantations in theconditions of contamination and urbanizationcompared to control against the samebackground of the hydrothermal conditionsFor example in June the sum of chlorophyllsin Tilia cordata decreases by 392 at ms 1and by 258 at ms 2 indicating thephysiological changes which occur in theplant body under action of pollutants

More intensive reduction of the sum ofchlorophylls in the leaves of species understudy is recorded at ms 1 compared to ms2 and control The significant difference wasrecorded in May under favorable weatherconditions in young leaves which are moresensitive to airborne pollutants of all speciesexcept Syringa vulgaris For example in theleaves of Acer negundo the chlorophyllcontent decreased by 517 at ms 1 and by317 at ms 2 compared to control The

lowest sensitivity to pollutants was foundfor the leaves of Robinia pseudoacacia andSyringa vulgaris Their sum of chlorophyllshas grown by 549 and 185 at ms 1respectively

During the first draught in June Apseudoplatanus (decrease in sum ofchlorophylls by 579 and 287 at ms1and ms2 respectively) Populus simonii (625 and 464 ms 1 and ms 2) P xcanadensis (252 and 724 at ms 1 andms 2) are more sensitive to contaminationAcer platanoides A negundo Syringa vulgarisL and Tilia cordata are less sensitive tocontamination chlorophyll content in themdecreases from 220 to 392 dependingon species at ms 1 compared to controlRobinia pseudoacacia is the most resistant tocontamination during drought in Junechlorophyll content increases by 15 at ms1 and ms 2 respectively

During the drought in October it isfound at ms 1 that contamination has lesssignificant impact on the condition ofphotosynthetic apparatus in all species dueto lower sensitivity of old leaves to adverseabiotic and anthropogenic factors of theenvironment High endurance againstcontamination and prolonged drought wasdemonstrated by A pseudoplatanus LPopulus simonii P x canadensis Robiniapseudoacacia and Syringa vulgaris

According to the results of studies it isestablished that at ms 1 and ms 2 thecarotenoid content in the leaves of modelspecimens increases compared to the controlbut the degree of increase depends on plantresistance as can be seen from the dynamicsof carotenoid content in June (Table 5)

The content of carotenoids in stablespecies (P simonii P times canadensis Robiniapseudoacacia) features almost no difference onKyivskyi avenue (ms 1) and in the Recreationand Entertainment Park (ms 2) duringvegetation The established pattern indicateshigh resistance of these woody plants toconditions of the urban environmentConcentration of yellow pigments in Acerpseudoplatanus and A negundo growing in the

48

Volodarets et al

park increases by 30ndash35 compared to ms3 showing the sufficient level of adaptationof these species to conditions of the urbanenvironment Considerable increase incarotenoids in street and park plantations isrecorded in Acer platanoides Syringa vulgarisand Tilia cordata which are less stable

The ratio of sum of chlorophylls tocarotenoids (a+bcar) as a rule is constantin the normal conditions and promptly

responds to changes in the environment so itis used as an indicator of plantsrsquo adaptation toextreme conditions (Petrova et al 2014) Inorder to understand the simultaneous actionof abiotic stress ndash drought and anthropogenicpressure the ratio a+bcar was calculated forJune 2012

In most species a+bcar varied from 486(Acer platanoides ms 1) to 905 (Tilia cordatams 3) (Fig4)

Table 1 Stepwise regression analysis for sum of chlorophylls of woody plants in thevegetation period of 2012 (Tonenke ms 3) Negatively correlated variables are highlightedin bold Statistical significance p-value lt 005 = lt 0001 = lt 00001

Species Step 1 Step 2 Step 3Populus times canadensis Falls 009 Falls Temp 069 -Populus simonii Temp 054 Temp Falls 006 Temp Falls Hum 014Tilia cordata Falls 004 Falls Hum 005Robinia pseudoacacia Falls 0008 Falls Hum 005 -Acer negundo - Hum 011Acer platanoides Falls 002 - -Acer pseudoplatanus Hum 030 Hum Falls 003 Hum Falls Temp 014Syringa vulgaris Temp 046 Temp Falls004

Table 2 Stepwise regression analysis for sum of chlorophylls of woody plants in thevegetation period of 2013 (Tonenke ms 3) Negatively correlated variables are highlightedin bold Statistical significance p-value lt 005 = lt 0001 = lt 00001

Species Step 1 Step 2 Step 3Acer pseudoplatanus Temp 022 - -Populus simonii Temp 066 - -

Fig 3 The carotenoids concentration in leaves of the investigated species from May toOctober at monitoring site 3 (Tonenke) in 2012

49

Assessment of Trees Vitality in the Urban Landscape of Steppe Zone

Table 3 Stepwise regression analysis for carotenoids concentration of woodyplants in the vegetation period of 2012 on the control site Negatively correlatedvariables are highlighted in bold Statistical significance p-value lt 005 = lt 0001 = lt00001=

Species Step 1 Step 2 Step 3

P times canadensis Hum002

HumFalls0005

HumFallsTemp002

P simonii Hum002

HumFalls0004 -

Tilia cordata Hum004

HumFalls001

HumFallsTemp009

Robinia pseudoacacia Hum002

HumFalls0006

HumFallsTemp005

Acer negundo Temp003

TempFalls0003

TempFallsHum001

A platanoides Temp012

TempFalls0004

A pseudoplatanus Hum002

HumFalls0004

HumFallsTemp003

Syringa vulgaris Temp012

TempFalls001 -

Table 4 Sum of chlorophylls of the species leaves at experimental sites during thevegetation period Statistical significance p-value lt 005 = lt 0001 = lt00001= compared to control

SpeciesMay June October

ms 1 ms 2 ms 3 ms 1 ms 2 ms 3 ms 1 ms 2 ms 3Acer

platanoides 143

plusmn005132

plusmn004325

plusmn005272

plusmn002314

plusmn005353

plusmn002113

plusmn006115

plusmn001174

plusmn001A

pseudoplatanus 149

plusmn011248

plusmn025332

plusmn005160

plusmn003271

plusmn007380

plusmn003072

plusmn008101

plusmn001073

plusmn002

A negundo 099plusmn011

140plusmn007

205plusmn005

319plusmn002

367plusmn011

409plusmn001

084plusmn003

027plusmn001

142plusmn001

Populussimonii

144plusmn008

234plusmn003

544plusmn004

277plusmn005

391plusmn012

730plusmn002

143plusmn006

081plusmn001

229plusmn002

P xcanadensis

099plusmn006

193plusmn006

306plusmn003

256plusmn003

636plusmn005

746plusmn004

355plusmn002

431plusmn001

475plusmn002

Robinia pseudoacacia

285plusmn007

243plusmn005

184plusmn002

335plusmn003

337plusmn002

291plusmn001

137plusmn003

164plusmn002

213plusmn002

Syringavulgaris

250plusmn006

285plusmn009

211plusmn002

257plusmn003

312plusmn007

372plusmn001

479plusmn003

471plusmn002

662plusmn002

Tilia cordata 166plusmn005

195plusmn004

399plusmn003

209plusmn004

255plusmn004

344plusmn003

125plusmn003

115plusmn002

232plusmn003

50

Volodarets et al

Table 5 Carotenoids content in some months of 2012 at experimental sites Statisticalsignificance p-value lt 005 = lt 0001 = lt00001= compared to control

SpeciesMay June October

ms 1 ms 2 ms 3 ms 1 ms 2 ms 3 ms 1 ms 2 ms 3Acer platanoides

065plusmn001

053plusmn002

040plusmn001

056plusmn002

051plusmn001

046plusmn001

270plusmn001

213plusmn001

155plusmn001

A pseudoplatanus

055plusmn002

043plusmn001

038plusmn001

073plusmn001

068plusmn001

063plusmn001

145plusmn001

115plusmn001

098plusmn002

A negundo 075plusmn002

062plusmn002

058plusmn001

075plusmn002

066plusmn002

057plusmn001

123plusmn002

101plusmn001

093plusmn002

Populus simonii

031plusmn001

027plusmn001

021plusmn001

038plusmn001

033plusmn001

029plusmn001

031plusmn001

027plusmn001

022plusmn001

P x canadensis 056plusmn002

049plusmn003

036plusmn001

060plusmn001

051=plusmn001

047plusmn001

095plusmn001

081plusmn001

078plusmn001

Robinia pseudoacacia

046plusmn002

039plusmn001

031plusmn001

061plusmn002

052plusmn002

049plusmn001

148plusmn002

131plusmn002

106plusmn003

Syringa vulgaris

033plusmn001

029plusmn001

022plusmn001

042plusmn001

039plusmn001

033plusmn001

223plusmn001

164plusmn002

145plusmn001

Tilia cordata 037plusmn001

033plusmn002

027plusmn001

047plusmn001

043plusmn001

038plusmn001

192plusmn001

171plusmn002

138plusmn002

Fig 4 The ratio of total chlorophylls to carotenoids in June 2012during the drought at monitoring sites

However this indicator inrepresentatives of Populus and Syringavulgaris genera exceeds the general rangeFor example for Populus simonii and Populustimes сanadensis the maximum level of the ratioin the control (2517 and 1587 respectively)is established and for Syringa vulgaris itmakes 1127 because of high chlorophyllconcentration and low content ofcarotenoids The tendency to growth of theconcentration of green pigments and

reduction of yellow ones in the control ismaintained for the other species exceptRobinia pseudoacacia The highest ratiochl a+bcar is found in this species for theplants in park plantations exceeding thisindicator at ms 1 and ms 3 by 11 times only

Therefore contamination in the parkplantations affects the plants which fact isconfirmed by changes in the composition ofthe pigment apparatus of leaves but in streetplantations in the conditions of heavy traffic

51

Assessment of Trees Vitality in the Urban Landscape of Steppe Zone

the reduction of chlorophyll content andincrease of carotenoids in the investigatedspecies is more significant In stable speciesof trees (Populus simonii P times canadensisRobinia pseudoacacia) these changes are lesscritical compared to medium-stable andnonsufficient stable species (Acerpseudoplatanus A negundo A platanoidesSyringa vulgaris and Tilia cordata)

DiscussionAs a result of our study it is found that

concentration of chlorophylls and carotenoidsin woody plants varies depending on themeteorological factors during the season andon the level of contamination of urban areasThe growth of chlorophyll content in the leavesof trees under study from May to September isestablished which is consistent with theliterature sources (Petrova et al 2017 Iusypivaamp Vegerich 2014) It is determined that themain factor influencing the chlorophyllformation is the air temperature Stable andmedium-stable species Robinia pseudoacaciaPopulus simonii Acer platanoides Populus timescanadensis Tilia cordata have the largestchlorophyll amount in drought periods As it isstated by Ballester et al (2017) fruit species oftrees also demonstrate high dependence on theformation of green pigments on the airtemperature During experiments for Rpseudoacia Tilia cordata and A platanoides directdependence on rainfall is established which isconsistent with the results of Iusypiva ampVegerich (2014) for Dnipro City in 2012 for Rрseudoacia in the leaves of which the maximumsum of chlorophylls was recorded in the monthwith the highest amount of rainfalls as wellThe established pattern indicates less adaptivecapacity of the representatives of Robinia Tiliaand Acer genera to the conditions ofhydrothermal stress

Under action of drought in the leaves ofrepresentatives of Acer genus (Swozcerna etal 2010) the chlorophyll content increaseswhich agrees with the results of ourexperiments for A pseudoplatanus when athigh temperatures and low rainfall inAugust 2013 the maximum amount of

chlorophylls in the leaves of this species wasrecorded This pattern indicates highadaptive capacity of sycamore maple in theconditions of South-East of Ukraine Anotherspecies Populus simonii is defined by a highconcentration of pigments under stressconditions at the start of vegetation period amore stable level of chlorophyll contentduring the growing season It should benoted that under the more prosperousconditions in June maximum is beingreached by chl a fraction under the stressconditions in August - due to the sharpincrease in the chl b fraction as well as it isfound out a higher relative content of chl b atthe end of the growing season The obtainedresults show that the various in stabilityspecies in urban environment differ in theratio of chl a and chl b under the action ofhydrothermal factors of different tensionsthat can be one of the part of thedemonstration of species adaptive strategy

Increase in sum of chlorophylls in Aplatanoides and A negundo in July andAugust 2012 when the amount of rainfallwas higher in 74 and 190 to the normalvalue accordingly occurred due to increasein the proportion of chlorophyll b whichplays the protective role in addition to itsmain function Chlorophyll b absorbs someof the rays expanding the range ofphotoactivity which is particularlyimportant in the conditions of considerablecloudiness in rainy weather Chlorophyll а ismore resistant to adverse environmentalfactors compared to chlorophyll b (Conzales-Dugo 2017 Bessonova et al 2006) Increasein the sum of chlorophylls during drought inAcer pseudoplatanus Populus x canadensis Psimonii Robinia pseudoacacia Syringa vulgarisat the expense of chlorophyll а indicates thenormal development of the photosyntheticapparatus of these species and their highadaptive reactions under conditions ofhydrothermal stress

The linear equations of total chlorophylland meteorological factors (falls andtemperature) for both years wereconstructed for two investigates species

52

Volodarets et al

Acer pseudoplatanus y = -51278-00258x1+04658x2 with R2 = 098 in 2012and y = -68888-00529x1+06888x2 with R2 =081 in 2013

Populus simonii y = -68888-00529x1+06888x2 with R2 = 060 in 2012and y = -12985+0058x1-03181x2 with R2 =077 in 2013 where y ndash sum of chlorophylls(mgg) x1 ndash amount of rainfall (mm) x2 ndashtemperature (ordmС)

As can be seen from the linearequations general tendency of pigmentsamount for change in the leaves despite thedifferent weather conditions remainsunchanged Linear equations obtained forAcer pseudoplatanus confirm the inverserelationship between air temperaturerainfall and sum of chlorophylls during thegrowing season in 2012

Maximum chlorophyll content in theleaves of Acer pseudoplatanus falls on hotmonths both in conditions of excessivehumidity (July 2012) and during thedrought period (August 2013) For Populussimonii the highest chlorophyll content isrecorded in June at high temperatures butvarying amount of rainfall The establishedpattern indicates high adaptive capacity ofA pseudoplatanus and Populus simonii duringthe drought

Carotenoids fulfill the protectivefunction by preventing the destruction ofchlorophyll molecules in the light in theprocess of photo-oxidation Photo-protectivefunction lies in the fact that yellow pigmentsprotect the reaction center from massiveenergy fluxes at high light intensities(Britton et al 2008 Bessonova 2006) Asshown by the results of our study insummer months the content of carotenoidsin species under study increases The highestindicators of carotenoids are found inautumn during the plantsrsquo preparation forwinter

During vegetation on the experimentalsites (ms 1 and ms 2) the content of greenpigments increases in late spring and duringsummer with the further decrease inconcentration in autumn which corresponds

to the dynamics of chlorophyll change in thecontrol According to Zayika amp Bondarenko(2018) the content of chlorophyll is reducedin the leaves of deciduous species in the areaof the western forest-steppe of Ukraine inautumn which is agreed with our results forthe southeastern steppe

Sum of chlorophylls in most species atthe monitoring sites is composed bychlorophyll a except for A platanoides and Anegundo as in control Formation ofchlorophyll b molecules is reduced becauseof inhibition of enzymes of its synthesisunder action of xenobiotics (Petrova et al2017 Bessonova et al 2015)

Covering of the question regardingchanges in carotenoids in the leaves of treesof street plantations in the literature isambiguous For example Petrova et al 2017for Acer heldreichii Boiss amp Heldr and Tiliatomentosa Moench point to the decrease incarotenoids at the contaminated sitehowever for Fraxinus excelsior ndash to growth oftheir content in the conditions of impact ofcar exhausts Reduced content of carotenoidsunder impact of car exhausts is also recordedby Joshi amp Swami (2009) Increase inconcentration of the yellow pigments underaction of car exhausts is established in thestudies of Sillanpaumlauml et al (2008) for Betulapendula Roth which may suggest differentadaptive capacity of trees and varying levelsof contamination Korshikov amp Vinogradova(2013) note the increase of carotenoids indamaged leaves of Acer pseudoplatanus andAcer platanoides under action of pollutantsfrom the work of internal combustionengines in Donetsk

According to results of our study thefunctional state of trees in street and parkplantations is worse compared to controlwhich is confirmed by the decrease inchlorophyll content and growth ofcarotenoids Carotenoid content at ms 2increases to 30 and at ms 1 ndash to 50 indicating the adaptive capacity of plantssince carotenoids possess high antioxidantpower The total number of chlorophylls isreduced by 20 to 30 in the trees of park

53

Assessment of Trees Vitality in the Urban Landscape of Steppe Zone

plantations and by 40ndash50 in the streetplantations compared to the clean site

It is to be noted that the representatives ofthe first group (stable species) such as Robiniapseudoacacia shows the exceedence of sum ofchlorophyls during the drought periode at ms1 and ms 2 At the same time the species of thesecond group (medium-stable species) forexample Syringa vulgaris decreases level ofchlorophyls content under the unfavorableurban and hydrothermal conditions as well asTilia cordata from the third (nonsufficientstable) groups decreases amount ofchlorophylls and increased carotenoid contentThe obtained predicted pain evidences theadaptive strategies of the studied species underanthropogenic and hydrothermal stress

Therefore it is found thatcontamination in the park plantations affectsthe plants which fact is confirmed bychanges in the composition of the pigmentapparatus of leaves but in street plantationsthe reduction of chlorophyll content andincrease of carotenoids in the investigatedspecies is more significant In stable treespecies (Populus simonii P times canadensisRobinia pseudoacacia) these changes are lesscritical than in less stable species (Acerpseudoplatanus A negundo A platanoidesSyringa vulgaris and Tilia cordata)

ConclusionAs a result of the study the functional

state of trees in street and parks plantationswas found to be weakened which indicatesa decrease in the content of green pigmentsand an increase in the concentration ofcarotenoids in the area of automobile vehicleexhaust The impact of hydrothermalconditions and factors of urban environmentdetermines the corresponding changes in theconcentration of photosynthetic pigments inwoody plants differentiated by vitality It isestablished among meteorological factors airtemperature as the main factor Changes inthe concentration of green pigments in theleaves of species under study depending onthe temperature and rainfall are describedby linear equations which is important for

predicting the growth and development ofplants during green building on urbanterritories in the conditions of the steppezone

References Ballester C Zarco-Tejada PJ Nicola E

Alarco JJ Fereres E Intrigliolo DSamp Gonzalez-Dugo V (2017)Evaluating the performance ofxanthophyll chlorophyll andstructure-sensitive spectral indices todetect water stress in five fruit treespecies In Precision Agric SpringerScience+Business Media New Yorkdoi 101007s11119-017-9512-y

Bessonova VP (2006) Influence of heavymetals on the photosynthesis of plantsDDAU Dnipropetrovsk (InUkrainian)

Bessonova VP Ivanchenko ОE ampPonomaryova EА (2015) Combinedimpact of heavy metals (Pb2+ and Cd2+)and salinity on the condition of Loliumperenne long-term assimilationapparatus - Vigravesnyk DnigravepropetrovskogoUnigravevercity Seria Bigraveology Ekology 23(1)15ndash20 (in Ukrainian) doi1015421011503

Glibovytska N Adamenko Ya (2017)Woody Plants Vitality of Urban Areasand Prospects of their GreeneryScientific Bulletin of North UniverdityCenter of Baia Mare Series D XXXI(1)21ndash34

Hopke PK (2009) Theory and applicationof Atmospheric source apportionmentIn Air quality and ecological impactsrelating sources to effects (pp 99ndash121)Elseiver Ltd

Iqbal MZ Shafig M Zaidi S amp Qamar AM(2015) Effect of automobile pollution onchlorophyll content of roadside urbantrees Global Journal of EnvironmentalScience Management 1(4) 283ndash296 doi107508gjesm201504003

Iusypiva T amp Vegerich V (2014) Dynamicsof Photosynthetic Pigments Content InWoody Plants Leaves Under

54

Assessment of Trees Vitality in the Urban Landscape of Steppe Zone

thermal power metallurgical chemicalprocessing and mining industry The resultof car enginesrsquo running is the release ofexhaust gases CO2 NxOy SO2 hydrocarbonsaldehydes soot and benzo(a)pyrene (Hopke2009) Among industrial pollutants sulfurdioxide and nitrogen oxides represent thegravest hazard for plants Premature fall ofleaves and needles occurs in woody plantsaffected by sulfur dioxide (Palau et all2009) The action of nitrogen oxides leads tochloroses of various types brownish-blacksections appear on the top and at the edgesof leaves (Spellberg 1998) The level ofpollution of a certain territory of the city isdetermined by the distance from the mainsources of contamination the majordirections of the wind rose the topographicfeatures and the city planning situation(Korshikov et al 2005)

Specific conditions of the southeasternsteppe with high temperatures in summerand low temperatures in winter seasonsstrong winds and low rainfall areexacerbated in the urban areas Almost allenvironmental components in the big city ndashatmosphere flora soil relief hydrographicnetwork groundwaters ndash undergo changesAnthropogenic factors affect the indicatorsof temperature humidity the formation ofair masses and light conditions which ingeneral leads to the emergence of peculiarmicroclimate Thermal chemical radiationelectromagnetic light sound vibrationfactors etc are the main negative urbanfactors In the cities they often actsimultaneously particularly with regard tothe motorways with heavy traffic (Zhang etal 2007 Nowak et al 2006 Morgenroth ampOumlstberg Iqbal et al 2015)

In Ukraine the large number of majorcities with powerful enterprises are situatedon the southeast It should be noted thatspecific conditions of the southeastern partof steppe zone of Ukraine with hightemperatures in summer and lowtemperatures in winter seasons strongwinds and low rainfall and drought areadditional stressed factors for plants at

urban territories In these settings thedurability and efficiency of urban treeplantations are diminished that has negativeenvironmental and economic impacts(Korshikov amp Vinogradova 2005) In thisconnection the urgent task of ecologicalresearch is to monitor and diagnose theliving condition of urban-steppe landscapesplantations of the steppe zone with thecomplex influencing negative anthropogenicand natural and climatic factors

In order to determine the vitality oftrees different approaches are used(Johnstone et al 2013) ndash from ocularestimate method of the general conditions ofthe individual on point scales (Suslova et al2013) biomorphological assessments ofgrowth development phenorhythm typesand reproductive ability (Korshikov ampKrasnoshtan 2012) to physiological andbiochemical indicators of the activity ofmetabolic processes and concentration offunctionally important compounds andmetabolites in the leaves - plastid pigmentstotal nitrogen soluble proteins non-structural pigments starch lipids etc(Glibovytska et al 2017) A wide range ofthese methods is able to give definitelycomprehensive assessment of the vital stateof plants At the same time in ecologicalinvestigations preferences are disposed tothe separate test-parameters and express-methods which characterize the mostadequately the state of plants under specificconditions depends on the performancetargets

Besides this the parameter ofphotosynthetic pigment concentration iswidely used in the conditions of industrialcontamination of the functional state of thewoody plants The similar studies areconducted to determine the droughtresistance of plants thereby the plantreaction to the pollution is the same as thereaction of dehydration factor Photosystemsof chloroplast especially photosystem II thatcontains light harvesting complexes ofphotosynthetic pigments are too sensitivesystems of deferential mesophyll cells and

42

Volodarets et al

their adaptability ensures the preservation ofthe photosynthetic apparatus and itsrestoration in case of damage (Morgenroth ampOumlstberg 2017) According to Bessonova et al(2015) sum of chlorophylls is reduced by theaction of car exhausts Changes of theconcentration of chlorophylls andcarotenoids indicate the decrease in theplantsrsquo metabolic processes under stress(Uhrin amp Supuka 2016) For quantityassessment of plants gas resistance has beensuggested air pollution tolerance index forthe calculation of which in addition to theleaf water content indexes pH of leaf tissueextract the parameter of chlorophyllconcentration is used (Tripathi et al 2009)

The physiological aspects of vital status ofwoody plants under the stressed hydrothermalurban conditions during the vegetative periodare not yet fully understood The easternmostcontinental area of the steppe zone of Ukraine ndashDonetsk city draws the biggest attention fromthis side A full-scale study of the viability ofthe urban tree plantations was conducted hereifn through inventory using the ocular estimatemethod (Suslova 2013) In some works thephysiological indicators of treesrsquo vitality in thecities of southeastern Ukraine were determinedFor example the vitality for certain species ofthe Acer genus was determined with the use ofchlorophyll concentration without taking intoaccount meteorological factors of the periodunder study (Korshikov amp Vinogradova 2005)Therefore the study of the impact of the urbanenvironment on the functional state of trees andprediction of its subsequent changes is relevantfor the proper management and planning ofgreen building in the steppe zone

The goal of the work was the assessmentof the vitality of trees in urban and industrialterritories in the conditions of continentaldrought climate of the steppe zone dependingon the dynamics of changes and quantitativedetermination of plastid pigments

Materials and MethodsResearch was conducted during two

years (2012 2013) in one of the largestindustrial cities of southeastern Ukraine ndash

Donetsk The city is located between 48deg 02rsquonorth latitude and 37deg 48rsquo east longitudeMonitoring sites 1 and 2 (ms 1 ms 2) aresituated in the residential area of the citywith inherent level of air pollution which isformed by the fumes from miningprocessing and metallurgical enterprises butthey differ in the content of individualingredients

Ms 1 is located on the Kyivskyi avenuewith intensive with heavy traffic and higherpollution ms 2 ndash in the large green area of theRecreation and Entertainment Park with less levelof pollution According to the Sectoral StateArchive of the Hydro-meteorological Service ofUkraine (Ukrainian hydrometeorological center)the total average daily concentration of SO2 NO2dust CO formaldehyde at ms 1 was 2175 and2102 mgm3 in the years of research whereasmt2 ndash 1712 and 2006 mgm3 It should be notedthat the level of SO2 content at the monitoringpoints in both years was within 02 MPC

Higher total level of pollution on ms 1 wasachieved due to the increased content of thebasic ingredients of exhaust gases in both yearsof research СО - 16925 and 16515 mgm3 andparticularly NO2 - 01771 and 01731 mgm3which was 443 and 433 MPC respectively Atms 2 the CO content was 12451 and 15234mgm3 NO2 - 00967 and 01575 mgm3 (242and 394 MPC) Besides this at ms 1 it wasestablished increased average dailyconcentrations of ammonia - 00730 mgm3 (182MPC) phenol mgm3 - 00036 (120 MPC) Allthis testifies to a higher level of air pollution onthe ms 1 - the central city highway comparedto the city park area (ms 2)

Control monitoring site (ms 3) isplaced at a distance of 15 km from thetown in the village of Tonenke There areno urban and industrial impacts on theenvironment and it is characterized by asmall (background to this region) contentof ingredients such as SO2 (00050 and00100 mgm3) and NO2 (0093 and 01060mgm3)

Species widely used in greening of thecity were studied during the growing seasonin 2012 and 2013 (from May to October)

43

Assessment of Trees Vitality in the Urban Landscape of Steppe Zone

which differ on the hydrothermal conditionsAs illustrated in Fig1 the first year wasprosperous for plants due to the temperatureregime and falls amount except of thedrought autumn period which was nottypical for the steppe zone The second yearwas characterized by the droughts in springand summer which is common for theclimate of the South-East of Ukraine and lesssuitable for normal growth and developmentof trees Monthly average temperatures airhumidity and rainfall were taken from thereports of the National Hydro-meteorological Center of Ukraine (Ukrainianhydrometeorological center)

a

b

Fig1 Hydrothermal conditions in the yearsof research in Donetsk a ndash 2012 b ndash 2013

- drought periods- dynamic of temperature during the year- dynamic of falls during the year

Eight tree species of the AceraceaSalicaceae Fabacea Malvaceae and Oleaceaegenera were studied at three monitoring sitesin different types of plantations in the linearstreet plantations on the Kyivskyi avenue (ms1) in the massive plantations in the Recreationand Entertainment Park (ms 2) plots in thefield shelter belts and village plantations ofvTonenke at control site (ms 3) We selected

7-8 even-aged model trees of each specieswith the most typical vital status for theplantations of monitoring sites

General vitality of the plants wasestablished under the ocular 8-point scaleby Savelieva (1975) which is commonlyused in the investigated area (Suslova et al2013 Polyakov et al 2012) The scale isbased on the criteria of the trunk and crowndamages inhibition of apical and lateralgrowths drying of branches dry tops thepresence of adventitious shoots vegetativeshoots on the trunk coppice shootsdevelopment on the trunk of trees fungiWe evaluated the absence of these criteriain plants as 8points Their appearance andimpact on the trees reduces the vitality ofthe plant from 7 to 1 point complete dryingof the whole tree and root system theabsence of shoots from the stump wasassessed as 0 point

We collected plants materials monthlyin sunny windless weather from May toOctober With the purpose of obtaining theaverage sample leaves were sampled from7-8 trees

Chlorophylls and carotenoids wereextracted in 80 acetone in triplicaterepetition We determined solutionabsorbency (D) by spectrophotometer ULAB108UV under the different wave length 663nm 646 nm and 470 nm Concentration ofpigments of the extract (mgl) wascalculated by the Lichtenthaler equations(Shlyk 1975) with the special extractioncoefficient for each component

Сchla = 1221 D663 ndash 281 D646Сchlb = 2013 D646 ndash 503 D663

Сcar = (1000 D470 ndash 327 Сchla ndash 100 Сchlb)229

We calculated quantity content of thechlorophyls a (chl a) chlorophyls b (chl b)and carotenoids (car) of plants material withcounting of obtained concentration ofpigments in the extract under volume of theextract (25 ml) and weighted amount ofplant material (01-02) g The result wasshown in mgg of wet weight

44

Volodarets et al

Mathematical data processing wasperformed using one-way analysis of variance(ANOVA) with the Tukeyrsquos a posterior analysisunder Levenersquos test The relationship betweenmonthly average meteo-indicators and pigmentconcentrations was determined by multipleregression analysis followed by the calculationof Durbin-Watson statistics and serialcorrelation in the program Statistica 100(StatSoft Inc 2011)

Results At the beginning of the experiment the

observation of planting conditions in the citywere conducted Taking into account the lack ofsensitivity of the method of visual estimation thegeneral vital status of the even-aged trees of eachspecies was determined on ms 1 and ms 2 Thefollowing groups were identified among theplant species under study the first group (8points) ndash the stable species Robinia pseudoacaciaL Populus simonii Carrieacuter the second group (6-7 points) medium-stable species Acer platanoidesL Populus timescanadensis Moench Syringa vulgarisL the third group (4-5 points) nonsufficientstable - Acer pseudoplatanus L Acer negundo LTilia cordata Mill

In order to determine the physiologicalaspects of the plantrsquos vitality due to thedifferent hydrothermal conditions of thevegetation period of two years of research weanalyzed the pigment content in the leaves ofthe investigated species in the control withoutinfluence of urban factors High level ofchlorophyls sum was established in theconditions of July and September 2012 whichwere prosperous to the plants mainly owing tochlorophyll a (Fig 2a) This reaction isprincipally shown in the species of the thirdgroup - Acer pseudoplatanus L Acer negundo LSyringa vulgaris L as well as in the trees of thesecond group - Acer platanoides L Amount ofrainfall in these months exceeds the limit by 74 in July and 189 in August of 2012 Itshould be noted that the concentration of greenpigments of these species under the conditionsof severe drought in September decreasesextremely except for Syringa vulgaris L thatcharacterizes with increasing of chl a and chl b

amount It is evidenced about the adaptationpotential of Syringa vulgaris The highchlorophyll concentration in more stable to theurban conditions species of the first and secondgroups were estimated on the start ofvegetation in the May-June under the lack ofhumidifying

It is found out the dynamic ofchlorophyll concentration of two speciesPopulus simonii and Acer pseudoplatanus thatrepresent the groups with the most and leaststable species under the influence of stresshydrothermal conditions in the growingseason 2013 (Fig2b)

As a result of multiple regression analysisthe rainfall and air humidity are determined asthe main factors influencing the content ofgreen pigments in the leaves of species from thesecond and third groups in the controlconditions (Table 1a) However chl a+b ofspecies where the maximum content of greenpigments is observed in drought periods of theyear depends on the air temperature Forexample for Populus simonii (stable species)correlation with air temperature is establishedin the same way as for the medium-stablespecies Syringa vulgaris (R2=081)

Sum of chlorophylls for the leaves ofSyringa vulgaris in 2012 is described by linearequation

y = 131192+00356x1-04561x2

where y ndash sum of chlorophylls (mgg)x1 ndash amount of rainfall (mm) x2 ndashtemperature (ordmС)

Content of carotenoids in all investigatedspecies in the control increases from May toOctober however the rate of its growth varies(Fig 3) The most significant difference betweencarotenoids content at the beginning and theend of vegetation is established for Acer platanoides (4 times in October comparedto May figure) Increase in the content of yellowpigments at the end of vegetation relates to thepreparation of plants for winter and destructionof green pigments The negative significantinfluence of temperature was revealed for thisspecies (Table 3)

45

Assessment of Trees Vitality in the Urban Landscape of Steppe Zone

Fig 2a The chlorophyll concentration (total chl a and chl b) in leaves of theinvestigated species from May to October at monitoring site 3 (Tonenke) ndash 2012

46

Volodarets et al

Fig 2b The chlorophyll concentration (total chl a and chl b) in leaves of theinvestigated species from May to October at monitoring site 3 (Tonenke) ndash 2013

47

Assessment of Trees Vitality in the Urban Landscape of Steppe Zone

Populus simonii and Populus timesсanadensis are characterized by the absenceof the autumn leaf color at the end ofvegetation unlike the other tree species Inconnection with this the content ofcarotenoids in the leaves of this species inOctober remains unchanged compared toMay (Fig 3) It should be noted that in Juneduring the drought the content ofcarotenoids in P simonii increases indicatingthe protective role of carotenoids

For stable species Populus simonii andnonsufficient stable species Acerpseudoplatanus (Fig2b) it is found that thedynamics of chlorophyll content differs fromyear to year but air temperature remains themain factor (Table 2)

The tendency of the pigment contentchanges during the growing season at ms 1and ms 2 corresponds to the dynamics incontrol (ms 3) so the results are presentedfor one month of each season (Table 4) Insummer and autumn June and October areselected as the drought periods withunfavorable conditions for the growth anddevelopment of trees (Table 4)

Analysis of obtained results (Table 4)shows that reduction of chlorophyll content isobserved in the leaves of species under studyin street and park plantations in theconditions of contamination and urbanizationcompared to control against the samebackground of the hydrothermal conditionsFor example in June the sum of chlorophyllsin Tilia cordata decreases by 392 at ms 1and by 258 at ms 2 indicating thephysiological changes which occur in theplant body under action of pollutants

More intensive reduction of the sum ofchlorophylls in the leaves of species understudy is recorded at ms 1 compared to ms2 and control The significant difference wasrecorded in May under favorable weatherconditions in young leaves which are moresensitive to airborne pollutants of all speciesexcept Syringa vulgaris For example in theleaves of Acer negundo the chlorophyllcontent decreased by 517 at ms 1 and by317 at ms 2 compared to control The

lowest sensitivity to pollutants was foundfor the leaves of Robinia pseudoacacia andSyringa vulgaris Their sum of chlorophyllshas grown by 549 and 185 at ms 1respectively

During the first draught in June Apseudoplatanus (decrease in sum ofchlorophylls by 579 and 287 at ms1and ms2 respectively) Populus simonii (625 and 464 ms 1 and ms 2) P xcanadensis (252 and 724 at ms 1 andms 2) are more sensitive to contaminationAcer platanoides A negundo Syringa vulgarisL and Tilia cordata are less sensitive tocontamination chlorophyll content in themdecreases from 220 to 392 dependingon species at ms 1 compared to controlRobinia pseudoacacia is the most resistant tocontamination during drought in Junechlorophyll content increases by 15 at ms1 and ms 2 respectively

During the drought in October it isfound at ms 1 that contamination has lesssignificant impact on the condition ofphotosynthetic apparatus in all species dueto lower sensitivity of old leaves to adverseabiotic and anthropogenic factors of theenvironment High endurance againstcontamination and prolonged drought wasdemonstrated by A pseudoplatanus LPopulus simonii P x canadensis Robiniapseudoacacia and Syringa vulgaris

According to the results of studies it isestablished that at ms 1 and ms 2 thecarotenoid content in the leaves of modelspecimens increases compared to the controlbut the degree of increase depends on plantresistance as can be seen from the dynamicsof carotenoid content in June (Table 5)

The content of carotenoids in stablespecies (P simonii P times canadensis Robiniapseudoacacia) features almost no difference onKyivskyi avenue (ms 1) and in the Recreationand Entertainment Park (ms 2) duringvegetation The established pattern indicateshigh resistance of these woody plants toconditions of the urban environmentConcentration of yellow pigments in Acerpseudoplatanus and A negundo growing in the

48

Volodarets et al

park increases by 30ndash35 compared to ms3 showing the sufficient level of adaptationof these species to conditions of the urbanenvironment Considerable increase incarotenoids in street and park plantations isrecorded in Acer platanoides Syringa vulgarisand Tilia cordata which are less stable

The ratio of sum of chlorophylls tocarotenoids (a+bcar) as a rule is constantin the normal conditions and promptly

responds to changes in the environment so itis used as an indicator of plantsrsquo adaptation toextreme conditions (Petrova et al 2014) Inorder to understand the simultaneous actionof abiotic stress ndash drought and anthropogenicpressure the ratio a+bcar was calculated forJune 2012

In most species a+bcar varied from 486(Acer platanoides ms 1) to 905 (Tilia cordatams 3) (Fig4)

Table 1 Stepwise regression analysis for sum of chlorophylls of woody plants in thevegetation period of 2012 (Tonenke ms 3) Negatively correlated variables are highlightedin bold Statistical significance p-value lt 005 = lt 0001 = lt 00001

Species Step 1 Step 2 Step 3Populus times canadensis Falls 009 Falls Temp 069 -Populus simonii Temp 054 Temp Falls 006 Temp Falls Hum 014Tilia cordata Falls 004 Falls Hum 005Robinia pseudoacacia Falls 0008 Falls Hum 005 -Acer negundo - Hum 011Acer platanoides Falls 002 - -Acer pseudoplatanus Hum 030 Hum Falls 003 Hum Falls Temp 014Syringa vulgaris Temp 046 Temp Falls004

Table 2 Stepwise regression analysis for sum of chlorophylls of woody plants in thevegetation period of 2013 (Tonenke ms 3) Negatively correlated variables are highlightedin bold Statistical significance p-value lt 005 = lt 0001 = lt 00001

Species Step 1 Step 2 Step 3Acer pseudoplatanus Temp 022 - -Populus simonii Temp 066 - -

Fig 3 The carotenoids concentration in leaves of the investigated species from May toOctober at monitoring site 3 (Tonenke) in 2012

49

Assessment of Trees Vitality in the Urban Landscape of Steppe Zone

Table 3 Stepwise regression analysis for carotenoids concentration of woodyplants in the vegetation period of 2012 on the control site Negatively correlatedvariables are highlighted in bold Statistical significance p-value lt 005 = lt 0001 = lt00001=

Species Step 1 Step 2 Step 3

P times canadensis Hum002

HumFalls0005

HumFallsTemp002

P simonii Hum002

HumFalls0004 -

Tilia cordata Hum004

HumFalls001

HumFallsTemp009

Robinia pseudoacacia Hum002

HumFalls0006

HumFallsTemp005

Acer negundo Temp003

TempFalls0003

TempFallsHum001

A platanoides Temp012

TempFalls0004

A pseudoplatanus Hum002

HumFalls0004

HumFallsTemp003

Syringa vulgaris Temp012

TempFalls001 -

Table 4 Sum of chlorophylls of the species leaves at experimental sites during thevegetation period Statistical significance p-value lt 005 = lt 0001 = lt00001= compared to control

SpeciesMay June October

ms 1 ms 2 ms 3 ms 1 ms 2 ms 3 ms 1 ms 2 ms 3Acer

platanoides 143

plusmn005132

plusmn004325

plusmn005272

plusmn002314

plusmn005353

plusmn002113

plusmn006115

plusmn001174

plusmn001A

pseudoplatanus 149

plusmn011248

plusmn025332

plusmn005160

plusmn003271

plusmn007380

plusmn003072

plusmn008101

plusmn001073

plusmn002

A negundo 099plusmn011

140plusmn007

205plusmn005

319plusmn002

367plusmn011

409plusmn001

084plusmn003

027plusmn001

142plusmn001

Populussimonii

144plusmn008

234plusmn003

544plusmn004

277plusmn005

391plusmn012

730plusmn002

143plusmn006

081plusmn001

229plusmn002

P xcanadensis

099plusmn006

193plusmn006

306plusmn003

256plusmn003

636plusmn005

746plusmn004

355plusmn002

431plusmn001

475plusmn002

Robinia pseudoacacia

285plusmn007

243plusmn005

184plusmn002

335plusmn003

337plusmn002

291plusmn001

137plusmn003

164plusmn002

213plusmn002

Syringavulgaris

250plusmn006

285plusmn009

211plusmn002

257plusmn003

312plusmn007

372plusmn001

479plusmn003

471plusmn002

662plusmn002

Tilia cordata 166plusmn005

195plusmn004

399plusmn003

209plusmn004

255plusmn004

344plusmn003

125plusmn003

115plusmn002

232plusmn003

50

Volodarets et al

Table 5 Carotenoids content in some months of 2012 at experimental sites Statisticalsignificance p-value lt 005 = lt 0001 = lt00001= compared to control

SpeciesMay June October

ms 1 ms 2 ms 3 ms 1 ms 2 ms 3 ms 1 ms 2 ms 3Acer platanoides

065plusmn001

053plusmn002

040plusmn001

056plusmn002

051plusmn001

046plusmn001

270plusmn001

213plusmn001

155plusmn001

A pseudoplatanus

055plusmn002

043plusmn001

038plusmn001

073plusmn001

068plusmn001

063plusmn001

145plusmn001

115plusmn001

098plusmn002

A negundo 075plusmn002

062plusmn002

058plusmn001

075plusmn002

066plusmn002

057plusmn001

123plusmn002

101plusmn001

093plusmn002

Populus simonii

031plusmn001

027plusmn001

021plusmn001

038plusmn001

033plusmn001

029plusmn001

031plusmn001

027plusmn001

022plusmn001

P x canadensis 056plusmn002

049plusmn003

036plusmn001

060plusmn001

051=plusmn001

047plusmn001

095plusmn001

081plusmn001

078plusmn001

Robinia pseudoacacia

046plusmn002

039plusmn001

031plusmn001

061plusmn002

052plusmn002

049plusmn001

148plusmn002

131plusmn002

106plusmn003

Syringa vulgaris

033plusmn001

029plusmn001

022plusmn001

042plusmn001

039plusmn001

033plusmn001

223plusmn001

164plusmn002

145plusmn001

Tilia cordata 037plusmn001

033plusmn002

027plusmn001

047plusmn001

043plusmn001

038plusmn001

192plusmn001

171plusmn002

138plusmn002

Fig 4 The ratio of total chlorophylls to carotenoids in June 2012during the drought at monitoring sites

However this indicator inrepresentatives of Populus and Syringavulgaris genera exceeds the general rangeFor example for Populus simonii and Populustimes сanadensis the maximum level of the ratioin the control (2517 and 1587 respectively)is established and for Syringa vulgaris itmakes 1127 because of high chlorophyllconcentration and low content ofcarotenoids The tendency to growth of theconcentration of green pigments and

reduction of yellow ones in the control ismaintained for the other species exceptRobinia pseudoacacia The highest ratiochl a+bcar is found in this species for theplants in park plantations exceeding thisindicator at ms 1 and ms 3 by 11 times only

Therefore contamination in the parkplantations affects the plants which fact isconfirmed by changes in the composition ofthe pigment apparatus of leaves but in streetplantations in the conditions of heavy traffic

51

Assessment of Trees Vitality in the Urban Landscape of Steppe Zone

the reduction of chlorophyll content andincrease of carotenoids in the investigatedspecies is more significant In stable speciesof trees (Populus simonii P times canadensisRobinia pseudoacacia) these changes are lesscritical compared to medium-stable andnonsufficient stable species (Acerpseudoplatanus A negundo A platanoidesSyringa vulgaris and Tilia cordata)

DiscussionAs a result of our study it is found that

concentration of chlorophylls and carotenoidsin woody plants varies depending on themeteorological factors during the season andon the level of contamination of urban areasThe growth of chlorophyll content in the leavesof trees under study from May to September isestablished which is consistent with theliterature sources (Petrova et al 2017 Iusypivaamp Vegerich 2014) It is determined that themain factor influencing the chlorophyllformation is the air temperature Stable andmedium-stable species Robinia pseudoacaciaPopulus simonii Acer platanoides Populus timescanadensis Tilia cordata have the largestchlorophyll amount in drought periods As it isstated by Ballester et al (2017) fruit species oftrees also demonstrate high dependence on theformation of green pigments on the airtemperature During experiments for Rpseudoacia Tilia cordata and A platanoides directdependence on rainfall is established which isconsistent with the results of Iusypiva ampVegerich (2014) for Dnipro City in 2012 for Rрseudoacia in the leaves of which the maximumsum of chlorophylls was recorded in the monthwith the highest amount of rainfalls as wellThe established pattern indicates less adaptivecapacity of the representatives of Robinia Tiliaand Acer genera to the conditions ofhydrothermal stress

Under action of drought in the leaves ofrepresentatives of Acer genus (Swozcerna etal 2010) the chlorophyll content increaseswhich agrees with the results of ourexperiments for A pseudoplatanus when athigh temperatures and low rainfall inAugust 2013 the maximum amount of

chlorophylls in the leaves of this species wasrecorded This pattern indicates highadaptive capacity of sycamore maple in theconditions of South-East of Ukraine Anotherspecies Populus simonii is defined by a highconcentration of pigments under stressconditions at the start of vegetation period amore stable level of chlorophyll contentduring the growing season It should benoted that under the more prosperousconditions in June maximum is beingreached by chl a fraction under the stressconditions in August - due to the sharpincrease in the chl b fraction as well as it isfound out a higher relative content of chl b atthe end of the growing season The obtainedresults show that the various in stabilityspecies in urban environment differ in theratio of chl a and chl b under the action ofhydrothermal factors of different tensionsthat can be one of the part of thedemonstration of species adaptive strategy

Increase in sum of chlorophylls in Aplatanoides and A negundo in July andAugust 2012 when the amount of rainfallwas higher in 74 and 190 to the normalvalue accordingly occurred due to increasein the proportion of chlorophyll b whichplays the protective role in addition to itsmain function Chlorophyll b absorbs someof the rays expanding the range ofphotoactivity which is particularlyimportant in the conditions of considerablecloudiness in rainy weather Chlorophyll а ismore resistant to adverse environmentalfactors compared to chlorophyll b (Conzales-Dugo 2017 Bessonova et al 2006) Increasein the sum of chlorophylls during drought inAcer pseudoplatanus Populus x canadensis Psimonii Robinia pseudoacacia Syringa vulgarisat the expense of chlorophyll а indicates thenormal development of the photosyntheticapparatus of these species and their highadaptive reactions under conditions ofhydrothermal stress

The linear equations of total chlorophylland meteorological factors (falls andtemperature) for both years wereconstructed for two investigates species

52

Volodarets et al

Acer pseudoplatanus y = -51278-00258x1+04658x2 with R2 = 098 in 2012and y = -68888-00529x1+06888x2 with R2 =081 in 2013

Populus simonii y = -68888-00529x1+06888x2 with R2 = 060 in 2012and y = -12985+0058x1-03181x2 with R2 =077 in 2013 where y ndash sum of chlorophylls(mgg) x1 ndash amount of rainfall (mm) x2 ndashtemperature (ordmС)

As can be seen from the linearequations general tendency of pigmentsamount for change in the leaves despite thedifferent weather conditions remainsunchanged Linear equations obtained forAcer pseudoplatanus confirm the inverserelationship between air temperaturerainfall and sum of chlorophylls during thegrowing season in 2012

Maximum chlorophyll content in theleaves of Acer pseudoplatanus falls on hotmonths both in conditions of excessivehumidity (July 2012) and during thedrought period (August 2013) For Populussimonii the highest chlorophyll content isrecorded in June at high temperatures butvarying amount of rainfall The establishedpattern indicates high adaptive capacity ofA pseudoplatanus and Populus simonii duringthe drought

Carotenoids fulfill the protectivefunction by preventing the destruction ofchlorophyll molecules in the light in theprocess of photo-oxidation Photo-protectivefunction lies in the fact that yellow pigmentsprotect the reaction center from massiveenergy fluxes at high light intensities(Britton et al 2008 Bessonova 2006) Asshown by the results of our study insummer months the content of carotenoidsin species under study increases The highestindicators of carotenoids are found inautumn during the plantsrsquo preparation forwinter

During vegetation on the experimentalsites (ms 1 and ms 2) the content of greenpigments increases in late spring and duringsummer with the further decrease inconcentration in autumn which corresponds

to the dynamics of chlorophyll change in thecontrol According to Zayika amp Bondarenko(2018) the content of chlorophyll is reducedin the leaves of deciduous species in the areaof the western forest-steppe of Ukraine inautumn which is agreed with our results forthe southeastern steppe

Sum of chlorophylls in most species atthe monitoring sites is composed bychlorophyll a except for A platanoides and Anegundo as in control Formation ofchlorophyll b molecules is reduced becauseof inhibition of enzymes of its synthesisunder action of xenobiotics (Petrova et al2017 Bessonova et al 2015)

Covering of the question regardingchanges in carotenoids in the leaves of treesof street plantations in the literature isambiguous For example Petrova et al 2017for Acer heldreichii Boiss amp Heldr and Tiliatomentosa Moench point to the decrease incarotenoids at the contaminated sitehowever for Fraxinus excelsior ndash to growth oftheir content in the conditions of impact ofcar exhausts Reduced content of carotenoidsunder impact of car exhausts is also recordedby Joshi amp Swami (2009) Increase inconcentration of the yellow pigments underaction of car exhausts is established in thestudies of Sillanpaumlauml et al (2008) for Betulapendula Roth which may suggest differentadaptive capacity of trees and varying levelsof contamination Korshikov amp Vinogradova(2013) note the increase of carotenoids indamaged leaves of Acer pseudoplatanus andAcer platanoides under action of pollutantsfrom the work of internal combustionengines in Donetsk

According to results of our study thefunctional state of trees in street and parkplantations is worse compared to controlwhich is confirmed by the decrease inchlorophyll content and growth ofcarotenoids Carotenoid content at ms 2increases to 30 and at ms 1 ndash to 50 indicating the adaptive capacity of plantssince carotenoids possess high antioxidantpower The total number of chlorophylls isreduced by 20 to 30 in the trees of park

53

Assessment of Trees Vitality in the Urban Landscape of Steppe Zone

plantations and by 40ndash50 in the streetplantations compared to the clean site

It is to be noted that the representatives ofthe first group (stable species) such as Robiniapseudoacacia shows the exceedence of sum ofchlorophyls during the drought periode at ms1 and ms 2 At the same time the species of thesecond group (medium-stable species) forexample Syringa vulgaris decreases level ofchlorophyls content under the unfavorableurban and hydrothermal conditions as well asTilia cordata from the third (nonsufficientstable) groups decreases amount ofchlorophylls and increased carotenoid contentThe obtained predicted pain evidences theadaptive strategies of the studied species underanthropogenic and hydrothermal stress

Therefore it is found thatcontamination in the park plantations affectsthe plants which fact is confirmed bychanges in the composition of the pigmentapparatus of leaves but in street plantationsthe reduction of chlorophyll content andincrease of carotenoids in the investigatedspecies is more significant In stable treespecies (Populus simonii P times canadensisRobinia pseudoacacia) these changes are lesscritical than in less stable species (Acerpseudoplatanus A negundo A platanoidesSyringa vulgaris and Tilia cordata)

ConclusionAs a result of the study the functional

state of trees in street and parks plantationswas found to be weakened which indicatesa decrease in the content of green pigmentsand an increase in the concentration ofcarotenoids in the area of automobile vehicleexhaust The impact of hydrothermalconditions and factors of urban environmentdetermines the corresponding changes in theconcentration of photosynthetic pigments inwoody plants differentiated by vitality It isestablished among meteorological factors airtemperature as the main factor Changes inthe concentration of green pigments in theleaves of species under study depending onthe temperature and rainfall are describedby linear equations which is important for

predicting the growth and development ofplants during green building on urbanterritories in the conditions of the steppezone

References Ballester C Zarco-Tejada PJ Nicola E

Alarco JJ Fereres E Intrigliolo DSamp Gonzalez-Dugo V (2017)Evaluating the performance ofxanthophyll chlorophyll andstructure-sensitive spectral indices todetect water stress in five fruit treespecies In Precision Agric SpringerScience+Business Media New Yorkdoi 101007s11119-017-9512-y

Bessonova VP (2006) Influence of heavymetals on the photosynthesis of plantsDDAU Dnipropetrovsk (InUkrainian)

Bessonova VP Ivanchenko ОE ampPonomaryova EА (2015) Combinedimpact of heavy metals (Pb2+ and Cd2+)and salinity on the condition of Loliumperenne long-term assimilationapparatus - Vigravesnyk DnigravepropetrovskogoUnigravevercity Seria Bigraveology Ekology 23(1)15ndash20 (in Ukrainian) doi1015421011503

Glibovytska N Adamenko Ya (2017)Woody Plants Vitality of Urban Areasand Prospects of their GreeneryScientific Bulletin of North UniverdityCenter of Baia Mare Series D XXXI(1)21ndash34

Hopke PK (2009) Theory and applicationof Atmospheric source apportionmentIn Air quality and ecological impactsrelating sources to effects (pp 99ndash121)Elseiver Ltd

Iqbal MZ Shafig M Zaidi S amp Qamar AM(2015) Effect of automobile pollution onchlorophyll content of roadside urbantrees Global Journal of EnvironmentalScience Management 1(4) 283ndash296 doi107508gjesm201504003

Iusypiva T amp Vegerich V (2014) Dynamicsof Photosynthetic Pigments Content InWoody Plants Leaves Under

54

Volodarets et al

their adaptability ensures the preservation ofthe photosynthetic apparatus and itsrestoration in case of damage (Morgenroth ampOumlstberg 2017) According to Bessonova et al(2015) sum of chlorophylls is reduced by theaction of car exhausts Changes of theconcentration of chlorophylls andcarotenoids indicate the decrease in theplantsrsquo metabolic processes under stress(Uhrin amp Supuka 2016) For quantityassessment of plants gas resistance has beensuggested air pollution tolerance index forthe calculation of which in addition to theleaf water content indexes pH of leaf tissueextract the parameter of chlorophyllconcentration is used (Tripathi et al 2009)

The physiological aspects of vital status ofwoody plants under the stressed hydrothermalurban conditions during the vegetative periodare not yet fully understood The easternmostcontinental area of the steppe zone of Ukraine ndashDonetsk city draws the biggest attention fromthis side A full-scale study of the viability ofthe urban tree plantations was conducted hereifn through inventory using the ocular estimatemethod (Suslova 2013) In some works thephysiological indicators of treesrsquo vitality in thecities of southeastern Ukraine were determinedFor example the vitality for certain species ofthe Acer genus was determined with the use ofchlorophyll concentration without taking intoaccount meteorological factors of the periodunder study (Korshikov amp Vinogradova 2005)Therefore the study of the impact of the urbanenvironment on the functional state of trees andprediction of its subsequent changes is relevantfor the proper management and planning ofgreen building in the steppe zone

The goal of the work was the assessmentof the vitality of trees in urban and industrialterritories in the conditions of continentaldrought climate of the steppe zone dependingon the dynamics of changes and quantitativedetermination of plastid pigments

Materials and MethodsResearch was conducted during two

years (2012 2013) in one of the largestindustrial cities of southeastern Ukraine ndash

Donetsk The city is located between 48deg 02rsquonorth latitude and 37deg 48rsquo east longitudeMonitoring sites 1 and 2 (ms 1 ms 2) aresituated in the residential area of the citywith inherent level of air pollution which isformed by the fumes from miningprocessing and metallurgical enterprises butthey differ in the content of individualingredients

Ms 1 is located on the Kyivskyi avenuewith intensive with heavy traffic and higherpollution ms 2 ndash in the large green area of theRecreation and Entertainment Park with less levelof pollution According to the Sectoral StateArchive of the Hydro-meteorological Service ofUkraine (Ukrainian hydrometeorological center)the total average daily concentration of SO2 NO2dust CO formaldehyde at ms 1 was 2175 and2102 mgm3 in the years of research whereasmt2 ndash 1712 and 2006 mgm3 It should be notedthat the level of SO2 content at the monitoringpoints in both years was within 02 MPC

Higher total level of pollution on ms 1 wasachieved due to the increased content of thebasic ingredients of exhaust gases in both yearsof research СО - 16925 and 16515 mgm3 andparticularly NO2 - 01771 and 01731 mgm3which was 443 and 433 MPC respectively Atms 2 the CO content was 12451 and 15234mgm3 NO2 - 00967 and 01575 mgm3 (242and 394 MPC) Besides this at ms 1 it wasestablished increased average dailyconcentrations of ammonia - 00730 mgm3 (182MPC) phenol mgm3 - 00036 (120 MPC) Allthis testifies to a higher level of air pollution onthe ms 1 - the central city highway comparedto the city park area (ms 2)

Control monitoring site (ms 3) isplaced at a distance of 15 km from thetown in the village of Tonenke There areno urban and industrial impacts on theenvironment and it is characterized by asmall (background to this region) contentof ingredients such as SO2 (00050 and00100 mgm3) and NO2 (0093 and 01060mgm3)

Species widely used in greening of thecity were studied during the growing seasonin 2012 and 2013 (from May to October)

43

Assessment of Trees Vitality in the Urban Landscape of Steppe Zone

which differ on the hydrothermal conditionsAs illustrated in Fig1 the first year wasprosperous for plants due to the temperatureregime and falls amount except of thedrought autumn period which was nottypical for the steppe zone The second yearwas characterized by the droughts in springand summer which is common for theclimate of the South-East of Ukraine and lesssuitable for normal growth and developmentof trees Monthly average temperatures airhumidity and rainfall were taken from thereports of the National Hydro-meteorological Center of Ukraine (Ukrainianhydrometeorological center)

a

b

Fig1 Hydrothermal conditions in the yearsof research in Donetsk a ndash 2012 b ndash 2013

- drought periods- dynamic of temperature during the year- dynamic of falls during the year

Eight tree species of the AceraceaSalicaceae Fabacea Malvaceae and Oleaceaegenera were studied at three monitoring sitesin different types of plantations in the linearstreet plantations on the Kyivskyi avenue (ms1) in the massive plantations in the Recreationand Entertainment Park (ms 2) plots in thefield shelter belts and village plantations ofvTonenke at control site (ms 3) We selected

7-8 even-aged model trees of each specieswith the most typical vital status for theplantations of monitoring sites

General vitality of the plants wasestablished under the ocular 8-point scaleby Savelieva (1975) which is commonlyused in the investigated area (Suslova et al2013 Polyakov et al 2012) The scale isbased on the criteria of the trunk and crowndamages inhibition of apical and lateralgrowths drying of branches dry tops thepresence of adventitious shoots vegetativeshoots on the trunk coppice shootsdevelopment on the trunk of trees fungiWe evaluated the absence of these criteriain plants as 8points Their appearance andimpact on the trees reduces the vitality ofthe plant from 7 to 1 point complete dryingof the whole tree and root system theabsence of shoots from the stump wasassessed as 0 point

We collected plants materials monthlyin sunny windless weather from May toOctober With the purpose of obtaining theaverage sample leaves were sampled from7-8 trees

Chlorophylls and carotenoids wereextracted in 80 acetone in triplicaterepetition We determined solutionabsorbency (D) by spectrophotometer ULAB108UV under the different wave length 663nm 646 nm and 470 nm Concentration ofpigments of the extract (mgl) wascalculated by the Lichtenthaler equations(Shlyk 1975) with the special extractioncoefficient for each component

Сchla = 1221 D663 ndash 281 D646Сchlb = 2013 D646 ndash 503 D663

Сcar = (1000 D470 ndash 327 Сchla ndash 100 Сchlb)229

We calculated quantity content of thechlorophyls a (chl a) chlorophyls b (chl b)and carotenoids (car) of plants material withcounting of obtained concentration ofpigments in the extract under volume of theextract (25 ml) and weighted amount ofplant material (01-02) g The result wasshown in mgg of wet weight

44

Volodarets et al

Mathematical data processing wasperformed using one-way analysis of variance(ANOVA) with the Tukeyrsquos a posterior analysisunder Levenersquos test The relationship betweenmonthly average meteo-indicators and pigmentconcentrations was determined by multipleregression analysis followed by the calculationof Durbin-Watson statistics and serialcorrelation in the program Statistica 100(StatSoft Inc 2011)

Results At the beginning of the experiment the

observation of planting conditions in the citywere conducted Taking into account the lack ofsensitivity of the method of visual estimation thegeneral vital status of the even-aged trees of eachspecies was determined on ms 1 and ms 2 Thefollowing groups were identified among theplant species under study the first group (8points) ndash the stable species Robinia pseudoacaciaL Populus simonii Carrieacuter the second group (6-7 points) medium-stable species Acer platanoidesL Populus timescanadensis Moench Syringa vulgarisL the third group (4-5 points) nonsufficientstable - Acer pseudoplatanus L Acer negundo LTilia cordata Mill

In order to determine the physiologicalaspects of the plantrsquos vitality due to thedifferent hydrothermal conditions of thevegetation period of two years of research weanalyzed the pigment content in the leaves ofthe investigated species in the control withoutinfluence of urban factors High level ofchlorophyls sum was established in theconditions of July and September 2012 whichwere prosperous to the plants mainly owing tochlorophyll a (Fig 2a) This reaction isprincipally shown in the species of the thirdgroup - Acer pseudoplatanus L Acer negundo LSyringa vulgaris L as well as in the trees of thesecond group - Acer platanoides L Amount ofrainfall in these months exceeds the limit by 74 in July and 189 in August of 2012 Itshould be noted that the concentration of greenpigments of these species under the conditionsof severe drought in September decreasesextremely except for Syringa vulgaris L thatcharacterizes with increasing of chl a and chl b

amount It is evidenced about the adaptationpotential of Syringa vulgaris The highchlorophyll concentration in more stable to theurban conditions species of the first and secondgroups were estimated on the start ofvegetation in the May-June under the lack ofhumidifying

It is found out the dynamic ofchlorophyll concentration of two speciesPopulus simonii and Acer pseudoplatanus thatrepresent the groups with the most and leaststable species under the influence of stresshydrothermal conditions in the growingseason 2013 (Fig2b)

As a result of multiple regression analysisthe rainfall and air humidity are determined asthe main factors influencing the content ofgreen pigments in the leaves of species from thesecond and third groups in the controlconditions (Table 1a) However chl a+b ofspecies where the maximum content of greenpigments is observed in drought periods of theyear depends on the air temperature Forexample for Populus simonii (stable species)correlation with air temperature is establishedin the same way as for the medium-stablespecies Syringa vulgaris (R2=081)

Sum of chlorophylls for the leaves ofSyringa vulgaris in 2012 is described by linearequation

y = 131192+00356x1-04561x2

where y ndash sum of chlorophylls (mgg)x1 ndash amount of rainfall (mm) x2 ndashtemperature (ordmС)

Content of carotenoids in all investigatedspecies in the control increases from May toOctober however the rate of its growth varies(Fig 3) The most significant difference betweencarotenoids content at the beginning and theend of vegetation is established for Acer platanoides (4 times in October comparedto May figure) Increase in the content of yellowpigments at the end of vegetation relates to thepreparation of plants for winter and destructionof green pigments The negative significantinfluence of temperature was revealed for thisspecies (Table 3)

45

Assessment of Trees Vitality in the Urban Landscape of Steppe Zone

Fig 2a The chlorophyll concentration (total chl a and chl b) in leaves of theinvestigated species from May to October at monitoring site 3 (Tonenke) ndash 2012

46

Volodarets et al

Fig 2b The chlorophyll concentration (total chl a and chl b) in leaves of theinvestigated species from May to October at monitoring site 3 (Tonenke) ndash 2013

47

Assessment of Trees Vitality in the Urban Landscape of Steppe Zone

Populus simonii and Populus timesсanadensis are characterized by the absenceof the autumn leaf color at the end ofvegetation unlike the other tree species Inconnection with this the content ofcarotenoids in the leaves of this species inOctober remains unchanged compared toMay (Fig 3) It should be noted that in Juneduring the drought the content ofcarotenoids in P simonii increases indicatingthe protective role of carotenoids

For stable species Populus simonii andnonsufficient stable species Acerpseudoplatanus (Fig2b) it is found that thedynamics of chlorophyll content differs fromyear to year but air temperature remains themain factor (Table 2)

The tendency of the pigment contentchanges during the growing season at ms 1and ms 2 corresponds to the dynamics incontrol (ms 3) so the results are presentedfor one month of each season (Table 4) Insummer and autumn June and October areselected as the drought periods withunfavorable conditions for the growth anddevelopment of trees (Table 4)

Analysis of obtained results (Table 4)shows that reduction of chlorophyll content isobserved in the leaves of species under studyin street and park plantations in theconditions of contamination and urbanizationcompared to control against the samebackground of the hydrothermal conditionsFor example in June the sum of chlorophyllsin Tilia cordata decreases by 392 at ms 1and by 258 at ms 2 indicating thephysiological changes which occur in theplant body under action of pollutants

More intensive reduction of the sum ofchlorophylls in the leaves of species understudy is recorded at ms 1 compared to ms2 and control The significant difference wasrecorded in May under favorable weatherconditions in young leaves which are moresensitive to airborne pollutants of all speciesexcept Syringa vulgaris For example in theleaves of Acer negundo the chlorophyllcontent decreased by 517 at ms 1 and by317 at ms 2 compared to control The

lowest sensitivity to pollutants was foundfor the leaves of Robinia pseudoacacia andSyringa vulgaris Their sum of chlorophyllshas grown by 549 and 185 at ms 1respectively

During the first draught in June Apseudoplatanus (decrease in sum ofchlorophylls by 579 and 287 at ms1and ms2 respectively) Populus simonii (625 and 464 ms 1 and ms 2) P xcanadensis (252 and 724 at ms 1 andms 2) are more sensitive to contaminationAcer platanoides A negundo Syringa vulgarisL and Tilia cordata are less sensitive tocontamination chlorophyll content in themdecreases from 220 to 392 dependingon species at ms 1 compared to controlRobinia pseudoacacia is the most resistant tocontamination during drought in Junechlorophyll content increases by 15 at ms1 and ms 2 respectively

During the drought in October it isfound at ms 1 that contamination has lesssignificant impact on the condition ofphotosynthetic apparatus in all species dueto lower sensitivity of old leaves to adverseabiotic and anthropogenic factors of theenvironment High endurance againstcontamination and prolonged drought wasdemonstrated by A pseudoplatanus LPopulus simonii P x canadensis Robiniapseudoacacia and Syringa vulgaris

According to the results of studies it isestablished that at ms 1 and ms 2 thecarotenoid content in the leaves of modelspecimens increases compared to the controlbut the degree of increase depends on plantresistance as can be seen from the dynamicsof carotenoid content in June (Table 5)

The content of carotenoids in stablespecies (P simonii P times canadensis Robiniapseudoacacia) features almost no difference onKyivskyi avenue (ms 1) and in the Recreationand Entertainment Park (ms 2) duringvegetation The established pattern indicateshigh resistance of these woody plants toconditions of the urban environmentConcentration of yellow pigments in Acerpseudoplatanus and A negundo growing in the

48

Volodarets et al

park increases by 30ndash35 compared to ms3 showing the sufficient level of adaptationof these species to conditions of the urbanenvironment Considerable increase incarotenoids in street and park plantations isrecorded in Acer platanoides Syringa vulgarisand Tilia cordata which are less stable

The ratio of sum of chlorophylls tocarotenoids (a+bcar) as a rule is constantin the normal conditions and promptly

responds to changes in the environment so itis used as an indicator of plantsrsquo adaptation toextreme conditions (Petrova et al 2014) Inorder to understand the simultaneous actionof abiotic stress ndash drought and anthropogenicpressure the ratio a+bcar was calculated forJune 2012

In most species a+bcar varied from 486(Acer platanoides ms 1) to 905 (Tilia cordatams 3) (Fig4)

Table 1 Stepwise regression analysis for sum of chlorophylls of woody plants in thevegetation period of 2012 (Tonenke ms 3) Negatively correlated variables are highlightedin bold Statistical significance p-value lt 005 = lt 0001 = lt 00001

Species Step 1 Step 2 Step 3Populus times canadensis Falls 009 Falls Temp 069 -Populus simonii Temp 054 Temp Falls 006 Temp Falls Hum 014Tilia cordata Falls 004 Falls Hum 005Robinia pseudoacacia Falls 0008 Falls Hum 005 -Acer negundo - Hum 011Acer platanoides Falls 002 - -Acer pseudoplatanus Hum 030 Hum Falls 003 Hum Falls Temp 014Syringa vulgaris Temp 046 Temp Falls004

Table 2 Stepwise regression analysis for sum of chlorophylls of woody plants in thevegetation period of 2013 (Tonenke ms 3) Negatively correlated variables are highlightedin bold Statistical significance p-value lt 005 = lt 0001 = lt 00001

Species Step 1 Step 2 Step 3Acer pseudoplatanus Temp 022 - -Populus simonii Temp 066 - -

Fig 3 The carotenoids concentration in leaves of the investigated species from May toOctober at monitoring site 3 (Tonenke) in 2012

49

Assessment of Trees Vitality in the Urban Landscape of Steppe Zone

Table 3 Stepwise regression analysis for carotenoids concentration of woodyplants in the vegetation period of 2012 on the control site Negatively correlatedvariables are highlighted in bold Statistical significance p-value lt 005 = lt 0001 = lt00001=

Species Step 1 Step 2 Step 3

P times canadensis Hum002

HumFalls0005

HumFallsTemp002

P simonii Hum002

HumFalls0004 -

Tilia cordata Hum004

HumFalls001

HumFallsTemp009

Robinia pseudoacacia Hum002

HumFalls0006

HumFallsTemp005

Acer negundo Temp003

TempFalls0003

TempFallsHum001

A platanoides Temp012

TempFalls0004

A pseudoplatanus Hum002

HumFalls0004

HumFallsTemp003

Syringa vulgaris Temp012

TempFalls001 -

Table 4 Sum of chlorophylls of the species leaves at experimental sites during thevegetation period Statistical significance p-value lt 005 = lt 0001 = lt00001= compared to control

SpeciesMay June October

ms 1 ms 2 ms 3 ms 1 ms 2 ms 3 ms 1 ms 2 ms 3Acer

platanoides 143

plusmn005132

plusmn004325

plusmn005272

plusmn002314

plusmn005353

plusmn002113

plusmn006115

plusmn001174

plusmn001A

pseudoplatanus 149

plusmn011248

plusmn025332

plusmn005160

plusmn003271

plusmn007380

plusmn003072

plusmn008101

plusmn001073

plusmn002

A negundo 099plusmn011

140plusmn007

205plusmn005

319plusmn002

367plusmn011

409plusmn001

084plusmn003

027plusmn001

142plusmn001

Populussimonii

144plusmn008

234plusmn003

544plusmn004

277plusmn005

391plusmn012

730plusmn002

143plusmn006

081plusmn001

229plusmn002

P xcanadensis

099plusmn006

193plusmn006

306plusmn003

256plusmn003

636plusmn005

746plusmn004

355plusmn002

431plusmn001

475plusmn002

Robinia pseudoacacia

285plusmn007

243plusmn005

184plusmn002

335plusmn003

337plusmn002

291plusmn001

137plusmn003

164plusmn002

213plusmn002

Syringavulgaris

250plusmn006

285plusmn009

211plusmn002

257plusmn003

312plusmn007

372plusmn001

479plusmn003

471plusmn002

662plusmn002

Tilia cordata 166plusmn005

195plusmn004

399plusmn003

209plusmn004

255plusmn004

344plusmn003

125plusmn003

115plusmn002

232plusmn003

50

Volodarets et al

Table 5 Carotenoids content in some months of 2012 at experimental sites Statisticalsignificance p-value lt 005 = lt 0001 = lt00001= compared to control

SpeciesMay June October

ms 1 ms 2 ms 3 ms 1 ms 2 ms 3 ms 1 ms 2 ms 3Acer platanoides

065plusmn001

053plusmn002

040plusmn001

056plusmn002

051plusmn001

046plusmn001

270plusmn001

213plusmn001

155plusmn001

A pseudoplatanus

055plusmn002

043plusmn001

038plusmn001

073plusmn001

068plusmn001

063plusmn001

145plusmn001

115plusmn001

098plusmn002

A negundo 075plusmn002

062plusmn002

058plusmn001

075plusmn002

066plusmn002

057plusmn001

123plusmn002

101plusmn001

093plusmn002

Populus simonii

031plusmn001

027plusmn001

021plusmn001

038plusmn001

033plusmn001

029plusmn001

031plusmn001

027plusmn001

022plusmn001

P x canadensis 056plusmn002

049plusmn003

036plusmn001

060plusmn001

051=plusmn001

047plusmn001

095plusmn001

081plusmn001

078plusmn001

Robinia pseudoacacia

046plusmn002

039plusmn001

031plusmn001

061plusmn002

052plusmn002

049plusmn001

148plusmn002

131plusmn002

106plusmn003

Syringa vulgaris

033plusmn001

029plusmn001

022plusmn001

042plusmn001

039plusmn001

033plusmn001

223plusmn001

164plusmn002

145plusmn001

Tilia cordata 037plusmn001

033plusmn002

027plusmn001

047plusmn001

043plusmn001

038plusmn001

192plusmn001

171plusmn002

138plusmn002

Fig 4 The ratio of total chlorophylls to carotenoids in June 2012during the drought at monitoring sites

However this indicator inrepresentatives of Populus and Syringavulgaris genera exceeds the general rangeFor example for Populus simonii and Populustimes сanadensis the maximum level of the ratioin the control (2517 and 1587 respectively)is established and for Syringa vulgaris itmakes 1127 because of high chlorophyllconcentration and low content ofcarotenoids The tendency to growth of theconcentration of green pigments and

reduction of yellow ones in the control ismaintained for the other species exceptRobinia pseudoacacia The highest ratiochl a+bcar is found in this species for theplants in park plantations exceeding thisindicator at ms 1 and ms 3 by 11 times only

Therefore contamination in the parkplantations affects the plants which fact isconfirmed by changes in the composition ofthe pigment apparatus of leaves but in streetplantations in the conditions of heavy traffic

51

Assessment of Trees Vitality in the Urban Landscape of Steppe Zone

the reduction of chlorophyll content andincrease of carotenoids in the investigatedspecies is more significant In stable speciesof trees (Populus simonii P times canadensisRobinia pseudoacacia) these changes are lesscritical compared to medium-stable andnonsufficient stable species (Acerpseudoplatanus A negundo A platanoidesSyringa vulgaris and Tilia cordata)

DiscussionAs a result of our study it is found that

concentration of chlorophylls and carotenoidsin woody plants varies depending on themeteorological factors during the season andon the level of contamination of urban areasThe growth of chlorophyll content in the leavesof trees under study from May to September isestablished which is consistent with theliterature sources (Petrova et al 2017 Iusypivaamp Vegerich 2014) It is determined that themain factor influencing the chlorophyllformation is the air temperature Stable andmedium-stable species Robinia pseudoacaciaPopulus simonii Acer platanoides Populus timescanadensis Tilia cordata have the largestchlorophyll amount in drought periods As it isstated by Ballester et al (2017) fruit species oftrees also demonstrate high dependence on theformation of green pigments on the airtemperature During experiments for Rpseudoacia Tilia cordata and A platanoides directdependence on rainfall is established which isconsistent with the results of Iusypiva ampVegerich (2014) for Dnipro City in 2012 for Rрseudoacia in the leaves of which the maximumsum of chlorophylls was recorded in the monthwith the highest amount of rainfalls as wellThe established pattern indicates less adaptivecapacity of the representatives of Robinia Tiliaand Acer genera to the conditions ofhydrothermal stress

Under action of drought in the leaves ofrepresentatives of Acer genus (Swozcerna etal 2010) the chlorophyll content increaseswhich agrees with the results of ourexperiments for A pseudoplatanus when athigh temperatures and low rainfall inAugust 2013 the maximum amount of

chlorophylls in the leaves of this species wasrecorded This pattern indicates highadaptive capacity of sycamore maple in theconditions of South-East of Ukraine Anotherspecies Populus simonii is defined by a highconcentration of pigments under stressconditions at the start of vegetation period amore stable level of chlorophyll contentduring the growing season It should benoted that under the more prosperousconditions in June maximum is beingreached by chl a fraction under the stressconditions in August - due to the sharpincrease in the chl b fraction as well as it isfound out a higher relative content of chl b atthe end of the growing season The obtainedresults show that the various in stabilityspecies in urban environment differ in theratio of chl a and chl b under the action ofhydrothermal factors of different tensionsthat can be one of the part of thedemonstration of species adaptive strategy

Increase in sum of chlorophylls in Aplatanoides and A negundo in July andAugust 2012 when the amount of rainfallwas higher in 74 and 190 to the normalvalue accordingly occurred due to increasein the proportion of chlorophyll b whichplays the protective role in addition to itsmain function Chlorophyll b absorbs someof the rays expanding the range ofphotoactivity which is particularlyimportant in the conditions of considerablecloudiness in rainy weather Chlorophyll а ismore resistant to adverse environmentalfactors compared to chlorophyll b (Conzales-Dugo 2017 Bessonova et al 2006) Increasein the sum of chlorophylls during drought inAcer pseudoplatanus Populus x canadensis Psimonii Robinia pseudoacacia Syringa vulgarisat the expense of chlorophyll а indicates thenormal development of the photosyntheticapparatus of these species and their highadaptive reactions under conditions ofhydrothermal stress

The linear equations of total chlorophylland meteorological factors (falls andtemperature) for both years wereconstructed for two investigates species

52

Volodarets et al

Acer pseudoplatanus y = -51278-00258x1+04658x2 with R2 = 098 in 2012and y = -68888-00529x1+06888x2 with R2 =081 in 2013

Populus simonii y = -68888-00529x1+06888x2 with R2 = 060 in 2012and y = -12985+0058x1-03181x2 with R2 =077 in 2013 where y ndash sum of chlorophylls(mgg) x1 ndash amount of rainfall (mm) x2 ndashtemperature (ordmС)

As can be seen from the linearequations general tendency of pigmentsamount for change in the leaves despite thedifferent weather conditions remainsunchanged Linear equations obtained forAcer pseudoplatanus confirm the inverserelationship between air temperaturerainfall and sum of chlorophylls during thegrowing season in 2012

Maximum chlorophyll content in theleaves of Acer pseudoplatanus falls on hotmonths both in conditions of excessivehumidity (July 2012) and during thedrought period (August 2013) For Populussimonii the highest chlorophyll content isrecorded in June at high temperatures butvarying amount of rainfall The establishedpattern indicates high adaptive capacity ofA pseudoplatanus and Populus simonii duringthe drought

Carotenoids fulfill the protectivefunction by preventing the destruction ofchlorophyll molecules in the light in theprocess of photo-oxidation Photo-protectivefunction lies in the fact that yellow pigmentsprotect the reaction center from massiveenergy fluxes at high light intensities(Britton et al 2008 Bessonova 2006) Asshown by the results of our study insummer months the content of carotenoidsin species under study increases The highestindicators of carotenoids are found inautumn during the plantsrsquo preparation forwinter

During vegetation on the experimentalsites (ms 1 and ms 2) the content of greenpigments increases in late spring and duringsummer with the further decrease inconcentration in autumn which corresponds

to the dynamics of chlorophyll change in thecontrol According to Zayika amp Bondarenko(2018) the content of chlorophyll is reducedin the leaves of deciduous species in the areaof the western forest-steppe of Ukraine inautumn which is agreed with our results forthe southeastern steppe

Sum of chlorophylls in most species atthe monitoring sites is composed bychlorophyll a except for A platanoides and Anegundo as in control Formation ofchlorophyll b molecules is reduced becauseof inhibition of enzymes of its synthesisunder action of xenobiotics (Petrova et al2017 Bessonova et al 2015)

Covering of the question regardingchanges in carotenoids in the leaves of treesof street plantations in the literature isambiguous For example Petrova et al 2017for Acer heldreichii Boiss amp Heldr and Tiliatomentosa Moench point to the decrease incarotenoids at the contaminated sitehowever for Fraxinus excelsior ndash to growth oftheir content in the conditions of impact ofcar exhausts Reduced content of carotenoidsunder impact of car exhausts is also recordedby Joshi amp Swami (2009) Increase inconcentration of the yellow pigments underaction of car exhausts is established in thestudies of Sillanpaumlauml et al (2008) for Betulapendula Roth which may suggest differentadaptive capacity of trees and varying levelsof contamination Korshikov amp Vinogradova(2013) note the increase of carotenoids indamaged leaves of Acer pseudoplatanus andAcer platanoides under action of pollutantsfrom the work of internal combustionengines in Donetsk

According to results of our study thefunctional state of trees in street and parkplantations is worse compared to controlwhich is confirmed by the decrease inchlorophyll content and growth ofcarotenoids Carotenoid content at ms 2increases to 30 and at ms 1 ndash to 50 indicating the adaptive capacity of plantssince carotenoids possess high antioxidantpower The total number of chlorophylls isreduced by 20 to 30 in the trees of park

53

Assessment of Trees Vitality in the Urban Landscape of Steppe Zone

plantations and by 40ndash50 in the streetplantations compared to the clean site

It is to be noted that the representatives ofthe first group (stable species) such as Robiniapseudoacacia shows the exceedence of sum ofchlorophyls during the drought periode at ms1 and ms 2 At the same time the species of thesecond group (medium-stable species) forexample Syringa vulgaris decreases level ofchlorophyls content under the unfavorableurban and hydrothermal conditions as well asTilia cordata from the third (nonsufficientstable) groups decreases amount ofchlorophylls and increased carotenoid contentThe obtained predicted pain evidences theadaptive strategies of the studied species underanthropogenic and hydrothermal stress

Therefore it is found thatcontamination in the park plantations affectsthe plants which fact is confirmed bychanges in the composition of the pigmentapparatus of leaves but in street plantationsthe reduction of chlorophyll content andincrease of carotenoids in the investigatedspecies is more significant In stable treespecies (Populus simonii P times canadensisRobinia pseudoacacia) these changes are lesscritical than in less stable species (Acerpseudoplatanus A negundo A platanoidesSyringa vulgaris and Tilia cordata)

ConclusionAs a result of the study the functional

state of trees in street and parks plantationswas found to be weakened which indicatesa decrease in the content of green pigmentsand an increase in the concentration ofcarotenoids in the area of automobile vehicleexhaust The impact of hydrothermalconditions and factors of urban environmentdetermines the corresponding changes in theconcentration of photosynthetic pigments inwoody plants differentiated by vitality It isestablished among meteorological factors airtemperature as the main factor Changes inthe concentration of green pigments in theleaves of species under study depending onthe temperature and rainfall are describedby linear equations which is important for

predicting the growth and development ofplants during green building on urbanterritories in the conditions of the steppezone

References Ballester C Zarco-Tejada PJ Nicola E

Alarco JJ Fereres E Intrigliolo DSamp Gonzalez-Dugo V (2017)Evaluating the performance ofxanthophyll chlorophyll andstructure-sensitive spectral indices todetect water stress in five fruit treespecies In Precision Agric SpringerScience+Business Media New Yorkdoi 101007s11119-017-9512-y

Bessonova VP (2006) Influence of heavymetals on the photosynthesis of plantsDDAU Dnipropetrovsk (InUkrainian)

Bessonova VP Ivanchenko ОE ampPonomaryova EА (2015) Combinedimpact of heavy metals (Pb2+ and Cd2+)and salinity on the condition of Loliumperenne long-term assimilationapparatus - Vigravesnyk DnigravepropetrovskogoUnigravevercity Seria Bigraveology Ekology 23(1)15ndash20 (in Ukrainian) doi1015421011503

Glibovytska N Adamenko Ya (2017)Woody Plants Vitality of Urban Areasand Prospects of their GreeneryScientific Bulletin of North UniverdityCenter of Baia Mare Series D XXXI(1)21ndash34

Hopke PK (2009) Theory and applicationof Atmospheric source apportionmentIn Air quality and ecological impactsrelating sources to effects (pp 99ndash121)Elseiver Ltd

Iqbal MZ Shafig M Zaidi S amp Qamar AM(2015) Effect of automobile pollution onchlorophyll content of roadside urbantrees Global Journal of EnvironmentalScience Management 1(4) 283ndash296 doi107508gjesm201504003

Iusypiva T amp Vegerich V (2014) Dynamicsof Photosynthetic Pigments Content InWoody Plants Leaves Under

54

Assessment of Trees Vitality in the Urban Landscape of Steppe Zone

which differ on the hydrothermal conditionsAs illustrated in Fig1 the first year wasprosperous for plants due to the temperatureregime and falls amount except of thedrought autumn period which was nottypical for the steppe zone The second yearwas characterized by the droughts in springand summer which is common for theclimate of the South-East of Ukraine and lesssuitable for normal growth and developmentof trees Monthly average temperatures airhumidity and rainfall were taken from thereports of the National Hydro-meteorological Center of Ukraine (Ukrainianhydrometeorological center)

a

b

Fig1 Hydrothermal conditions in the yearsof research in Donetsk a ndash 2012 b ndash 2013

- drought periods- dynamic of temperature during the year- dynamic of falls during the year

Eight tree species of the AceraceaSalicaceae Fabacea Malvaceae and Oleaceaegenera were studied at three monitoring sitesin different types of plantations in the linearstreet plantations on the Kyivskyi avenue (ms1) in the massive plantations in the Recreationand Entertainment Park (ms 2) plots in thefield shelter belts and village plantations ofvTonenke at control site (ms 3) We selected

7-8 even-aged model trees of each specieswith the most typical vital status for theplantations of monitoring sites

General vitality of the plants wasestablished under the ocular 8-point scaleby Savelieva (1975) which is commonlyused in the investigated area (Suslova et al2013 Polyakov et al 2012) The scale isbased on the criteria of the trunk and crowndamages inhibition of apical and lateralgrowths drying of branches dry tops thepresence of adventitious shoots vegetativeshoots on the trunk coppice shootsdevelopment on the trunk of trees fungiWe evaluated the absence of these criteriain plants as 8points Their appearance andimpact on the trees reduces the vitality ofthe plant from 7 to 1 point complete dryingof the whole tree and root system theabsence of shoots from the stump wasassessed as 0 point

We collected plants materials monthlyin sunny windless weather from May toOctober With the purpose of obtaining theaverage sample leaves were sampled from7-8 trees

Chlorophylls and carotenoids wereextracted in 80 acetone in triplicaterepetition We determined solutionabsorbency (D) by spectrophotometer ULAB108UV under the different wave length 663nm 646 nm and 470 nm Concentration ofpigments of the extract (mgl) wascalculated by the Lichtenthaler equations(Shlyk 1975) with the special extractioncoefficient for each component

Сchla = 1221 D663 ndash 281 D646Сchlb = 2013 D646 ndash 503 D663

Сcar = (1000 D470 ndash 327 Сchla ndash 100 Сchlb)229

We calculated quantity content of thechlorophyls a (chl a) chlorophyls b (chl b)and carotenoids (car) of plants material withcounting of obtained concentration ofpigments in the extract under volume of theextract (25 ml) and weighted amount ofplant material (01-02) g The result wasshown in mgg of wet weight

44

Volodarets et al

Mathematical data processing wasperformed using one-way analysis of variance(ANOVA) with the Tukeyrsquos a posterior analysisunder Levenersquos test The relationship betweenmonthly average meteo-indicators and pigmentconcentrations was determined by multipleregression analysis followed by the calculationof Durbin-Watson statistics and serialcorrelation in the program Statistica 100(StatSoft Inc 2011)

Results At the beginning of the experiment the

observation of planting conditions in the citywere conducted Taking into account the lack ofsensitivity of the method of visual estimation thegeneral vital status of the even-aged trees of eachspecies was determined on ms 1 and ms 2 Thefollowing groups were identified among theplant species under study the first group (8points) ndash the stable species Robinia pseudoacaciaL Populus simonii Carrieacuter the second group (6-7 points) medium-stable species Acer platanoidesL Populus timescanadensis Moench Syringa vulgarisL the third group (4-5 points) nonsufficientstable - Acer pseudoplatanus L Acer negundo LTilia cordata Mill

In order to determine the physiologicalaspects of the plantrsquos vitality due to thedifferent hydrothermal conditions of thevegetation period of two years of research weanalyzed the pigment content in the leaves ofthe investigated species in the control withoutinfluence of urban factors High level ofchlorophyls sum was established in theconditions of July and September 2012 whichwere prosperous to the plants mainly owing tochlorophyll a (Fig 2a) This reaction isprincipally shown in the species of the thirdgroup - Acer pseudoplatanus L Acer negundo LSyringa vulgaris L as well as in the trees of thesecond group - Acer platanoides L Amount ofrainfall in these months exceeds the limit by 74 in July and 189 in August of 2012 Itshould be noted that the concentration of greenpigments of these species under the conditionsof severe drought in September decreasesextremely except for Syringa vulgaris L thatcharacterizes with increasing of chl a and chl b

amount It is evidenced about the adaptationpotential of Syringa vulgaris The highchlorophyll concentration in more stable to theurban conditions species of the first and secondgroups were estimated on the start ofvegetation in the May-June under the lack ofhumidifying

It is found out the dynamic ofchlorophyll concentration of two speciesPopulus simonii and Acer pseudoplatanus thatrepresent the groups with the most and leaststable species under the influence of stresshydrothermal conditions in the growingseason 2013 (Fig2b)

As a result of multiple regression analysisthe rainfall and air humidity are determined asthe main factors influencing the content ofgreen pigments in the leaves of species from thesecond and third groups in the controlconditions (Table 1a) However chl a+b ofspecies where the maximum content of greenpigments is observed in drought periods of theyear depends on the air temperature Forexample for Populus simonii (stable species)correlation with air temperature is establishedin the same way as for the medium-stablespecies Syringa vulgaris (R2=081)

Sum of chlorophylls for the leaves ofSyringa vulgaris in 2012 is described by linearequation

y = 131192+00356x1-04561x2

where y ndash sum of chlorophylls (mgg)x1 ndash amount of rainfall (mm) x2 ndashtemperature (ordmС)

Content of carotenoids in all investigatedspecies in the control increases from May toOctober however the rate of its growth varies(Fig 3) The most significant difference betweencarotenoids content at the beginning and theend of vegetation is established for Acer platanoides (4 times in October comparedto May figure) Increase in the content of yellowpigments at the end of vegetation relates to thepreparation of plants for winter and destructionof green pigments The negative significantinfluence of temperature was revealed for thisspecies (Table 3)

45

Assessment of Trees Vitality in the Urban Landscape of Steppe Zone

Fig 2a The chlorophyll concentration (total chl a and chl b) in leaves of theinvestigated species from May to October at monitoring site 3 (Tonenke) ndash 2012

46

Volodarets et al

Fig 2b The chlorophyll concentration (total chl a and chl b) in leaves of theinvestigated species from May to October at monitoring site 3 (Tonenke) ndash 2013

47

Assessment of Trees Vitality in the Urban Landscape of Steppe Zone

Populus simonii and Populus timesсanadensis are characterized by the absenceof the autumn leaf color at the end ofvegetation unlike the other tree species Inconnection with this the content ofcarotenoids in the leaves of this species inOctober remains unchanged compared toMay (Fig 3) It should be noted that in Juneduring the drought the content ofcarotenoids in P simonii increases indicatingthe protective role of carotenoids

For stable species Populus simonii andnonsufficient stable species Acerpseudoplatanus (Fig2b) it is found that thedynamics of chlorophyll content differs fromyear to year but air temperature remains themain factor (Table 2)

The tendency of the pigment contentchanges during the growing season at ms 1and ms 2 corresponds to the dynamics incontrol (ms 3) so the results are presentedfor one month of each season (Table 4) Insummer and autumn June and October areselected as the drought periods withunfavorable conditions for the growth anddevelopment of trees (Table 4)

Analysis of obtained results (Table 4)shows that reduction of chlorophyll content isobserved in the leaves of species under studyin street and park plantations in theconditions of contamination and urbanizationcompared to control against the samebackground of the hydrothermal conditionsFor example in June the sum of chlorophyllsin Tilia cordata decreases by 392 at ms 1and by 258 at ms 2 indicating thephysiological changes which occur in theplant body under action of pollutants

More intensive reduction of the sum ofchlorophylls in the leaves of species understudy is recorded at ms 1 compared to ms2 and control The significant difference wasrecorded in May under favorable weatherconditions in young leaves which are moresensitive to airborne pollutants of all speciesexcept Syringa vulgaris For example in theleaves of Acer negundo the chlorophyllcontent decreased by 517 at ms 1 and by317 at ms 2 compared to control The

lowest sensitivity to pollutants was foundfor the leaves of Robinia pseudoacacia andSyringa vulgaris Their sum of chlorophyllshas grown by 549 and 185 at ms 1respectively

During the first draught in June Apseudoplatanus (decrease in sum ofchlorophylls by 579 and 287 at ms1and ms2 respectively) Populus simonii (625 and 464 ms 1 and ms 2) P xcanadensis (252 and 724 at ms 1 andms 2) are more sensitive to contaminationAcer platanoides A negundo Syringa vulgarisL and Tilia cordata are less sensitive tocontamination chlorophyll content in themdecreases from 220 to 392 dependingon species at ms 1 compared to controlRobinia pseudoacacia is the most resistant tocontamination during drought in Junechlorophyll content increases by 15 at ms1 and ms 2 respectively

During the drought in October it isfound at ms 1 that contamination has lesssignificant impact on the condition ofphotosynthetic apparatus in all species dueto lower sensitivity of old leaves to adverseabiotic and anthropogenic factors of theenvironment High endurance againstcontamination and prolonged drought wasdemonstrated by A pseudoplatanus LPopulus simonii P x canadensis Robiniapseudoacacia and Syringa vulgaris

According to the results of studies it isestablished that at ms 1 and ms 2 thecarotenoid content in the leaves of modelspecimens increases compared to the controlbut the degree of increase depends on plantresistance as can be seen from the dynamicsof carotenoid content in June (Table 5)

The content of carotenoids in stablespecies (P simonii P times canadensis Robiniapseudoacacia) features almost no difference onKyivskyi avenue (ms 1) and in the Recreationand Entertainment Park (ms 2) duringvegetation The established pattern indicateshigh resistance of these woody plants toconditions of the urban environmentConcentration of yellow pigments in Acerpseudoplatanus and A negundo growing in the

48

Volodarets et al

park increases by 30ndash35 compared to ms3 showing the sufficient level of adaptationof these species to conditions of the urbanenvironment Considerable increase incarotenoids in street and park plantations isrecorded in Acer platanoides Syringa vulgarisand Tilia cordata which are less stable

The ratio of sum of chlorophylls tocarotenoids (a+bcar) as a rule is constantin the normal conditions and promptly

responds to changes in the environment so itis used as an indicator of plantsrsquo adaptation toextreme conditions (Petrova et al 2014) Inorder to understand the simultaneous actionof abiotic stress ndash drought and anthropogenicpressure the ratio a+bcar was calculated forJune 2012

In most species a+bcar varied from 486(Acer platanoides ms 1) to 905 (Tilia cordatams 3) (Fig4)

Table 1 Stepwise regression analysis for sum of chlorophylls of woody plants in thevegetation period of 2012 (Tonenke ms 3) Negatively correlated variables are highlightedin bold Statistical significance p-value lt 005 = lt 0001 = lt 00001

Species Step 1 Step 2 Step 3Populus times canadensis Falls 009 Falls Temp 069 -Populus simonii Temp 054 Temp Falls 006 Temp Falls Hum 014Tilia cordata Falls 004 Falls Hum 005Robinia pseudoacacia Falls 0008 Falls Hum 005 -Acer negundo - Hum 011Acer platanoides Falls 002 - -Acer pseudoplatanus Hum 030 Hum Falls 003 Hum Falls Temp 014Syringa vulgaris Temp 046 Temp Falls004

Table 2 Stepwise regression analysis for sum of chlorophylls of woody plants in thevegetation period of 2013 (Tonenke ms 3) Negatively correlated variables are highlightedin bold Statistical significance p-value lt 005 = lt 0001 = lt 00001

Species Step 1 Step 2 Step 3Acer pseudoplatanus Temp 022 - -Populus simonii Temp 066 - -

Fig 3 The carotenoids concentration in leaves of the investigated species from May toOctober at monitoring site 3 (Tonenke) in 2012

49

Assessment of Trees Vitality in the Urban Landscape of Steppe Zone

Table 3 Stepwise regression analysis for carotenoids concentration of woodyplants in the vegetation period of 2012 on the control site Negatively correlatedvariables are highlighted in bold Statistical significance p-value lt 005 = lt 0001 = lt00001=

Species Step 1 Step 2 Step 3

P times canadensis Hum002

HumFalls0005

HumFallsTemp002

P simonii Hum002

HumFalls0004 -

Tilia cordata Hum004

HumFalls001

HumFallsTemp009

Robinia pseudoacacia Hum002

HumFalls0006

HumFallsTemp005

Acer negundo Temp003

TempFalls0003

TempFallsHum001

A platanoides Temp012

TempFalls0004

A pseudoplatanus Hum002

HumFalls0004

HumFallsTemp003

Syringa vulgaris Temp012

TempFalls001 -

Table 4 Sum of chlorophylls of the species leaves at experimental sites during thevegetation period Statistical significance p-value lt 005 = lt 0001 = lt00001= compared to control

SpeciesMay June October

ms 1 ms 2 ms 3 ms 1 ms 2 ms 3 ms 1 ms 2 ms 3Acer

platanoides 143

plusmn005132

plusmn004325

plusmn005272

plusmn002314

plusmn005353

plusmn002113

plusmn006115

plusmn001174

plusmn001A

pseudoplatanus 149

plusmn011248

plusmn025332

plusmn005160

plusmn003271

plusmn007380

plusmn003072

plusmn008101

plusmn001073

plusmn002

A negundo 099plusmn011

140plusmn007

205plusmn005

319plusmn002

367plusmn011

409plusmn001

084plusmn003

027plusmn001

142plusmn001

Populussimonii

144plusmn008

234plusmn003

544plusmn004

277plusmn005

391plusmn012

730plusmn002

143plusmn006

081plusmn001

229plusmn002

P xcanadensis

099plusmn006

193plusmn006

306plusmn003

256plusmn003

636plusmn005

746plusmn004

355plusmn002

431plusmn001

475plusmn002

Robinia pseudoacacia

285plusmn007

243plusmn005

184plusmn002

335plusmn003

337plusmn002

291plusmn001

137plusmn003

164plusmn002

213plusmn002

Syringavulgaris

250plusmn006

285plusmn009

211plusmn002

257plusmn003

312plusmn007

372plusmn001

479plusmn003

471plusmn002

662plusmn002

Tilia cordata 166plusmn005

195plusmn004

399plusmn003

209plusmn004

255plusmn004

344plusmn003

125plusmn003

115plusmn002

232plusmn003

50

Volodarets et al

Table 5 Carotenoids content in some months of 2012 at experimental sites Statisticalsignificance p-value lt 005 = lt 0001 = lt00001= compared to control

SpeciesMay June October

ms 1 ms 2 ms 3 ms 1 ms 2 ms 3 ms 1 ms 2 ms 3Acer platanoides

065plusmn001

053plusmn002

040plusmn001

056plusmn002

051plusmn001

046plusmn001

270plusmn001

213plusmn001

155plusmn001

A pseudoplatanus

055plusmn002

043plusmn001

038plusmn001

073plusmn001

068plusmn001

063plusmn001

145plusmn001

115plusmn001

098plusmn002

A negundo 075plusmn002

062plusmn002

058plusmn001

075plusmn002

066plusmn002

057plusmn001

123plusmn002

101plusmn001

093plusmn002

Populus simonii

031plusmn001

027plusmn001

021plusmn001

038plusmn001

033plusmn001

029plusmn001

031plusmn001

027plusmn001

022plusmn001

P x canadensis 056plusmn002

049plusmn003

036plusmn001

060plusmn001

051=plusmn001

047plusmn001

095plusmn001

081plusmn001

078plusmn001

Robinia pseudoacacia

046plusmn002

039plusmn001

031plusmn001

061plusmn002

052plusmn002

049plusmn001

148plusmn002

131plusmn002

106plusmn003

Syringa vulgaris

033plusmn001

029plusmn001

022plusmn001

042plusmn001

039plusmn001

033plusmn001

223plusmn001

164plusmn002

145plusmn001

Tilia cordata 037plusmn001

033plusmn002

027plusmn001

047plusmn001

043plusmn001

038plusmn001

192plusmn001

171plusmn002

138plusmn002

Fig 4 The ratio of total chlorophylls to carotenoids in June 2012during the drought at monitoring sites

However this indicator inrepresentatives of Populus and Syringavulgaris genera exceeds the general rangeFor example for Populus simonii and Populustimes сanadensis the maximum level of the ratioin the control (2517 and 1587 respectively)is established and for Syringa vulgaris itmakes 1127 because of high chlorophyllconcentration and low content ofcarotenoids The tendency to growth of theconcentration of green pigments and

reduction of yellow ones in the control ismaintained for the other species exceptRobinia pseudoacacia The highest ratiochl a+bcar is found in this species for theplants in park plantations exceeding thisindicator at ms 1 and ms 3 by 11 times only

Therefore contamination in the parkplantations affects the plants which fact isconfirmed by changes in the composition ofthe pigment apparatus of leaves but in streetplantations in the conditions of heavy traffic

51

Assessment of Trees Vitality in the Urban Landscape of Steppe Zone

the reduction of chlorophyll content andincrease of carotenoids in the investigatedspecies is more significant In stable speciesof trees (Populus simonii P times canadensisRobinia pseudoacacia) these changes are lesscritical compared to medium-stable andnonsufficient stable species (Acerpseudoplatanus A negundo A platanoidesSyringa vulgaris and Tilia cordata)

DiscussionAs a result of our study it is found that

concentration of chlorophylls and carotenoidsin woody plants varies depending on themeteorological factors during the season andon the level of contamination of urban areasThe growth of chlorophyll content in the leavesof trees under study from May to September isestablished which is consistent with theliterature sources (Petrova et al 2017 Iusypivaamp Vegerich 2014) It is determined that themain factor influencing the chlorophyllformation is the air temperature Stable andmedium-stable species Robinia pseudoacaciaPopulus simonii Acer platanoides Populus timescanadensis Tilia cordata have the largestchlorophyll amount in drought periods As it isstated by Ballester et al (2017) fruit species oftrees also demonstrate high dependence on theformation of green pigments on the airtemperature During experiments for Rpseudoacia Tilia cordata and A platanoides directdependence on rainfall is established which isconsistent with the results of Iusypiva ampVegerich (2014) for Dnipro City in 2012 for Rрseudoacia in the leaves of which the maximumsum of chlorophylls was recorded in the monthwith the highest amount of rainfalls as wellThe established pattern indicates less adaptivecapacity of the representatives of Robinia Tiliaand Acer genera to the conditions ofhydrothermal stress

Under action of drought in the leaves ofrepresentatives of Acer genus (Swozcerna etal 2010) the chlorophyll content increaseswhich agrees with the results of ourexperiments for A pseudoplatanus when athigh temperatures and low rainfall inAugust 2013 the maximum amount of

chlorophylls in the leaves of this species wasrecorded This pattern indicates highadaptive capacity of sycamore maple in theconditions of South-East of Ukraine Anotherspecies Populus simonii is defined by a highconcentration of pigments under stressconditions at the start of vegetation period amore stable level of chlorophyll contentduring the growing season It should benoted that under the more prosperousconditions in June maximum is beingreached by chl a fraction under the stressconditions in August - due to the sharpincrease in the chl b fraction as well as it isfound out a higher relative content of chl b atthe end of the growing season The obtainedresults show that the various in stabilityspecies in urban environment differ in theratio of chl a and chl b under the action ofhydrothermal factors of different tensionsthat can be one of the part of thedemonstration of species adaptive strategy

Increase in sum of chlorophylls in Aplatanoides and A negundo in July andAugust 2012 when the amount of rainfallwas higher in 74 and 190 to the normalvalue accordingly occurred due to increasein the proportion of chlorophyll b whichplays the protective role in addition to itsmain function Chlorophyll b absorbs someof the rays expanding the range ofphotoactivity which is particularlyimportant in the conditions of considerablecloudiness in rainy weather Chlorophyll а ismore resistant to adverse environmentalfactors compared to chlorophyll b (Conzales-Dugo 2017 Bessonova et al 2006) Increasein the sum of chlorophylls during drought inAcer pseudoplatanus Populus x canadensis Psimonii Robinia pseudoacacia Syringa vulgarisat the expense of chlorophyll а indicates thenormal development of the photosyntheticapparatus of these species and their highadaptive reactions under conditions ofhydrothermal stress

The linear equations of total chlorophylland meteorological factors (falls andtemperature) for both years wereconstructed for two investigates species

52

Volodarets et al

Acer pseudoplatanus y = -51278-00258x1+04658x2 with R2 = 098 in 2012and y = -68888-00529x1+06888x2 with R2 =081 in 2013

Populus simonii y = -68888-00529x1+06888x2 with R2 = 060 in 2012and y = -12985+0058x1-03181x2 with R2 =077 in 2013 where y ndash sum of chlorophylls(mgg) x1 ndash amount of rainfall (mm) x2 ndashtemperature (ordmС)

As can be seen from the linearequations general tendency of pigmentsamount for change in the leaves despite thedifferent weather conditions remainsunchanged Linear equations obtained forAcer pseudoplatanus confirm the inverserelationship between air temperaturerainfall and sum of chlorophylls during thegrowing season in 2012

Maximum chlorophyll content in theleaves of Acer pseudoplatanus falls on hotmonths both in conditions of excessivehumidity (July 2012) and during thedrought period (August 2013) For Populussimonii the highest chlorophyll content isrecorded in June at high temperatures butvarying amount of rainfall The establishedpattern indicates high adaptive capacity ofA pseudoplatanus and Populus simonii duringthe drought

Carotenoids fulfill the protectivefunction by preventing the destruction ofchlorophyll molecules in the light in theprocess of photo-oxidation Photo-protectivefunction lies in the fact that yellow pigmentsprotect the reaction center from massiveenergy fluxes at high light intensities(Britton et al 2008 Bessonova 2006) Asshown by the results of our study insummer months the content of carotenoidsin species under study increases The highestindicators of carotenoids are found inautumn during the plantsrsquo preparation forwinter

During vegetation on the experimentalsites (ms 1 and ms 2) the content of greenpigments increases in late spring and duringsummer with the further decrease inconcentration in autumn which corresponds

to the dynamics of chlorophyll change in thecontrol According to Zayika amp Bondarenko(2018) the content of chlorophyll is reducedin the leaves of deciduous species in the areaof the western forest-steppe of Ukraine inautumn which is agreed with our results forthe southeastern steppe

Sum of chlorophylls in most species atthe monitoring sites is composed bychlorophyll a except for A platanoides and Anegundo as in control Formation ofchlorophyll b molecules is reduced becauseof inhibition of enzymes of its synthesisunder action of xenobiotics (Petrova et al2017 Bessonova et al 2015)

Covering of the question regardingchanges in carotenoids in the leaves of treesof street plantations in the literature isambiguous For example Petrova et al 2017for Acer heldreichii Boiss amp Heldr and Tiliatomentosa Moench point to the decrease incarotenoids at the contaminated sitehowever for Fraxinus excelsior ndash to growth oftheir content in the conditions of impact ofcar exhausts Reduced content of carotenoidsunder impact of car exhausts is also recordedby Joshi amp Swami (2009) Increase inconcentration of the yellow pigments underaction of car exhausts is established in thestudies of Sillanpaumlauml et al (2008) for Betulapendula Roth which may suggest differentadaptive capacity of trees and varying levelsof contamination Korshikov amp Vinogradova(2013) note the increase of carotenoids indamaged leaves of Acer pseudoplatanus andAcer platanoides under action of pollutantsfrom the work of internal combustionengines in Donetsk

According to results of our study thefunctional state of trees in street and parkplantations is worse compared to controlwhich is confirmed by the decrease inchlorophyll content and growth ofcarotenoids Carotenoid content at ms 2increases to 30 and at ms 1 ndash to 50 indicating the adaptive capacity of plantssince carotenoids possess high antioxidantpower The total number of chlorophylls isreduced by 20 to 30 in the trees of park

53

Assessment of Trees Vitality in the Urban Landscape of Steppe Zone

plantations and by 40ndash50 in the streetplantations compared to the clean site

It is to be noted that the representatives ofthe first group (stable species) such as Robiniapseudoacacia shows the exceedence of sum ofchlorophyls during the drought periode at ms1 and ms 2 At the same time the species of thesecond group (medium-stable species) forexample Syringa vulgaris decreases level ofchlorophyls content under the unfavorableurban and hydrothermal conditions as well asTilia cordata from the third (nonsufficientstable) groups decreases amount ofchlorophylls and increased carotenoid contentThe obtained predicted pain evidences theadaptive strategies of the studied species underanthropogenic and hydrothermal stress

Therefore it is found thatcontamination in the park plantations affectsthe plants which fact is confirmed bychanges in the composition of the pigmentapparatus of leaves but in street plantationsthe reduction of chlorophyll content andincrease of carotenoids in the investigatedspecies is more significant In stable treespecies (Populus simonii P times canadensisRobinia pseudoacacia) these changes are lesscritical than in less stable species (Acerpseudoplatanus A negundo A platanoidesSyringa vulgaris and Tilia cordata)

ConclusionAs a result of the study the functional

state of trees in street and parks plantationswas found to be weakened which indicatesa decrease in the content of green pigmentsand an increase in the concentration ofcarotenoids in the area of automobile vehicleexhaust The impact of hydrothermalconditions and factors of urban environmentdetermines the corresponding changes in theconcentration of photosynthetic pigments inwoody plants differentiated by vitality It isestablished among meteorological factors airtemperature as the main factor Changes inthe concentration of green pigments in theleaves of species under study depending onthe temperature and rainfall are describedby linear equations which is important for

predicting the growth and development ofplants during green building on urbanterritories in the conditions of the steppezone

References Ballester C Zarco-Tejada PJ Nicola E

Alarco JJ Fereres E Intrigliolo DSamp Gonzalez-Dugo V (2017)Evaluating the performance ofxanthophyll chlorophyll andstructure-sensitive spectral indices todetect water stress in five fruit treespecies In Precision Agric SpringerScience+Business Media New Yorkdoi 101007s11119-017-9512-y

Bessonova VP (2006) Influence of heavymetals on the photosynthesis of plantsDDAU Dnipropetrovsk (InUkrainian)

Bessonova VP Ivanchenko ОE ampPonomaryova EА (2015) Combinedimpact of heavy metals (Pb2+ and Cd2+)and salinity on the condition of Loliumperenne long-term assimilationapparatus - Vigravesnyk DnigravepropetrovskogoUnigravevercity Seria Bigraveology Ekology 23(1)15ndash20 (in Ukrainian) doi1015421011503

Glibovytska N Adamenko Ya (2017)Woody Plants Vitality of Urban Areasand Prospects of their GreeneryScientific Bulletin of North UniverdityCenter of Baia Mare Series D XXXI(1)21ndash34

Hopke PK (2009) Theory and applicationof Atmospheric source apportionmentIn Air quality and ecological impactsrelating sources to effects (pp 99ndash121)Elseiver Ltd

Iqbal MZ Shafig M Zaidi S amp Qamar AM(2015) Effect of automobile pollution onchlorophyll content of roadside urbantrees Global Journal of EnvironmentalScience Management 1(4) 283ndash296 doi107508gjesm201504003

Iusypiva T amp Vegerich V (2014) Dynamicsof Photosynthetic Pigments Content InWoody Plants Leaves Under

54

Volodarets et al

Mathematical data processing wasperformed using one-way analysis of variance(ANOVA) with the Tukeyrsquos a posterior analysisunder Levenersquos test The relationship betweenmonthly average meteo-indicators and pigmentconcentrations was determined by multipleregression analysis followed by the calculationof Durbin-Watson statistics and serialcorrelation in the program Statistica 100(StatSoft Inc 2011)

Results At the beginning of the experiment the

observation of planting conditions in the citywere conducted Taking into account the lack ofsensitivity of the method of visual estimation thegeneral vital status of the even-aged trees of eachspecies was determined on ms 1 and ms 2 Thefollowing groups were identified among theplant species under study the first group (8points) ndash the stable species Robinia pseudoacaciaL Populus simonii Carrieacuter the second group (6-7 points) medium-stable species Acer platanoidesL Populus timescanadensis Moench Syringa vulgarisL the third group (4-5 points) nonsufficientstable - Acer pseudoplatanus L Acer negundo LTilia cordata Mill

In order to determine the physiologicalaspects of the plantrsquos vitality due to thedifferent hydrothermal conditions of thevegetation period of two years of research weanalyzed the pigment content in the leaves ofthe investigated species in the control withoutinfluence of urban factors High level ofchlorophyls sum was established in theconditions of July and September 2012 whichwere prosperous to the plants mainly owing tochlorophyll a (Fig 2a) This reaction isprincipally shown in the species of the thirdgroup - Acer pseudoplatanus L Acer negundo LSyringa vulgaris L as well as in the trees of thesecond group - Acer platanoides L Amount ofrainfall in these months exceeds the limit by 74 in July and 189 in August of 2012 Itshould be noted that the concentration of greenpigments of these species under the conditionsof severe drought in September decreasesextremely except for Syringa vulgaris L thatcharacterizes with increasing of chl a and chl b

amount It is evidenced about the adaptationpotential of Syringa vulgaris The highchlorophyll concentration in more stable to theurban conditions species of the first and secondgroups were estimated on the start ofvegetation in the May-June under the lack ofhumidifying

It is found out the dynamic ofchlorophyll concentration of two speciesPopulus simonii and Acer pseudoplatanus thatrepresent the groups with the most and leaststable species under the influence of stresshydrothermal conditions in the growingseason 2013 (Fig2b)

As a result of multiple regression analysisthe rainfall and air humidity are determined asthe main factors influencing the content ofgreen pigments in the leaves of species from thesecond and third groups in the controlconditions (Table 1a) However chl a+b ofspecies where the maximum content of greenpigments is observed in drought periods of theyear depends on the air temperature Forexample for Populus simonii (stable species)correlation with air temperature is establishedin the same way as for the medium-stablespecies Syringa vulgaris (R2=081)

Sum of chlorophylls for the leaves ofSyringa vulgaris in 2012 is described by linearequation

y = 131192+00356x1-04561x2

where y ndash sum of chlorophylls (mgg)x1 ndash amount of rainfall (mm) x2 ndashtemperature (ordmС)

Content of carotenoids in all investigatedspecies in the control increases from May toOctober however the rate of its growth varies(Fig 3) The most significant difference betweencarotenoids content at the beginning and theend of vegetation is established for Acer platanoides (4 times in October comparedto May figure) Increase in the content of yellowpigments at the end of vegetation relates to thepreparation of plants for winter and destructionof green pigments The negative significantinfluence of temperature was revealed for thisspecies (Table 3)

45

Assessment of Trees Vitality in the Urban Landscape of Steppe Zone

Fig 2a The chlorophyll concentration (total chl a and chl b) in leaves of theinvestigated species from May to October at monitoring site 3 (Tonenke) ndash 2012

46

Volodarets et al

Fig 2b The chlorophyll concentration (total chl a and chl b) in leaves of theinvestigated species from May to October at monitoring site 3 (Tonenke) ndash 2013

47

Assessment of Trees Vitality in the Urban Landscape of Steppe Zone

Populus simonii and Populus timesсanadensis are characterized by the absenceof the autumn leaf color at the end ofvegetation unlike the other tree species Inconnection with this the content ofcarotenoids in the leaves of this species inOctober remains unchanged compared toMay (Fig 3) It should be noted that in Juneduring the drought the content ofcarotenoids in P simonii increases indicatingthe protective role of carotenoids

For stable species Populus simonii andnonsufficient stable species Acerpseudoplatanus (Fig2b) it is found that thedynamics of chlorophyll content differs fromyear to year but air temperature remains themain factor (Table 2)

The tendency of the pigment contentchanges during the growing season at ms 1and ms 2 corresponds to the dynamics incontrol (ms 3) so the results are presentedfor one month of each season (Table 4) Insummer and autumn June and October areselected as the drought periods withunfavorable conditions for the growth anddevelopment of trees (Table 4)

Analysis of obtained results (Table 4)shows that reduction of chlorophyll content isobserved in the leaves of species under studyin street and park plantations in theconditions of contamination and urbanizationcompared to control against the samebackground of the hydrothermal conditionsFor example in June the sum of chlorophyllsin Tilia cordata decreases by 392 at ms 1and by 258 at ms 2 indicating thephysiological changes which occur in theplant body under action of pollutants

More intensive reduction of the sum ofchlorophylls in the leaves of species understudy is recorded at ms 1 compared to ms2 and control The significant difference wasrecorded in May under favorable weatherconditions in young leaves which are moresensitive to airborne pollutants of all speciesexcept Syringa vulgaris For example in theleaves of Acer negundo the chlorophyllcontent decreased by 517 at ms 1 and by317 at ms 2 compared to control The

lowest sensitivity to pollutants was foundfor the leaves of Robinia pseudoacacia andSyringa vulgaris Their sum of chlorophyllshas grown by 549 and 185 at ms 1respectively

During the first draught in June Apseudoplatanus (decrease in sum ofchlorophylls by 579 and 287 at ms1and ms2 respectively) Populus simonii (625 and 464 ms 1 and ms 2) P xcanadensis (252 and 724 at ms 1 andms 2) are more sensitive to contaminationAcer platanoides A negundo Syringa vulgarisL and Tilia cordata are less sensitive tocontamination chlorophyll content in themdecreases from 220 to 392 dependingon species at ms 1 compared to controlRobinia pseudoacacia is the most resistant tocontamination during drought in Junechlorophyll content increases by 15 at ms1 and ms 2 respectively

During the drought in October it isfound at ms 1 that contamination has lesssignificant impact on the condition ofphotosynthetic apparatus in all species dueto lower sensitivity of old leaves to adverseabiotic and anthropogenic factors of theenvironment High endurance againstcontamination and prolonged drought wasdemonstrated by A pseudoplatanus LPopulus simonii P x canadensis Robiniapseudoacacia and Syringa vulgaris

According to the results of studies it isestablished that at ms 1 and ms 2 thecarotenoid content in the leaves of modelspecimens increases compared to the controlbut the degree of increase depends on plantresistance as can be seen from the dynamicsof carotenoid content in June (Table 5)

The content of carotenoids in stablespecies (P simonii P times canadensis Robiniapseudoacacia) features almost no difference onKyivskyi avenue (ms 1) and in the Recreationand Entertainment Park (ms 2) duringvegetation The established pattern indicateshigh resistance of these woody plants toconditions of the urban environmentConcentration of yellow pigments in Acerpseudoplatanus and A negundo growing in the

48

Volodarets et al

park increases by 30ndash35 compared to ms3 showing the sufficient level of adaptationof these species to conditions of the urbanenvironment Considerable increase incarotenoids in street and park plantations isrecorded in Acer platanoides Syringa vulgarisand Tilia cordata which are less stable

The ratio of sum of chlorophylls tocarotenoids (a+bcar) as a rule is constantin the normal conditions and promptly

responds to changes in the environment so itis used as an indicator of plantsrsquo adaptation toextreme conditions (Petrova et al 2014) Inorder to understand the simultaneous actionof abiotic stress ndash drought and anthropogenicpressure the ratio a+bcar was calculated forJune 2012

In most species a+bcar varied from 486(Acer platanoides ms 1) to 905 (Tilia cordatams 3) (Fig4)

Table 1 Stepwise regression analysis for sum of chlorophylls of woody plants in thevegetation period of 2012 (Tonenke ms 3) Negatively correlated variables are highlightedin bold Statistical significance p-value lt 005 = lt 0001 = lt 00001

Species Step 1 Step 2 Step 3Populus times canadensis Falls 009 Falls Temp 069 -Populus simonii Temp 054 Temp Falls 006 Temp Falls Hum 014Tilia cordata Falls 004 Falls Hum 005Robinia pseudoacacia Falls 0008 Falls Hum 005 -Acer negundo - Hum 011Acer platanoides Falls 002 - -Acer pseudoplatanus Hum 030 Hum Falls 003 Hum Falls Temp 014Syringa vulgaris Temp 046 Temp Falls004

Table 2 Stepwise regression analysis for sum of chlorophylls of woody plants in thevegetation period of 2013 (Tonenke ms 3) Negatively correlated variables are highlightedin bold Statistical significance p-value lt 005 = lt 0001 = lt 00001

Species Step 1 Step 2 Step 3Acer pseudoplatanus Temp 022 - -Populus simonii Temp 066 - -

Fig 3 The carotenoids concentration in leaves of the investigated species from May toOctober at monitoring site 3 (Tonenke) in 2012

49

Assessment of Trees Vitality in the Urban Landscape of Steppe Zone

Table 3 Stepwise regression analysis for carotenoids concentration of woodyplants in the vegetation period of 2012 on the control site Negatively correlatedvariables are highlighted in bold Statistical significance p-value lt 005 = lt 0001 = lt00001=

Species Step 1 Step 2 Step 3

P times canadensis Hum002

HumFalls0005

HumFallsTemp002

P simonii Hum002

HumFalls0004 -

Tilia cordata Hum004

HumFalls001

HumFallsTemp009

Robinia pseudoacacia Hum002

HumFalls0006

HumFallsTemp005

Acer negundo Temp003

TempFalls0003

TempFallsHum001

A platanoides Temp012

TempFalls0004

A pseudoplatanus Hum002

HumFalls0004

HumFallsTemp003

Syringa vulgaris Temp012

TempFalls001 -

Table 4 Sum of chlorophylls of the species leaves at experimental sites during thevegetation period Statistical significance p-value lt 005 = lt 0001 = lt00001= compared to control

SpeciesMay June October

ms 1 ms 2 ms 3 ms 1 ms 2 ms 3 ms 1 ms 2 ms 3Acer

platanoides 143

plusmn005132

plusmn004325

plusmn005272

plusmn002314

plusmn005353

plusmn002113

plusmn006115

plusmn001174

plusmn001A

pseudoplatanus 149

plusmn011248

plusmn025332

plusmn005160

plusmn003271

plusmn007380

plusmn003072

plusmn008101

plusmn001073

plusmn002

A negundo 099plusmn011

140plusmn007

205plusmn005

319plusmn002

367plusmn011

409plusmn001

084plusmn003

027plusmn001

142plusmn001

Populussimonii

144plusmn008

234plusmn003

544plusmn004

277plusmn005

391plusmn012

730plusmn002

143plusmn006

081plusmn001

229plusmn002

P xcanadensis

099plusmn006

193plusmn006

306plusmn003

256plusmn003

636plusmn005

746plusmn004

355plusmn002

431plusmn001

475plusmn002

Robinia pseudoacacia

285plusmn007

243plusmn005

184plusmn002

335plusmn003

337plusmn002

291plusmn001

137plusmn003

164plusmn002

213plusmn002

Syringavulgaris

250plusmn006

285plusmn009

211plusmn002

257plusmn003

312plusmn007

372plusmn001

479plusmn003

471plusmn002

662plusmn002

Tilia cordata 166plusmn005

195plusmn004

399plusmn003

209plusmn004

255plusmn004

344plusmn003

125plusmn003

115plusmn002

232plusmn003

50

Volodarets et al

Table 5 Carotenoids content in some months of 2012 at experimental sites Statisticalsignificance p-value lt 005 = lt 0001 = lt00001= compared to control

SpeciesMay June October

ms 1 ms 2 ms 3 ms 1 ms 2 ms 3 ms 1 ms 2 ms 3Acer platanoides

065plusmn001

053plusmn002

040plusmn001

056plusmn002

051plusmn001

046plusmn001

270plusmn001

213plusmn001

155plusmn001

A pseudoplatanus

055plusmn002

043plusmn001

038plusmn001

073plusmn001

068plusmn001

063plusmn001

145plusmn001

115plusmn001

098plusmn002

A negundo 075plusmn002

062plusmn002

058plusmn001

075plusmn002

066plusmn002

057plusmn001

123plusmn002

101plusmn001

093plusmn002

Populus simonii

031plusmn001

027plusmn001

021plusmn001

038plusmn001

033plusmn001

029plusmn001

031plusmn001

027plusmn001

022plusmn001

P x canadensis 056plusmn002

049plusmn003

036plusmn001

060plusmn001

051=plusmn001

047plusmn001

095plusmn001

081plusmn001

078plusmn001

Robinia pseudoacacia

046plusmn002

039plusmn001

031plusmn001

061plusmn002

052plusmn002

049plusmn001

148plusmn002

131plusmn002

106plusmn003

Syringa vulgaris

033plusmn001

029plusmn001

022plusmn001

042plusmn001

039plusmn001

033plusmn001

223plusmn001

164plusmn002

145plusmn001

Tilia cordata 037plusmn001

033plusmn002

027plusmn001

047plusmn001

043plusmn001

038plusmn001

192plusmn001

171plusmn002

138plusmn002

Fig 4 The ratio of total chlorophylls to carotenoids in June 2012during the drought at monitoring sites

However this indicator inrepresentatives of Populus and Syringavulgaris genera exceeds the general rangeFor example for Populus simonii and Populustimes сanadensis the maximum level of the ratioin the control (2517 and 1587 respectively)is established and for Syringa vulgaris itmakes 1127 because of high chlorophyllconcentration and low content ofcarotenoids The tendency to growth of theconcentration of green pigments and

reduction of yellow ones in the control ismaintained for the other species exceptRobinia pseudoacacia The highest ratiochl a+bcar is found in this species for theplants in park plantations exceeding thisindicator at ms 1 and ms 3 by 11 times only

Therefore contamination in the parkplantations affects the plants which fact isconfirmed by changes in the composition ofthe pigment apparatus of leaves but in streetplantations in the conditions of heavy traffic

51

Assessment of Trees Vitality in the Urban Landscape of Steppe Zone

the reduction of chlorophyll content andincrease of carotenoids in the investigatedspecies is more significant In stable speciesof trees (Populus simonii P times canadensisRobinia pseudoacacia) these changes are lesscritical compared to medium-stable andnonsufficient stable species (Acerpseudoplatanus A negundo A platanoidesSyringa vulgaris and Tilia cordata)

DiscussionAs a result of our study it is found that

concentration of chlorophylls and carotenoidsin woody plants varies depending on themeteorological factors during the season andon the level of contamination of urban areasThe growth of chlorophyll content in the leavesof trees under study from May to September isestablished which is consistent with theliterature sources (Petrova et al 2017 Iusypivaamp Vegerich 2014) It is determined that themain factor influencing the chlorophyllformation is the air temperature Stable andmedium-stable species Robinia pseudoacaciaPopulus simonii Acer platanoides Populus timescanadensis Tilia cordata have the largestchlorophyll amount in drought periods As it isstated by Ballester et al (2017) fruit species oftrees also demonstrate high dependence on theformation of green pigments on the airtemperature During experiments for Rpseudoacia Tilia cordata and A platanoides directdependence on rainfall is established which isconsistent with the results of Iusypiva ampVegerich (2014) for Dnipro City in 2012 for Rрseudoacia in the leaves of which the maximumsum of chlorophylls was recorded in the monthwith the highest amount of rainfalls as wellThe established pattern indicates less adaptivecapacity of the representatives of Robinia Tiliaand Acer genera to the conditions ofhydrothermal stress

Under action of drought in the leaves ofrepresentatives of Acer genus (Swozcerna etal 2010) the chlorophyll content increaseswhich agrees with the results of ourexperiments for A pseudoplatanus when athigh temperatures and low rainfall inAugust 2013 the maximum amount of

chlorophylls in the leaves of this species wasrecorded This pattern indicates highadaptive capacity of sycamore maple in theconditions of South-East of Ukraine Anotherspecies Populus simonii is defined by a highconcentration of pigments under stressconditions at the start of vegetation period amore stable level of chlorophyll contentduring the growing season It should benoted that under the more prosperousconditions in June maximum is beingreached by chl a fraction under the stressconditions in August - due to the sharpincrease in the chl b fraction as well as it isfound out a higher relative content of chl b atthe end of the growing season The obtainedresults show that the various in stabilityspecies in urban environment differ in theratio of chl a and chl b under the action ofhydrothermal factors of different tensionsthat can be one of the part of thedemonstration of species adaptive strategy

Increase in sum of chlorophylls in Aplatanoides and A negundo in July andAugust 2012 when the amount of rainfallwas higher in 74 and 190 to the normalvalue accordingly occurred due to increasein the proportion of chlorophyll b whichplays the protective role in addition to itsmain function Chlorophyll b absorbs someof the rays expanding the range ofphotoactivity which is particularlyimportant in the conditions of considerablecloudiness in rainy weather Chlorophyll а ismore resistant to adverse environmentalfactors compared to chlorophyll b (Conzales-Dugo 2017 Bessonova et al 2006) Increasein the sum of chlorophylls during drought inAcer pseudoplatanus Populus x canadensis Psimonii Robinia pseudoacacia Syringa vulgarisat the expense of chlorophyll а indicates thenormal development of the photosyntheticapparatus of these species and their highadaptive reactions under conditions ofhydrothermal stress

The linear equations of total chlorophylland meteorological factors (falls andtemperature) for both years wereconstructed for two investigates species

52

Volodarets et al

Acer pseudoplatanus y = -51278-00258x1+04658x2 with R2 = 098 in 2012and y = -68888-00529x1+06888x2 with R2 =081 in 2013

Populus simonii y = -68888-00529x1+06888x2 with R2 = 060 in 2012and y = -12985+0058x1-03181x2 with R2 =077 in 2013 where y ndash sum of chlorophylls(mgg) x1 ndash amount of rainfall (mm) x2 ndashtemperature (ordmС)

As can be seen from the linearequations general tendency of pigmentsamount for change in the leaves despite thedifferent weather conditions remainsunchanged Linear equations obtained forAcer pseudoplatanus confirm the inverserelationship between air temperaturerainfall and sum of chlorophylls during thegrowing season in 2012

Maximum chlorophyll content in theleaves of Acer pseudoplatanus falls on hotmonths both in conditions of excessivehumidity (July 2012) and during thedrought period (August 2013) For Populussimonii the highest chlorophyll content isrecorded in June at high temperatures butvarying amount of rainfall The establishedpattern indicates high adaptive capacity ofA pseudoplatanus and Populus simonii duringthe drought

Carotenoids fulfill the protectivefunction by preventing the destruction ofchlorophyll molecules in the light in theprocess of photo-oxidation Photo-protectivefunction lies in the fact that yellow pigmentsprotect the reaction center from massiveenergy fluxes at high light intensities(Britton et al 2008 Bessonova 2006) Asshown by the results of our study insummer months the content of carotenoidsin species under study increases The highestindicators of carotenoids are found inautumn during the plantsrsquo preparation forwinter

During vegetation on the experimentalsites (ms 1 and ms 2) the content of greenpigments increases in late spring and duringsummer with the further decrease inconcentration in autumn which corresponds

to the dynamics of chlorophyll change in thecontrol According to Zayika amp Bondarenko(2018) the content of chlorophyll is reducedin the leaves of deciduous species in the areaof the western forest-steppe of Ukraine inautumn which is agreed with our results forthe southeastern steppe

Sum of chlorophylls in most species atthe monitoring sites is composed bychlorophyll a except for A platanoides and Anegundo as in control Formation ofchlorophyll b molecules is reduced becauseof inhibition of enzymes of its synthesisunder action of xenobiotics (Petrova et al2017 Bessonova et al 2015)

Covering of the question regardingchanges in carotenoids in the leaves of treesof street plantations in the literature isambiguous For example Petrova et al 2017for Acer heldreichii Boiss amp Heldr and Tiliatomentosa Moench point to the decrease incarotenoids at the contaminated sitehowever for Fraxinus excelsior ndash to growth oftheir content in the conditions of impact ofcar exhausts Reduced content of carotenoidsunder impact of car exhausts is also recordedby Joshi amp Swami (2009) Increase inconcentration of the yellow pigments underaction of car exhausts is established in thestudies of Sillanpaumlauml et al (2008) for Betulapendula Roth which may suggest differentadaptive capacity of trees and varying levelsof contamination Korshikov amp Vinogradova(2013) note the increase of carotenoids indamaged leaves of Acer pseudoplatanus andAcer platanoides under action of pollutantsfrom the work of internal combustionengines in Donetsk

According to results of our study thefunctional state of trees in street and parkplantations is worse compared to controlwhich is confirmed by the decrease inchlorophyll content and growth ofcarotenoids Carotenoid content at ms 2increases to 30 and at ms 1 ndash to 50 indicating the adaptive capacity of plantssince carotenoids possess high antioxidantpower The total number of chlorophylls isreduced by 20 to 30 in the trees of park

53

Assessment of Trees Vitality in the Urban Landscape of Steppe Zone

plantations and by 40ndash50 in the streetplantations compared to the clean site

It is to be noted that the representatives ofthe first group (stable species) such as Robiniapseudoacacia shows the exceedence of sum ofchlorophyls during the drought periode at ms1 and ms 2 At the same time the species of thesecond group (medium-stable species) forexample Syringa vulgaris decreases level ofchlorophyls content under the unfavorableurban and hydrothermal conditions as well asTilia cordata from the third (nonsufficientstable) groups decreases amount ofchlorophylls and increased carotenoid contentThe obtained predicted pain evidences theadaptive strategies of the studied species underanthropogenic and hydrothermal stress

Therefore it is found thatcontamination in the park plantations affectsthe plants which fact is confirmed bychanges in the composition of the pigmentapparatus of leaves but in street plantationsthe reduction of chlorophyll content andincrease of carotenoids in the investigatedspecies is more significant In stable treespecies (Populus simonii P times canadensisRobinia pseudoacacia) these changes are lesscritical than in less stable species (Acerpseudoplatanus A negundo A platanoidesSyringa vulgaris and Tilia cordata)

ConclusionAs a result of the study the functional

state of trees in street and parks plantationswas found to be weakened which indicatesa decrease in the content of green pigmentsand an increase in the concentration ofcarotenoids in the area of automobile vehicleexhaust The impact of hydrothermalconditions and factors of urban environmentdetermines the corresponding changes in theconcentration of photosynthetic pigments inwoody plants differentiated by vitality It isestablished among meteorological factors airtemperature as the main factor Changes inthe concentration of green pigments in theleaves of species under study depending onthe temperature and rainfall are describedby linear equations which is important for

predicting the growth and development ofplants during green building on urbanterritories in the conditions of the steppezone

References Ballester C Zarco-Tejada PJ Nicola E

Alarco JJ Fereres E Intrigliolo DSamp Gonzalez-Dugo V (2017)Evaluating the performance ofxanthophyll chlorophyll andstructure-sensitive spectral indices todetect water stress in five fruit treespecies In Precision Agric SpringerScience+Business Media New Yorkdoi 101007s11119-017-9512-y

Bessonova VP (2006) Influence of heavymetals on the photosynthesis of plantsDDAU Dnipropetrovsk (InUkrainian)

Bessonova VP Ivanchenko ОE ampPonomaryova EА (2015) Combinedimpact of heavy metals (Pb2+ and Cd2+)and salinity on the condition of Loliumperenne long-term assimilationapparatus - Vigravesnyk DnigravepropetrovskogoUnigravevercity Seria Bigraveology Ekology 23(1)15ndash20 (in Ukrainian) doi1015421011503

Glibovytska N Adamenko Ya (2017)Woody Plants Vitality of Urban Areasand Prospects of their GreeneryScientific Bulletin of North UniverdityCenter of Baia Mare Series D XXXI(1)21ndash34

Hopke PK (2009) Theory and applicationof Atmospheric source apportionmentIn Air quality and ecological impactsrelating sources to effects (pp 99ndash121)Elseiver Ltd

Iqbal MZ Shafig M Zaidi S amp Qamar AM(2015) Effect of automobile pollution onchlorophyll content of roadside urbantrees Global Journal of EnvironmentalScience Management 1(4) 283ndash296 doi107508gjesm201504003

Iusypiva T amp Vegerich V (2014) Dynamicsof Photosynthetic Pigments Content InWoody Plants Leaves Under

54

Assessment of Trees Vitality in the Urban Landscape of Steppe Zone

Fig 2a The chlorophyll concentration (total chl a and chl b) in leaves of theinvestigated species from May to October at monitoring site 3 (Tonenke) ndash 2012

46

Volodarets et al

Fig 2b The chlorophyll concentration (total chl a and chl b) in leaves of theinvestigated species from May to October at monitoring site 3 (Tonenke) ndash 2013

47

Assessment of Trees Vitality in the Urban Landscape of Steppe Zone

Populus simonii and Populus timesсanadensis are characterized by the absenceof the autumn leaf color at the end ofvegetation unlike the other tree species Inconnection with this the content ofcarotenoids in the leaves of this species inOctober remains unchanged compared toMay (Fig 3) It should be noted that in Juneduring the drought the content ofcarotenoids in P simonii increases indicatingthe protective role of carotenoids

For stable species Populus simonii andnonsufficient stable species Acerpseudoplatanus (Fig2b) it is found that thedynamics of chlorophyll content differs fromyear to year but air temperature remains themain factor (Table 2)

The tendency of the pigment contentchanges during the growing season at ms 1and ms 2 corresponds to the dynamics incontrol (ms 3) so the results are presentedfor one month of each season (Table 4) Insummer and autumn June and October areselected as the drought periods withunfavorable conditions for the growth anddevelopment of trees (Table 4)

Analysis of obtained results (Table 4)shows that reduction of chlorophyll content isobserved in the leaves of species under studyin street and park plantations in theconditions of contamination and urbanizationcompared to control against the samebackground of the hydrothermal conditionsFor example in June the sum of chlorophyllsin Tilia cordata decreases by 392 at ms 1and by 258 at ms 2 indicating thephysiological changes which occur in theplant body under action of pollutants

More intensive reduction of the sum ofchlorophylls in the leaves of species understudy is recorded at ms 1 compared to ms2 and control The significant difference wasrecorded in May under favorable weatherconditions in young leaves which are moresensitive to airborne pollutants of all speciesexcept Syringa vulgaris For example in theleaves of Acer negundo the chlorophyllcontent decreased by 517 at ms 1 and by317 at ms 2 compared to control The

lowest sensitivity to pollutants was foundfor the leaves of Robinia pseudoacacia andSyringa vulgaris Their sum of chlorophyllshas grown by 549 and 185 at ms 1respectively

During the first draught in June Apseudoplatanus (decrease in sum ofchlorophylls by 579 and 287 at ms1and ms2 respectively) Populus simonii (625 and 464 ms 1 and ms 2) P xcanadensis (252 and 724 at ms 1 andms 2) are more sensitive to contaminationAcer platanoides A negundo Syringa vulgarisL and Tilia cordata are less sensitive tocontamination chlorophyll content in themdecreases from 220 to 392 dependingon species at ms 1 compared to controlRobinia pseudoacacia is the most resistant tocontamination during drought in Junechlorophyll content increases by 15 at ms1 and ms 2 respectively

During the drought in October it isfound at ms 1 that contamination has lesssignificant impact on the condition ofphotosynthetic apparatus in all species dueto lower sensitivity of old leaves to adverseabiotic and anthropogenic factors of theenvironment High endurance againstcontamination and prolonged drought wasdemonstrated by A pseudoplatanus LPopulus simonii P x canadensis Robiniapseudoacacia and Syringa vulgaris

According to the results of studies it isestablished that at ms 1 and ms 2 thecarotenoid content in the leaves of modelspecimens increases compared to the controlbut the degree of increase depends on plantresistance as can be seen from the dynamicsof carotenoid content in June (Table 5)

The content of carotenoids in stablespecies (P simonii P times canadensis Robiniapseudoacacia) features almost no difference onKyivskyi avenue (ms 1) and in the Recreationand Entertainment Park (ms 2) duringvegetation The established pattern indicateshigh resistance of these woody plants toconditions of the urban environmentConcentration of yellow pigments in Acerpseudoplatanus and A negundo growing in the

48

Volodarets et al

park increases by 30ndash35 compared to ms3 showing the sufficient level of adaptationof these species to conditions of the urbanenvironment Considerable increase incarotenoids in street and park plantations isrecorded in Acer platanoides Syringa vulgarisand Tilia cordata which are less stable

The ratio of sum of chlorophylls tocarotenoids (a+bcar) as a rule is constantin the normal conditions and promptly

responds to changes in the environment so itis used as an indicator of plantsrsquo adaptation toextreme conditions (Petrova et al 2014) Inorder to understand the simultaneous actionof abiotic stress ndash drought and anthropogenicpressure the ratio a+bcar was calculated forJune 2012

In most species a+bcar varied from 486(Acer platanoides ms 1) to 905 (Tilia cordatams 3) (Fig4)

Table 1 Stepwise regression analysis for sum of chlorophylls of woody plants in thevegetation period of 2012 (Tonenke ms 3) Negatively correlated variables are highlightedin bold Statistical significance p-value lt 005 = lt 0001 = lt 00001

Species Step 1 Step 2 Step 3Populus times canadensis Falls 009 Falls Temp 069 -Populus simonii Temp 054 Temp Falls 006 Temp Falls Hum 014Tilia cordata Falls 004 Falls Hum 005Robinia pseudoacacia Falls 0008 Falls Hum 005 -Acer negundo - Hum 011Acer platanoides Falls 002 - -Acer pseudoplatanus Hum 030 Hum Falls 003 Hum Falls Temp 014Syringa vulgaris Temp 046 Temp Falls004

Table 2 Stepwise regression analysis for sum of chlorophylls of woody plants in thevegetation period of 2013 (Tonenke ms 3) Negatively correlated variables are highlightedin bold Statistical significance p-value lt 005 = lt 0001 = lt 00001

Species Step 1 Step 2 Step 3Acer pseudoplatanus Temp 022 - -Populus simonii Temp 066 - -

Fig 3 The carotenoids concentration in leaves of the investigated species from May toOctober at monitoring site 3 (Tonenke) in 2012

49

Assessment of Trees Vitality in the Urban Landscape of Steppe Zone

Table 3 Stepwise regression analysis for carotenoids concentration of woodyplants in the vegetation period of 2012 on the control site Negatively correlatedvariables are highlighted in bold Statistical significance p-value lt 005 = lt 0001 = lt00001=

Species Step 1 Step 2 Step 3

P times canadensis Hum002

HumFalls0005

HumFallsTemp002

P simonii Hum002

HumFalls0004 -

Tilia cordata Hum004

HumFalls001

HumFallsTemp009

Robinia pseudoacacia Hum002

HumFalls0006

HumFallsTemp005

Acer negundo Temp003

TempFalls0003

TempFallsHum001

A platanoides Temp012

TempFalls0004

A pseudoplatanus Hum002

HumFalls0004

HumFallsTemp003

Syringa vulgaris Temp012

TempFalls001 -

Table 4 Sum of chlorophylls of the species leaves at experimental sites during thevegetation period Statistical significance p-value lt 005 = lt 0001 = lt00001= compared to control

SpeciesMay June October

ms 1 ms 2 ms 3 ms 1 ms 2 ms 3 ms 1 ms 2 ms 3Acer

platanoides 143

plusmn005132

plusmn004325

plusmn005272

plusmn002314

plusmn005353

plusmn002113

plusmn006115

plusmn001174

plusmn001A

pseudoplatanus 149

plusmn011248

plusmn025332

plusmn005160

plusmn003271

plusmn007380

plusmn003072

plusmn008101

plusmn001073

plusmn002

A negundo 099plusmn011

140plusmn007

205plusmn005

319plusmn002

367plusmn011

409plusmn001

084plusmn003

027plusmn001

142plusmn001

Populussimonii

144plusmn008

234plusmn003

544plusmn004

277plusmn005

391plusmn012

730plusmn002

143plusmn006

081plusmn001

229plusmn002

P xcanadensis

099plusmn006

193plusmn006

306plusmn003

256plusmn003

636plusmn005

746plusmn004

355plusmn002

431plusmn001

475plusmn002

Robinia pseudoacacia

285plusmn007

243plusmn005

184plusmn002

335plusmn003

337plusmn002

291plusmn001

137plusmn003

164plusmn002

213plusmn002

Syringavulgaris

250plusmn006

285plusmn009

211plusmn002

257plusmn003

312plusmn007

372plusmn001

479plusmn003

471plusmn002

662plusmn002

Tilia cordata 166plusmn005

195plusmn004

399plusmn003

209plusmn004

255plusmn004

344plusmn003

125plusmn003

115plusmn002

232plusmn003

50

Volodarets et al

Table 5 Carotenoids content in some months of 2012 at experimental sites Statisticalsignificance p-value lt 005 = lt 0001 = lt00001= compared to control

SpeciesMay June October

ms 1 ms 2 ms 3 ms 1 ms 2 ms 3 ms 1 ms 2 ms 3Acer platanoides

065plusmn001

053plusmn002

040plusmn001

056plusmn002

051plusmn001

046plusmn001

270plusmn001

213plusmn001

155plusmn001

A pseudoplatanus

055plusmn002

043plusmn001

038plusmn001

073plusmn001

068plusmn001

063plusmn001

145plusmn001

115plusmn001

098plusmn002

A negundo 075plusmn002

062plusmn002

058plusmn001

075plusmn002

066plusmn002

057plusmn001

123plusmn002

101plusmn001

093plusmn002

Populus simonii

031plusmn001

027plusmn001

021plusmn001

038plusmn001

033plusmn001

029plusmn001

031plusmn001

027plusmn001

022plusmn001

P x canadensis 056plusmn002

049plusmn003

036plusmn001

060plusmn001

051=plusmn001

047plusmn001

095plusmn001

081plusmn001

078plusmn001

Robinia pseudoacacia

046plusmn002

039plusmn001

031plusmn001

061plusmn002

052plusmn002

049plusmn001

148plusmn002

131plusmn002

106plusmn003

Syringa vulgaris

033plusmn001

029plusmn001

022plusmn001

042plusmn001

039plusmn001

033plusmn001

223plusmn001

164plusmn002

145plusmn001

Tilia cordata 037plusmn001

033plusmn002

027plusmn001

047plusmn001

043plusmn001

038plusmn001

192plusmn001

171plusmn002

138plusmn002

Fig 4 The ratio of total chlorophylls to carotenoids in June 2012during the drought at monitoring sites

However this indicator inrepresentatives of Populus and Syringavulgaris genera exceeds the general rangeFor example for Populus simonii and Populustimes сanadensis the maximum level of the ratioin the control (2517 and 1587 respectively)is established and for Syringa vulgaris itmakes 1127 because of high chlorophyllconcentration and low content ofcarotenoids The tendency to growth of theconcentration of green pigments and

reduction of yellow ones in the control ismaintained for the other species exceptRobinia pseudoacacia The highest ratiochl a+bcar is found in this species for theplants in park plantations exceeding thisindicator at ms 1 and ms 3 by 11 times only

Therefore contamination in the parkplantations affects the plants which fact isconfirmed by changes in the composition ofthe pigment apparatus of leaves but in streetplantations in the conditions of heavy traffic

51

Assessment of Trees Vitality in the Urban Landscape of Steppe Zone

the reduction of chlorophyll content andincrease of carotenoids in the investigatedspecies is more significant In stable speciesof trees (Populus simonii P times canadensisRobinia pseudoacacia) these changes are lesscritical compared to medium-stable andnonsufficient stable species (Acerpseudoplatanus A negundo A platanoidesSyringa vulgaris and Tilia cordata)

DiscussionAs a result of our study it is found that

concentration of chlorophylls and carotenoidsin woody plants varies depending on themeteorological factors during the season andon the level of contamination of urban areasThe growth of chlorophyll content in the leavesof trees under study from May to September isestablished which is consistent with theliterature sources (Petrova et al 2017 Iusypivaamp Vegerich 2014) It is determined that themain factor influencing the chlorophyllformation is the air temperature Stable andmedium-stable species Robinia pseudoacaciaPopulus simonii Acer platanoides Populus timescanadensis Tilia cordata have the largestchlorophyll amount in drought periods As it isstated by Ballester et al (2017) fruit species oftrees also demonstrate high dependence on theformation of green pigments on the airtemperature During experiments for Rpseudoacia Tilia cordata and A platanoides directdependence on rainfall is established which isconsistent with the results of Iusypiva ampVegerich (2014) for Dnipro City in 2012 for Rрseudoacia in the leaves of which the maximumsum of chlorophylls was recorded in the monthwith the highest amount of rainfalls as wellThe established pattern indicates less adaptivecapacity of the representatives of Robinia Tiliaand Acer genera to the conditions ofhydrothermal stress

Under action of drought in the leaves ofrepresentatives of Acer genus (Swozcerna etal 2010) the chlorophyll content increaseswhich agrees with the results of ourexperiments for A pseudoplatanus when athigh temperatures and low rainfall inAugust 2013 the maximum amount of

chlorophylls in the leaves of this species wasrecorded This pattern indicates highadaptive capacity of sycamore maple in theconditions of South-East of Ukraine Anotherspecies Populus simonii is defined by a highconcentration of pigments under stressconditions at the start of vegetation period amore stable level of chlorophyll contentduring the growing season It should benoted that under the more prosperousconditions in June maximum is beingreached by chl a fraction under the stressconditions in August - due to the sharpincrease in the chl b fraction as well as it isfound out a higher relative content of chl b atthe end of the growing season The obtainedresults show that the various in stabilityspecies in urban environment differ in theratio of chl a and chl b under the action ofhydrothermal factors of different tensionsthat can be one of the part of thedemonstration of species adaptive strategy

Increase in sum of chlorophylls in Aplatanoides and A negundo in July andAugust 2012 when the amount of rainfallwas higher in 74 and 190 to the normalvalue accordingly occurred due to increasein the proportion of chlorophyll b whichplays the protective role in addition to itsmain function Chlorophyll b absorbs someof the rays expanding the range ofphotoactivity which is particularlyimportant in the conditions of considerablecloudiness in rainy weather Chlorophyll а ismore resistant to adverse environmentalfactors compared to chlorophyll b (Conzales-Dugo 2017 Bessonova et al 2006) Increasein the sum of chlorophylls during drought inAcer pseudoplatanus Populus x canadensis Psimonii Robinia pseudoacacia Syringa vulgarisat the expense of chlorophyll а indicates thenormal development of the photosyntheticapparatus of these species and their highadaptive reactions under conditions ofhydrothermal stress

The linear equations of total chlorophylland meteorological factors (falls andtemperature) for both years wereconstructed for two investigates species

52

Volodarets et al

Acer pseudoplatanus y = -51278-00258x1+04658x2 with R2 = 098 in 2012and y = -68888-00529x1+06888x2 with R2 =081 in 2013

Populus simonii y = -68888-00529x1+06888x2 with R2 = 060 in 2012and y = -12985+0058x1-03181x2 with R2 =077 in 2013 where y ndash sum of chlorophylls(mgg) x1 ndash amount of rainfall (mm) x2 ndashtemperature (ordmС)

As can be seen from the linearequations general tendency of pigmentsamount for change in the leaves despite thedifferent weather conditions remainsunchanged Linear equations obtained forAcer pseudoplatanus confirm the inverserelationship between air temperaturerainfall and sum of chlorophylls during thegrowing season in 2012

Maximum chlorophyll content in theleaves of Acer pseudoplatanus falls on hotmonths both in conditions of excessivehumidity (July 2012) and during thedrought period (August 2013) For Populussimonii the highest chlorophyll content isrecorded in June at high temperatures butvarying amount of rainfall The establishedpattern indicates high adaptive capacity ofA pseudoplatanus and Populus simonii duringthe drought

Carotenoids fulfill the protectivefunction by preventing the destruction ofchlorophyll molecules in the light in theprocess of photo-oxidation Photo-protectivefunction lies in the fact that yellow pigmentsprotect the reaction center from massiveenergy fluxes at high light intensities(Britton et al 2008 Bessonova 2006) Asshown by the results of our study insummer months the content of carotenoidsin species under study increases The highestindicators of carotenoids are found inautumn during the plantsrsquo preparation forwinter

During vegetation on the experimentalsites (ms 1 and ms 2) the content of greenpigments increases in late spring and duringsummer with the further decrease inconcentration in autumn which corresponds

to the dynamics of chlorophyll change in thecontrol According to Zayika amp Bondarenko(2018) the content of chlorophyll is reducedin the leaves of deciduous species in the areaof the western forest-steppe of Ukraine inautumn which is agreed with our results forthe southeastern steppe

Sum of chlorophylls in most species atthe monitoring sites is composed bychlorophyll a except for A platanoides and Anegundo as in control Formation ofchlorophyll b molecules is reduced becauseof inhibition of enzymes of its synthesisunder action of xenobiotics (Petrova et al2017 Bessonova et al 2015)

Covering of the question regardingchanges in carotenoids in the leaves of treesof street plantations in the literature isambiguous For example Petrova et al 2017for Acer heldreichii Boiss amp Heldr and Tiliatomentosa Moench point to the decrease incarotenoids at the contaminated sitehowever for Fraxinus excelsior ndash to growth oftheir content in the conditions of impact ofcar exhausts Reduced content of carotenoidsunder impact of car exhausts is also recordedby Joshi amp Swami (2009) Increase inconcentration of the yellow pigments underaction of car exhausts is established in thestudies of Sillanpaumlauml et al (2008) for Betulapendula Roth which may suggest differentadaptive capacity of trees and varying levelsof contamination Korshikov amp Vinogradova(2013) note the increase of carotenoids indamaged leaves of Acer pseudoplatanus andAcer platanoides under action of pollutantsfrom the work of internal combustionengines in Donetsk

According to results of our study thefunctional state of trees in street and parkplantations is worse compared to controlwhich is confirmed by the decrease inchlorophyll content and growth ofcarotenoids Carotenoid content at ms 2increases to 30 and at ms 1 ndash to 50 indicating the adaptive capacity of plantssince carotenoids possess high antioxidantpower The total number of chlorophylls isreduced by 20 to 30 in the trees of park

53

Assessment of Trees Vitality in the Urban Landscape of Steppe Zone

plantations and by 40ndash50 in the streetplantations compared to the clean site

It is to be noted that the representatives ofthe first group (stable species) such as Robiniapseudoacacia shows the exceedence of sum ofchlorophyls during the drought periode at ms1 and ms 2 At the same time the species of thesecond group (medium-stable species) forexample Syringa vulgaris decreases level ofchlorophyls content under the unfavorableurban and hydrothermal conditions as well asTilia cordata from the third (nonsufficientstable) groups decreases amount ofchlorophylls and increased carotenoid contentThe obtained predicted pain evidences theadaptive strategies of the studied species underanthropogenic and hydrothermal stress

Therefore it is found thatcontamination in the park plantations affectsthe plants which fact is confirmed bychanges in the composition of the pigmentapparatus of leaves but in street plantationsthe reduction of chlorophyll content andincrease of carotenoids in the investigatedspecies is more significant In stable treespecies (Populus simonii P times canadensisRobinia pseudoacacia) these changes are lesscritical than in less stable species (Acerpseudoplatanus A negundo A platanoidesSyringa vulgaris and Tilia cordata)

ConclusionAs a result of the study the functional

state of trees in street and parks plantationswas found to be weakened which indicatesa decrease in the content of green pigmentsand an increase in the concentration ofcarotenoids in the area of automobile vehicleexhaust The impact of hydrothermalconditions and factors of urban environmentdetermines the corresponding changes in theconcentration of photosynthetic pigments inwoody plants differentiated by vitality It isestablished among meteorological factors airtemperature as the main factor Changes inthe concentration of green pigments in theleaves of species under study depending onthe temperature and rainfall are describedby linear equations which is important for

predicting the growth and development ofplants during green building on urbanterritories in the conditions of the steppezone

References Ballester C Zarco-Tejada PJ Nicola E

Alarco JJ Fereres E Intrigliolo DSamp Gonzalez-Dugo V (2017)Evaluating the performance ofxanthophyll chlorophyll andstructure-sensitive spectral indices todetect water stress in five fruit treespecies In Precision Agric SpringerScience+Business Media New Yorkdoi 101007s11119-017-9512-y

Bessonova VP (2006) Influence of heavymetals on the photosynthesis of plantsDDAU Dnipropetrovsk (InUkrainian)

Bessonova VP Ivanchenko ОE ampPonomaryova EА (2015) Combinedimpact of heavy metals (Pb2+ and Cd2+)and salinity on the condition of Loliumperenne long-term assimilationapparatus - Vigravesnyk DnigravepropetrovskogoUnigravevercity Seria Bigraveology Ekology 23(1)15ndash20 (in Ukrainian) doi1015421011503

Glibovytska N Adamenko Ya (2017)Woody Plants Vitality of Urban Areasand Prospects of their GreeneryScientific Bulletin of North UniverdityCenter of Baia Mare Series D XXXI(1)21ndash34

Hopke PK (2009) Theory and applicationof Atmospheric source apportionmentIn Air quality and ecological impactsrelating sources to effects (pp 99ndash121)Elseiver Ltd

Iqbal MZ Shafig M Zaidi S amp Qamar AM(2015) Effect of automobile pollution onchlorophyll content of roadside urbantrees Global Journal of EnvironmentalScience Management 1(4) 283ndash296 doi107508gjesm201504003

Iusypiva T amp Vegerich V (2014) Dynamicsof Photosynthetic Pigments Content InWoody Plants Leaves Under

54

Volodarets et al

Fig 2b The chlorophyll concentration (total chl a and chl b) in leaves of theinvestigated species from May to October at monitoring site 3 (Tonenke) ndash 2013

47

Assessment of Trees Vitality in the Urban Landscape of Steppe Zone

Populus simonii and Populus timesсanadensis are characterized by the absenceof the autumn leaf color at the end ofvegetation unlike the other tree species Inconnection with this the content ofcarotenoids in the leaves of this species inOctober remains unchanged compared toMay (Fig 3) It should be noted that in Juneduring the drought the content ofcarotenoids in P simonii increases indicatingthe protective role of carotenoids

For stable species Populus simonii andnonsufficient stable species Acerpseudoplatanus (Fig2b) it is found that thedynamics of chlorophyll content differs fromyear to year but air temperature remains themain factor (Table 2)

The tendency of the pigment contentchanges during the growing season at ms 1and ms 2 corresponds to the dynamics incontrol (ms 3) so the results are presentedfor one month of each season (Table 4) Insummer and autumn June and October areselected as the drought periods withunfavorable conditions for the growth anddevelopment of trees (Table 4)

Analysis of obtained results (Table 4)shows that reduction of chlorophyll content isobserved in the leaves of species under studyin street and park plantations in theconditions of contamination and urbanizationcompared to control against the samebackground of the hydrothermal conditionsFor example in June the sum of chlorophyllsin Tilia cordata decreases by 392 at ms 1and by 258 at ms 2 indicating thephysiological changes which occur in theplant body under action of pollutants

More intensive reduction of the sum ofchlorophylls in the leaves of species understudy is recorded at ms 1 compared to ms2 and control The significant difference wasrecorded in May under favorable weatherconditions in young leaves which are moresensitive to airborne pollutants of all speciesexcept Syringa vulgaris For example in theleaves of Acer negundo the chlorophyllcontent decreased by 517 at ms 1 and by317 at ms 2 compared to control The

lowest sensitivity to pollutants was foundfor the leaves of Robinia pseudoacacia andSyringa vulgaris Their sum of chlorophyllshas grown by 549 and 185 at ms 1respectively

During the first draught in June Apseudoplatanus (decrease in sum ofchlorophylls by 579 and 287 at ms1and ms2 respectively) Populus simonii (625 and 464 ms 1 and ms 2) P xcanadensis (252 and 724 at ms 1 andms 2) are more sensitive to contaminationAcer platanoides A negundo Syringa vulgarisL and Tilia cordata are less sensitive tocontamination chlorophyll content in themdecreases from 220 to 392 dependingon species at ms 1 compared to controlRobinia pseudoacacia is the most resistant tocontamination during drought in Junechlorophyll content increases by 15 at ms1 and ms 2 respectively

During the drought in October it isfound at ms 1 that contamination has lesssignificant impact on the condition ofphotosynthetic apparatus in all species dueto lower sensitivity of old leaves to adverseabiotic and anthropogenic factors of theenvironment High endurance againstcontamination and prolonged drought wasdemonstrated by A pseudoplatanus LPopulus simonii P x canadensis Robiniapseudoacacia and Syringa vulgaris

According to the results of studies it isestablished that at ms 1 and ms 2 thecarotenoid content in the leaves of modelspecimens increases compared to the controlbut the degree of increase depends on plantresistance as can be seen from the dynamicsof carotenoid content in June (Table 5)

The content of carotenoids in stablespecies (P simonii P times canadensis Robiniapseudoacacia) features almost no difference onKyivskyi avenue (ms 1) and in the Recreationand Entertainment Park (ms 2) duringvegetation The established pattern indicateshigh resistance of these woody plants toconditions of the urban environmentConcentration of yellow pigments in Acerpseudoplatanus and A negundo growing in the

48

Volodarets et al

park increases by 30ndash35 compared to ms3 showing the sufficient level of adaptationof these species to conditions of the urbanenvironment Considerable increase incarotenoids in street and park plantations isrecorded in Acer platanoides Syringa vulgarisand Tilia cordata which are less stable

The ratio of sum of chlorophylls tocarotenoids (a+bcar) as a rule is constantin the normal conditions and promptly

responds to changes in the environment so itis used as an indicator of plantsrsquo adaptation toextreme conditions (Petrova et al 2014) Inorder to understand the simultaneous actionof abiotic stress ndash drought and anthropogenicpressure the ratio a+bcar was calculated forJune 2012

In most species a+bcar varied from 486(Acer platanoides ms 1) to 905 (Tilia cordatams 3) (Fig4)

Table 1 Stepwise regression analysis for sum of chlorophylls of woody plants in thevegetation period of 2012 (Tonenke ms 3) Negatively correlated variables are highlightedin bold Statistical significance p-value lt 005 = lt 0001 = lt 00001

Species Step 1 Step 2 Step 3Populus times canadensis Falls 009 Falls Temp 069 -Populus simonii Temp 054 Temp Falls 006 Temp Falls Hum 014Tilia cordata Falls 004 Falls Hum 005Robinia pseudoacacia Falls 0008 Falls Hum 005 -Acer negundo - Hum 011Acer platanoides Falls 002 - -Acer pseudoplatanus Hum 030 Hum Falls 003 Hum Falls Temp 014Syringa vulgaris Temp 046 Temp Falls004

Table 2 Stepwise regression analysis for sum of chlorophylls of woody plants in thevegetation period of 2013 (Tonenke ms 3) Negatively correlated variables are highlightedin bold Statistical significance p-value lt 005 = lt 0001 = lt 00001

Species Step 1 Step 2 Step 3Acer pseudoplatanus Temp 022 - -Populus simonii Temp 066 - -

Fig 3 The carotenoids concentration in leaves of the investigated species from May toOctober at monitoring site 3 (Tonenke) in 2012

49

Assessment of Trees Vitality in the Urban Landscape of Steppe Zone

Table 3 Stepwise regression analysis for carotenoids concentration of woodyplants in the vegetation period of 2012 on the control site Negatively correlatedvariables are highlighted in bold Statistical significance p-value lt 005 = lt 0001 = lt00001=

Species Step 1 Step 2 Step 3

P times canadensis Hum002

HumFalls0005

HumFallsTemp002

P simonii Hum002

HumFalls0004 -

Tilia cordata Hum004

HumFalls001

HumFallsTemp009

Robinia pseudoacacia Hum002

HumFalls0006

HumFallsTemp005

Acer negundo Temp003

TempFalls0003

TempFallsHum001

A platanoides Temp012

TempFalls0004

A pseudoplatanus Hum002

HumFalls0004

HumFallsTemp003

Syringa vulgaris Temp012

TempFalls001 -

Table 4 Sum of chlorophylls of the species leaves at experimental sites during thevegetation period Statistical significance p-value lt 005 = lt 0001 = lt00001= compared to control

SpeciesMay June October

ms 1 ms 2 ms 3 ms 1 ms 2 ms 3 ms 1 ms 2 ms 3Acer

platanoides 143

plusmn005132

plusmn004325

plusmn005272

plusmn002314

plusmn005353

plusmn002113

plusmn006115

plusmn001174

plusmn001A

pseudoplatanus 149

plusmn011248

plusmn025332

plusmn005160

plusmn003271

plusmn007380

plusmn003072

plusmn008101

plusmn001073

plusmn002

A negundo 099plusmn011

140plusmn007

205plusmn005

319plusmn002

367plusmn011

409plusmn001

084plusmn003

027plusmn001

142plusmn001

Populussimonii

144plusmn008

234plusmn003

544plusmn004

277plusmn005

391plusmn012

730plusmn002

143plusmn006

081plusmn001

229plusmn002

P xcanadensis

099plusmn006

193plusmn006

306plusmn003

256plusmn003

636plusmn005

746plusmn004

355plusmn002

431plusmn001

475plusmn002

Robinia pseudoacacia

285plusmn007

243plusmn005

184plusmn002

335plusmn003

337plusmn002

291plusmn001

137plusmn003

164plusmn002

213plusmn002

Syringavulgaris

250plusmn006

285plusmn009

211plusmn002

257plusmn003

312plusmn007

372plusmn001

479plusmn003

471plusmn002

662plusmn002

Tilia cordata 166plusmn005

195plusmn004

399plusmn003

209plusmn004

255plusmn004

344plusmn003

125plusmn003

115plusmn002

232plusmn003

50

Volodarets et al

Table 5 Carotenoids content in some months of 2012 at experimental sites Statisticalsignificance p-value lt 005 = lt 0001 = lt00001= compared to control

SpeciesMay June October

ms 1 ms 2 ms 3 ms 1 ms 2 ms 3 ms 1 ms 2 ms 3Acer platanoides

065plusmn001

053plusmn002

040plusmn001

056plusmn002

051plusmn001

046plusmn001

270plusmn001

213plusmn001

155plusmn001

A pseudoplatanus

055plusmn002

043plusmn001

038plusmn001

073plusmn001

068plusmn001

063plusmn001

145plusmn001

115plusmn001

098plusmn002

A negundo 075plusmn002

062plusmn002

058plusmn001

075plusmn002

066plusmn002

057plusmn001

123plusmn002

101plusmn001

093plusmn002

Populus simonii

031plusmn001

027plusmn001

021plusmn001

038plusmn001

033plusmn001

029plusmn001

031plusmn001

027plusmn001

022plusmn001

P x canadensis 056plusmn002

049plusmn003

036plusmn001

060plusmn001

051=plusmn001

047plusmn001

095plusmn001

081plusmn001

078plusmn001

Robinia pseudoacacia

046plusmn002

039plusmn001

031plusmn001

061plusmn002

052plusmn002

049plusmn001

148plusmn002

131plusmn002

106plusmn003

Syringa vulgaris

033plusmn001

029plusmn001

022plusmn001

042plusmn001

039plusmn001

033plusmn001

223plusmn001

164plusmn002

145plusmn001

Tilia cordata 037plusmn001

033plusmn002

027plusmn001

047plusmn001

043plusmn001

038plusmn001

192plusmn001

171plusmn002

138plusmn002

Fig 4 The ratio of total chlorophylls to carotenoids in June 2012during the drought at monitoring sites

However this indicator inrepresentatives of Populus and Syringavulgaris genera exceeds the general rangeFor example for Populus simonii and Populustimes сanadensis the maximum level of the ratioin the control (2517 and 1587 respectively)is established and for Syringa vulgaris itmakes 1127 because of high chlorophyllconcentration and low content ofcarotenoids The tendency to growth of theconcentration of green pigments and

reduction of yellow ones in the control ismaintained for the other species exceptRobinia pseudoacacia The highest ratiochl a+bcar is found in this species for theplants in park plantations exceeding thisindicator at ms 1 and ms 3 by 11 times only

Therefore contamination in the parkplantations affects the plants which fact isconfirmed by changes in the composition ofthe pigment apparatus of leaves but in streetplantations in the conditions of heavy traffic

51

Assessment of Trees Vitality in the Urban Landscape of Steppe Zone

the reduction of chlorophyll content andincrease of carotenoids in the investigatedspecies is more significant In stable speciesof trees (Populus simonii P times canadensisRobinia pseudoacacia) these changes are lesscritical compared to medium-stable andnonsufficient stable species (Acerpseudoplatanus A negundo A platanoidesSyringa vulgaris and Tilia cordata)

DiscussionAs a result of our study it is found that

concentration of chlorophylls and carotenoidsin woody plants varies depending on themeteorological factors during the season andon the level of contamination of urban areasThe growth of chlorophyll content in the leavesof trees under study from May to September isestablished which is consistent with theliterature sources (Petrova et al 2017 Iusypivaamp Vegerich 2014) It is determined that themain factor influencing the chlorophyllformation is the air temperature Stable andmedium-stable species Robinia pseudoacaciaPopulus simonii Acer platanoides Populus timescanadensis Tilia cordata have the largestchlorophyll amount in drought periods As it isstated by Ballester et al (2017) fruit species oftrees also demonstrate high dependence on theformation of green pigments on the airtemperature During experiments for Rpseudoacia Tilia cordata and A platanoides directdependence on rainfall is established which isconsistent with the results of Iusypiva ampVegerich (2014) for Dnipro City in 2012 for Rрseudoacia in the leaves of which the maximumsum of chlorophylls was recorded in the monthwith the highest amount of rainfalls as wellThe established pattern indicates less adaptivecapacity of the representatives of Robinia Tiliaand Acer genera to the conditions ofhydrothermal stress

Under action of drought in the leaves ofrepresentatives of Acer genus (Swozcerna etal 2010) the chlorophyll content increaseswhich agrees with the results of ourexperiments for A pseudoplatanus when athigh temperatures and low rainfall inAugust 2013 the maximum amount of

chlorophylls in the leaves of this species wasrecorded This pattern indicates highadaptive capacity of sycamore maple in theconditions of South-East of Ukraine Anotherspecies Populus simonii is defined by a highconcentration of pigments under stressconditions at the start of vegetation period amore stable level of chlorophyll contentduring the growing season It should benoted that under the more prosperousconditions in June maximum is beingreached by chl a fraction under the stressconditions in August - due to the sharpincrease in the chl b fraction as well as it isfound out a higher relative content of chl b atthe end of the growing season The obtainedresults show that the various in stabilityspecies in urban environment differ in theratio of chl a and chl b under the action ofhydrothermal factors of different tensionsthat can be one of the part of thedemonstration of species adaptive strategy

Increase in sum of chlorophylls in Aplatanoides and A negundo in July andAugust 2012 when the amount of rainfallwas higher in 74 and 190 to the normalvalue accordingly occurred due to increasein the proportion of chlorophyll b whichplays the protective role in addition to itsmain function Chlorophyll b absorbs someof the rays expanding the range ofphotoactivity which is particularlyimportant in the conditions of considerablecloudiness in rainy weather Chlorophyll а ismore resistant to adverse environmentalfactors compared to chlorophyll b (Conzales-Dugo 2017 Bessonova et al 2006) Increasein the sum of chlorophylls during drought inAcer pseudoplatanus Populus x canadensis Psimonii Robinia pseudoacacia Syringa vulgarisat the expense of chlorophyll а indicates thenormal development of the photosyntheticapparatus of these species and their highadaptive reactions under conditions ofhydrothermal stress

The linear equations of total chlorophylland meteorological factors (falls andtemperature) for both years wereconstructed for two investigates species

52

Volodarets et al

Acer pseudoplatanus y = -51278-00258x1+04658x2 with R2 = 098 in 2012and y = -68888-00529x1+06888x2 with R2 =081 in 2013

Populus simonii y = -68888-00529x1+06888x2 with R2 = 060 in 2012and y = -12985+0058x1-03181x2 with R2 =077 in 2013 where y ndash sum of chlorophylls(mgg) x1 ndash amount of rainfall (mm) x2 ndashtemperature (ordmС)

As can be seen from the linearequations general tendency of pigmentsamount for change in the leaves despite thedifferent weather conditions remainsunchanged Linear equations obtained forAcer pseudoplatanus confirm the inverserelationship between air temperaturerainfall and sum of chlorophylls during thegrowing season in 2012

Maximum chlorophyll content in theleaves of Acer pseudoplatanus falls on hotmonths both in conditions of excessivehumidity (July 2012) and during thedrought period (August 2013) For Populussimonii the highest chlorophyll content isrecorded in June at high temperatures butvarying amount of rainfall The establishedpattern indicates high adaptive capacity ofA pseudoplatanus and Populus simonii duringthe drought

Carotenoids fulfill the protectivefunction by preventing the destruction ofchlorophyll molecules in the light in theprocess of photo-oxidation Photo-protectivefunction lies in the fact that yellow pigmentsprotect the reaction center from massiveenergy fluxes at high light intensities(Britton et al 2008 Bessonova 2006) Asshown by the results of our study insummer months the content of carotenoidsin species under study increases The highestindicators of carotenoids are found inautumn during the plantsrsquo preparation forwinter

During vegetation on the experimentalsites (ms 1 and ms 2) the content of greenpigments increases in late spring and duringsummer with the further decrease inconcentration in autumn which corresponds

to the dynamics of chlorophyll change in thecontrol According to Zayika amp Bondarenko(2018) the content of chlorophyll is reducedin the leaves of deciduous species in the areaof the western forest-steppe of Ukraine inautumn which is agreed with our results forthe southeastern steppe

Sum of chlorophylls in most species atthe monitoring sites is composed bychlorophyll a except for A platanoides and Anegundo as in control Formation ofchlorophyll b molecules is reduced becauseof inhibition of enzymes of its synthesisunder action of xenobiotics (Petrova et al2017 Bessonova et al 2015)

Covering of the question regardingchanges in carotenoids in the leaves of treesof street plantations in the literature isambiguous For example Petrova et al 2017for Acer heldreichii Boiss amp Heldr and Tiliatomentosa Moench point to the decrease incarotenoids at the contaminated sitehowever for Fraxinus excelsior ndash to growth oftheir content in the conditions of impact ofcar exhausts Reduced content of carotenoidsunder impact of car exhausts is also recordedby Joshi amp Swami (2009) Increase inconcentration of the yellow pigments underaction of car exhausts is established in thestudies of Sillanpaumlauml et al (2008) for Betulapendula Roth which may suggest differentadaptive capacity of trees and varying levelsof contamination Korshikov amp Vinogradova(2013) note the increase of carotenoids indamaged leaves of Acer pseudoplatanus andAcer platanoides under action of pollutantsfrom the work of internal combustionengines in Donetsk

According to results of our study thefunctional state of trees in street and parkplantations is worse compared to controlwhich is confirmed by the decrease inchlorophyll content and growth ofcarotenoids Carotenoid content at ms 2increases to 30 and at ms 1 ndash to 50 indicating the adaptive capacity of plantssince carotenoids possess high antioxidantpower The total number of chlorophylls isreduced by 20 to 30 in the trees of park

53

Assessment of Trees Vitality in the Urban Landscape of Steppe Zone

plantations and by 40ndash50 in the streetplantations compared to the clean site

It is to be noted that the representatives ofthe first group (stable species) such as Robiniapseudoacacia shows the exceedence of sum ofchlorophyls during the drought periode at ms1 and ms 2 At the same time the species of thesecond group (medium-stable species) forexample Syringa vulgaris decreases level ofchlorophyls content under the unfavorableurban and hydrothermal conditions as well asTilia cordata from the third (nonsufficientstable) groups decreases amount ofchlorophylls and increased carotenoid contentThe obtained predicted pain evidences theadaptive strategies of the studied species underanthropogenic and hydrothermal stress

Therefore it is found thatcontamination in the park plantations affectsthe plants which fact is confirmed bychanges in the composition of the pigmentapparatus of leaves but in street plantationsthe reduction of chlorophyll content andincrease of carotenoids in the investigatedspecies is more significant In stable treespecies (Populus simonii P times canadensisRobinia pseudoacacia) these changes are lesscritical than in less stable species (Acerpseudoplatanus A negundo A platanoidesSyringa vulgaris and Tilia cordata)

ConclusionAs a result of the study the functional

state of trees in street and parks plantationswas found to be weakened which indicatesa decrease in the content of green pigmentsand an increase in the concentration ofcarotenoids in the area of automobile vehicleexhaust The impact of hydrothermalconditions and factors of urban environmentdetermines the corresponding changes in theconcentration of photosynthetic pigments inwoody plants differentiated by vitality It isestablished among meteorological factors airtemperature as the main factor Changes inthe concentration of green pigments in theleaves of species under study depending onthe temperature and rainfall are describedby linear equations which is important for

predicting the growth and development ofplants during green building on urbanterritories in the conditions of the steppezone

References Ballester C Zarco-Tejada PJ Nicola E

Alarco JJ Fereres E Intrigliolo DSamp Gonzalez-Dugo V (2017)Evaluating the performance ofxanthophyll chlorophyll andstructure-sensitive spectral indices todetect water stress in five fruit treespecies In Precision Agric SpringerScience+Business Media New Yorkdoi 101007s11119-017-9512-y

Bessonova VP (2006) Influence of heavymetals on the photosynthesis of plantsDDAU Dnipropetrovsk (InUkrainian)

Bessonova VP Ivanchenko ОE ampPonomaryova EА (2015) Combinedimpact of heavy metals (Pb2+ and Cd2+)and salinity on the condition of Loliumperenne long-term assimilationapparatus - Vigravesnyk DnigravepropetrovskogoUnigravevercity Seria Bigraveology Ekology 23(1)15ndash20 (in Ukrainian) doi1015421011503

Glibovytska N Adamenko Ya (2017)Woody Plants Vitality of Urban Areasand Prospects of their GreeneryScientific Bulletin of North UniverdityCenter of Baia Mare Series D XXXI(1)21ndash34

Hopke PK (2009) Theory and applicationof Atmospheric source apportionmentIn Air quality and ecological impactsrelating sources to effects (pp 99ndash121)Elseiver Ltd

Iqbal MZ Shafig M Zaidi S amp Qamar AM(2015) Effect of automobile pollution onchlorophyll content of roadside urbantrees Global Journal of EnvironmentalScience Management 1(4) 283ndash296 doi107508gjesm201504003

Iusypiva T amp Vegerich V (2014) Dynamicsof Photosynthetic Pigments Content InWoody Plants Leaves Under

54

Assessment of Trees Vitality in the Urban Landscape of Steppe Zone

Populus simonii and Populus timesсanadensis are characterized by the absenceof the autumn leaf color at the end ofvegetation unlike the other tree species Inconnection with this the content ofcarotenoids in the leaves of this species inOctober remains unchanged compared toMay (Fig 3) It should be noted that in Juneduring the drought the content ofcarotenoids in P simonii increases indicatingthe protective role of carotenoids

For stable species Populus simonii andnonsufficient stable species Acerpseudoplatanus (Fig2b) it is found that thedynamics of chlorophyll content differs fromyear to year but air temperature remains themain factor (Table 2)

The tendency of the pigment contentchanges during the growing season at ms 1and ms 2 corresponds to the dynamics incontrol (ms 3) so the results are presentedfor one month of each season (Table 4) Insummer and autumn June and October areselected as the drought periods withunfavorable conditions for the growth anddevelopment of trees (Table 4)

Analysis of obtained results (Table 4)shows that reduction of chlorophyll content isobserved in the leaves of species under studyin street and park plantations in theconditions of contamination and urbanizationcompared to control against the samebackground of the hydrothermal conditionsFor example in June the sum of chlorophyllsin Tilia cordata decreases by 392 at ms 1and by 258 at ms 2 indicating thephysiological changes which occur in theplant body under action of pollutants

More intensive reduction of the sum ofchlorophylls in the leaves of species understudy is recorded at ms 1 compared to ms2 and control The significant difference wasrecorded in May under favorable weatherconditions in young leaves which are moresensitive to airborne pollutants of all speciesexcept Syringa vulgaris For example in theleaves of Acer negundo the chlorophyllcontent decreased by 517 at ms 1 and by317 at ms 2 compared to control The

lowest sensitivity to pollutants was foundfor the leaves of Robinia pseudoacacia andSyringa vulgaris Their sum of chlorophyllshas grown by 549 and 185 at ms 1respectively

During the first draught in June Apseudoplatanus (decrease in sum ofchlorophylls by 579 and 287 at ms1and ms2 respectively) Populus simonii (625 and 464 ms 1 and ms 2) P xcanadensis (252 and 724 at ms 1 andms 2) are more sensitive to contaminationAcer platanoides A negundo Syringa vulgarisL and Tilia cordata are less sensitive tocontamination chlorophyll content in themdecreases from 220 to 392 dependingon species at ms 1 compared to controlRobinia pseudoacacia is the most resistant tocontamination during drought in Junechlorophyll content increases by 15 at ms1 and ms 2 respectively

During the drought in October it isfound at ms 1 that contamination has lesssignificant impact on the condition ofphotosynthetic apparatus in all species dueto lower sensitivity of old leaves to adverseabiotic and anthropogenic factors of theenvironment High endurance againstcontamination and prolonged drought wasdemonstrated by A pseudoplatanus LPopulus simonii P x canadensis Robiniapseudoacacia and Syringa vulgaris

According to the results of studies it isestablished that at ms 1 and ms 2 thecarotenoid content in the leaves of modelspecimens increases compared to the controlbut the degree of increase depends on plantresistance as can be seen from the dynamicsof carotenoid content in June (Table 5)

The content of carotenoids in stablespecies (P simonii P times canadensis Robiniapseudoacacia) features almost no difference onKyivskyi avenue (ms 1) and in the Recreationand Entertainment Park (ms 2) duringvegetation The established pattern indicateshigh resistance of these woody plants toconditions of the urban environmentConcentration of yellow pigments in Acerpseudoplatanus and A negundo growing in the

48

Volodarets et al

park increases by 30ndash35 compared to ms3 showing the sufficient level of adaptationof these species to conditions of the urbanenvironment Considerable increase incarotenoids in street and park plantations isrecorded in Acer platanoides Syringa vulgarisand Tilia cordata which are less stable

The ratio of sum of chlorophylls tocarotenoids (a+bcar) as a rule is constantin the normal conditions and promptly

responds to changes in the environment so itis used as an indicator of plantsrsquo adaptation toextreme conditions (Petrova et al 2014) Inorder to understand the simultaneous actionof abiotic stress ndash drought and anthropogenicpressure the ratio a+bcar was calculated forJune 2012

In most species a+bcar varied from 486(Acer platanoides ms 1) to 905 (Tilia cordatams 3) (Fig4)

Table 1 Stepwise regression analysis for sum of chlorophylls of woody plants in thevegetation period of 2012 (Tonenke ms 3) Negatively correlated variables are highlightedin bold Statistical significance p-value lt 005 = lt 0001 = lt 00001

Species Step 1 Step 2 Step 3Populus times canadensis Falls 009 Falls Temp 069 -Populus simonii Temp 054 Temp Falls 006 Temp Falls Hum 014Tilia cordata Falls 004 Falls Hum 005Robinia pseudoacacia Falls 0008 Falls Hum 005 -Acer negundo - Hum 011Acer platanoides Falls 002 - -Acer pseudoplatanus Hum 030 Hum Falls 003 Hum Falls Temp 014Syringa vulgaris Temp 046 Temp Falls004

Table 2 Stepwise regression analysis for sum of chlorophylls of woody plants in thevegetation period of 2013 (Tonenke ms 3) Negatively correlated variables are highlightedin bold Statistical significance p-value lt 005 = lt 0001 = lt 00001

Species Step 1 Step 2 Step 3Acer pseudoplatanus Temp 022 - -Populus simonii Temp 066 - -

Fig 3 The carotenoids concentration in leaves of the investigated species from May toOctober at monitoring site 3 (Tonenke) in 2012

49

Assessment of Trees Vitality in the Urban Landscape of Steppe Zone

Table 3 Stepwise regression analysis for carotenoids concentration of woodyplants in the vegetation period of 2012 on the control site Negatively correlatedvariables are highlighted in bold Statistical significance p-value lt 005 = lt 0001 = lt00001=

Species Step 1 Step 2 Step 3

P times canadensis Hum002

HumFalls0005

HumFallsTemp002

P simonii Hum002

HumFalls0004 -

Tilia cordata Hum004

HumFalls001

HumFallsTemp009

Robinia pseudoacacia Hum002

HumFalls0006

HumFallsTemp005

Acer negundo Temp003

TempFalls0003

TempFallsHum001

A platanoides Temp012

TempFalls0004

A pseudoplatanus Hum002

HumFalls0004

HumFallsTemp003

Syringa vulgaris Temp012

TempFalls001 -

Table 4 Sum of chlorophylls of the species leaves at experimental sites during thevegetation period Statistical significance p-value lt 005 = lt 0001 = lt00001= compared to control

SpeciesMay June October

ms 1 ms 2 ms 3 ms 1 ms 2 ms 3 ms 1 ms 2 ms 3Acer

platanoides 143

plusmn005132

plusmn004325

plusmn005272

plusmn002314

plusmn005353

plusmn002113

plusmn006115

plusmn001174

plusmn001A

pseudoplatanus 149

plusmn011248

plusmn025332

plusmn005160

plusmn003271

plusmn007380

plusmn003072

plusmn008101

plusmn001073

plusmn002

A negundo 099plusmn011

140plusmn007

205plusmn005

319plusmn002

367plusmn011

409plusmn001

084plusmn003

027plusmn001

142plusmn001

Populussimonii

144plusmn008

234plusmn003

544plusmn004

277plusmn005

391plusmn012

730plusmn002

143plusmn006

081plusmn001

229plusmn002

P xcanadensis

099plusmn006

193plusmn006

306plusmn003

256plusmn003

636plusmn005

746plusmn004

355plusmn002

431plusmn001

475plusmn002

Robinia pseudoacacia

285plusmn007

243plusmn005

184plusmn002

335plusmn003

337plusmn002

291plusmn001

137plusmn003

164plusmn002

213plusmn002

Syringavulgaris

250plusmn006

285plusmn009

211plusmn002

257plusmn003

312plusmn007

372plusmn001

479plusmn003

471plusmn002

662plusmn002

Tilia cordata 166plusmn005

195plusmn004

399plusmn003

209plusmn004

255plusmn004

344plusmn003

125plusmn003

115plusmn002

232plusmn003

50

Volodarets et al

Table 5 Carotenoids content in some months of 2012 at experimental sites Statisticalsignificance p-value lt 005 = lt 0001 = lt00001= compared to control

SpeciesMay June October

ms 1 ms 2 ms 3 ms 1 ms 2 ms 3 ms 1 ms 2 ms 3Acer platanoides

065plusmn001

053plusmn002

040plusmn001

056plusmn002

051plusmn001

046plusmn001

270plusmn001

213plusmn001

155plusmn001

A pseudoplatanus

055plusmn002

043plusmn001

038plusmn001

073plusmn001

068plusmn001

063plusmn001

145plusmn001

115plusmn001

098plusmn002

A negundo 075plusmn002

062plusmn002

058plusmn001

075plusmn002

066plusmn002

057plusmn001

123plusmn002

101plusmn001

093plusmn002

Populus simonii

031plusmn001

027plusmn001

021plusmn001

038plusmn001

033plusmn001

029plusmn001

031plusmn001

027plusmn001

022plusmn001

P x canadensis 056plusmn002

049plusmn003

036plusmn001

060plusmn001

051=plusmn001

047plusmn001

095plusmn001

081plusmn001

078plusmn001

Robinia pseudoacacia

046plusmn002

039plusmn001

031plusmn001

061plusmn002

052plusmn002

049plusmn001

148plusmn002

131plusmn002

106plusmn003

Syringa vulgaris

033plusmn001

029plusmn001

022plusmn001

042plusmn001

039plusmn001

033plusmn001

223plusmn001

164plusmn002

145plusmn001

Tilia cordata 037plusmn001

033plusmn002

027plusmn001

047plusmn001

043plusmn001

038plusmn001

192plusmn001

171plusmn002

138plusmn002

Fig 4 The ratio of total chlorophylls to carotenoids in June 2012during the drought at monitoring sites

However this indicator inrepresentatives of Populus and Syringavulgaris genera exceeds the general rangeFor example for Populus simonii and Populustimes сanadensis the maximum level of the ratioin the control (2517 and 1587 respectively)is established and for Syringa vulgaris itmakes 1127 because of high chlorophyllconcentration and low content ofcarotenoids The tendency to growth of theconcentration of green pigments and

reduction of yellow ones in the control ismaintained for the other species exceptRobinia pseudoacacia The highest ratiochl a+bcar is found in this species for theplants in park plantations exceeding thisindicator at ms 1 and ms 3 by 11 times only

Therefore contamination in the parkplantations affects the plants which fact isconfirmed by changes in the composition ofthe pigment apparatus of leaves but in streetplantations in the conditions of heavy traffic

51

Assessment of Trees Vitality in the Urban Landscape of Steppe Zone

the reduction of chlorophyll content andincrease of carotenoids in the investigatedspecies is more significant In stable speciesof trees (Populus simonii P times canadensisRobinia pseudoacacia) these changes are lesscritical compared to medium-stable andnonsufficient stable species (Acerpseudoplatanus A negundo A platanoidesSyringa vulgaris and Tilia cordata)

DiscussionAs a result of our study it is found that

concentration of chlorophylls and carotenoidsin woody plants varies depending on themeteorological factors during the season andon the level of contamination of urban areasThe growth of chlorophyll content in the leavesof trees under study from May to September isestablished which is consistent with theliterature sources (Petrova et al 2017 Iusypivaamp Vegerich 2014) It is determined that themain factor influencing the chlorophyllformation is the air temperature Stable andmedium-stable species Robinia pseudoacaciaPopulus simonii Acer platanoides Populus timescanadensis Tilia cordata have the largestchlorophyll amount in drought periods As it isstated by Ballester et al (2017) fruit species oftrees also demonstrate high dependence on theformation of green pigments on the airtemperature During experiments for Rpseudoacia Tilia cordata and A platanoides directdependence on rainfall is established which isconsistent with the results of Iusypiva ampVegerich (2014) for Dnipro City in 2012 for Rрseudoacia in the leaves of which the maximumsum of chlorophylls was recorded in the monthwith the highest amount of rainfalls as wellThe established pattern indicates less adaptivecapacity of the representatives of Robinia Tiliaand Acer genera to the conditions ofhydrothermal stress

Under action of drought in the leaves ofrepresentatives of Acer genus (Swozcerna etal 2010) the chlorophyll content increaseswhich agrees with the results of ourexperiments for A pseudoplatanus when athigh temperatures and low rainfall inAugust 2013 the maximum amount of

chlorophylls in the leaves of this species wasrecorded This pattern indicates highadaptive capacity of sycamore maple in theconditions of South-East of Ukraine Anotherspecies Populus simonii is defined by a highconcentration of pigments under stressconditions at the start of vegetation period amore stable level of chlorophyll contentduring the growing season It should benoted that under the more prosperousconditions in June maximum is beingreached by chl a fraction under the stressconditions in August - due to the sharpincrease in the chl b fraction as well as it isfound out a higher relative content of chl b atthe end of the growing season The obtainedresults show that the various in stabilityspecies in urban environment differ in theratio of chl a and chl b under the action ofhydrothermal factors of different tensionsthat can be one of the part of thedemonstration of species adaptive strategy

Increase in sum of chlorophylls in Aplatanoides and A negundo in July andAugust 2012 when the amount of rainfallwas higher in 74 and 190 to the normalvalue accordingly occurred due to increasein the proportion of chlorophyll b whichplays the protective role in addition to itsmain function Chlorophyll b absorbs someof the rays expanding the range ofphotoactivity which is particularlyimportant in the conditions of considerablecloudiness in rainy weather Chlorophyll а ismore resistant to adverse environmentalfactors compared to chlorophyll b (Conzales-Dugo 2017 Bessonova et al 2006) Increasein the sum of chlorophylls during drought inAcer pseudoplatanus Populus x canadensis Psimonii Robinia pseudoacacia Syringa vulgarisat the expense of chlorophyll а indicates thenormal development of the photosyntheticapparatus of these species and their highadaptive reactions under conditions ofhydrothermal stress

The linear equations of total chlorophylland meteorological factors (falls andtemperature) for both years wereconstructed for two investigates species

52

Volodarets et al

Acer pseudoplatanus y = -51278-00258x1+04658x2 with R2 = 098 in 2012and y = -68888-00529x1+06888x2 with R2 =081 in 2013

Populus simonii y = -68888-00529x1+06888x2 with R2 = 060 in 2012and y = -12985+0058x1-03181x2 with R2 =077 in 2013 where y ndash sum of chlorophylls(mgg) x1 ndash amount of rainfall (mm) x2 ndashtemperature (ordmС)

As can be seen from the linearequations general tendency of pigmentsamount for change in the leaves despite thedifferent weather conditions remainsunchanged Linear equations obtained forAcer pseudoplatanus confirm the inverserelationship between air temperaturerainfall and sum of chlorophylls during thegrowing season in 2012

Maximum chlorophyll content in theleaves of Acer pseudoplatanus falls on hotmonths both in conditions of excessivehumidity (July 2012) and during thedrought period (August 2013) For Populussimonii the highest chlorophyll content isrecorded in June at high temperatures butvarying amount of rainfall The establishedpattern indicates high adaptive capacity ofA pseudoplatanus and Populus simonii duringthe drought

Carotenoids fulfill the protectivefunction by preventing the destruction ofchlorophyll molecules in the light in theprocess of photo-oxidation Photo-protectivefunction lies in the fact that yellow pigmentsprotect the reaction center from massiveenergy fluxes at high light intensities(Britton et al 2008 Bessonova 2006) Asshown by the results of our study insummer months the content of carotenoidsin species under study increases The highestindicators of carotenoids are found inautumn during the plantsrsquo preparation forwinter

During vegetation on the experimentalsites (ms 1 and ms 2) the content of greenpigments increases in late spring and duringsummer with the further decrease inconcentration in autumn which corresponds

to the dynamics of chlorophyll change in thecontrol According to Zayika amp Bondarenko(2018) the content of chlorophyll is reducedin the leaves of deciduous species in the areaof the western forest-steppe of Ukraine inautumn which is agreed with our results forthe southeastern steppe

Sum of chlorophylls in most species atthe monitoring sites is composed bychlorophyll a except for A platanoides and Anegundo as in control Formation ofchlorophyll b molecules is reduced becauseof inhibition of enzymes of its synthesisunder action of xenobiotics (Petrova et al2017 Bessonova et al 2015)

Covering of the question regardingchanges in carotenoids in the leaves of treesof street plantations in the literature isambiguous For example Petrova et al 2017for Acer heldreichii Boiss amp Heldr and Tiliatomentosa Moench point to the decrease incarotenoids at the contaminated sitehowever for Fraxinus excelsior ndash to growth oftheir content in the conditions of impact ofcar exhausts Reduced content of carotenoidsunder impact of car exhausts is also recordedby Joshi amp Swami (2009) Increase inconcentration of the yellow pigments underaction of car exhausts is established in thestudies of Sillanpaumlauml et al (2008) for Betulapendula Roth which may suggest differentadaptive capacity of trees and varying levelsof contamination Korshikov amp Vinogradova(2013) note the increase of carotenoids indamaged leaves of Acer pseudoplatanus andAcer platanoides under action of pollutantsfrom the work of internal combustionengines in Donetsk

According to results of our study thefunctional state of trees in street and parkplantations is worse compared to controlwhich is confirmed by the decrease inchlorophyll content and growth ofcarotenoids Carotenoid content at ms 2increases to 30 and at ms 1 ndash to 50 indicating the adaptive capacity of plantssince carotenoids possess high antioxidantpower The total number of chlorophylls isreduced by 20 to 30 in the trees of park

53

Assessment of Trees Vitality in the Urban Landscape of Steppe Zone

plantations and by 40ndash50 in the streetplantations compared to the clean site

It is to be noted that the representatives ofthe first group (stable species) such as Robiniapseudoacacia shows the exceedence of sum ofchlorophyls during the drought periode at ms1 and ms 2 At the same time the species of thesecond group (medium-stable species) forexample Syringa vulgaris decreases level ofchlorophyls content under the unfavorableurban and hydrothermal conditions as well asTilia cordata from the third (nonsufficientstable) groups decreases amount ofchlorophylls and increased carotenoid contentThe obtained predicted pain evidences theadaptive strategies of the studied species underanthropogenic and hydrothermal stress

Therefore it is found thatcontamination in the park plantations affectsthe plants which fact is confirmed bychanges in the composition of the pigmentapparatus of leaves but in street plantationsthe reduction of chlorophyll content andincrease of carotenoids in the investigatedspecies is more significant In stable treespecies (Populus simonii P times canadensisRobinia pseudoacacia) these changes are lesscritical than in less stable species (Acerpseudoplatanus A negundo A platanoidesSyringa vulgaris and Tilia cordata)

ConclusionAs a result of the study the functional

state of trees in street and parks plantationswas found to be weakened which indicatesa decrease in the content of green pigmentsand an increase in the concentration ofcarotenoids in the area of automobile vehicleexhaust The impact of hydrothermalconditions and factors of urban environmentdetermines the corresponding changes in theconcentration of photosynthetic pigments inwoody plants differentiated by vitality It isestablished among meteorological factors airtemperature as the main factor Changes inthe concentration of green pigments in theleaves of species under study depending onthe temperature and rainfall are describedby linear equations which is important for

predicting the growth and development ofplants during green building on urbanterritories in the conditions of the steppezone

References Ballester C Zarco-Tejada PJ Nicola E

Alarco JJ Fereres E Intrigliolo DSamp Gonzalez-Dugo V (2017)Evaluating the performance ofxanthophyll chlorophyll andstructure-sensitive spectral indices todetect water stress in five fruit treespecies In Precision Agric SpringerScience+Business Media New Yorkdoi 101007s11119-017-9512-y

Bessonova VP (2006) Influence of heavymetals on the photosynthesis of plantsDDAU Dnipropetrovsk (InUkrainian)

Bessonova VP Ivanchenko ОE ampPonomaryova EА (2015) Combinedimpact of heavy metals (Pb2+ and Cd2+)and salinity on the condition of Loliumperenne long-term assimilationapparatus - Vigravesnyk DnigravepropetrovskogoUnigravevercity Seria Bigraveology Ekology 23(1)15ndash20 (in Ukrainian) doi1015421011503

Glibovytska N Adamenko Ya (2017)Woody Plants Vitality of Urban Areasand Prospects of their GreeneryScientific Bulletin of North UniverdityCenter of Baia Mare Series D XXXI(1)21ndash34

Hopke PK (2009) Theory and applicationof Atmospheric source apportionmentIn Air quality and ecological impactsrelating sources to effects (pp 99ndash121)Elseiver Ltd

Iqbal MZ Shafig M Zaidi S amp Qamar AM(2015) Effect of automobile pollution onchlorophyll content of roadside urbantrees Global Journal of EnvironmentalScience Management 1(4) 283ndash296 doi107508gjesm201504003

Iusypiva T amp Vegerich V (2014) Dynamicsof Photosynthetic Pigments Content InWoody Plants Leaves Under

54

Volodarets et al

park increases by 30ndash35 compared to ms3 showing the sufficient level of adaptationof these species to conditions of the urbanenvironment Considerable increase incarotenoids in street and park plantations isrecorded in Acer platanoides Syringa vulgarisand Tilia cordata which are less stable

The ratio of sum of chlorophylls tocarotenoids (a+bcar) as a rule is constantin the normal conditions and promptly

responds to changes in the environment so itis used as an indicator of plantsrsquo adaptation toextreme conditions (Petrova et al 2014) Inorder to understand the simultaneous actionof abiotic stress ndash drought and anthropogenicpressure the ratio a+bcar was calculated forJune 2012

In most species a+bcar varied from 486(Acer platanoides ms 1) to 905 (Tilia cordatams 3) (Fig4)

Table 1 Stepwise regression analysis for sum of chlorophylls of woody plants in thevegetation period of 2012 (Tonenke ms 3) Negatively correlated variables are highlightedin bold Statistical significance p-value lt 005 = lt 0001 = lt 00001

Species Step 1 Step 2 Step 3Populus times canadensis Falls 009 Falls Temp 069 -Populus simonii Temp 054 Temp Falls 006 Temp Falls Hum 014Tilia cordata Falls 004 Falls Hum 005Robinia pseudoacacia Falls 0008 Falls Hum 005 -Acer negundo - Hum 011Acer platanoides Falls 002 - -Acer pseudoplatanus Hum 030 Hum Falls 003 Hum Falls Temp 014Syringa vulgaris Temp 046 Temp Falls004

Table 2 Stepwise regression analysis for sum of chlorophylls of woody plants in thevegetation period of 2013 (Tonenke ms 3) Negatively correlated variables are highlightedin bold Statistical significance p-value lt 005 = lt 0001 = lt 00001

Species Step 1 Step 2 Step 3Acer pseudoplatanus Temp 022 - -Populus simonii Temp 066 - -

Fig 3 The carotenoids concentration in leaves of the investigated species from May toOctober at monitoring site 3 (Tonenke) in 2012

49

Assessment of Trees Vitality in the Urban Landscape of Steppe Zone

Table 3 Stepwise regression analysis for carotenoids concentration of woodyplants in the vegetation period of 2012 on the control site Negatively correlatedvariables are highlighted in bold Statistical significance p-value lt 005 = lt 0001 = lt00001=

Species Step 1 Step 2 Step 3

P times canadensis Hum002

HumFalls0005

HumFallsTemp002

P simonii Hum002

HumFalls0004 -

Tilia cordata Hum004

HumFalls001

HumFallsTemp009

Robinia pseudoacacia Hum002

HumFalls0006

HumFallsTemp005

Acer negundo Temp003

TempFalls0003

TempFallsHum001

A platanoides Temp012

TempFalls0004

A pseudoplatanus Hum002

HumFalls0004

HumFallsTemp003

Syringa vulgaris Temp012

TempFalls001 -

Table 4 Sum of chlorophylls of the species leaves at experimental sites during thevegetation period Statistical significance p-value lt 005 = lt 0001 = lt00001= compared to control

SpeciesMay June October

ms 1 ms 2 ms 3 ms 1 ms 2 ms 3 ms 1 ms 2 ms 3Acer

platanoides 143

plusmn005132

plusmn004325

plusmn005272

plusmn002314

plusmn005353

plusmn002113

plusmn006115

plusmn001174

plusmn001A

pseudoplatanus 149

plusmn011248

plusmn025332

plusmn005160

plusmn003271

plusmn007380

plusmn003072

plusmn008101

plusmn001073

plusmn002

A negundo 099plusmn011

140plusmn007

205plusmn005

319plusmn002

367plusmn011

409plusmn001

084plusmn003

027plusmn001

142plusmn001

Populussimonii

144plusmn008

234plusmn003

544plusmn004

277plusmn005

391plusmn012

730plusmn002

143plusmn006

081plusmn001

229plusmn002

P xcanadensis

099plusmn006

193plusmn006

306plusmn003

256plusmn003

636plusmn005

746plusmn004

355plusmn002

431plusmn001

475plusmn002

Robinia pseudoacacia

285plusmn007

243plusmn005

184plusmn002

335plusmn003

337plusmn002

291plusmn001

137plusmn003

164plusmn002

213plusmn002

Syringavulgaris

250plusmn006

285plusmn009

211plusmn002

257plusmn003

312plusmn007

372plusmn001

479plusmn003

471plusmn002

662plusmn002

Tilia cordata 166plusmn005

195plusmn004

399plusmn003

209plusmn004

255plusmn004

344plusmn003

125plusmn003

115plusmn002

232plusmn003

50

Volodarets et al

Table 5 Carotenoids content in some months of 2012 at experimental sites Statisticalsignificance p-value lt 005 = lt 0001 = lt00001= compared to control

SpeciesMay June October

ms 1 ms 2 ms 3 ms 1 ms 2 ms 3 ms 1 ms 2 ms 3Acer platanoides

065plusmn001

053plusmn002

040plusmn001

056plusmn002

051plusmn001

046plusmn001

270plusmn001

213plusmn001

155plusmn001

A pseudoplatanus

055plusmn002

043plusmn001

038plusmn001

073plusmn001

068plusmn001

063plusmn001

145plusmn001

115plusmn001

098plusmn002

A negundo 075plusmn002

062plusmn002

058plusmn001

075plusmn002

066plusmn002

057plusmn001

123plusmn002

101plusmn001

093plusmn002

Populus simonii

031plusmn001

027plusmn001

021plusmn001

038plusmn001

033plusmn001

029plusmn001

031plusmn001

027plusmn001

022plusmn001

P x canadensis 056plusmn002

049plusmn003

036plusmn001

060plusmn001

051=plusmn001

047plusmn001

095plusmn001

081plusmn001

078plusmn001

Robinia pseudoacacia

046plusmn002

039plusmn001

031plusmn001

061plusmn002

052plusmn002

049plusmn001

148plusmn002

131plusmn002

106plusmn003

Syringa vulgaris

033plusmn001

029plusmn001

022plusmn001

042plusmn001

039plusmn001

033plusmn001

223plusmn001

164plusmn002

145plusmn001

Tilia cordata 037plusmn001

033plusmn002

027plusmn001

047plusmn001

043plusmn001

038plusmn001

192plusmn001

171plusmn002

138plusmn002

Fig 4 The ratio of total chlorophylls to carotenoids in June 2012during the drought at monitoring sites

However this indicator inrepresentatives of Populus and Syringavulgaris genera exceeds the general rangeFor example for Populus simonii and Populustimes сanadensis the maximum level of the ratioin the control (2517 and 1587 respectively)is established and for Syringa vulgaris itmakes 1127 because of high chlorophyllconcentration and low content ofcarotenoids The tendency to growth of theconcentration of green pigments and

reduction of yellow ones in the control ismaintained for the other species exceptRobinia pseudoacacia The highest ratiochl a+bcar is found in this species for theplants in park plantations exceeding thisindicator at ms 1 and ms 3 by 11 times only

Therefore contamination in the parkplantations affects the plants which fact isconfirmed by changes in the composition ofthe pigment apparatus of leaves but in streetplantations in the conditions of heavy traffic

51

Assessment of Trees Vitality in the Urban Landscape of Steppe Zone

the reduction of chlorophyll content andincrease of carotenoids in the investigatedspecies is more significant In stable speciesof trees (Populus simonii P times canadensisRobinia pseudoacacia) these changes are lesscritical compared to medium-stable andnonsufficient stable species (Acerpseudoplatanus A negundo A platanoidesSyringa vulgaris and Tilia cordata)

DiscussionAs a result of our study it is found that

concentration of chlorophylls and carotenoidsin woody plants varies depending on themeteorological factors during the season andon the level of contamination of urban areasThe growth of chlorophyll content in the leavesof trees under study from May to September isestablished which is consistent with theliterature sources (Petrova et al 2017 Iusypivaamp Vegerich 2014) It is determined that themain factor influencing the chlorophyllformation is the air temperature Stable andmedium-stable species Robinia pseudoacaciaPopulus simonii Acer platanoides Populus timescanadensis Tilia cordata have the largestchlorophyll amount in drought periods As it isstated by Ballester et al (2017) fruit species oftrees also demonstrate high dependence on theformation of green pigments on the airtemperature During experiments for Rpseudoacia Tilia cordata and A platanoides directdependence on rainfall is established which isconsistent with the results of Iusypiva ampVegerich (2014) for Dnipro City in 2012 for Rрseudoacia in the leaves of which the maximumsum of chlorophylls was recorded in the monthwith the highest amount of rainfalls as wellThe established pattern indicates less adaptivecapacity of the representatives of Robinia Tiliaand Acer genera to the conditions ofhydrothermal stress

Under action of drought in the leaves ofrepresentatives of Acer genus (Swozcerna etal 2010) the chlorophyll content increaseswhich agrees with the results of ourexperiments for A pseudoplatanus when athigh temperatures and low rainfall inAugust 2013 the maximum amount of

chlorophylls in the leaves of this species wasrecorded This pattern indicates highadaptive capacity of sycamore maple in theconditions of South-East of Ukraine Anotherspecies Populus simonii is defined by a highconcentration of pigments under stressconditions at the start of vegetation period amore stable level of chlorophyll contentduring the growing season It should benoted that under the more prosperousconditions in June maximum is beingreached by chl a fraction under the stressconditions in August - due to the sharpincrease in the chl b fraction as well as it isfound out a higher relative content of chl b atthe end of the growing season The obtainedresults show that the various in stabilityspecies in urban environment differ in theratio of chl a and chl b under the action ofhydrothermal factors of different tensionsthat can be one of the part of thedemonstration of species adaptive strategy

Increase in sum of chlorophylls in Aplatanoides and A negundo in July andAugust 2012 when the amount of rainfallwas higher in 74 and 190 to the normalvalue accordingly occurred due to increasein the proportion of chlorophyll b whichplays the protective role in addition to itsmain function Chlorophyll b absorbs someof the rays expanding the range ofphotoactivity which is particularlyimportant in the conditions of considerablecloudiness in rainy weather Chlorophyll а ismore resistant to adverse environmentalfactors compared to chlorophyll b (Conzales-Dugo 2017 Bessonova et al 2006) Increasein the sum of chlorophylls during drought inAcer pseudoplatanus Populus x canadensis Psimonii Robinia pseudoacacia Syringa vulgarisat the expense of chlorophyll а indicates thenormal development of the photosyntheticapparatus of these species and their highadaptive reactions under conditions ofhydrothermal stress

The linear equations of total chlorophylland meteorological factors (falls andtemperature) for both years wereconstructed for two investigates species

52

Volodarets et al

Acer pseudoplatanus y = -51278-00258x1+04658x2 with R2 = 098 in 2012and y = -68888-00529x1+06888x2 with R2 =081 in 2013

Populus simonii y = -68888-00529x1+06888x2 with R2 = 060 in 2012and y = -12985+0058x1-03181x2 with R2 =077 in 2013 where y ndash sum of chlorophylls(mgg) x1 ndash amount of rainfall (mm) x2 ndashtemperature (ordmС)

As can be seen from the linearequations general tendency of pigmentsamount for change in the leaves despite thedifferent weather conditions remainsunchanged Linear equations obtained forAcer pseudoplatanus confirm the inverserelationship between air temperaturerainfall and sum of chlorophylls during thegrowing season in 2012

Maximum chlorophyll content in theleaves of Acer pseudoplatanus falls on hotmonths both in conditions of excessivehumidity (July 2012) and during thedrought period (August 2013) For Populussimonii the highest chlorophyll content isrecorded in June at high temperatures butvarying amount of rainfall The establishedpattern indicates high adaptive capacity ofA pseudoplatanus and Populus simonii duringthe drought

Carotenoids fulfill the protectivefunction by preventing the destruction ofchlorophyll molecules in the light in theprocess of photo-oxidation Photo-protectivefunction lies in the fact that yellow pigmentsprotect the reaction center from massiveenergy fluxes at high light intensities(Britton et al 2008 Bessonova 2006) Asshown by the results of our study insummer months the content of carotenoidsin species under study increases The highestindicators of carotenoids are found inautumn during the plantsrsquo preparation forwinter

During vegetation on the experimentalsites (ms 1 and ms 2) the content of greenpigments increases in late spring and duringsummer with the further decrease inconcentration in autumn which corresponds

to the dynamics of chlorophyll change in thecontrol According to Zayika amp Bondarenko(2018) the content of chlorophyll is reducedin the leaves of deciduous species in the areaof the western forest-steppe of Ukraine inautumn which is agreed with our results forthe southeastern steppe

Sum of chlorophylls in most species atthe monitoring sites is composed bychlorophyll a except for A platanoides and Anegundo as in control Formation ofchlorophyll b molecules is reduced becauseof inhibition of enzymes of its synthesisunder action of xenobiotics (Petrova et al2017 Bessonova et al 2015)

Covering of the question regardingchanges in carotenoids in the leaves of treesof street plantations in the literature isambiguous For example Petrova et al 2017for Acer heldreichii Boiss amp Heldr and Tiliatomentosa Moench point to the decrease incarotenoids at the contaminated sitehowever for Fraxinus excelsior ndash to growth oftheir content in the conditions of impact ofcar exhausts Reduced content of carotenoidsunder impact of car exhausts is also recordedby Joshi amp Swami (2009) Increase inconcentration of the yellow pigments underaction of car exhausts is established in thestudies of Sillanpaumlauml et al (2008) for Betulapendula Roth which may suggest differentadaptive capacity of trees and varying levelsof contamination Korshikov amp Vinogradova(2013) note the increase of carotenoids indamaged leaves of Acer pseudoplatanus andAcer platanoides under action of pollutantsfrom the work of internal combustionengines in Donetsk

According to results of our study thefunctional state of trees in street and parkplantations is worse compared to controlwhich is confirmed by the decrease inchlorophyll content and growth ofcarotenoids Carotenoid content at ms 2increases to 30 and at ms 1 ndash to 50 indicating the adaptive capacity of plantssince carotenoids possess high antioxidantpower The total number of chlorophylls isreduced by 20 to 30 in the trees of park

53

Assessment of Trees Vitality in the Urban Landscape of Steppe Zone

plantations and by 40ndash50 in the streetplantations compared to the clean site

It is to be noted that the representatives ofthe first group (stable species) such as Robiniapseudoacacia shows the exceedence of sum ofchlorophyls during the drought periode at ms1 and ms 2 At the same time the species of thesecond group (medium-stable species) forexample Syringa vulgaris decreases level ofchlorophyls content under the unfavorableurban and hydrothermal conditions as well asTilia cordata from the third (nonsufficientstable) groups decreases amount ofchlorophylls and increased carotenoid contentThe obtained predicted pain evidences theadaptive strategies of the studied species underanthropogenic and hydrothermal stress

Therefore it is found thatcontamination in the park plantations affectsthe plants which fact is confirmed bychanges in the composition of the pigmentapparatus of leaves but in street plantationsthe reduction of chlorophyll content andincrease of carotenoids in the investigatedspecies is more significant In stable treespecies (Populus simonii P times canadensisRobinia pseudoacacia) these changes are lesscritical than in less stable species (Acerpseudoplatanus A negundo A platanoidesSyringa vulgaris and Tilia cordata)

ConclusionAs a result of the study the functional

state of trees in street and parks plantationswas found to be weakened which indicatesa decrease in the content of green pigmentsand an increase in the concentration ofcarotenoids in the area of automobile vehicleexhaust The impact of hydrothermalconditions and factors of urban environmentdetermines the corresponding changes in theconcentration of photosynthetic pigments inwoody plants differentiated by vitality It isestablished among meteorological factors airtemperature as the main factor Changes inthe concentration of green pigments in theleaves of species under study depending onthe temperature and rainfall are describedby linear equations which is important for

predicting the growth and development ofplants during green building on urbanterritories in the conditions of the steppezone

References Ballester C Zarco-Tejada PJ Nicola E

Alarco JJ Fereres E Intrigliolo DSamp Gonzalez-Dugo V (2017)Evaluating the performance ofxanthophyll chlorophyll andstructure-sensitive spectral indices todetect water stress in five fruit treespecies In Precision Agric SpringerScience+Business Media New Yorkdoi 101007s11119-017-9512-y

Bessonova VP (2006) Influence of heavymetals on the photosynthesis of plantsDDAU Dnipropetrovsk (InUkrainian)

Bessonova VP Ivanchenko ОE ampPonomaryova EА (2015) Combinedimpact of heavy metals (Pb2+ and Cd2+)and salinity on the condition of Loliumperenne long-term assimilationapparatus - Vigravesnyk DnigravepropetrovskogoUnigravevercity Seria Bigraveology Ekology 23(1)15ndash20 (in Ukrainian) doi1015421011503

Glibovytska N Adamenko Ya (2017)Woody Plants Vitality of Urban Areasand Prospects of their GreeneryScientific Bulletin of North UniverdityCenter of Baia Mare Series D XXXI(1)21ndash34

Hopke PK (2009) Theory and applicationof Atmospheric source apportionmentIn Air quality and ecological impactsrelating sources to effects (pp 99ndash121)Elseiver Ltd

Iqbal MZ Shafig M Zaidi S amp Qamar AM(2015) Effect of automobile pollution onchlorophyll content of roadside urbantrees Global Journal of EnvironmentalScience Management 1(4) 283ndash296 doi107508gjesm201504003

Iusypiva T amp Vegerich V (2014) Dynamicsof Photosynthetic Pigments Content InWoody Plants Leaves Under

54

Assessment of Trees Vitality in the Urban Landscape of Steppe Zone

Table 3 Stepwise regression analysis for carotenoids concentration of woodyplants in the vegetation period of 2012 on the control site Negatively correlatedvariables are highlighted in bold Statistical significance p-value lt 005 = lt 0001 = lt00001=

Species Step 1 Step 2 Step 3

P times canadensis Hum002

HumFalls0005

HumFallsTemp002

P simonii Hum002

HumFalls0004 -

Tilia cordata Hum004

HumFalls001

HumFallsTemp009

Robinia pseudoacacia Hum002

HumFalls0006

HumFallsTemp005

Acer negundo Temp003

TempFalls0003

TempFallsHum001

A platanoides Temp012

TempFalls0004

A pseudoplatanus Hum002

HumFalls0004

HumFallsTemp003

Syringa vulgaris Temp012

TempFalls001 -

Table 4 Sum of chlorophylls of the species leaves at experimental sites during thevegetation period Statistical significance p-value lt 005 = lt 0001 = lt00001= compared to control

SpeciesMay June October

ms 1 ms 2 ms 3 ms 1 ms 2 ms 3 ms 1 ms 2 ms 3Acer

platanoides 143

plusmn005132

plusmn004325

plusmn005272

plusmn002314

plusmn005353

plusmn002113

plusmn006115

plusmn001174

plusmn001A

pseudoplatanus 149

plusmn011248

plusmn025332

plusmn005160

plusmn003271

plusmn007380

plusmn003072

plusmn008101

plusmn001073

plusmn002

A negundo 099plusmn011

140plusmn007

205plusmn005

319plusmn002

367plusmn011

409plusmn001

084plusmn003

027plusmn001

142plusmn001

Populussimonii

144plusmn008

234plusmn003

544plusmn004

277plusmn005

391plusmn012

730plusmn002

143plusmn006

081plusmn001

229plusmn002

P xcanadensis

099plusmn006

193plusmn006

306plusmn003

256plusmn003

636plusmn005

746plusmn004

355plusmn002

431plusmn001

475plusmn002

Robinia pseudoacacia

285plusmn007

243plusmn005

184plusmn002

335plusmn003

337plusmn002

291plusmn001

137plusmn003

164plusmn002

213plusmn002

Syringavulgaris

250plusmn006

285plusmn009

211plusmn002

257plusmn003

312plusmn007

372plusmn001

479plusmn003

471plusmn002

662plusmn002

Tilia cordata 166plusmn005

195plusmn004

399plusmn003

209plusmn004

255plusmn004

344plusmn003

125plusmn003

115plusmn002

232plusmn003

50

Volodarets et al

Table 5 Carotenoids content in some months of 2012 at experimental sites Statisticalsignificance p-value lt 005 = lt 0001 = lt00001= compared to control

SpeciesMay June October

ms 1 ms 2 ms 3 ms 1 ms 2 ms 3 ms 1 ms 2 ms 3Acer platanoides

065plusmn001

053plusmn002

040plusmn001

056plusmn002

051plusmn001

046plusmn001

270plusmn001

213plusmn001

155plusmn001

A pseudoplatanus

055plusmn002

043plusmn001

038plusmn001

073plusmn001

068plusmn001

063plusmn001

145plusmn001

115plusmn001

098plusmn002

A negundo 075plusmn002

062plusmn002

058plusmn001

075plusmn002

066plusmn002

057plusmn001

123plusmn002

101plusmn001

093plusmn002

Populus simonii

031plusmn001

027plusmn001

021plusmn001

038plusmn001

033plusmn001

029plusmn001

031plusmn001

027plusmn001

022plusmn001

P x canadensis 056plusmn002

049plusmn003

036plusmn001

060plusmn001

051=plusmn001

047plusmn001

095plusmn001

081plusmn001

078plusmn001

Robinia pseudoacacia

046plusmn002

039plusmn001

031plusmn001

061plusmn002

052plusmn002

049plusmn001

148plusmn002

131plusmn002

106plusmn003

Syringa vulgaris

033plusmn001

029plusmn001

022plusmn001

042plusmn001

039plusmn001

033plusmn001

223plusmn001

164plusmn002

145plusmn001

Tilia cordata 037plusmn001

033plusmn002

027plusmn001

047plusmn001

043plusmn001

038plusmn001

192plusmn001

171plusmn002

138plusmn002

Fig 4 The ratio of total chlorophylls to carotenoids in June 2012during the drought at monitoring sites

However this indicator inrepresentatives of Populus and Syringavulgaris genera exceeds the general rangeFor example for Populus simonii and Populustimes сanadensis the maximum level of the ratioin the control (2517 and 1587 respectively)is established and for Syringa vulgaris itmakes 1127 because of high chlorophyllconcentration and low content ofcarotenoids The tendency to growth of theconcentration of green pigments and

reduction of yellow ones in the control ismaintained for the other species exceptRobinia pseudoacacia The highest ratiochl a+bcar is found in this species for theplants in park plantations exceeding thisindicator at ms 1 and ms 3 by 11 times only

Therefore contamination in the parkplantations affects the plants which fact isconfirmed by changes in the composition ofthe pigment apparatus of leaves but in streetplantations in the conditions of heavy traffic

51

Assessment of Trees Vitality in the Urban Landscape of Steppe Zone

the reduction of chlorophyll content andincrease of carotenoids in the investigatedspecies is more significant In stable speciesof trees (Populus simonii P times canadensisRobinia pseudoacacia) these changes are lesscritical compared to medium-stable andnonsufficient stable species (Acerpseudoplatanus A negundo A platanoidesSyringa vulgaris and Tilia cordata)

DiscussionAs a result of our study it is found that

concentration of chlorophylls and carotenoidsin woody plants varies depending on themeteorological factors during the season andon the level of contamination of urban areasThe growth of chlorophyll content in the leavesof trees under study from May to September isestablished which is consistent with theliterature sources (Petrova et al 2017 Iusypivaamp Vegerich 2014) It is determined that themain factor influencing the chlorophyllformation is the air temperature Stable andmedium-stable species Robinia pseudoacaciaPopulus simonii Acer platanoides Populus timescanadensis Tilia cordata have the largestchlorophyll amount in drought periods As it isstated by Ballester et al (2017) fruit species oftrees also demonstrate high dependence on theformation of green pigments on the airtemperature During experiments for Rpseudoacia Tilia cordata and A platanoides directdependence on rainfall is established which isconsistent with the results of Iusypiva ampVegerich (2014) for Dnipro City in 2012 for Rрseudoacia in the leaves of which the maximumsum of chlorophylls was recorded in the monthwith the highest amount of rainfalls as wellThe established pattern indicates less adaptivecapacity of the representatives of Robinia Tiliaand Acer genera to the conditions ofhydrothermal stress

Under action of drought in the leaves ofrepresentatives of Acer genus (Swozcerna etal 2010) the chlorophyll content increaseswhich agrees with the results of ourexperiments for A pseudoplatanus when athigh temperatures and low rainfall inAugust 2013 the maximum amount of

chlorophylls in the leaves of this species wasrecorded This pattern indicates highadaptive capacity of sycamore maple in theconditions of South-East of Ukraine Anotherspecies Populus simonii is defined by a highconcentration of pigments under stressconditions at the start of vegetation period amore stable level of chlorophyll contentduring the growing season It should benoted that under the more prosperousconditions in June maximum is beingreached by chl a fraction under the stressconditions in August - due to the sharpincrease in the chl b fraction as well as it isfound out a higher relative content of chl b atthe end of the growing season The obtainedresults show that the various in stabilityspecies in urban environment differ in theratio of chl a and chl b under the action ofhydrothermal factors of different tensionsthat can be one of the part of thedemonstration of species adaptive strategy

Increase in sum of chlorophylls in Aplatanoides and A negundo in July andAugust 2012 when the amount of rainfallwas higher in 74 and 190 to the normalvalue accordingly occurred due to increasein the proportion of chlorophyll b whichplays the protective role in addition to itsmain function Chlorophyll b absorbs someof the rays expanding the range ofphotoactivity which is particularlyimportant in the conditions of considerablecloudiness in rainy weather Chlorophyll а ismore resistant to adverse environmentalfactors compared to chlorophyll b (Conzales-Dugo 2017 Bessonova et al 2006) Increasein the sum of chlorophylls during drought inAcer pseudoplatanus Populus x canadensis Psimonii Robinia pseudoacacia Syringa vulgarisat the expense of chlorophyll а indicates thenormal development of the photosyntheticapparatus of these species and their highadaptive reactions under conditions ofhydrothermal stress

The linear equations of total chlorophylland meteorological factors (falls andtemperature) for both years wereconstructed for two investigates species

52

Volodarets et al

Acer pseudoplatanus y = -51278-00258x1+04658x2 with R2 = 098 in 2012and y = -68888-00529x1+06888x2 with R2 =081 in 2013

Populus simonii y = -68888-00529x1+06888x2 with R2 = 060 in 2012and y = -12985+0058x1-03181x2 with R2 =077 in 2013 where y ndash sum of chlorophylls(mgg) x1 ndash amount of rainfall (mm) x2 ndashtemperature (ordmС)

As can be seen from the linearequations general tendency of pigmentsamount for change in the leaves despite thedifferent weather conditions remainsunchanged Linear equations obtained forAcer pseudoplatanus confirm the inverserelationship between air temperaturerainfall and sum of chlorophylls during thegrowing season in 2012

Maximum chlorophyll content in theleaves of Acer pseudoplatanus falls on hotmonths both in conditions of excessivehumidity (July 2012) and during thedrought period (August 2013) For Populussimonii the highest chlorophyll content isrecorded in June at high temperatures butvarying amount of rainfall The establishedpattern indicates high adaptive capacity ofA pseudoplatanus and Populus simonii duringthe drought

Carotenoids fulfill the protectivefunction by preventing the destruction ofchlorophyll molecules in the light in theprocess of photo-oxidation Photo-protectivefunction lies in the fact that yellow pigmentsprotect the reaction center from massiveenergy fluxes at high light intensities(Britton et al 2008 Bessonova 2006) Asshown by the results of our study insummer months the content of carotenoidsin species under study increases The highestindicators of carotenoids are found inautumn during the plantsrsquo preparation forwinter

During vegetation on the experimentalsites (ms 1 and ms 2) the content of greenpigments increases in late spring and duringsummer with the further decrease inconcentration in autumn which corresponds

to the dynamics of chlorophyll change in thecontrol According to Zayika amp Bondarenko(2018) the content of chlorophyll is reducedin the leaves of deciduous species in the areaof the western forest-steppe of Ukraine inautumn which is agreed with our results forthe southeastern steppe

Sum of chlorophylls in most species atthe monitoring sites is composed bychlorophyll a except for A platanoides and Anegundo as in control Formation ofchlorophyll b molecules is reduced becauseof inhibition of enzymes of its synthesisunder action of xenobiotics (Petrova et al2017 Bessonova et al 2015)

Covering of the question regardingchanges in carotenoids in the leaves of treesof street plantations in the literature isambiguous For example Petrova et al 2017for Acer heldreichii Boiss amp Heldr and Tiliatomentosa Moench point to the decrease incarotenoids at the contaminated sitehowever for Fraxinus excelsior ndash to growth oftheir content in the conditions of impact ofcar exhausts Reduced content of carotenoidsunder impact of car exhausts is also recordedby Joshi amp Swami (2009) Increase inconcentration of the yellow pigments underaction of car exhausts is established in thestudies of Sillanpaumlauml et al (2008) for Betulapendula Roth which may suggest differentadaptive capacity of trees and varying levelsof contamination Korshikov amp Vinogradova(2013) note the increase of carotenoids indamaged leaves of Acer pseudoplatanus andAcer platanoides under action of pollutantsfrom the work of internal combustionengines in Donetsk

According to results of our study thefunctional state of trees in street and parkplantations is worse compared to controlwhich is confirmed by the decrease inchlorophyll content and growth ofcarotenoids Carotenoid content at ms 2increases to 30 and at ms 1 ndash to 50 indicating the adaptive capacity of plantssince carotenoids possess high antioxidantpower The total number of chlorophylls isreduced by 20 to 30 in the trees of park

53

Assessment of Trees Vitality in the Urban Landscape of Steppe Zone

plantations and by 40ndash50 in the streetplantations compared to the clean site

It is to be noted that the representatives ofthe first group (stable species) such as Robiniapseudoacacia shows the exceedence of sum ofchlorophyls during the drought periode at ms1 and ms 2 At the same time the species of thesecond group (medium-stable species) forexample Syringa vulgaris decreases level ofchlorophyls content under the unfavorableurban and hydrothermal conditions as well asTilia cordata from the third (nonsufficientstable) groups decreases amount ofchlorophylls and increased carotenoid contentThe obtained predicted pain evidences theadaptive strategies of the studied species underanthropogenic and hydrothermal stress

Therefore it is found thatcontamination in the park plantations affectsthe plants which fact is confirmed bychanges in the composition of the pigmentapparatus of leaves but in street plantationsthe reduction of chlorophyll content andincrease of carotenoids in the investigatedspecies is more significant In stable treespecies (Populus simonii P times canadensisRobinia pseudoacacia) these changes are lesscritical than in less stable species (Acerpseudoplatanus A negundo A platanoidesSyringa vulgaris and Tilia cordata)

ConclusionAs a result of the study the functional

state of trees in street and parks plantationswas found to be weakened which indicatesa decrease in the content of green pigmentsand an increase in the concentration ofcarotenoids in the area of automobile vehicleexhaust The impact of hydrothermalconditions and factors of urban environmentdetermines the corresponding changes in theconcentration of photosynthetic pigments inwoody plants differentiated by vitality It isestablished among meteorological factors airtemperature as the main factor Changes inthe concentration of green pigments in theleaves of species under study depending onthe temperature and rainfall are describedby linear equations which is important for

predicting the growth and development ofplants during green building on urbanterritories in the conditions of the steppezone

References Ballester C Zarco-Tejada PJ Nicola E

Alarco JJ Fereres E Intrigliolo DSamp Gonzalez-Dugo V (2017)Evaluating the performance ofxanthophyll chlorophyll andstructure-sensitive spectral indices todetect water stress in five fruit treespecies In Precision Agric SpringerScience+Business Media New Yorkdoi 101007s11119-017-9512-y

Bessonova VP (2006) Influence of heavymetals on the photosynthesis of plantsDDAU Dnipropetrovsk (InUkrainian)

Bessonova VP Ivanchenko ОE ampPonomaryova EА (2015) Combinedimpact of heavy metals (Pb2+ and Cd2+)and salinity on the condition of Loliumperenne long-term assimilationapparatus - Vigravesnyk DnigravepropetrovskogoUnigravevercity Seria Bigraveology Ekology 23(1)15ndash20 (in Ukrainian) doi1015421011503

Glibovytska N Adamenko Ya (2017)Woody Plants Vitality of Urban Areasand Prospects of their GreeneryScientific Bulletin of North UniverdityCenter of Baia Mare Series D XXXI(1)21ndash34

Hopke PK (2009) Theory and applicationof Atmospheric source apportionmentIn Air quality and ecological impactsrelating sources to effects (pp 99ndash121)Elseiver Ltd

Iqbal MZ Shafig M Zaidi S amp Qamar AM(2015) Effect of automobile pollution onchlorophyll content of roadside urbantrees Global Journal of EnvironmentalScience Management 1(4) 283ndash296 doi107508gjesm201504003

Iusypiva T amp Vegerich V (2014) Dynamicsof Photosynthetic Pigments Content InWoody Plants Leaves Under

54

Volodarets et al

Table 5 Carotenoids content in some months of 2012 at experimental sites Statisticalsignificance p-value lt 005 = lt 0001 = lt00001= compared to control

SpeciesMay June October

ms 1 ms 2 ms 3 ms 1 ms 2 ms 3 ms 1 ms 2 ms 3Acer platanoides

065plusmn001

053plusmn002

040plusmn001

056plusmn002

051plusmn001

046plusmn001

270plusmn001

213plusmn001

155plusmn001

A pseudoplatanus

055plusmn002

043plusmn001

038plusmn001

073plusmn001

068plusmn001

063plusmn001

145plusmn001

115plusmn001

098plusmn002

A negundo 075plusmn002

062plusmn002

058plusmn001

075plusmn002

066plusmn002

057plusmn001

123plusmn002

101plusmn001

093plusmn002

Populus simonii

031plusmn001

027plusmn001

021plusmn001

038plusmn001

033plusmn001

029plusmn001

031plusmn001

027plusmn001

022plusmn001

P x canadensis 056plusmn002

049plusmn003

036plusmn001

060plusmn001

051=plusmn001

047plusmn001

095plusmn001

081plusmn001

078plusmn001

Robinia pseudoacacia

046plusmn002

039plusmn001

031plusmn001

061plusmn002

052plusmn002

049plusmn001

148plusmn002

131plusmn002

106plusmn003

Syringa vulgaris

033plusmn001

029plusmn001

022plusmn001

042plusmn001

039plusmn001

033plusmn001

223plusmn001

164plusmn002

145plusmn001

Tilia cordata 037plusmn001

033plusmn002

027plusmn001

047plusmn001

043plusmn001

038plusmn001

192plusmn001

171plusmn002

138plusmn002

Fig 4 The ratio of total chlorophylls to carotenoids in June 2012during the drought at monitoring sites

However this indicator inrepresentatives of Populus and Syringavulgaris genera exceeds the general rangeFor example for Populus simonii and Populustimes сanadensis the maximum level of the ratioin the control (2517 and 1587 respectively)is established and for Syringa vulgaris itmakes 1127 because of high chlorophyllconcentration and low content ofcarotenoids The tendency to growth of theconcentration of green pigments and

reduction of yellow ones in the control ismaintained for the other species exceptRobinia pseudoacacia The highest ratiochl a+bcar is found in this species for theplants in park plantations exceeding thisindicator at ms 1 and ms 3 by 11 times only

Therefore contamination in the parkplantations affects the plants which fact isconfirmed by changes in the composition ofthe pigment apparatus of leaves but in streetplantations in the conditions of heavy traffic

51

Assessment of Trees Vitality in the Urban Landscape of Steppe Zone

the reduction of chlorophyll content andincrease of carotenoids in the investigatedspecies is more significant In stable speciesof trees (Populus simonii P times canadensisRobinia pseudoacacia) these changes are lesscritical compared to medium-stable andnonsufficient stable species (Acerpseudoplatanus A negundo A platanoidesSyringa vulgaris and Tilia cordata)

DiscussionAs a result of our study it is found that

concentration of chlorophylls and carotenoidsin woody plants varies depending on themeteorological factors during the season andon the level of contamination of urban areasThe growth of chlorophyll content in the leavesof trees under study from May to September isestablished which is consistent with theliterature sources (Petrova et al 2017 Iusypivaamp Vegerich 2014) It is determined that themain factor influencing the chlorophyllformation is the air temperature Stable andmedium-stable species Robinia pseudoacaciaPopulus simonii Acer platanoides Populus timescanadensis Tilia cordata have the largestchlorophyll amount in drought periods As it isstated by Ballester et al (2017) fruit species oftrees also demonstrate high dependence on theformation of green pigments on the airtemperature During experiments for Rpseudoacia Tilia cordata and A platanoides directdependence on rainfall is established which isconsistent with the results of Iusypiva ampVegerich (2014) for Dnipro City in 2012 for Rрseudoacia in the leaves of which the maximumsum of chlorophylls was recorded in the monthwith the highest amount of rainfalls as wellThe established pattern indicates less adaptivecapacity of the representatives of Robinia Tiliaand Acer genera to the conditions ofhydrothermal stress

Under action of drought in the leaves ofrepresentatives of Acer genus (Swozcerna etal 2010) the chlorophyll content increaseswhich agrees with the results of ourexperiments for A pseudoplatanus when athigh temperatures and low rainfall inAugust 2013 the maximum amount of

chlorophylls in the leaves of this species wasrecorded This pattern indicates highadaptive capacity of sycamore maple in theconditions of South-East of Ukraine Anotherspecies Populus simonii is defined by a highconcentration of pigments under stressconditions at the start of vegetation period amore stable level of chlorophyll contentduring the growing season It should benoted that under the more prosperousconditions in June maximum is beingreached by chl a fraction under the stressconditions in August - due to the sharpincrease in the chl b fraction as well as it isfound out a higher relative content of chl b atthe end of the growing season The obtainedresults show that the various in stabilityspecies in urban environment differ in theratio of chl a and chl b under the action ofhydrothermal factors of different tensionsthat can be one of the part of thedemonstration of species adaptive strategy

Increase in sum of chlorophylls in Aplatanoides and A negundo in July andAugust 2012 when the amount of rainfallwas higher in 74 and 190 to the normalvalue accordingly occurred due to increasein the proportion of chlorophyll b whichplays the protective role in addition to itsmain function Chlorophyll b absorbs someof the rays expanding the range ofphotoactivity which is particularlyimportant in the conditions of considerablecloudiness in rainy weather Chlorophyll а ismore resistant to adverse environmentalfactors compared to chlorophyll b (Conzales-Dugo 2017 Bessonova et al 2006) Increasein the sum of chlorophylls during drought inAcer pseudoplatanus Populus x canadensis Psimonii Robinia pseudoacacia Syringa vulgarisat the expense of chlorophyll а indicates thenormal development of the photosyntheticapparatus of these species and their highadaptive reactions under conditions ofhydrothermal stress

The linear equations of total chlorophylland meteorological factors (falls andtemperature) for both years wereconstructed for two investigates species

52

Volodarets et al

Acer pseudoplatanus y = -51278-00258x1+04658x2 with R2 = 098 in 2012and y = -68888-00529x1+06888x2 with R2 =081 in 2013

Populus simonii y = -68888-00529x1+06888x2 with R2 = 060 in 2012and y = -12985+0058x1-03181x2 with R2 =077 in 2013 where y ndash sum of chlorophylls(mgg) x1 ndash amount of rainfall (mm) x2 ndashtemperature (ordmС)

As can be seen from the linearequations general tendency of pigmentsamount for change in the leaves despite thedifferent weather conditions remainsunchanged Linear equations obtained forAcer pseudoplatanus confirm the inverserelationship between air temperaturerainfall and sum of chlorophylls during thegrowing season in 2012

Maximum chlorophyll content in theleaves of Acer pseudoplatanus falls on hotmonths both in conditions of excessivehumidity (July 2012) and during thedrought period (August 2013) For Populussimonii the highest chlorophyll content isrecorded in June at high temperatures butvarying amount of rainfall The establishedpattern indicates high adaptive capacity ofA pseudoplatanus and Populus simonii duringthe drought

Carotenoids fulfill the protectivefunction by preventing the destruction ofchlorophyll molecules in the light in theprocess of photo-oxidation Photo-protectivefunction lies in the fact that yellow pigmentsprotect the reaction center from massiveenergy fluxes at high light intensities(Britton et al 2008 Bessonova 2006) Asshown by the results of our study insummer months the content of carotenoidsin species under study increases The highestindicators of carotenoids are found inautumn during the plantsrsquo preparation forwinter

During vegetation on the experimentalsites (ms 1 and ms 2) the content of greenpigments increases in late spring and duringsummer with the further decrease inconcentration in autumn which corresponds

to the dynamics of chlorophyll change in thecontrol According to Zayika amp Bondarenko(2018) the content of chlorophyll is reducedin the leaves of deciduous species in the areaof the western forest-steppe of Ukraine inautumn which is agreed with our results forthe southeastern steppe

Sum of chlorophylls in most species atthe monitoring sites is composed bychlorophyll a except for A platanoides and Anegundo as in control Formation ofchlorophyll b molecules is reduced becauseof inhibition of enzymes of its synthesisunder action of xenobiotics (Petrova et al2017 Bessonova et al 2015)

Covering of the question regardingchanges in carotenoids in the leaves of treesof street plantations in the literature isambiguous For example Petrova et al 2017for Acer heldreichii Boiss amp Heldr and Tiliatomentosa Moench point to the decrease incarotenoids at the contaminated sitehowever for Fraxinus excelsior ndash to growth oftheir content in the conditions of impact ofcar exhausts Reduced content of carotenoidsunder impact of car exhausts is also recordedby Joshi amp Swami (2009) Increase inconcentration of the yellow pigments underaction of car exhausts is established in thestudies of Sillanpaumlauml et al (2008) for Betulapendula Roth which may suggest differentadaptive capacity of trees and varying levelsof contamination Korshikov amp Vinogradova(2013) note the increase of carotenoids indamaged leaves of Acer pseudoplatanus andAcer platanoides under action of pollutantsfrom the work of internal combustionengines in Donetsk

According to results of our study thefunctional state of trees in street and parkplantations is worse compared to controlwhich is confirmed by the decrease inchlorophyll content and growth ofcarotenoids Carotenoid content at ms 2increases to 30 and at ms 1 ndash to 50 indicating the adaptive capacity of plantssince carotenoids possess high antioxidantpower The total number of chlorophylls isreduced by 20 to 30 in the trees of park

53

Assessment of Trees Vitality in the Urban Landscape of Steppe Zone

plantations and by 40ndash50 in the streetplantations compared to the clean site

It is to be noted that the representatives ofthe first group (stable species) such as Robiniapseudoacacia shows the exceedence of sum ofchlorophyls during the drought periode at ms1 and ms 2 At the same time the species of thesecond group (medium-stable species) forexample Syringa vulgaris decreases level ofchlorophyls content under the unfavorableurban and hydrothermal conditions as well asTilia cordata from the third (nonsufficientstable) groups decreases amount ofchlorophylls and increased carotenoid contentThe obtained predicted pain evidences theadaptive strategies of the studied species underanthropogenic and hydrothermal stress

Therefore it is found thatcontamination in the park plantations affectsthe plants which fact is confirmed bychanges in the composition of the pigmentapparatus of leaves but in street plantationsthe reduction of chlorophyll content andincrease of carotenoids in the investigatedspecies is more significant In stable treespecies (Populus simonii P times canadensisRobinia pseudoacacia) these changes are lesscritical than in less stable species (Acerpseudoplatanus A negundo A platanoidesSyringa vulgaris and Tilia cordata)

ConclusionAs a result of the study the functional

state of trees in street and parks plantationswas found to be weakened which indicatesa decrease in the content of green pigmentsand an increase in the concentration ofcarotenoids in the area of automobile vehicleexhaust The impact of hydrothermalconditions and factors of urban environmentdetermines the corresponding changes in theconcentration of photosynthetic pigments inwoody plants differentiated by vitality It isestablished among meteorological factors airtemperature as the main factor Changes inthe concentration of green pigments in theleaves of species under study depending onthe temperature and rainfall are describedby linear equations which is important for

predicting the growth and development ofplants during green building on urbanterritories in the conditions of the steppezone

References Ballester C Zarco-Tejada PJ Nicola E

Alarco JJ Fereres E Intrigliolo DSamp Gonzalez-Dugo V (2017)Evaluating the performance ofxanthophyll chlorophyll andstructure-sensitive spectral indices todetect water stress in five fruit treespecies In Precision Agric SpringerScience+Business Media New Yorkdoi 101007s11119-017-9512-y

Bessonova VP (2006) Influence of heavymetals on the photosynthesis of plantsDDAU Dnipropetrovsk (InUkrainian)

Bessonova VP Ivanchenko ОE ampPonomaryova EА (2015) Combinedimpact of heavy metals (Pb2+ and Cd2+)and salinity on the condition of Loliumperenne long-term assimilationapparatus - Vigravesnyk DnigravepropetrovskogoUnigravevercity Seria Bigraveology Ekology 23(1)15ndash20 (in Ukrainian) doi1015421011503

Glibovytska N Adamenko Ya (2017)Woody Plants Vitality of Urban Areasand Prospects of their GreeneryScientific Bulletin of North UniverdityCenter of Baia Mare Series D XXXI(1)21ndash34

Hopke PK (2009) Theory and applicationof Atmospheric source apportionmentIn Air quality and ecological impactsrelating sources to effects (pp 99ndash121)Elseiver Ltd

Iqbal MZ Shafig M Zaidi S amp Qamar AM(2015) Effect of automobile pollution onchlorophyll content of roadside urbantrees Global Journal of EnvironmentalScience Management 1(4) 283ndash296 doi107508gjesm201504003

Iusypiva T amp Vegerich V (2014) Dynamicsof Photosynthetic Pigments Content InWoody Plants Leaves Under

54

Assessment of Trees Vitality in the Urban Landscape of Steppe Zone

the reduction of chlorophyll content andincrease of carotenoids in the investigatedspecies is more significant In stable speciesof trees (Populus simonii P times canadensisRobinia pseudoacacia) these changes are lesscritical compared to medium-stable andnonsufficient stable species (Acerpseudoplatanus A negundo A platanoidesSyringa vulgaris and Tilia cordata)

DiscussionAs a result of our study it is found that

concentration of chlorophylls and carotenoidsin woody plants varies depending on themeteorological factors during the season andon the level of contamination of urban areasThe growth of chlorophyll content in the leavesof trees under study from May to September isestablished which is consistent with theliterature sources (Petrova et al 2017 Iusypivaamp Vegerich 2014) It is determined that themain factor influencing the chlorophyllformation is the air temperature Stable andmedium-stable species Robinia pseudoacaciaPopulus simonii Acer platanoides Populus timescanadensis Tilia cordata have the largestchlorophyll amount in drought periods As it isstated by Ballester et al (2017) fruit species oftrees also demonstrate high dependence on theformation of green pigments on the airtemperature During experiments for Rpseudoacia Tilia cordata and A platanoides directdependence on rainfall is established which isconsistent with the results of Iusypiva ampVegerich (2014) for Dnipro City in 2012 for Rрseudoacia in the leaves of which the maximumsum of chlorophylls was recorded in the monthwith the highest amount of rainfalls as wellThe established pattern indicates less adaptivecapacity of the representatives of Robinia Tiliaand Acer genera to the conditions ofhydrothermal stress

Under action of drought in the leaves ofrepresentatives of Acer genus (Swozcerna etal 2010) the chlorophyll content increaseswhich agrees with the results of ourexperiments for A pseudoplatanus when athigh temperatures and low rainfall inAugust 2013 the maximum amount of

chlorophylls in the leaves of this species wasrecorded This pattern indicates highadaptive capacity of sycamore maple in theconditions of South-East of Ukraine Anotherspecies Populus simonii is defined by a highconcentration of pigments under stressconditions at the start of vegetation period amore stable level of chlorophyll contentduring the growing season It should benoted that under the more prosperousconditions in June maximum is beingreached by chl a fraction under the stressconditions in August - due to the sharpincrease in the chl b fraction as well as it isfound out a higher relative content of chl b atthe end of the growing season The obtainedresults show that the various in stabilityspecies in urban environment differ in theratio of chl a and chl b under the action ofhydrothermal factors of different tensionsthat can be one of the part of thedemonstration of species adaptive strategy

Increase in sum of chlorophylls in Aplatanoides and A negundo in July andAugust 2012 when the amount of rainfallwas higher in 74 and 190 to the normalvalue accordingly occurred due to increasein the proportion of chlorophyll b whichplays the protective role in addition to itsmain function Chlorophyll b absorbs someof the rays expanding the range ofphotoactivity which is particularlyimportant in the conditions of considerablecloudiness in rainy weather Chlorophyll а ismore resistant to adverse environmentalfactors compared to chlorophyll b (Conzales-Dugo 2017 Bessonova et al 2006) Increasein the sum of chlorophylls during drought inAcer pseudoplatanus Populus x canadensis Psimonii Robinia pseudoacacia Syringa vulgarisat the expense of chlorophyll а indicates thenormal development of the photosyntheticapparatus of these species and their highadaptive reactions under conditions ofhydrothermal stress

The linear equations of total chlorophylland meteorological factors (falls andtemperature) for both years wereconstructed for two investigates species

52

Volodarets et al

Acer pseudoplatanus y = -51278-00258x1+04658x2 with R2 = 098 in 2012and y = -68888-00529x1+06888x2 with R2 =081 in 2013

Populus simonii y = -68888-00529x1+06888x2 with R2 = 060 in 2012and y = -12985+0058x1-03181x2 with R2 =077 in 2013 where y ndash sum of chlorophylls(mgg) x1 ndash amount of rainfall (mm) x2 ndashtemperature (ordmС)

As can be seen from the linearequations general tendency of pigmentsamount for change in the leaves despite thedifferent weather conditions remainsunchanged Linear equations obtained forAcer pseudoplatanus confirm the inverserelationship between air temperaturerainfall and sum of chlorophylls during thegrowing season in 2012

Maximum chlorophyll content in theleaves of Acer pseudoplatanus falls on hotmonths both in conditions of excessivehumidity (July 2012) and during thedrought period (August 2013) For Populussimonii the highest chlorophyll content isrecorded in June at high temperatures butvarying amount of rainfall The establishedpattern indicates high adaptive capacity ofA pseudoplatanus and Populus simonii duringthe drought

Carotenoids fulfill the protectivefunction by preventing the destruction ofchlorophyll molecules in the light in theprocess of photo-oxidation Photo-protectivefunction lies in the fact that yellow pigmentsprotect the reaction center from massiveenergy fluxes at high light intensities(Britton et al 2008 Bessonova 2006) Asshown by the results of our study insummer months the content of carotenoidsin species under study increases The highestindicators of carotenoids are found inautumn during the plantsrsquo preparation forwinter

During vegetation on the experimentalsites (ms 1 and ms 2) the content of greenpigments increases in late spring and duringsummer with the further decrease inconcentration in autumn which corresponds

to the dynamics of chlorophyll change in thecontrol According to Zayika amp Bondarenko(2018) the content of chlorophyll is reducedin the leaves of deciduous species in the areaof the western forest-steppe of Ukraine inautumn which is agreed with our results forthe southeastern steppe

Sum of chlorophylls in most species atthe monitoring sites is composed bychlorophyll a except for A platanoides and Anegundo as in control Formation ofchlorophyll b molecules is reduced becauseof inhibition of enzymes of its synthesisunder action of xenobiotics (Petrova et al2017 Bessonova et al 2015)

Covering of the question regardingchanges in carotenoids in the leaves of treesof street plantations in the literature isambiguous For example Petrova et al 2017for Acer heldreichii Boiss amp Heldr and Tiliatomentosa Moench point to the decrease incarotenoids at the contaminated sitehowever for Fraxinus excelsior ndash to growth oftheir content in the conditions of impact ofcar exhausts Reduced content of carotenoidsunder impact of car exhausts is also recordedby Joshi amp Swami (2009) Increase inconcentration of the yellow pigments underaction of car exhausts is established in thestudies of Sillanpaumlauml et al (2008) for Betulapendula Roth which may suggest differentadaptive capacity of trees and varying levelsof contamination Korshikov amp Vinogradova(2013) note the increase of carotenoids indamaged leaves of Acer pseudoplatanus andAcer platanoides under action of pollutantsfrom the work of internal combustionengines in Donetsk

According to results of our study thefunctional state of trees in street and parkplantations is worse compared to controlwhich is confirmed by the decrease inchlorophyll content and growth ofcarotenoids Carotenoid content at ms 2increases to 30 and at ms 1 ndash to 50 indicating the adaptive capacity of plantssince carotenoids possess high antioxidantpower The total number of chlorophylls isreduced by 20 to 30 in the trees of park

53

Assessment of Trees Vitality in the Urban Landscape of Steppe Zone

plantations and by 40ndash50 in the streetplantations compared to the clean site

It is to be noted that the representatives ofthe first group (stable species) such as Robiniapseudoacacia shows the exceedence of sum ofchlorophyls during the drought periode at ms1 and ms 2 At the same time the species of thesecond group (medium-stable species) forexample Syringa vulgaris decreases level ofchlorophyls content under the unfavorableurban and hydrothermal conditions as well asTilia cordata from the third (nonsufficientstable) groups decreases amount ofchlorophylls and increased carotenoid contentThe obtained predicted pain evidences theadaptive strategies of the studied species underanthropogenic and hydrothermal stress

Therefore it is found thatcontamination in the park plantations affectsthe plants which fact is confirmed bychanges in the composition of the pigmentapparatus of leaves but in street plantationsthe reduction of chlorophyll content andincrease of carotenoids in the investigatedspecies is more significant In stable treespecies (Populus simonii P times canadensisRobinia pseudoacacia) these changes are lesscritical than in less stable species (Acerpseudoplatanus A negundo A platanoidesSyringa vulgaris and Tilia cordata)

ConclusionAs a result of the study the functional

state of trees in street and parks plantationswas found to be weakened which indicatesa decrease in the content of green pigmentsand an increase in the concentration ofcarotenoids in the area of automobile vehicleexhaust The impact of hydrothermalconditions and factors of urban environmentdetermines the corresponding changes in theconcentration of photosynthetic pigments inwoody plants differentiated by vitality It isestablished among meteorological factors airtemperature as the main factor Changes inthe concentration of green pigments in theleaves of species under study depending onthe temperature and rainfall are describedby linear equations which is important for

predicting the growth and development ofplants during green building on urbanterritories in the conditions of the steppezone

References Ballester C Zarco-Tejada PJ Nicola E

Alarco JJ Fereres E Intrigliolo DSamp Gonzalez-Dugo V (2017)Evaluating the performance ofxanthophyll chlorophyll andstructure-sensitive spectral indices todetect water stress in five fruit treespecies In Precision Agric SpringerScience+Business Media New Yorkdoi 101007s11119-017-9512-y

Bessonova VP (2006) Influence of heavymetals on the photosynthesis of plantsDDAU Dnipropetrovsk (InUkrainian)

Bessonova VP Ivanchenko ОE ampPonomaryova EА (2015) Combinedimpact of heavy metals (Pb2+ and Cd2+)and salinity on the condition of Loliumperenne long-term assimilationapparatus - Vigravesnyk DnigravepropetrovskogoUnigravevercity Seria Bigraveology Ekology 23(1)15ndash20 (in Ukrainian) doi1015421011503

Glibovytska N Adamenko Ya (2017)Woody Plants Vitality of Urban Areasand Prospects of their GreeneryScientific Bulletin of North UniverdityCenter of Baia Mare Series D XXXI(1)21ndash34

Hopke PK (2009) Theory and applicationof Atmospheric source apportionmentIn Air quality and ecological impactsrelating sources to effects (pp 99ndash121)Elseiver Ltd

Iqbal MZ Shafig M Zaidi S amp Qamar AM(2015) Effect of automobile pollution onchlorophyll content of roadside urbantrees Global Journal of EnvironmentalScience Management 1(4) 283ndash296 doi107508gjesm201504003

Iusypiva T amp Vegerich V (2014) Dynamicsof Photosynthetic Pigments Content InWoody Plants Leaves Under

54

Volodarets et al

Acer pseudoplatanus y = -51278-00258x1+04658x2 with R2 = 098 in 2012and y = -68888-00529x1+06888x2 with R2 =081 in 2013

Populus simonii y = -68888-00529x1+06888x2 with R2 = 060 in 2012and y = -12985+0058x1-03181x2 with R2 =077 in 2013 where y ndash sum of chlorophylls(mgg) x1 ndash amount of rainfall (mm) x2 ndashtemperature (ordmС)

As can be seen from the linearequations general tendency of pigmentsamount for change in the leaves despite thedifferent weather conditions remainsunchanged Linear equations obtained forAcer pseudoplatanus confirm the inverserelationship between air temperaturerainfall and sum of chlorophylls during thegrowing season in 2012

Maximum chlorophyll content in theleaves of Acer pseudoplatanus falls on hotmonths both in conditions of excessivehumidity (July 2012) and during thedrought period (August 2013) For Populussimonii the highest chlorophyll content isrecorded in June at high temperatures butvarying amount of rainfall The establishedpattern indicates high adaptive capacity ofA pseudoplatanus and Populus simonii duringthe drought

Carotenoids fulfill the protectivefunction by preventing the destruction ofchlorophyll molecules in the light in theprocess of photo-oxidation Photo-protectivefunction lies in the fact that yellow pigmentsprotect the reaction center from massiveenergy fluxes at high light intensities(Britton et al 2008 Bessonova 2006) Asshown by the results of our study insummer months the content of carotenoidsin species under study increases The highestindicators of carotenoids are found inautumn during the plantsrsquo preparation forwinter

During vegetation on the experimentalsites (ms 1 and ms 2) the content of greenpigments increases in late spring and duringsummer with the further decrease inconcentration in autumn which corresponds

to the dynamics of chlorophyll change in thecontrol According to Zayika amp Bondarenko(2018) the content of chlorophyll is reducedin the leaves of deciduous species in the areaof the western forest-steppe of Ukraine inautumn which is agreed with our results forthe southeastern steppe

Sum of chlorophylls in most species atthe monitoring sites is composed bychlorophyll a except for A platanoides and Anegundo as in control Formation ofchlorophyll b molecules is reduced becauseof inhibition of enzymes of its synthesisunder action of xenobiotics (Petrova et al2017 Bessonova et al 2015)

Covering of the question regardingchanges in carotenoids in the leaves of treesof street plantations in the literature isambiguous For example Petrova et al 2017for Acer heldreichii Boiss amp Heldr and Tiliatomentosa Moench point to the decrease incarotenoids at the contaminated sitehowever for Fraxinus excelsior ndash to growth oftheir content in the conditions of impact ofcar exhausts Reduced content of carotenoidsunder impact of car exhausts is also recordedby Joshi amp Swami (2009) Increase inconcentration of the yellow pigments underaction of car exhausts is established in thestudies of Sillanpaumlauml et al (2008) for Betulapendula Roth which may suggest differentadaptive capacity of trees and varying levelsof contamination Korshikov amp Vinogradova(2013) note the increase of carotenoids indamaged leaves of Acer pseudoplatanus andAcer platanoides under action of pollutantsfrom the work of internal combustionengines in Donetsk

According to results of our study thefunctional state of trees in street and parkplantations is worse compared to controlwhich is confirmed by the decrease inchlorophyll content and growth ofcarotenoids Carotenoid content at ms 2increases to 30 and at ms 1 ndash to 50 indicating the adaptive capacity of plantssince carotenoids possess high antioxidantpower The total number of chlorophylls isreduced by 20 to 30 in the trees of park

53

Assessment of Trees Vitality in the Urban Landscape of Steppe Zone

plantations and by 40ndash50 in the streetplantations compared to the clean site

It is to be noted that the representatives ofthe first group (stable species) such as Robiniapseudoacacia shows the exceedence of sum ofchlorophyls during the drought periode at ms1 and ms 2 At the same time the species of thesecond group (medium-stable species) forexample Syringa vulgaris decreases level ofchlorophyls content under the unfavorableurban and hydrothermal conditions as well asTilia cordata from the third (nonsufficientstable) groups decreases amount ofchlorophylls and increased carotenoid contentThe obtained predicted pain evidences theadaptive strategies of the studied species underanthropogenic and hydrothermal stress

Therefore it is found thatcontamination in the park plantations affectsthe plants which fact is confirmed bychanges in the composition of the pigmentapparatus of leaves but in street plantationsthe reduction of chlorophyll content andincrease of carotenoids in the investigatedspecies is more significant In stable treespecies (Populus simonii P times canadensisRobinia pseudoacacia) these changes are lesscritical than in less stable species (Acerpseudoplatanus A negundo A platanoidesSyringa vulgaris and Tilia cordata)

ConclusionAs a result of the study the functional

state of trees in street and parks plantationswas found to be weakened which indicatesa decrease in the content of green pigmentsand an increase in the concentration ofcarotenoids in the area of automobile vehicleexhaust The impact of hydrothermalconditions and factors of urban environmentdetermines the corresponding changes in theconcentration of photosynthetic pigments inwoody plants differentiated by vitality It isestablished among meteorological factors airtemperature as the main factor Changes inthe concentration of green pigments in theleaves of species under study depending onthe temperature and rainfall are describedby linear equations which is important for

predicting the growth and development ofplants during green building on urbanterritories in the conditions of the steppezone

References Ballester C Zarco-Tejada PJ Nicola E

Alarco JJ Fereres E Intrigliolo DSamp Gonzalez-Dugo V (2017)Evaluating the performance ofxanthophyll chlorophyll andstructure-sensitive spectral indices todetect water stress in five fruit treespecies In Precision Agric SpringerScience+Business Media New Yorkdoi 101007s11119-017-9512-y

Bessonova VP (2006) Influence of heavymetals on the photosynthesis of plantsDDAU Dnipropetrovsk (InUkrainian)

Bessonova VP Ivanchenko ОE ampPonomaryova EА (2015) Combinedimpact of heavy metals (Pb2+ and Cd2+)and salinity on the condition of Loliumperenne long-term assimilationapparatus - Vigravesnyk DnigravepropetrovskogoUnigravevercity Seria Bigraveology Ekology 23(1)15ndash20 (in Ukrainian) doi1015421011503

Glibovytska N Adamenko Ya (2017)Woody Plants Vitality of Urban Areasand Prospects of their GreeneryScientific Bulletin of North UniverdityCenter of Baia Mare Series D XXXI(1)21ndash34

Hopke PK (2009) Theory and applicationof Atmospheric source apportionmentIn Air quality and ecological impactsrelating sources to effects (pp 99ndash121)Elseiver Ltd

Iqbal MZ Shafig M Zaidi S amp Qamar AM(2015) Effect of automobile pollution onchlorophyll content of roadside urbantrees Global Journal of EnvironmentalScience Management 1(4) 283ndash296 doi107508gjesm201504003

Iusypiva T amp Vegerich V (2014) Dynamicsof Photosynthetic Pigments Content InWoody Plants Leaves Under

54

Assessment of Trees Vitality in the Urban Landscape of Steppe Zone

plantations and by 40ndash50 in the streetplantations compared to the clean site

It is to be noted that the representatives ofthe first group (stable species) such as Robiniapseudoacacia shows the exceedence of sum ofchlorophyls during the drought periode at ms1 and ms 2 At the same time the species of thesecond group (medium-stable species) forexample Syringa vulgaris decreases level ofchlorophyls content under the unfavorableurban and hydrothermal conditions as well asTilia cordata from the third (nonsufficientstable) groups decreases amount ofchlorophylls and increased carotenoid contentThe obtained predicted pain evidences theadaptive strategies of the studied species underanthropogenic and hydrothermal stress

Therefore it is found thatcontamination in the park plantations affectsthe plants which fact is confirmed bychanges in the composition of the pigmentapparatus of leaves but in street plantationsthe reduction of chlorophyll content andincrease of carotenoids in the investigatedspecies is more significant In stable treespecies (Populus simonii P times canadensisRobinia pseudoacacia) these changes are lesscritical than in less stable species (Acerpseudoplatanus A negundo A platanoidesSyringa vulgaris and Tilia cordata)

ConclusionAs a result of the study the functional

state of trees in street and parks plantationswas found to be weakened which indicatesa decrease in the content of green pigmentsand an increase in the concentration ofcarotenoids in the area of automobile vehicleexhaust The impact of hydrothermalconditions and factors of urban environmentdetermines the corresponding changes in theconcentration of photosynthetic pigments inwoody plants differentiated by vitality It isestablished among meteorological factors airtemperature as the main factor Changes inthe concentration of green pigments in theleaves of species under study depending onthe temperature and rainfall are describedby linear equations which is important for

predicting the growth and development ofplants during green building on urbanterritories in the conditions of the steppezone

References Ballester C Zarco-Tejada PJ Nicola E

Alarco JJ Fereres E Intrigliolo DSamp Gonzalez-Dugo V (2017)Evaluating the performance ofxanthophyll chlorophyll andstructure-sensitive spectral indices todetect water stress in five fruit treespecies In Precision Agric SpringerScience+Business Media New Yorkdoi 101007s11119-017-9512-y

Bessonova VP (2006) Influence of heavymetals on the photosynthesis of plantsDDAU Dnipropetrovsk (InUkrainian)

Bessonova VP Ivanchenko ОE ampPonomaryova EА (2015) Combinedimpact of heavy metals (Pb2+ and Cd2+)and salinity on the condition of Loliumperenne long-term assimilationapparatus - Vigravesnyk DnigravepropetrovskogoUnigravevercity Seria Bigraveology Ekology 23(1)15ndash20 (in Ukrainian) doi1015421011503

Glibovytska N Adamenko Ya (2017)Woody Plants Vitality of Urban Areasand Prospects of their GreeneryScientific Bulletin of North UniverdityCenter of Baia Mare Series D XXXI(1)21ndash34

Hopke PK (2009) Theory and applicationof Atmospheric source apportionmentIn Air quality and ecological impactsrelating sources to effects (pp 99ndash121)Elseiver Ltd

Iqbal MZ Shafig M Zaidi S amp Qamar AM(2015) Effect of automobile pollution onchlorophyll content of roadside urbantrees Global Journal of EnvironmentalScience Management 1(4) 283ndash296 doi107508gjesm201504003

Iusypiva T amp Vegerich V (2014) Dynamicsof Photosynthetic Pigments Content InWoody Plants Leaves Under

54

Volodarets et al

Technogenic Growth Conditions)Visnyk of the Lviv University SeriesBiology 65 189ndash196 (in Ukrainian)

Johnstone D Moore G Tausz M ampNicolas M (2013) The measurementof plant vitality in landscape treesArboricultural Journal The InternationalJournal of Urban Forestry 35(1) 18ndash27doi 101080030713752013783746

Joshi PC amp Swami A (2009) Air pollutioninduced changes in the photosyntheticpigments of selected plant speciesJournal of Environmental Biology 30(2)295ndash298

Korshikov II amp Vinogradova EN (2005)Variation of physiological andbiochemical indices of Acer platanoidesL and Acer pseudoplatanus L leavesfrom the trees differing in tolerance toexhaust gases in stands along ahighway Industrial botany 5 75ndash84 (inUkrainian)

Korshikov II amp Krasnoshtan OV (2012)Vitality of woody plants at Krivorozhyairon-ore dumps Donetsk Ukraine (inUkrainian)

Morgenroth J amp Oumlstberg J (2017) Measuringand Monitoring urban trees and urbanforests ndash In Ferrini F et al (Eds)Routledge Handbook of Urban Forestry doi1043249781315627106ch3

Nowak DJ Crane DE amp Stevens JC(2006) Air pollution removal by urbantrees and shrubs in the United StatesUrban Forestry amp Urban Greening 4115ndash123

Palau JL Krupa SV Calatayud V SanzM amp Millan M (2009) Relating source-specific atmospheric sulfur dioxideinputs to ecological effects assessmentin a complex terrain In Air quality andecological impacts relating sources toeffects (pp 99ndash121) Elseiver Ltd

Petrova S Todorova K Dakova MMehmed E Nikolov B Denev IStratiev M Georgiev G Delchev AStamenov S Firkova L Gesheva NKadirova D amp Velcheva I (2017)Photosynthetic Pigments as

ParametersIndicators of TreeTolerance to Urban Environment(Plovdiv Bulgaria) Ecologia Balkanica9(1) 53ndash62

Petrova ST Yurukova LD amp VelchevaIG (2014) Assessment of the urbantrees health status on the base ofnutrient and pigment content in theirleaves Journal of BioScienceBiotechnology 3(1) 69 ndash77

Polyakov AK Suslova EP amp NezvetovMV (2012) Dendroflora of urbanterritories of Donbass) Vesti Biosherezapvidnika ldquoAskania-Novardquo 14 397ndash399(in Ukrainian)

Savelieva LS (1975) Tolerance of trees andshrubs in protective tree plantationsLesnaya Promyshlennost Moscow (inRussian)

Shlyk АА (1975) Biochemical methods inthe plants physiology NaukaMoscow (In Russian)

Spellerberg IF (1998) Ecological Effects ofRoads and Traffic A LiteratureReview Global Ecology andBiogeography Letters 5 317-333

StatSoft Inc 2011 STATISTICA (Dataanalysis software system) Vers 10Computer software Retrieved fromstatsoftru

Suslova E Polyakov A amp Kharkhota L(2013) Monitoring of woody plants inthe park stands of the industrial citiesin the south-east of Ukraine Biologija59(3) 271ndash278 (in Russian)

Swoczyna T Kalaji HM Pietkiewicz SBorowski J amp Zara-Januszkiewicz E(2010) Photosynthetic apparatusefficiency of eight tree taxa as anindicator of their tolerance to urbanenvironments Dendrobiology 63 65-75

Tripathi A Tivari TB amp Mahima SD(2009) Assessment of air pollutiontolerance index of some trees inMorabad city India Journal ofEnvironmental Biology 30(4) 545ndash550

Uhrin P amp Supuka J (2016) QualityAssessment of Urban Trees UsingGrowth Visual And Chlorophyll

55

Assessment of Trees Vitality in the Urban Landscape of Steppe Zone

Fluorescence Indicators Ekoloacutegia(Bratislava) 35(2) 160-172 doi101515eko-2016-0013

Ukrainian hydrometeorological center(2020) Retrieved from meteogovua

Zayika V amp Bondarenko T (2018) Thecontent of chlorophyll a andchlorophyll b in leaves of undergrowthspecies in hornbeam-oak forest standsof the forest-steppe zone in WesternUkraine Leśne Prace Badawcze 79(1)23ndash28 doi 102478frp-2018-0003

Zhang K Wen Z amp Du Bin SG (2007) AMultiple-Indicators Approach toMonitoring Urban Sustainable

Development In MM Carreiro SYong-Chang J Wu (Eds) EcologyPlanning and Management of UrbanForests International Perspective (pp35-39) USA SpringerScience+Business Media LLC

Received 02032020Accepted 15042020

56