Research Article Distribution Characteristic of Soil

Research ArticleDistribution Characteristic of Soil Organic Carbon Fraction inDifferent Types of Wetland in Hongze Lake of China

Yan Lu12 and Hongwen Xu1

1 School of Urban and Environmental Science Huaiyin Normal University Huairsquoan 223300 China2 Jiangsu Key Laboratory for Eco-Agricultural Biotechnology around Hongze Lake Huairsquoan 223300 China

Correspondence should be addressed to Hongwen Xu hongwen xu163com

Received 10 May 2014 Accepted 13 May 2014 Published 22 May 2014

Academic Editor Hongbo Shao

Copyright copy 2014 Y Lu and H Xu This is an open access article distributed under the Creative Commons Attribution Licensewhich permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited

Soil organic carbon fractions included microbial biomass carbon (MBC) dissolved organic carbon (DOC) and labile organiccarbon (LOC) which was investigated over a 0ndash20 cm depth profile in three types of wetland in Hongze Lake of China Theirecoenvironmental effect and the relationships with soil organic carbon (SOC) were analyzed in present experiment The resultsshowed that both active and SOC contents were in order reduced by estuarinewetland flood plain and out-of-lakewetland Pearsoncorrelative analysis indicated that MBC and DOC were positively related to SOC The lowest ratios of MBC and DOC to SOC inthe estuarine wetland suggested that the turnover rate of microbial active carbon pool was fairly low in this kind of wetland Ourresults showed that estuarine wetland had a strong carbon sink function which played important role in reducing greenhouse gasemissions besides changes of water condition might affect the accumulation and decomposition of organic carbon in the wetlandsoils

1 Introduction

Wetland played a key role in the global cycles of carbonwhich had important function in the global carbon balanceand climate change mitigation [1ndash3] Carbon cycle processin different types of wetland could provide basis for furtherunderstanding of the mechanism of carbon sources andsinks in terrestrial ecosystem [4ndash6] Decrease of carbonstorage and vegetation biomass in wetland soils might releasemore carbon into atmosphere thus causing the increase ofatmospheric carbon dioxide concentration [7ndash10] Mean-while global warming could accelerate decomposition ofsoil organic matter and release of carbon into atmospherewhich would further strengthen the trend of global warming[11 12] Original alteration in soil organic carbon pool ofwetland occurred mainly on the part easily to be decom-posed and mineralized that is activated carbon [13] Soilactivated carbon was referred to the part of the organiccarbon with poor stability and higher activity for plantsand soil microorganisms [14] Soil microbial biomass carbon(MBC) and dissolved organic carbon (DOC) were importantcharacteristic indicators for expressing the activity of active

soil organic carbon pool [15] Although active organic carbonwas just a very small part of total carbon its sizes andturnover rates were of great importance to the content andrecycling of soil available nutrients and it was directly relatedto greenhouse gas emissions [16] Therefore exploring thechanges of soil active organic carbon in different types ofwetland was helpful in achieving deep understanding ofthe characteristics of wetland soil organic carbon and theresponse to climate change

Hongze Lake (33∘061015840Nsim33∘401015840N 118∘101015840Esim118∘551015840E) isthe fourth largest fresh water lake in China It is locatedin the northwest of Jiangsu province and its water area is1597 km2 The lake and the surrounding area have composeda relatively intact inland wetland as typical lake wetlandof China Differences might exist in soil carbon pool dueto various hydrological conditions and vegetation for kindsof wetland Although researches on soil carbon in wetlandhave beenwell documented limited systematic investigationsfocus on different types of natural lakes wetland soil carbonand their ecological environment effect In order to study thedistribution characteristics of different types of wetland soilactive organic carbon about Hongze Lake Wetland MBC

Hindawi Publishing Corporatione Scientific World JournalVolume 2014 Article ID 487961 5 pageshttpdxdoiorg1011552014487961

2 The Scientific World Journal

Estuarine wetland Flood plain0

30

60

90

120

150

180

SOC

(gmiddotk

gminus1)

Out-of-lake wetland

Figure 1 Changes of SOC content under different types of wetlandin Hongze Lake of China

soluble organic carbon (SOC) DOC labile organic carbon(LOC) and their ecological environment effects were studiedin the present experiment

The objective of this research was to study the role whichdifferent types of wetland soil active organic carbon played inthe biogeochemical cycle and thereby to provide a theoreticalbasis for a good deal of insight into biogeochemical cyclemechanism of wetland soil carbon

2 Material and Methods

21 Experimental Design The experimental site is locatedat Hongze Lake China Three sample plots were selectedin south east and west bank of Hongze Lake Wetland(representing Estuary wetland flood plain and out of lakewetland separately)The research sample point of three typesof wetlands was chosen in the middle of April 2012 andthe indicators related to surface vegetation distribution andhydrological conditions were observed and recorded Soilof 0ndash20 cm depth was collected into a sterile bag by usingthe multipoint-mix-sampling method the soil samples weretaken back to the laboratory quickly and divided into twoparts One part was refrigerated under 4∘C which was usedto measure soil water content DOC andMBC Another partof the soil sample was just put in the air and taken through a025mm sieve after being dried and grinded The latter partwas applied to the analysis of SOC and LOC

22 Measurements Soil organic carbon was determined bytaking potassium dichromate volumetric method MBC wasmeasured using chloroform fumigation-K

2SO4extraction

method TOC instrument was used to determine DOCconcentration Content of LOC estimation was performedaccording to the method of potassium permanganate oxida-tion

23 Data Analysis The data was analyzed by one-way anal-ysis of variance (ANOVA) followed by Duncanrsquos test at 005


500

1000

1500

2000

2500

MBC

(m

gmiddotkg

minus1)

Out-of-lake wetland

Figure 2 Changes ofMBC content under different types of wetlandin Hongze Lake of China

significance level to compare the means using SPSS 160 forWindows

3 Results

31 Distribution Characteristics of Soluble Organic CarbonSoil was considered as a carbon source and sink if organicmatter content in soil reduced by one percent atmosphericCO2concentration would increase by 5mgsdotmminus3 The differ-

ence between soil texture and number of vegetation typeswould lead to variety of input and output of organic matterand causing differences in SOC content Figure 1 showedthe change trend of SOC content at 0ndash20 cm depth in threekinds of typical natural wetlands It also could be seen thatthe SOC content in the estuary wetland had the peak valuewith 16167 gsdotkgminus1 which was significantly higher than thatof two other types of wetlands SOC content of wetland soildepended largely on the circulation and decomposition rateof vegetation annually Estuary wetland was under floodedcondition all the year round resulting in the slow decompo-sition of organic residue which caused accumulating of SOCA seasonal depletion that occurred in flood plain aerobicmicroorganisms and soil enzyme hydrolysis could bringabout higher decomposition of organic matter than estuarinewetland when it was not flooding [17] However ventilationcondition in flood plain was relatively poor compared without-of-lake wetlandTherefore the organic carbon content offlood plain was fairly higher than the latter

32 Distribution Characteristics of Microbial Biomass CarbonMBC was referred to the internal carbon in live bacteriafungi algae and soil animals whose volume was less than 5ndash105 120583m3 it accounted for only a small portion of total carbonin soil however it was the most active section in soil organicmatter [18] Besides it was taken on as the main driving forcefor decomposition of nutrient pool [19ndash21] As an importantsource of soil nutrients it correlated closely with cycling ofthe nutrients such as C N P and S [22] Changes of MBC

The Scientific World Journal 3


300

600

900

DO

C(m

gmiddotkg

minus1) 1200

1500

1800

Out-of-lake wetland

Figure 3 Changes of DOC content under different types of wetlandin Hongze Lake of China

were in accordance with SOC and significant difference ofMBC content in soil of three different types of wetland wasfound in present experiment (Figure 2) (119875 lt 001) Positiverelationship was found between soil MBC content and SOCcontent of three kinds of wetland (119903 = 0823 119875 lt 005)The ratio ofMBC and SOC reflected the conversion efficiencyfrom the organic matter into MBC which could imply theturnover rate of biologically active soil organic carbon poolThe specific value of MBCSOC of estuary wetland floodplain and out-of-lake wetland was 128 212 and 16which suggested that flooded condition could inhibit aerobicmicrobial activity

33 Distribution Characteristics of Dissolved Organic CarbonDOCmainly originated from the recent humus of plant litterand soil organic matter which included a series of organicmatter from simple organic acids to the complex of macro-molecular substances such as humic acid and fulvic acid[23ndash25] And it was taken as organic carbon source directedusing for soil microbes and affecting the transformationmigration and degradation of soil organics and inorganics[26ndash28] The formation migration and transformation ofDOC in the wetland had important influence on soil carbonflux [29] Similar changing trend in DOC and MBC in 0ndash20 cm of soil appeared in Figure 3 and ANOVA analysisshowed that the DOC content of estuarine wetland wassignificantly higher than that of flood plain and out-of-lakewetland (119875 lt 001) This was due to the flooded condition ofestuary wetland which could improve the dissolution of soilorganic carbon and the dispersion of soil aggregate [30 31]Pearson correlation suggested that it was significantly andpositively related toDOCand SOCof the three different typesof wetland soil (119903 = 0872 119875 lt 001) which indicated thatSOC was the main source of DOCThe ratio of DOC to SOCof estuary wetland flood plain and out-of-lake wetland was009 119 and 112 individually The lowest proportionthat occurred in estuarine wetland would declare the lower

Estuarine wetland Flood plain Out-of-lake wetland0

10000

20000

30000

40000

50000

LOC

(mgmiddot

kgminus

1)

Figure 4 Changes of LOC content under different types of wetlandin Hongze Lake of China

turnover rate of biological active soil organic carbon pool inestuary wetland

34 Distribution Characteristics of Labile Organic CarbonSoil LOC content and the ratio of LOC to SOC were theindexes to reflect the stability of soil carbon And the twoindexes of estuarine wetland soil were significantly higherthan that of flood plain and out-of-lake wetland (Figure 4)Positively significant correlation between LOC and SOCin different types of wetland soil was found in presentexperiment (119903 = 0952 119875 lt 001) thus the quantity ofSOC could determine the abundance of LOC The higherthe proportion of LOCSOC was the worse the stabilitywas Special hydrological conditions of wetland would makethe anaerobic environment when hydrological conditionschanged fromanaerobic into aerobic environment huge LOCwould be decomposed and consumed by microbes [32 33]

4 Conclusions

From this study we concluded that estuarine wetland hadfairly important environmental function in the greenhousegas emissions reduction and the climate change mitigationAnd we supported the speculation that variation in watercondition would have a real impact on the accumulation anddecomposition of organic carbon in the wetland soils

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

Acknowledgments

This work was supported by the National Natural ScienceFoundation of China (41201559 41301314) and the NaturalScience Foundation of Jiangsu province (BK2011412)


References

[1] N Saintilan K Rogers D Mazumder and C WoodroffeldquoAllochthonous and autochthonous contributions to carbonaccumulation and carbon store in southeastern Australiancoastal wetlands Estuarinerdquo Coastal and Shelf Science vol 128no 10 pp 84ndash92 2014

[2] J Q Gao G C Lei X W Zhang and G X Wang ldquoCan 12057513Cabundance water-soluble carbon and light fraction carbon bepotential indicators of soil organic carbon dynamics in Zoigewetlandrdquo Catena vol 119 no 8 pp 21ndash27 2014

[3] M Liu Z J ZhangQHeHWang andX Li ldquoJonathan SchoerExogenous phosphorus inputs alter complexity of soil-dissolvedorganic carbon in agricultural riparianwetlandsrdquoChemospherevol 95 pp 572ndash580 2014

[4] A C Barbera M Borin A Ioppolo G L Cirelli and CMaucieri ldquoCarbon dioxide emissions from horizontal sub-surface constructed wetlands in the Mediterranean BasinrdquoEcological Engineering vol 64 no 3 pp 57ndash61 2014

[5] W Yang H Zhao X L Chen S L Yin X Y Chen and S QAn ldquoConsequences of short-term C

4

plant Spartina alterniflorainvasions for soil organic carbon dynamics in a coastal wetlandof Eastern Chinardquo Ecological Engineering A vol 61 no 12 pp50ndash57 2013

[6] J Wang C Song X Wang and Y Song ldquoChanges in labilesoil organic carbon fractions in wetland ecosystems along alatitudinal gradient inNortheast ChinardquoCatena vol 96 pp 83ndash89 2012

[7] Q S Lu Z Q Gao Z H Zhao J C Ning and X L BildquoDynamics of wetlands and their effects on carbon emissionsin China coastal regionmdashcase study in Bohai Economic RimrdquoOcean amp Coastal Management vol 87 no 1 pp 61ndash67 2014

[8] L Huo Z Chen Y Zou X Lu J Guo and X Tang ldquoEffect ofZoige alpine wetland degradation on the density and fractionsof soil organic carbonrdquo Ecological Engineering vol 51 pp 287ndash295 2013

[9] X Yang W Ren B Sun and S Zhang ldquoEffects of contrastingsoil management regimes on total and labile soil organic carbonfractions in a loess soil in Chinardquo Geoderma vol 177-178 pp49ndash56 2012

[10] J Beringer S J Livesley J Randle and L B Hutley ldquoCarbondioxide fluxes dominate the greenhouse gas exchanges of aseasonal wetland in the wet-dry tropics of northern AustraliardquoAgricultural and ForestMeteorology vol 182-183 no 12 pp 239ndash247 2013

[11] D S Jenkinson D E Adams and A Wild ldquoModel estimatesof CO

2

emissions from soil in response to global warmingrdquoNature vol 351 no 6324 pp 304ndash306 1991

[12] L X Yang and J J Pan ldquoProgress in the study of measurementsof soil active organic carbon poolrdquo Chinese Journal of SoilScience vol 35 no 4 pp 502ndash506 2004 (Chinese)

[13] J Q Gao H Ouyang and J H Bai ldquoVertical distribution char-acteristics of soil labile organic carbon in Ruoergai wetlandrdquoJournal of Soil and Water Conservation vol 20 no 1 pp 76ndash79 2006 (Chinese)

[14] H Shen Z Y Cao and Z Y Hu ldquoCharacteristics and ecologicaleffects of the active organic carbon in soilrdquo Chinese Journal ofEcology vol 18 no 3 pp 32ndash38 1999 (Chinese)

[15] B C Liang M Schnitzer C M Monreal A F MacKenzie PR Voroney and R P Beyaert ldquoManagement-induced changein labile soil organic matter under continuous corn in eastern

Canadian soilsrdquo Biology and Fertility of Soils vol 26 no 2 pp88ndash94 1998

[16] J ZNi JM Xu andZMXie ldquoThe size and characterization ofbiologically active organic carbon pool in soilsrdquo Plant Nutritionand Fertilizer Science vol 7 no 1 pp 56ndash63 2001 (Chinese)

[17] Q Liang R T Gao B D Xi Y Zhang and H Zhang ldquoLong-term effects of irrigation using water from the river receivingtreated industrial wastewater on soil organic carbon fractionsand enzyme activitiesrdquo Agricultural Water Management vol135 no 3 pp 100ndash108 2014

[18] T H Anderson and K H Domsch ldquoApplication of eco-physiological quotients (qCO

2

and qD) onmicrobial biomassesfrom soils of different cropping historiesrdquo Soil Biology andBiochemistry vol 22 no 2 pp 251ndash255 1990

[19] Z H Shang Q S Feng G L Wu G H Ren and R J LongldquoGrasslandification has significant impacts on soil carbonnitrogen and phosphorus of alpine wetlands on the TibetanPlateaurdquo Ecological Engineering vol 58 no 2 pp 170ndash179 2013

[20] X Wang C Song X Sun J Wang X Zhang and R MaoldquoSoil carbon andnitrogen acrosswetland types in discontinuouspermafrost zone of the Xiao Xingrsquoan Mountains northeasternChinardquo Catena vol 101 pp 31ndash37 2013

[21] X Ye A J Wang and J Chen ldquoTemporal-spatial variation andsource analysis of carbon and nitrogen in a tidal wetland ofLuoyuan Bayrdquo Acta Ecologica Sinica vol 33 no 3 pp 150ndash1572013

[22] Y Lu H W Xu and C C Song ldquoEffects of plants on N2

Oemission in freshwater marsh ecosystemrdquo Journal of FoodAgriculture and Environment vol 10 no 1 pp 662ndash666 2012

[23] C Mu H Lu B Wang X Bao and W Cui ldquoShort-term effectsof harvesting on carbon storage of boreal Larix gmelinii-Carexschmidtii forested wetlands in Daxingrsquoanling northeast ChinardquoForest Ecology and Management vol 293 no 4 pp 140ndash1482013

[24] H Wu D P Batzer X Yan X Lu and D Wu ldquoContributionsof ant mounds to soil carbon and nitrogen pools in a marshwetland of Northeastern Chinardquo Applied Soil Ecology vol 70pp 9ndash15 2013

[25] J N Sun B C Wang G Xu and H B Shao ldquoEffects ofwheat straw biochar on carbon mineralization and guidancefor large-scale soil quality improvement in the coastal wetlandrdquoEcological Engineering vol 62 no 1 pp 43ndash47 2014

[26] J R Burford and J M Bremner ldquoRelationships between thedenitrification capacities of soils and total water-soluble andreadily decomposable soil organic matterrdquo Soil Biology andBiochemistry vol 7 no 6 pp 389ndash394 1975

[27] J Z Ni J M Xu and Z M Xie ldquoAdvances in soil water-solubleorganic carbon researchrdquo Ecology and Environment vol 12 no1 pp 71ndash75 2003 (Chinese)

[28] M M Wander S J Traina B R Stinner and S E PetersldquoOrganic and conventional management effects on biologicallyactive soil organic matter poolsrdquo Soil Science Society of AmericaJournal vol 58 no 4 pp 1130ndash1139 1994

[29] C C Song Y Y Wang and B X Yan ldquoThe changes of the soilhydrothermal condition and the dynamics of CN after themiretillagerdquo Environmental Science vol 25 no 3 pp 168ndash172 2004(Chinese)

[30] Z P Li T L Zhang and B Y Chen ldquoDynamics of solubleorganic carbon and its relation to mineralization of soil organiccarbonrdquoActa Pedologica Sinica vol 41 no 4 pp 544ndash552 2004(Chinese)


[31] A O Olaleye T Nkheloane R Mating et al ldquoWetlands inKhalong-la-Lithunya catchment in Lesotho soil organic carboncontents vegetation isotopic signatures and hydrochemistryrdquoCatena vol 115 no 4 pp 71ndash78 2014

[32] Y Zhang Y Li L Wang et al ldquoSoil microbiological variabilityunder different successional stages of the Chongming Dongtanwetland and its effect on soil organic carbon storagerdquo EcologicalEngineering vol 52 pp 308ndash315 2013

[33] Y Hu L Wang Y S Tang et al ldquoVariability in soil microbialcommunity and activity between coastal and riparian wetlandsin the Yangtze River estuary-Potential impacts on carbonsequestrationrdquo Soil Biology and Biochemistry vol 70 no 1 pp221ndash228 2014

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

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BioinformaticsAdvances in

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Signal TransductionJournal of


BioMed Research International

Evolutionary BiologyInternational Journal of



Biochemistry Research International

ArchaeaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014


Genetics Research International


Advances in

Virolog y

Hindawi Publishing Corporationhttpwwwhindawicom

Nucleic AcidsJournal of

Volume 2014

Stem CellsInternational



Enzyme Research



Microbiology



30

60

90

120

150

180

SOC

(gmiddotk

gminus1)

Out-of-lake wetland

Figure 1 Changes of SOC content under different types of wetlandin Hongze Lake of China

soluble organic carbon (SOC) DOC labile organic carbon(LOC) and their ecological environment effects were studiedin the present experiment

The objective of this research was to study the role whichdifferent types of wetland soil active organic carbon played inthe biogeochemical cycle and thereby to provide a theoreticalbasis for a good deal of insight into biogeochemical cyclemechanism of wetland soil carbon

2 Material and Methods

21 Experimental Design The experimental site is locatedat Hongze Lake China Three sample plots were selectedin south east and west bank of Hongze Lake Wetland(representing Estuary wetland flood plain and out of lakewetland separately)The research sample point of three typesof wetlands was chosen in the middle of April 2012 andthe indicators related to surface vegetation distribution andhydrological conditions were observed and recorded Soilof 0ndash20 cm depth was collected into a sterile bag by usingthe multipoint-mix-sampling method the soil samples weretaken back to the laboratory quickly and divided into twoparts One part was refrigerated under 4∘C which was usedto measure soil water content DOC andMBC Another partof the soil sample was just put in the air and taken through a025mm sieve after being dried and grinded The latter partwas applied to the analysis of SOC and LOC

22 Measurements Soil organic carbon was determined bytaking potassium dichromate volumetric method MBC wasmeasured using chloroform fumigation-K

2SO4extraction

method TOC instrument was used to determine DOCconcentration Content of LOC estimation was performedaccording to the method of potassium permanganate oxida-tion

23 Data Analysis The data was analyzed by one-way anal-ysis of variance (ANOVA) followed by Duncanrsquos test at 005


500

1000

1500

2000

2500

MBC

(m

gmiddotkg

minus1)

Out-of-lake wetland

Figure 2 Changes ofMBC content under different types of wetlandin Hongze Lake of China

significance level to compare the means using SPSS 160 forWindows

3 Results

31 Distribution Characteristics of Soluble Organic CarbonSoil was considered as a carbon source and sink if organicmatter content in soil reduced by one percent atmosphericCO2concentration would increase by 5mgsdotmminus3 The differ-

ence between soil texture and number of vegetation typeswould lead to variety of input and output of organic matterand causing differences in SOC content Figure 1 showedthe change trend of SOC content at 0ndash20 cm depth in threekinds of typical natural wetlands It also could be seen thatthe SOC content in the estuary wetland had the peak valuewith 16167 gsdotkgminus1 which was significantly higher than thatof two other types of wetlands SOC content of wetland soildepended largely on the circulation and decomposition rateof vegetation annually Estuary wetland was under floodedcondition all the year round resulting in the slow decompo-sition of organic residue which caused accumulating of SOCA seasonal depletion that occurred in flood plain aerobicmicroorganisms and soil enzyme hydrolysis could bringabout higher decomposition of organic matter than estuarinewetland when it was not flooding [17] However ventilationcondition in flood plain was relatively poor compared without-of-lake wetlandTherefore the organic carbon content offlood plain was fairly higher than the latter

32 Distribution Characteristics of Microbial Biomass CarbonMBC was referred to the internal carbon in live bacteriafungi algae and soil animals whose volume was less than 5ndash105 120583m3 it accounted for only a small portion of total carbonin soil however it was the most active section in soil organicmatter [18] Besides it was taken on as the main driving forcefor decomposition of nutrient pool [19ndash21] As an importantsource of soil nutrients it correlated closely with cycling ofthe nutrients such as C N P and S [22] Changes of MBC



300

600

900

DO

C(m

gmiddotkg

minus1) 1200

1500

1800

Out-of-lake wetland





10000

20000

30000

40000

50000

LOC

(mgmiddot

kgminus

1)




4 Conclusions




Acknowledgments



References






4








2










2


























Volume 2014

Zoology






















Advances in

Virolog y



Volume 2014




Enzyme Research



Microbiology



300

600

900

DO

C(m

gmiddotkg

minus1) 1200

1500

1800

Out-of-lake wetland





10000

20000

30000

40000

50000

LOC

(mgmiddot

kgminus

1)




4 Conclusions




Acknowledgments



References






4








2










2


























Volume 2014

Zoology






















Advances in

Virolog y



Volume 2014




Enzyme Research



Microbiology


References






4








2










2


























Volume 2014

Zoology






















Advances in

Virolog y



Volume 2014




Enzyme Research



Microbiology












Volume 2014

Zoology






















Advances in

Virolog y



Volume 2014




Enzyme Research



Microbiology








Volume 2014

Zoology






















Advances in

Virolog y



Volume 2014




Enzyme Research



Microbiology

Documents

Research Article Distribution Characteristic of Soil