Eugeniusz Moczydłowski, Ewa Piroznikow University of Warsaw Brench in Białystok, Poland

XX Polar Symposium Lublin, 1993

THE TEMPERATURES IN THE PLANT COMMUNITIES OF THE ARIEKAMMEN-FUGLEBERGET CATCHMENT AREA (WEST SPITSBERGEN)

INTRODUCTION

The plant cover of the Ariekammen-Fugleberget catchment area is composed of plant communities typical for this region of the Arctic (Godzik 1987). The influence of biotic factors on the distribution of plant communities in this area has been recently investigated (Klekowski and Opaliński 1986). However, research has not been conducted on the relationship between abiotic environ-mental stressors and plant distribution. General elaborations of climatic and hydrological conditions of the Hornsund region make up the works of Baranowski (1968), (1975), Baranowski and Głowicki (1975), Rodzik and Stępko (1985), Głowicki (1985, 1985a), Miętus (1988), (1991), Wielbińska and Skrzypczak (1988), Angiel (1990). In the polar regions, temperature and water control the life processes to a large extent (Block 1985, Aleksandrowa 1983). Occasional measurements indicate the influence of plant cover on the tem-perature of the tundra surface in the Hormsund area (Baranowski 1968).

The aims of the paper are: (1) to determine temperature differences between plant communities, (2) to compare the temperatures in Saxifraga oppositifolia with the temperature of neighbouring dominant plants in various communities.

METHODS

The investigations were carried out in July and August of 1986. In the three plant communities, five measurement sites were establised from 700 m to 1000 m to the north from the Polar Station Hornsund; site (1) in Chrysoplenium tetrandarum — Cochleria officinalis — Cerastium alpinum, (2) and (5) in Calliergon stramineum — Sanionia uncinata, (3) and (4) in Cladonia mitis — Cetraria nivalis — Rhacomitrium lanuginosum.

The structure of plant cover around the measurement sites were investigated in an area of 50 m 2 (fields 5 x 10 m) divided into 1 m 2 plots. For each plot, the plant cover in percent was estimated, and the number of vascular plant species were determined. Elaborated results present Fig. 1 and Table 2.

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In each site two measurement points were located at a distance of 0.5 m: the one in the cushion of Saxifraga oppositifolia (So) and the second among the plants dominating the particular community (Op). All measurements of air temperature, the daily maximum air temperature, and ground temperature at two levels have been made with mercury thermometers (accuracy = 0.1 °C was tested in IMiGW in Warsaw).

RESULTS AND DISCUSSION

The average values of temperatures in site (1) were 2°C to 4°C higher than in other investigated sites (Table 1). The differences of the temperatures between sites located in the same type of plant community (sites 2, 5, and sites 3, 4) were statistically insignificant (t-test). We also did not find significant differencies between microsites of S. oppositifolia cushions and neighbouring plants with the exception of site 4 in which the average value of the daily maximum air temperature was 3°C higher in S. oppositifolia than over the surface of the surrounding lichens and mosses (Tab. 1).

The different plant communities as well as communities of the same type were distinctly different in respect to cover of plants (Table 2). Site (1), in comparison to all other sites, was distinguished by a high frequency of plots in which from 5 to 8 species of vascular plants were recorded (Fig. 1).

Investigations did not detect temperature differences in neighbouring mic-rosites like measurements made by Sholberg and Bliss (1984). The lack of differences between the dry lichen-moss tundra and the saturated moss tundra indicates that the water supply and radiative properties of plants slightly affects the temperature regime during the second part of the vegetation period. Most likely moss tundra is rather cold at the beginning of summer when the tundra is saturated with thawing water. The relatively high temperatures in the site (1) located on the slope of Ariekammen suggest that in the area investigated solar exposition is the main factor determining the temperature regime of plants. The warm sites like site number (1) are covered almost entirely with vascular plants (Table 2). Factors other than temperature control plant distribution in the colder sites of the area studied. It is possible that the indirect effect of temperature on plants is more significant than its direct influence (Chapin III 1988). Generally obtained results suggest that during the investigated period the tundra of the Ariekammen-Fugleberget cachment was rather homogeneous in temperature, and heterogeneous in respect to plant cover.

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REFERENCES

Aleksandrom У. D., 1983: Rastitielnost polarnykh pustyń. Nauka, Leningrad, 142 pp. Angiel M., 1990: Thermic and humidity relations of chosen Spitsbergen soil during spring

ablation of the snow cover. Pol Polar Res 11: 25-37. Baranowski S., 1968: Termika tundry peryglacjalnej SW Spitsbergen. Acta Univ Wratislaviensis

68: 5-75. Baranowski S., 1975: The climate of West Spitsbergen in the light of material obtained from

Isfiord Radio and Hornsund. Acta Univ Wratislaviensis 251: 21-34. Baranowski S., GlowickiB., 1975: Meteorological and hydrological investigation in the Hornsund

region made in 1970. Acta Univ Wratislaviensis 251: 35-59. Block W., 1980: Survival on land. Biologist 32: 133-138. Godzik В., 1987: Zbiorowiska roślinne zlewni Ariekammen-Fugleberget (Hornsund) in: Aktualne

problemy badawcze w Arktyce i Antarktyce, XIV Sympozjum Polarne. Instytut Nauk o Ziemi Uniwersytetu Marii Curie-Sklodowskiej, Lublin, 221-222.

Glowicki В., 1985: Radiation conditions in the Hornsund area, Spitsbergen:. Pol Polar Res. 6/3: 301-318.

Glowicki В., 1985a: Heat exchange in the subsurface soil layer in the Hornsund area, Spitsbergen:. Pol Polar Res 6/3.

Klekowski R. Z., Opaliński К. W., 1986: Matter and energy flow in Spitsbergen ornithogenic tundra. Pol Res 4.

Miętus Л/., 1988: Annual variation of soil temperature at Polar Station in Hornsund, Spitsbergen. Pol Polar Res 9/1: 87-94.

Miętus M., 1988a: Short period changes of soil temperature against advective changes of air temperature in Hornsund, Spitsbergen. Pol.Polar Res. 9/1: 95-103.

Pietroń Z., Ziemiański M., 1985: Results of some meteorological measurements and observations carried out at Hornsund, (Spitsbergen), from 1 August, 1983 to 31 July, 1984. Pol Polar Res 6/3: 365-376.

Rodzik J., Stępko W., 1985: Climatic conditions in Hornsund, 1978-1983:. Pol Polar Res 6/4: 561-576.

Sholberg E. H. Bliss L. C., 1984: Microscale pattern of vascular plants distribution in two high arctic plant communities. J. Can Bot 62: 2033-2042.

Wielbińska D. Skrzypczak E., 1988: Mean air temperature at definite wind direction in Hornsund, Spitsbergen. Pol Polar Res 9/1: 105-119.

Addresses of the authors: dr Eugeniusz Moczydłowski, dr Ewa Pirożnikow, University of Warsaw, Branch in Białystok, Świerkowa 20 В, 15-950 Białystok, Poland.

TEMPERATURY W ZBIOROWISKACH ROŚLINNYCH W ZLEWNI ARIEKAMMEN-FUGLEBERGET (ZACHODNI SPITSBERGEN)

Streszczenie

W lipcu i sierpniu 1986 roku w zlewni Ariekammen-Fugleberget mierzono temperatury na powierzchni roślin i w gruncie w 3 różnych zbiorowiskach roślinnych, w 5 stanowiskach. Badania wykazały, że tundra badanego obszaru jest niemal jednorodna pod względem temperatury, a wyraźnie zróżnicowana pod względem struktury zbiorowisk roślinnych.

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T a b l e 1. Mean v a l u e s of the a i r t empera tu re , and t h e ground tempera tu re C ° 0 ± 95>S con f i dence l i m i t s , in the p l an t communities of Ar iekammen-Fug leberget catchment a r e a , Hornsund.

S i t e Та Tmax Tg5 TglO

5 0 1 7 . 2 6 ± 0 . 8 7 1 3 . 4 4 ± O . 3 4 6 . 1 2 ± 0 . 1 6 5 . 4 6 ± 0 . 1 2 O p i 7 . 6 6 ± 0 . 0 0 1 1 . 3 0 ± 0 . 2 8 5 . 7 3 ± 0 . 1 0 4 . 9 1 ± 0 . 0 6

5 0 2 4 . 8 5 ± 0 . 4 4 9 . 2 8 ± 0 . 1 6 2 . 7 9 ± 0 . 0 5 2 . 5 8 ± 0 . 0 4 O p z 5 . 0 8 ± 0 . 4 8 9 . 1 3 ± 0 . 1 5 3 . 1 3 ± 0 . 0 5 2 . 4 1 ± 0 . 0 4

S o b 5 . 5 6 ± 0 . 2 7 1 0 . 5 2 ± 0 , 1 8 4 . 7 3 ± 0 . 0 7 4 . 6 9 ± 0 . 0 7 О р з 5 . 5 3 + 0 . 3 0 1 1 . 6 4 ± 0 . 3 2 4 . 8 2 ± 0 . 0 7 4 . 6 3 ± 0 . 0 6

S o 4 5 . 4 4 ± 0 . 2 9 1 0 . 5 0 ± 0 . 2 0 5 . 1 4 ± 0 . 0 8 4 . 8 8 ± 0 . 0 6

О p * 4 . 9 7 ± 0 . 2 4 6 . 7 1 ± 0 . 1 6 5 . 4 0 ± 0 . 0 6 4 . 9 2 ± 0 . 0 7

5 0 3 4 . 4 6 ± 0 . 2 6 9 . 5 7 ± 0 . 2 0 3 . 2 4 ± O . 0 6 2 . 6 1 ± 0 . 0 4 О р э 4 . 0 3 ± 0 . 2 1 8 . 5 3 ± О . 1 7 3 . 1 2 ± 0 . 0 5 2 . 5 0 ± 0 . 0 4

Та - mean v a l u e s of the a i r t empera ture 0 . 5 cm above p l a n t s , n=38 measurements made between 13 and 31 of August 1986.

Tmax - mean for the p e r i o d 16 of J u l y - 31 of August 1986 of d a i l y maximum of t h e a i r t empera tu re 0 . 5 cm above p l a n t s , n = 46.

Тдз, Tgio - mean v a l u e s of the ground tempera tu res a t 5 cm and 10 cm, n = 63 measurements made between 16 of J u l y and 31 of August 1986.

Tab l e 2. S t r u c t u r e of the p l a n t communities of the Ar iekammen-Fug leberget catchment a rea . Mean cover С SO for n = 50 p l o t s of each s i t e .

Si t e

1 г 3 4 5

Cover of vase , p l a n t s 90. 3 IS . 7 15. 7 29. 9 O. 2 Cover of mosses 10. 4 100. 0 29. 1 29. 3 lOO. 0 Cover of l i c h e n s 0. 0 0. 2 41 . 6 51 . 6 O. 5. Cover of Saxifraga sp. 13. 5 9. 1 7. 7 7. 8 0. 1

Number of s p e c i e s of v a s c u l a r p l a n t s 11 11 8 11 2

с 40

э 30 cr • 20

- 10 _rt il

3 4 5 8 7 1 2 3 4 5 0 1 2 3 4 3 4 5 6 7 0 1

number of , p a с la s of vascular plants

F i g u r e 1. Frequency CJO o f p l o t s l n ! w i th d i f f e r e n t numbers of s p e c i e s of v a s cu l a r p l a n t s i n 5 s i t e s of t h e Ariekammen -F u g l e b e r g e t catchment a r e a .