Studies were performed in the summer of 1989 in the vicinity of the Polish Polar Station at Hornsund, Svalbard, in an attempt to characterize the functioning of selected tundra soils in terms of bioenergetics. The intensity of bioenergetical processes in the soil was evaluated by the rates of O2 consumption and CO2 production, measured in the laboratory under controlled hydrothermic conditions. Soils metabolic processes are markedly correlated with soil water content and dependent upon soil structure, water capacity and character of plant cover. The strongest correlation was observed in the more aerated soils with small water capacity and without vegetation. The respiratory quotient (RQ) decreased with the growth of soil moisture content. Soil metabolic activity began directly after the summer melting of the ground, when the soil temperature reached 0°C, and ceased in autumn, when temperatures fell below 0°C again.
Soils of Russian European North were investigated in terms of stability and quality of organic matter as well as in terms of soils organic matter elemental composi-tion. Therefore, soil humic acids (HAs), extracted from soils of different natural zones of Russian North-East were studied to characterize the degree of soil organic matter stabilization along a zonal gradient. HAs were extracted from soil of different zonal environments of the Komi Republic: south, middle and north taiga as well as south tundra. Data on elemental composition of humic acids and fulvic acids (FAs) extracted from different soil types were obtained to assess humus formation mechanisms in the soils of taiga and tundra of the European North-East of Russia. The specificity of HAs elemental composition are discussed in relation to environmental conditions. The higher moisture degree of taiga soils results in the higher H/C ratio in humic substances. This reflects the reduced microbiologic activity in Albeluvisols sods and subsequent conser-vation of carbohydrate and amino acid fragments in HAs. HAs of tundra soils, shows the H/C values decreasing within the depth of the soils, which reflects increasing of aromatic compounds in HA structure of mineral soil horizons. FAs were more oxidized and contains less carbon while compared with the HAs. Humic acids, extracted from soil of different polar and boreal environments differ in terms of elemental composition winch reflects the climatic and hydrological regimes of humification.
Species diversity of Collembola was studied in the vicinity of Polish Polar Station, Hornsund area, West Spitsbergen. A list of 32 species has been compiled, and their distribution over microlandscapes and microhabitats in the study area has been presented.
Communities of soil invertebrates were studied in 4 types of tundra ecosystems on Spitsbergen (Hornsund area) during the vegetative season of 1989. Taxonomic composition, density and biomass of soil fauna were evaluated in the sites along a gradient of increase in the biogenic impact of bird colonies, i.e. in polygonal tundra, mossy/lichenous tundra, Calliergon stramineum moss association, and mossy associations near a colony of Little Auks (Alle die). Average total biomass of soil invertebrates increased in this site sequence from 1.1 to 25.0 g wet weight x m-2 (mainly due to collembolans and nematodes). Seasonal dynamics of all groups of soil meso- and macrofauna (Nematoda, Enchytraeidae, Aranei, Acarina, Collembola, Coleoptera, Diptera larvae) is presented and discussed.
In surface horizons of Gelic Regosols. Gelic Gleysols and Gelic Cambisols from 5 sites in Kaffiöyra. 26 taxa of blue-green algae have been determined. Species of the genera Gleocapsa, Schizothrix, Tolypothrix and Calothix were the most common. In Gelic Regosols blue-green algae formed during the last 100 years the 0.5 cm thick horizon A, containing 8.6% of humus.
Physical and chemical properties (granulometric composition, pH, carbonates, organic carbon, nitrogen etc.) as well as bioenergetic activity of Spitsbergen tundra soils were studied at three chosen stations situated near Polish polar station "Hornsund". It was found that biological activity of Arctic tundra soils depended mainly on its physical properties, whereas the chemical composition of organic matter did not effect directly the bioenergetics of these soils. This bioenergetic activity depends mainly on the richness of micro- and mesofauna communities inhabiting the soil.