Home – Home – Jornals – Contemporary Problems of Ecology 2002 number 3

The bio-mass of soil microorganisms and other biological characteristics of soils (respiratory and phosphatase activity) and the microbial component of soils (metabolic coefficient of the biomass and the k_C factor) were studied in the soils of southern and northern subzones of subarctic tundra of Middle Siberia (the Taimyr peninsula). It has been found that the soil microorganisms biomass content, the respiratory activity of the soil and its phosphatase activity strongly vary within the limits of the zone under study, which reflects the special chaoticity of microecotopes of the tundra zone. Thus, the biomass content varied from 1 mg C/100 g (in the soil directly adjoining the permafrost layer in the lower part of the cryoturbation spot in the south of the zone) to 140 mg C/g (in the peated humic gley horizon under grass-moss tundra in the south of the zone). The obtained values of the microbial metabolic coefficient for tundra soils (0.1 to 5 mcg C-CO₂ ^. mg-1 biomass C/hr) are within the limits of values established for soils of other bioclimatic zones. A study of behavior of the microbial component of tundra soils under laboratory conditions has demonstrated that as the temperature increases, the phosphorus immobilization by the microbial biomass bacomes more intense.