Microbial activity in soils from Antarctica (Casey Station, Wilkes Land)

During austral summer 1985/86 a comprehensive study on Antarctic soils was carried out at Casey Station, Wilkes Land. Samples of different locations were analyzed for inorganic nutrients and several organic constituents as well as for related microbiological properties. The data set of this presentation comprises data from 12 top layers of soils covered by different organic material: lichens, mosses and algae. Microbial properties are described by total CO_2-evolution, ^C-glucose uptake and thereof derived parameters such as turnover times of organic matter and their relationships to microbial biomass, estimated from ATP levels, and bacterial biomass and numbers, estimated by epifluorescence microscopy. Results indicate high metabolic rates in these environments. Albeit ratios between gross metabolism (CO_2-evolution) and bacterial activity (^C-turnover rates) show that a high contribution of the total metabolism must be due to other organisms than bacteria. This meets the results of fairly high amounts of ATP on the one hand and low bacterial biomass on the other hand