On a southern slope in the Austrian Central Alps (Hohe Tauern Mountains) at altitudes of 2550 m, 1920 m and 1650 m above sea level, respectively, microbial activities were investigated by measuring the decomposition of litter, the cellulase and xylanase activities, CO2-evolution and the cell counts of viable non differentiated and cellulolytic bacteria. After one year 46% of litter exposed was decomposed at an altitude of 2550 m, 76% at 1920 m and 86% at 1560 m. Investigations with litter bags of different mesh sizes (25 μm and 1000 μm) revealed that small soil animals (<1 mm) did not significantly influence the decomposition of litter at different altitudes and in different vegetation types. The enzymatic activities and the CO2-evolution of soils decreased with increasing altitude. Plate counts of bacteria from soils at the alpine zone (2550 m) and the tall grass meadow (1650 m) indicated that in some cases the lower metabolic activities caused by bad climatic conditions were compensated by an increase in cell numbers.
