SPATIAL-DISTRIBUTION OF NEMATODES IN POLAR DESERT SOILS OF ANTARCTICA

The vertical and horizontal distribution of nematodes in polar desert soils was investigated at two field sites in the Taylor Valley, Antarc tica. Soil samples were collected from horizontal (2-m interval) and v ertical (depths of 0-2.5 cm, 2.5-5 cm, 5-10 cm, 10-20 cm) grids on the north and south shores of Lake Hoare, and nematodes were extracted, i dentified to genus and life-cycle stage, and enumerated. Nematodes occ urred primarily at depths between 2.5 and 10 cm in the soil profile, a nd were less abundant at the surface (0-2.5 cm) and at 10-20 cm. Distr ibution along the horizontal grid was patchy. This aggregation may ind icate favorable microhabitat sites for nematode growth and reproductio n, and provide information about the potential influence of environmen tal parameters on nematode distribution and population structure in An tarctic soils.