Effect of sand-dune slope orientation on soil free-living nematode abundance and diversity

The spatial and temporal dynamics and composition of a soil free-living nematode community were studied in order to determine the impact of slope orientation on the community on the xeric south- and the mesic north-facing sand-dune slopes. A significant effect of sampling location on organic matter, total number of free-living nematodes, and trophic diversity was found. Although soil moisture had a significant effect on separate nematode trophic groups and on most of the applied ecological indices, no differences in soil moisture were observed between slopes. Organic matter was found to have a significant effect on the fungivore nematodes. The obtained results indicate that the south-facing slope is more favorable for the observed free-living nematodes than the other sampling sites. Twenty-four of the 77 nematode species that were found in the observed area showed dependence on dune slope orientation. The fungibacteria ratio, Simpson's dominance index, and basal index were useful tools for determining slope differences.