Nematode community structure in desert soils: nematode recovery.

The sugar-flotation-sieving (SFS) and Baermann-funnel (BF) methods were compared for nematode extraction efficiency. The SFS method recovered nematodes from more trophic groups whereas greater total numbers of individuals were recovered by BF. In a test to validate the efficiency of SFS, virtually 100% of the nematodes added to desert soil prior to extraction were recovered by four consecutive SFS washings of each soil sample. Estimations of nematode biomass in desert soils based on numbers of nematodes extracted by the two methods were similar unless there was large reserve of eggs in the soil. The biomass of nematodes from a Colorado desert soil was 0.9 g/m(2) as determined by both methods, whereas BF gave 0.17 g/m(2) for nematodes from a Mojave desert soil as compared to 0.9 g/m(2) with SFS.