SOIL NEMATODE BIODIVERSITY IN TERRESTRIAL ECOSYSTEMS

A review of the literature on nematode diversity (= number of species identified) of soil inhabiting nematodes was undertaken and analysed w ith regard to distance from the equator, vegetation type and sampling effort. After applying a correction factor for sampling effort the res ults indicated that species richness was greatest in temperate broadle af forest (61.7 species per sample) followed by cultivated soil, grass land, tropical rainforest, temperate coniferous forests and polar vege tation. The maintenance of high biodiversity in cultivated soils is un expected but may reflect the impact of dominance in calculating many i ndices. Species richness was greatest between latitudes 30-40 degrees (93.9 species per sample) and least above 70 degrees, the mean richnes s near the equator (i.e. 0-10 degrees) was 80.6 species per sample. Wh ile these data would suggest that nematode diversity is not necessaril y greatest at the equator, and evidence to support a 'humped back' the ory of species richness is not conclusive, they contradict the suggest ion that nematode diversity increases with increased latitude.