In the Dry Valleys, food webs are particularly isolated compared to other soil food webs, which should reduce the recruitment of lower trophic level species for their consumers. The low connectivity of the food webs in the Dry Valleys is thus expected to translate into lower immigration and higher extinction rates. This is expected to create high spatial and temporal variability in species composition and richness, and contributes to food webs dominated by generalist primary consumers with very few secondary consumers