Does body size–abundance allometry in soil fauna vary with environment? A field test for nematode communities in response to fertilization

Abstract

The “energetic equivalence rule” predicts that abundance should always scale as the −3/4 power of body size within a trophic group, but if the body size–abundance allometry (BSA) of soil fauna in fact is labile then the relationship could potentially be used as a standard descriptor for shifts in community functional structure in response to environmental change. To assess the possibility that the BSA could serve as an index of community functional structure, we measured the effect of fertilization on the slope and intercept of the BSA in nematode communities in a rice–wheat crop rotation over three years. Fertilization increased the BSA intercept but did not affect the slope in either rice or wheat phases, which highlights the stable scaling of BSA.