Abundance-body mass relationships in size-structured food webs

摘要: In communities sharing a common energy source, the energetic equivalence hypothesis predicts that numerical abundance (N) scales with body mass (M )a sM )0.75 . However, in size-structured food webs all individuals do not share and available (E ) to larger is constrained by inefficient transfer through chains support them. This expected lead steeper scalings of N M. Here, we formalize test an existing model for predicting abundance–body scaling, where decline E M calculated from mean predator–prey ratio (from size-based nitrogen stable isotope analysis) trophic efficiency. We show steep predicted (N as )1.2 , B )0.2 marine web are consistent empirical estimates can be attributed small (106 : 1). As previous study has shown environmental stability may favour low ratios long chains, predict relationships will found more environments.