The relevance of ecological pyramids in community assemblages

In this paper, we investigate the trophic pyramid structure of 17 commonly studied ecosystems (terrestrial and varying aquatic environments). Food-web taxa from these ecosystems are classified into six functional groups: primary producers, herbivores, carnivores, omnivores, detritus, and detrital feeder; we find that the majority of the food webs exhibit an inverted pyramid structure with more higher trophic groups than lower ones. We find the average pyramid and inverted pyramid trophic distributions for these webs, and along with the uniform distribution, construct large-scale ecological networks based on these distributions. By creating and analyzing structural and flow matrices of these distributions using the cyber-ecosystem community assembly rule model, we compare the ecological parameters cycling, amplification, homogenization, indirect effects, and synergism. Excluding amplification, which does not occur in larger-scale models, we find that all network parameters show strong characteristic behaviors regardless of the trophic structure. Therefore, ecological network parameters are not considerably sensitive to different structures, indicating there may not be a preferred diet distribution.