Effects of food web construction by evolution or immigration

TL;DR

This study compares food webs constructed through evolution versus immigration, revealing structural similarities but key differences in species composition and responses to resource availability, with implications for understanding ecological complexity.

Contribution

It introduces a comparative analysis of food web structures formed by evolution and immigration, highlighting distinct patterns in species composition and resource response.

Findings

Food webs from evolution and immigration are structurally similar.

Differences mainly in basal and top species percentages.

Species-area curves differ between the two processes.

Abstract

We present results contrasting food webs constructed using the same model where the source of species was either evolution or immigration from a previously evolved species pool. The overall structure of the webs are remarkably similar, although we find some important differences which mainly relate to the percentage of basal and top species. Food webs assembled from evolved webs also show distinct plateaux in the number of tropic levels as the resources available to system increase, in contrast to evolved webs. By equating the resources available to basal species to area, we are able to examine the species-area curve created by each process separately. They are found to correspond to different regimes of the tri-phasic species-area curve.