Dispersal evolution in metacommunities of tri-trophic systems

Abstract

Species interactions potentially affect dispersal evolution. However, previous studies about dispersal focused mostly on one or two species systems, and dispersal evolution in metacommunities composed of more than two interacting species is left to study. Here, we use a spatially explicit individual-based model to investigate the concurrent evolution of dispersal probabilities in metacommunities of tri-trophic interaction systems with one host, parasitoid, and hyperparasitoid species. We vary search efficiency (interaction intensity) of parasitoid on host and search efficiency of hyperparasitoid on parasitoid under different dispersal mortalities. Our results indicate that the tri-trophic system can persist in limited range of search efficiency of parasitoid and hyperparasitoid. Higher search efficiency of hyperparasitoid generally resulted in the evolution of higher dispersal probabilities of all species, while higher search efficiency of parasitoid increases only host and parasitoid dispersal probabilities but decreases hyperparasitoid dispersal probabilities. Dispersal mortality has a negative effect on emergent dispersal probabilities for all three species. Moreover, an increase in dispersal mortality desynchronizes population dynamics and widens the range of parasitoid and hyperparasitoid search efficiencies under which the tri-trophic system can persist.