Interspecific dispersal constraints suppress pattern formation in metacommunities

TL;DR

This study reveals that interspecific dispersal behaviors, especially adaptive constraints like prey tracking and predator avoidance, significantly influence spatial pattern formation in metacommunities, often suppressing patterns unless webs are large.

Contribution

It demonstrates how realistic interspecific dispersal constraints alter pattern formation in metacommunities, extending understanding from simple motifs to complex food webs.

Findings

Adaptive dispersal constraints suppress pattern formation in small webs.

Large species-rich webs tend to restore pattern-forming dynamics.

Interspecific dispersal rules critically influence spatial ecosystem structures.

Abstract

Decisions to disperse from a habitat stand out among organismal behaviors as pivotal drivers of ecosystem dynamics across scales. Encounters with other species are an important component of adaptive decision-making in dispersal, resulting in widespread behaviors like tracking resources or avoiding consumers in space. Despite this, metacommunity models often treat dispersal as a function of intraspecific density alone. We show, focusing initially on three-species network motifs, that interspecific dispersal rules generally drive a transition in metacommunities from homogeneous steady states to self-organized heterogeneous spatial patterns. However, when ecologically realistic constraints reflecting adaptive behaviors are imposed -- prey tracking and predator avoidance -- a pronounced homogenizing effect emerges where spatial pattern formation is suppressed. We demonstrate this effect for each motif by computing master stability functions that separate the contributions of local and spatial interactions to pattern formation. We extend this result to species rich food webs using a random matrix approach, where we find that eventually webs become large enough to override the homogenizing effect of adaptive dispersal behaviors, leading once again to predominately pattern forming dynamics. Our results emphasize the critical role of interspecific dispersal rules in shaping spatial patterns across landscapes, highlighting the need to incorporate adaptive behavioral constraints in efforts to link local species interactions and metacommunity structure.