Causes and consequences of dispersal in biodiverse spatially structured systems: what is old and what is new?

TL;DR

This paper explores how dispersal evolves in biodiverse, spatially structured communities, highlighting differences from single-species systems and emphasizing the complexity introduced by multiple interacting species.

Contribution

It discusses the transferability of single-species dispersal knowledge to multispecies systems and highlights the role of trait dimensionality and co-dispersal in dispersal evolution.

Findings

Dispersal evolution in multispecies systems may be slower and more diffuse.

Biotic interactions influence fitness expectations and dispersal patterns.

Increased trait dimensionality affects dispersal evolution in biodiverse systems.

Abstract

Dispersal is a well recognized driver of ecological and evolutionary dynamics, and simultaneously an evolving trait. Dispersal evolution has traditionally been studied in single-species metapopulations so that it remains unclear how dispersal evolves in spatially structured communities and food webs. Since most natural systems are biodiverse and spatially structured, and thus affected by dispersal and its evolution, this knowledge gap should be bridged. Here we discuss whether knowledge established in single-species systems holds in spatially structured multispecies systems and highlight generally valid and fundamental principles. Most biotic interactions form the ecological theatre for the evolutionary dispersal play because interactions mediate patterns of fitness expectations in space and time. While this allows for a simple transposition of certain known drivers to a multispecies context, other drivers may require more complex transpositions, or might not be transferred. We discuss an important quantitative modulator of dispersal evolution in the increased trait dimensionality of biodiverse meta-systems and an additional driver in co-dispersal. We speculate that scale and selection pressure mismatches due to co-dispersal, together with increased trait dimensionality may lead to slower and more "diffuse" evolution in biodiverse meta-systems. Open questions and potential consequences in both ecological and evolutionary terms call for more investigation.