A review on the definitions and forms of dispersal syndromes

Abstract

Dispersal plays an important role in species response to adverse climate changes. It is a complex multi-stage process that involves multiple components, making its measurement and interpretation challenging. Dispersal syndromes i.e. phenotypic traits correlated with dispersal, may offer an alternative framework that might help overcome some of the challenges of predicting dispersal. However, the definition and usage of the term ‘dispersal syndrome’ varies across taxa, and phenotypic correlations with dispersal are very heterogeneous. This review takes a closer look at dispersal syndromes across plant and animal taxa in search of general patterns and trends that could help put these inconsistencies in perspective. I find that the prediction of dispersal rates is complicated by the lack of consistent phenotypic associations with dispersal. In animals, phenotypic correlations are constrained by differences in costs and benefits of dispersal across its stages and the environmental context in which dispersal is being studied. In plants, dispersal syndromes are inferred based on presumed modes of dispersal that are seldom tested directly on field, thus making prediction of dispersal potential erratic. Most studies in plant dispersal literature are focused on how dispersal vectors affect dispersal potential, thus underestimating the importance of maternal plant traits and their plasticity in modulating dispersal. In both, the integration of context-dependent environmental effects is therefore an important emerging focus in the study of dispersal evolution.