Community and ecosystem ecology often focuses on a single community, but communities are often linked because organisms disperse between them. This exchange of individuals means that the composition of communities can change spatially and temporally via community assembly. It is important to acknowledge the role of dispersal in community assembly due to its potential effects on ecosystem function and consequences for a community’s response to environmental change. We undertook a meta-analysis of experimental datasets of both plant and plankton communities that compared ‘closed’ (where exchanges are constrained or prevented) and ‘open’ ecosystems (where exchanges are allowed or facilitated). Datasets had to have individuals identified to species-level and a measure of ecosystem function. We used the Price equation to partition the effects of species richness and changes in composition between communities on ecosystem function. We further compared these Price partitions between closed and open systems with pairwise distances and PERMANOVA within studies and effect sizes between studies.
Results/Conclusions
Communities with dispersal exhibited higher levels of species richness and turnover in composition, which led to stronger positive impacts on ecosystem function. This analysis illustrates the importance of metacommunity processes for both diversity and ecosystem function dynamics, showing increased ecosystem function with species dispersal. Ecosystem function is not solely dependent upon species richness but also on ‘who’ makes up that richness. Incorporating dispersal – and its impacts on community composition and turnover - into our understanding of ecosystem function relationships adds new dimensions to previous research largely focused on local species richness dynamics. Furthermore, incorporating dispersal into our understanding of ecosystem function and biodiversity relationships will allow us to better predict how resilient communities and ecosystem function will be to environmental change. Higher resilience is expected in open ecosystems where dispersal of species might enhance recovery from perturbations and, by extension, the ability of communities to track environmental changes and maintain ecosystem function.