Integrating and assessing metacommunity drivers of ecosystem function and resilience in benthic algal systems

Understanding the scales and mechanisms by which species composition interacts with ecosystem functions is critical for forecasting the effects of environmental perturbations on ecosystem services. However, the linkages between what regulates the ecosystem functions of dispersal‐capable networks of communities (metacommunities) and what regulates a metacommunity's capacity to maintain its compositional and functional regimes when disturbances occur (resilience) has been under‐studied. Benthic algal communities provide a good model for revealing these compositional and functional connections and disturbance responses, because benthic algae respond rapidly to environmental changes in trait‐dependent ways that influence function. Here we propose a metacommunity framework to assess how local‐scale benthic algal community dynamics drive regional‐scale ecosystem functions, linking metacommunity concepts of dispersal, species traits, environmental regulation, and biotic interactions to ecosystem concepts of resilience and stability. We operationally define metacommunity resilience sensu Holling, review the processes by which algal metacommunity dynamics affect the stability and resilience of ecosystem functions, and describe quantitative approaches for assessing metacommunity resilience. We apply this framework to a systematic synthesis of literature on benthic algal responses to disturbances, to assess the state of the literature and reporting trends of algal resilience. This synthesis found that benthic algae are often reported to be non‐resistant and adaptive to disturbances, and particularly non‐resilient to press disturbances. However, resilience to pulse disturbances was commonly reported, wherein reports typically demonstrated greater degrees of recovery and low or no regime shift. Several areas of under‐reporting were found within the scope of the literature synthesis, including spatially explicit and large‐scale experimental research, quantifications of baseline variance, and assessments of metacommunity‐specific properties of disturbance response. Ultimately, we combine findings from our review and synthesis to make recommendations for addressing literature gaps through additional research on metacommunity resilience, for which we suggest best practice approaches.