The resilience of coastal ecosystems: A functional trait-based perspective

Coastal ecosystems provide important services to human population, such as nurseries for fish, carbon storage and coastal protection. However, the pressure faced by these systems due to global changes will strongly challenge the capacity of coastal ecosystems to persist. Therefore, it is crucial to understand the resilience of coastal ecosystems. Here, I propose that combining a resilience framework based on ecosystem properties with the functional trait response–effect framework would allow researchers and managers to quantify the resilience of coastal ecosystems. I place emphasis on salt marsh and sand dunes because of the higher availability of studies for these systems. First, I introduce the resilience framework based on ecosystem properties and, second, I show how adopting a functional trait perspective in this framework would allow researchers to link how environmental changes influence ecosystem properties. In turn, measuring the changes in ecosystem properties would allow researchers to measure the resilience of the system. Synthesis. I reviewed several types of disturbances (e.g. storms and sea-level rise) that are threatening the persistence of coastal ecosystems, with an emphasis on salt marshes and sand dunes. Applying this resilience framework reveals, for instance, that the same suite of traits (e.g. plant density and stiffness) increase marsh resistance to multiple threats (e.g. storms and sea-level rise); yet, these traits vary along environmental gradients (e.g. along estuaries) and, therefore, the resilience of marshes vary accordingly. Overall, this framework would allow researchers to gather crucial insights on the resilience of coastal ecosystems and to set reference marks for measuring their resilience under environmental changes.