Limited theoretical and empirical evidence that response diversity determines the resilience of ecosystems to environmental change

Response diversity describes the variation in species' ecological responses to environmental change, where higher response diversity represents a greater variety of species–environment responses. The concept complements the insurance hypothesis that biodiversity increases and stabilizes ecosystem functions because population declines of one species with environmental change are compensated for by opposing responses of others. Accordingly, response diversity is a promising, but still largely untested, candidate mechanism explaining the generally positive relationship between biodiversity and ecosystem stability across a range of systems. In the 10 years since, Mori et al. (2013, Biological Reviews, 88, 349–364) reviewed the relationship between response diversity and ecological resilience (a key dimension of stability), the topic has garnered significant attention. Their review has attracted over 600 citations to date and continues to be well cited. However, in a recent review of empirical work on response diversity, we found fewer than 50 studies empirically measuring what the authors called response diversity. Here we discuss possible reasons for the slow uptake of empirical response diversity research, including lack of standardized methods and heavy data requirements, as well as next steps to achieve a robust framework for empirical research on response diversity and stability, such as by leveraging new methods and coordinating research efforts through interdisciplinarity. By identifying a disconnect between interest in response diversity and theoretical and empirical work on the topic, we hope this article will shed light on the challenges studies of response diversity must overcome, in turn catalyzing new avenues of research on response diversity, ecological stability, and ecosystem functioning.