Will among‐population variation in seed traits improve the chance of species persistence under climate change?

Abstract

Aim: Seed traits related to recruitment have direct relevance for plant fitness and persistence. Trait variation in time and among populations may increase species resilience and ultimately reduce the risk of extinction. However, patterns of among‐population variation in critical recruitment traits remain poorly known and are often disregarded when considering extinction risk under future climates. Location: Global. Methods: In this paper we review and synthesize current knowledge about among‐population variation in physiological and morphological traits related to plant recruitment. We outline the consequences of that variation for species persistence under climate change, and discuss the implications for conservation, management and restoration. Results: The evaluated studies provide compelling evidence that among‐population variation in traits underpinning seedling emergence, growth and establishment is widespread. Contrary to expectations, environmental gradients do not appear to be reliable predictors of variation among populations and responses are often individualistic. Likewise, well‐established cross‐species patterns are not consistently reflected among populations within a species. As the pattern of this variation is unpredictable, we cannot make simple generalizations about how this variation is allocated across geographic ranges or the extent of environmental versus fixed genetic differences. Nor do these patterns clearly elucidate the potential for this variation to mitigate negative effects of climate change. Main conclusions: If we ignore among‐population variation in seed traits, or assume it will follow simple environmental clines, we do so at our own peril. The consequences of such an approach are likely to include biased forecasts of future range dynamics, hindering identification of the genetic material most appropriate for conservation, restoration and management. Further research that integrates ecology and emerging evolutionary genetic techniques to identify the distribution of seed traits within foundation species and the mechanisms driving them is urgently required to guide the management and maintenance of systems in the face of rapidly changing climates.