Predicting persistence in a changing climate: flow direction and limitations to redistribution

Synthesis Impending climate changes beg the question: which populations and species will go extinct and which will persist under future environmental conditions? When tolerance in situ is not possible, then species must undergo range shifts to avoid extinction. This synthesis explores ways in which directional air and water flow could impede such redistribution and the characteristics that might allow species to disperse against the flow. Considering flow patterns in tandem with climate and range projections has the potential to improve predictions of persistence for the earth’s many non‐moving foundation and basal species as well as the communities and food webs that they support. Predicting which populations and species will persist (i.e. avoid extinction and continue to exist) in the face of climate change requires an understanding of mechanisms that allow species to cope with altered environmental conditions. When processes of tolerance, acclimation, and adaptation are insufficient to allow persistence in situ, redistribution is required for population or species persistence. Here, I review evidence that directional flows of water and air have the potential to restrict species’ range boundaries under ambient conditions, the spread of introduced species, and the redistribution of native species under changing climatic conditions. I develop the hypothesis that flow patterns, such as the speed and directionality (i.e. poleward vs equatorward) of asymmetric air and water currents, may need to be considered when assessing the vulnerability of populations and species to climate change. To the degree that directional flows are found to limit redistribution, there may be disproportionate losses of diversity where the dominant flow direction opposes that of shifting climate space. Within this context, I highlight flow conditions and life‐history traits that could help the most passively‐dispersed species redistribute to track changing climate. These predictions merit further examination in order to better anticipate which populations, species, and associated communities are likely to persist under climate change.