Patchy range retractions in response to climate change and implications for terrestrial species conservation

ContextEfforts to adapt conservation to climate change often focus on facilitating range shifts to higher latitudes, by enhancing landscape capacity for poleward expansion. The need to protect populations at trailing edges of species distributions, and how and where to do so, has received less attention.ObjectivesWe assess how population declines caused by variation over space and time in exposure to climate change can necessitate conservation adaptation to climate change throughout species' geographic ranges. We propose approaches for conservation in landscapes where species are vulnerable.MethodsWe synthesize primary literature relating to recent landscape-scale changes to species distributions to identify evidence for patchy patterns of climate-driven decline. We use this evidence to propose a framework to adapt terrestrial species conservation.ResultsPatchy retractions occur throughout species ranges as environmental heterogeneity results in spatial variation in climate and rates of climate change, whereas equatorward range margins are often not the first place to exceed climatic limits. Furthermore, climate effects on fitness, survival and reproduction interact with habitat quality, creating both localized extinction hotspots and climatically resilient microrefugial landscapes across species ranges. Conservation can benefit from the identification of vulnerable versus microrefugial landscapes, and implementation of targeted interventions.ConclusionsA focus on expansions and retractions at broad latitudinal range margins risks overlooking declines throughout species' distributions. Understanding fine-resolution ecological responses to the climate can help to identify resilient microrefugial landscapes, and targeted management to promote cooler or more stable conditions can complement facilitation of broader-scale range shifts.

Automated summary

This study assesses how population declines caused by spatial and temporal variation in exposure to climate change can lead to the need for conservation adaptation throughout species' geographic ranges. The study proposes approaches for conservation in landscapes where species are vulnerable.