Noah's Parks: A partial antidote to the Anthropocene extinction event

Abstract

Climate change will rapidly alter the abiotic environment of many localities leading to significant losses of biodiversity in ecosystems unable to adapt quickly. However, local extirpation will be least likely where environmental change is slowest. Such locations will offer refugia for species with narrow environmental ranges, provide persistent sources of colonists, offer transitory homes for dispersers and serve as platform sites on which new community assemblages develop. Consequently, networks of protected areas that include such sites will conserve more biodiversity. Conventional protected area network selection algorithms give priority to areas with the lowest current cost. I added projected environmental change as a cost factor. I applied the modified algorithm in three arctic ecoregions where climate change is predicted to be extremely rapid and to 20 tropical ecoregions where the pace of climate change will be slower but many species are vulnerable to small changes. I identified protected area networks that protect places where change will be slowest in all ecoregions. These climate-adaptive protected area networks differ substantially from both current protected area networks and near-optimal networks that are based only on current costs. The modified method will help protected area planners to acquire potential climate refugia and to help implement adaptive conservation strategies for potential refugia that are already protected. It will also help reduce the risk that projected refugia are unknowingly allocated to land uses incompatible with their critical role in biodiversity conservation.