Climate change going deep: the effects of global climatic alterations on cave ecosystems

The role of terrestrial caves as ideal natural laboratories has been recognized long ago. Because caves are semi-closed systems characterized by a remarkable thermal stability, they should represent one of the most insightful systems for determining the effects of climate change on biodiversity in situ. Whilst a number of recent advances suggest that this a new, exciting and fast-moving field of research, a lack of synthesis possibly hinders the establishment of caves as standard models for the study of climate change in environment. In this review, we illustrate the rationale supporting the use of caves as laboratories for the study of global warming. Then, we critically evaluate the recent contrasting results obtained by different research groups on the response of different subterranean organisms to altered temperature. We finally provide a forward-looking view of prospects offered by cave studies for deepening our understanding of eco-evolutionary responses to recent climate change. Together with other species that live in confined habitats such as islands and mountain summits, we argue that cave species may be especially sensitive to climate change, and we stress out the pressing need for future research.