Climate change effects on the Iberian subterranean biodiversity: state of knowledge and perspectives

Abstract

Subterranean ecosystems provide key ecosystem services and host an important proportion of global biodiversity, threatened by human activities and global warming. However, they have been systematically neglected in global agendas on climate change and biodiversity conservation. We conducted a systematic review of studies on the effects of climate change on subterranean biodiversity in the Iberian Peninsula, describing the variability of experimental approaches applied, habitats, taxa and responses studied, levels of biological organization, degree of specificity for the subterranean environment and factors that may interact with a temperature increase. We reviewed 15 articles that comprise a total of 135 terrestrial taxa (11 chiropters and 124 invertebrates, mainly Coleoptera). Two types of responses have been studied: thermal tolerance (through physiological experiments) in invertebrates and range shifts under different climate change scenarios (through ecological niche modelling), mainly in Chiroptera. In general, thermal physiology studies show that species with a higher degree of subterranean specialization have lower heat tolerance, and distribution models predict range contractions in the Iberian Peninsula for most of the species studied. No article has analysed behavioural, reproductive, life history or phenological responses, nor community level responses or biological interactions. This review allowed us to identify the main knowledge gaps on the effects of climate change on Iberian subterranean biodiversity and to propose priority lines on which to focus research efforts in the upcoming years.