Climate change in action: local elevational shifts on Iberian amphibians and reptiles

Species are shifting their elevational ranges in response to climate change. Elevational shifts have been documented frequently in many species of flora and fauna but very few times in amphibians and reptiles. Here, I compare 74 transects in the western part of the Central System mountain range (Salamanca province, Spain) sampled in two periods: 2000-2002 and 2016-2018. I compared between sampling periods the species richness and composition by transect using the Bray-Curtis and Jaccard indices, the species elevational ranges with the non-parametric Wilcoxon test for paired data, and the species' climatic niches with ecospat, an R package for spatial analyses and modelling of species' niches and distributions. I also analysed the changes over time in climate and land use in the study area. The maximum annual temperature increased over time in five meteorological stations inside and close to the study area. The transects did not undergo land use changes between periods. Some transects differed in the species composition, but in general, the species richness was similar. Only two species (one amphibian, Salamandra salamandra; one reptile, Psammodromus algirus) increased their mean elevation (+ 75 and + 163 m, respectively). Several species have slightly shifted their climatic realised niche between sampling periods. Atlantic species are losing suitable habitats, and Mediterranean species are gaining suitable habitats; both types of species are moving towards higher elevations. Climate change might be promoting extinction processes in Atlantic species.