Assessing the habitat and anthropogenic drivers on meso- and macromammals diversity in the western Mediterranean basin

Abstract

In the Mediterranean Basin, considered a biodiversity hotspot, 184 mammal species are found. Its presence and abundance inside the region are influenced by several factors. This work aims to determine if landscape heterogeneity, anthropization degree and variation of both during the last 30 years affect the alpha and beta diversity of terrestrial macro and meso-mammals in this region. To do so, data from camera trapping in 29 Carnivores Permanent Tracking Plots (PSPCs) located along Catalonia was used. Detected species of terrestrial mammals with a weight higher than 1 kg were classified between domestic carnivores, domestic herbivores, wild carnivores, wild ungulates, and lagomorphs and big rodents. The alpha and beta diversity of each group, as well as the one for all wild mammals, have been calculated. Simple linear regressions and multimodal analysis have been conducted between diversities and different variables related with climate and environmental conditions, landscape heterogeneity and anthropization degree. With those, redundancy analyses (RDAs) have been conducted to know the variables and species that determine the composition of mammalian communities. Indexes that measure in a direct way landscape heterogeneity, anthropization degree and its change in the last 30 years have shown no correlation with diversity. However, differences in elevation inside the PSPC and RAI of domestic carnivores have shown a greater correlation. Nonetheless, the variables that showed more correlation with diversity are the environmental ones, like rainfall and mean elevation. RDAs show a few species, both generalists (red fox and roe deer) and open field specialists (rabbit), with a very high influence on the configuration of communities. That shows the importance of conserving open areas, as well as the Pyrenees, only habitat of some of the detected species. The disparity among results depending on the chosen variable to measure a factor does not allow drawing firm conclusions about the initial hypothesis. However, the fact that climatic variables have been generally found as the most important determinants of mammal diversity, shows that in the future climate change might be the largest threat to mammal populations in this area