Current climate, but also long‐term climate changes and human impacts, determine the geographic distribution of European mammal diversity

Abstract

Aim Historical climate variations, current climate and human impacts are known to influence current species richness, but their effects on phylogenetic and trait diversity have been seldom studied. We investigated the relationship of these three factors with the independent variations of species, phylogenetic and trait diversity of European mammals. Considering the position of the 0 ºC isotherm in the Last Glacial Maximum as a tipping point, we tested the following hypotheses: northern European assemblages host fewer species than southern European ones; northern areas harbour trait and phylogenetically clustered assemblages, while the more stable southern areas host random or overdispersed assemblages; and species richness correlates positively with human influence, while phylogenetic and trait diversity show clustered patterns in areas with stronger human influence. Location Western Palaearctic. Time period Current and Late Pleistocene effects on present‐day diversity. Major taxa studied Terrestrial mammals. Methods We used a novel analytical approach based on distance matrices to separate the independent variations of species, phylogenetic and trait diversity, and assessed their relationships with current climate, climate stability and human influence through structural equation models. Results The species‐poor assemblages from northern Europe show higher phylogenetic and trait clustering than the more stable richer southern areas. However, no assemblage presented trait or phylogenetic overdispersion. Current climate is the primary driver of phylogenetic and trait diversity, while species richness is affected similarly by both current and past climates. Higher human influence correlates positively with species richness and trait diversity, both directly and by mediating indirect effects of present climate. Main conclusions Current climate, climate stability and human influence affect the studied aspects of diversity, although the form and magnitude of their effects vary through space. Importantly, higher levels of human disturbances correlate with more species rich and trait diverse assemblages, an apparently counterintuitive result that deserves further study.

Iberian Protected Areas Capture Regional Functional, Phylogenetic and Taxonomic Diversity of Most Tetrapod Groups

“…However, although the climatic characteristics within the PAs did not differ significantly from the regions where they are located (see Supplementary Appendix 2 in Data Sheet 1), our results showed that both diversity facets were influenced by the climatic conditions found within the PA's boundaries. These results agree with the findings of Santos et al (2020), who concluded that current climate strongly affects both functional and phylogenetic diversity gradients of European mammals. Particularly, we found a tendency for higher functional and phylogenetic diversity than expected from the regional pool in PAs with high annual precipitations and low annual mean temperature.…”

“…and Dufour, 2007). This methodology has been widely used in the literature in studies including similar goals to ours (e.g., Roa-Fuentes et al, 2019;Santos et al, 2020). Then, the Iberian functional dendrogram of each tetrapod group was pruned to each regional pool (composed by the species observed in each PA and respective buffer zone).…”

“…Although the computation of Gower's distance allows missing data, trait completeness was overall high across all groups (97.9%, 97.8%, 99.9%, and 100% completed for amphibians, reptiles, birds, and mammals, respectively). Likewise, Faith's (1992) Phylogenetic Diversity (PD) index was used to calculate the phylogenetic diversity of each PA and the null assemblages of the respective regional pool, following the same procedure described above for FD but using the molecular phylogenies instead of the functional dendrogram (see Santos et al, 2020 for a similar approach). We assessed whether the set of species of each taxonomic group inhabiting each PA represents its regional functional and phylogenetic diversity by comparing the FD and PD observed in the PAs with a null distribution generated by the random assembly of species from their corresponding regional pool (i.e., PA plus buffer zone).…”

“…A preliminary analysis based on a paired Student t-test indicated there are no significant differences in the climatic conditions found within the PAs and their surrounding regions (see more details in Supplementary Appendix 2 in Data Sheet 1). However, as climate is known to have important effects on vertebrates' functional and/or phylogenetic diversity, both at continental (Santos et al, 2020) and smaller scales (García-Llamas et al, 2019), we considered important including these variables in the analyses (see below).…”

Wild Boar Survives in a Landscape That Prohibits Anthropogenic Persecution

“…However, the fit of the initial a priori model was not good; according to the guidance of modification indices (MIs), we respecified the model by adding new relationships. We sequentially added new relationships with biological meaning until an adequate model fit was achieved (Santos et al, 2020). After fitting the final model, we tested the goodness of fit of the models by means of maximum-likelihood estimation on the variance-covariance matrix.…”