Tetrapod diversity facets in jeopardy during the Anthropocene

Abstract

We are in the midst of a sixth mass extinction but little is known about the global patterns of biodiversity when accounting for taxonomic, phylogenetic and functional information. Here, we present the first integrated analysis of global variation in taxonomic, functional diversity and phylogenetic diversity of more than 17,000 tetrapod species (terrestrial mammals, amphibians, reptiles and birds). We used a new metric (z-Diversity) able to synthetize taxonomic, functional and phylogenetic information across different sets of species to provide a comprehensive estimation of biodiversity. Our analyses reveal that hotspots of tetrapod diversity are clustered in specific regions of the world such as central Africa and the Indian peninsula, and that climate stability and energy availability have an overarching importance in explaining tetrapod spatial patterns. Future research might take advantage of these methods to perform an informed prioritization of protected areas.

Global patterns and determinants of multiple facets of plant diversity

“…lower dispersal from the tropics to temperate zones; Wiens & Donoghue, 2004) or the higher ecological stability of these areas over evolutionary time‐scales might have favoured the maintenance of older lineages which, in turn, may have promoted higher diversity (Trew & Maclean, 2021). Furthermore, we found an overlap between the areas of global importance for plants with the ones of tetrapod species, especially mammals and reptiles (Tordoni et al., 2021), further highlighting the importance of these regions in the conservation of global biodiversity. When considering the spatial overlap of global land area for the regions hosting the highest μ‐diversity (top 10%), only Papua New Guinea stands out, suggesting that more efforts are needed to successfully capture different facets of biodiversity for prioritization analyses (Brum et al., 2017; Guo et al., 2022).…”

“…This can have important consequences for biodiversity conservation, as also recently outlined by other studies showing how biodiversity conservation would benefit from considering multiple biodiversity dimensions (Pollock et al., 2017; Tordoni et al., 2021), given also their small spatial overlap. Specifically, when considering the most diverse botanical countries (top 50%), we clearly detected that different areas on Earth can be considered of primary importance for different dimensions of biodiversity with relevant implications when planning biodiversity conservation actions and restoration efforts (Guo et al., 2022).…”

“…Our study expands these findings for other dimensions of biodiversity, showing that Papuasia, Philippines, Sundaland and Indo-Burma regions along with the forests of northeastern Australia are not only rich in species but also characterized by unique evolutionary history and functional features. Notably, we detected a congruence between seed plant PD and FD (Table S3), which is not mirrored in tetrapod species (Tordoni et al, 2021). This might suggest that these centres of diversification promoted the evolution of unique features in plants, thanks also to the disproportionate accumulation of extremely rare species (Enquist et al, 2019), especially in tropical mountains (Testolin et al, 2021).…”

“…This scenario entails to add a new tip to the 1/2 point of the family branch with some exceptions (Jin & Qian, 2019;Qian & Jin, 2016). To obtain a complete trait matrix, we imputed missing traits only for species having at least one trait and phylogenetic information as described in recently published papers (average trait completeness = 34.05%, range = 23%-59%; see shows also the accuracy and robustness of trait imputation procedure (Carmona, Bueno, et al 2021;Tordoni et al, 2021;Toussaint et al, 2021). In order to make a comparable effort between phylogenetic and functional dimensions, we subset from the phylogenetic tree only species with functional trait data, leaving 34,694 species for further analysis on functional and phylogenetic facets.…”

“…Given the pivotal role of different diversity aspects on ecosystem functioning and stability (Cadotte et al., 2012; Flynn et al., 2011; van der Plas, 2019), and considering that each facet provides complementary information (Cadotte et al., 2019; Mazel et al., 2018; Owen et al., 2019; Tucker et al., 2018), integrating multiple diversity facets is an overarching issue for conservation (Pollock et al., 2020; Tordoni et al., 2021; Veron et al., 2017). Indeed, synthetic indices accounting for different aspects of diversity can even be combined across multiple taxa to provide an overall estimation of the total biodiversity in a given area, allowing conservationists not to be focused on specific aspects of diversity when developing conservation programs (Brum et al., 2017; Isaac et al., 2007).…”