Bird Phylogenetic Diversity Increases With Temperature Worldwide

[Aim] Temperature significantly influences the composition and structure of biotic communities at large scales. While its rolein shaping taxonomic diversity is well-documented, its relationship with other facets of biodiversity, like phylogenetic diversity,remains poorly known. Understanding how and to which extent temperature contributes to global patterns of phylogeneticdiversity compared to other biodiversity-structuring factors is crucial for comprehending how bird assemblages are structuredworldwide, predicting their response to global-change drivers and supporting conservation policies focused on preserving birdgenetic diversity and evolutionary history.

[Location] Worldwide

[Methods] We analyse the role of temperature in predicting bird regional phylogenetic richness (PD) and divergence (MPD)worldwide, before and after controlling for the effect of species richness (SR). We also assess the shape of this relationship in dif-ferent biogeographic realms and compare its explanatory power with other key biodiversity-structuring factors such as elevation,human impact index, net primary productivity and land use diversity.

[Results] Our findings underscore the high significance and consistency of temperature as a key predictor positively associatedwith bird PD and MPD across the six main biogeographic realms, even after accounting for SR and latitude, suggesting thattemperature modulates the intrinsic capacity of environments to support a diverse array of lineages. In addition, PD and MPDtended to increase at low elevations, but the human-impact index did not effectively predict bird phylogenetic diversity at thisscale. Furthermore, high PD was linked to regions with high primary productivity and high land-use diversity, although both ofthese relationships were strongly mediated by SR.

[Conclusions] This study unveils the key role of temperature in explaining bird phylogenetic diversity worldwide over other keybiodiversity-structuring factors and points to the profound implications that climate change will have on the amount of evolu-tionary history held in bird assemblages, beyond species extinctions or range shifts alone.

This work was supported by Ministerio de Ciencia e Innovación, FJC2021- 046829-I

Peer reviewed