DOI: 10.5061/dryad.bzkh189f0
title: Body size and trophic levels explain global asymmetric response of tetrapod diversity to climate effects

description: Although climate-based hypotheses are widely used to explain large-scale
 diversity patterns, they fall short of explaining the spatial variation
 among taxonomic groups. Integrating food web and metabolic theories into
 macroecology is a promising step forward, as they allow including explicit
 taxon-specific traits that can potentially mediate the relationship
 between climate and diversity. Our investigation focuses on the role of
 body size and trophic structure in mediating the influence of contemporary
 climate and historical climate change on global tetrapods species
 richness. We used piecewise structural equation modeling to assess the
 direct effects of contemporary climate and climate instability of species
 richness and  the indirect effects of climate on tetrapod
 richness mediated by community-wide species traits. We found that birds
 and mammals are less sensitive to the direct effect of contemporary
 climate than amphibians and squamates. Contemporary climate and climate
 instability favored the species richness in mammals and amphibians.
 However, for birds and squamates, this link is only associated with
 contemporary climate. Moreover, we demonstrated that community-wide traits
 favored the species richness gradients of tetrapod groups, except
 amphibians, but this link depends on traits and taxonomic groups.
 Specifically, bird communities with smaller bodies and bottom-heavy
 structures support higher species richness. Squamates also tend to be more
 diverse in communities with prevalence of smaller bodies, while mammals
 are correlated with top-heavy structures. Moreover, we show that higher
 contemporary climate and climate instability reduce the species richness
 of birds and mammals through community-wide traits and tend indirectly
 improve squamate species richness. Thus, we showed the significance of
 body size and trophic structure effect in driving a global asymmetric
 response of tetrapod diversity to climate effects highlights the
 limitations of applying "typical" climate-based hypotheses.
 Furthermore, by combining multiple theories, our research contributes to a
 more realistic and mechanistic understanding of diversity patterns across
 taxonomic groups.
description: # BODY SIZE AND TROPHIC LEVELS EXPLAIN GLOBAL ASYMMETRIC RESPONSE OF
 TETRAPOD DIVERSITY TO CLIMATE EFFECTS ### Datasets included: 1\) Bird *
 Data_bird: Data of occorrence and traits of communities (i.e., median of
 body size, variance and mean trophiv level) * Script_bird: Script to
 reproduce the results of birds. Contens the models, dbMEM and pSEM. 2\)
 Mammals * Data_mammal: Data of occorrence and traits of communities (i.e.,
 median of body size, variance and mean trophiv level) * Script_mammal:
 Script to reproduce the results of mammals. Contens the models, dbMEM and
 pSEM. 3\) Amphibian * Data_amph: Data of occorrence and traits of
 communities (i.e., median of body size, variance and mean trophiv level) *
 Script_amph: Script to reproduce the results of Amphibians. Contens the
 models, dbMEM and pSEM. 4\) Squamates * Data_lizards: Data of occorrence
 and traits of communities (i.e., median of body size, variance and mean
 trophiv level) * Script_lizards: Script to reproduce the results of
 Squamates. Contens the models, dbMEM and pSEM. .R: Data of each group,
 Moran eingvector and climate datas. Script R: Script to reproduce the
 results of the paper