Animal stoichiometry influences critical processes from organismal physiology to biogeochemical cycles. However, it remains uncertain whether animal stoichiometry follows predictable scaling relationships with body mass and whether adaptation to terrestrial or aquatic environments constrains elemental allocation. We tested both interspecific and intraspecific body-mass scaling relationships for nitrogen (N), phosphorus (P), and N:P content using a subset of the StoichLife database, which includes 9,933 individual animals across 1,543 species spanning 10 orders of magnitude in body mass from terrestrial, freshwater, and marine realms. Our results show that body mass predicts intraspecific stoichiometric variation, accounting for 42-45% of the variation in 27% of vertebrate and 35% of invertebrate species. However, body mass was less effective at explaining interspecific variation, with taxonomic identity emerging as a more significant factor. Differences between aquatic and terrestrial organisms were observed only in invertebrate interspecific %N, suggesting that realm has a relatively minor influence on elemental allocation. Our study, based on the most comprehensive animal stoichiometry database to date, revealed that while body mass is a good predictor of intraspecific elemental content, it is less effective for interspecific patterns. This highlights the importance of evolutionary history and taxonomic identity over general scaling laws in explaining stoichiometric variation.

Understanding what drives the vast variability in species range size is still an outstanding question. Among the several processes potentially affecting species ranges, dispersal is one of the most prominent hypothesized predictors. However, the theoretical expectation of a positive dispersal-range size relationship has received mixed empirical support. Here, we synthesized results from 84 studies to investigate in which context dispersal is most important in driving species range size. We found that dispersal traits -- proxies for dispersal ability -- explain range sizes more often in temperate and subtropical regions than in tropical regions, when considering multiple components of dispersal, and when investigating a large number of species to capture dispersal and range size variation. In plants, positive effects of dispersal on range size were less often detected when examining broad taxonomic levels. In animals, dispersal is more important for range size increase in ectotherms than in endotherms. Our synthesis emphasizes the importance of considering different aspects of the dispersal process -departure, transfer, settlement-, niche aspects and evolutionary components, like time for range expansion and past geological-environmental dynamics. We therefore call for a more integrative view of the dispersal process and its causal relationship with range size.

Mutualistic interactions are essential for ecosystem functioning, such as seed dispersal of plants by animals (frugivory). However, it remains unclear how species extinctions impact interaction network architecture and interaction outcomes. Here, we developed a hierarchical rewiring model based on abundances, traits and phylogeny to identify which frugivory-related traits influence changes in networks and frugivore diets in response to plant species loss. We demonstrate that network architecture and diet are strongly influenced by the total reward and the consumption frequency of fruits with unique combinations of macronutrients. However, there was an uncoupling between network architecture and diet change, suggesting that different plant species modulate network structures and frugivore diets, and the ability of frugivores to shift partners reduced the impact of fruit loss on dietary outcome. Altogether, we reveal mechanistic links between extinctions, architecture and outcomes in mutualistic ecological networks, important to predict species interactions and ecosystem functioning in a changing world.

Short title Macroevolution and ecology drive multiple facets of tree diversityMartha Paola Barajas Barbosa*1,2(paolabarajas@gmail.com)Tiffany M. Knight1,3,4 Renske Onstein5,1 Jonathan Chase1,2 1 German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig, Germany2 Department of Computer Science, Martin Luther University Halle-Wittenberg, Germany3 Department for Community Ecology, Helmholtz Centre for Environmental Research–UFZ, Leipzig, Germany4 Institute of Biology, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany5 Naturalis Biodiversity Center, Darwinweg 2, 2333CR Leiden, the Netherlands*Corresponding author