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Aim: Patterns of beta diversity reflect the formation dynamics of ecological communities. Here, we integrated geographic, phylogenetic, and phenotypic information of coastal woody vegetation to investigate (1) whether the observed dissimilarity between assemblages differs from that expected by chance, examining the roles of spatial and deterministic processes; (2) the relative contribution of beta‐diversity components (turnover and nestedness) for taxonomic, phylogenetic, and functional beta diversity; and (3) what environmental factors drive the differences in composition between assemblages for all these dimensions. Location: Brazil. Taxon: Angiosperm trees. Methods: We built dissimilarity matrices and partitioned the taxonomic, phylogenetic, and functional beta diversity from an incidence matrix, a phylogeny including the region's plants, and a matrix expressing functional distances. Using linear regressions, we tested the effects of different environmental predictors representative of the effects of water availability, thermal energy, habitat heterogeneity, edaphic constraints, climatic stability, and human influence on beta‐diversity patterns. Results: Taxonomic, phylogenetic, and functional dissimilarities exhibited a typical pattern of greater dissimilarity with distance (i.e., as expected by chance). However, these patterns showed different contributions of beta‐diversity components, predominating turnover in taxonomic and phylogenetic dissimilarity, and nestedness in functional dissimilarity. Water availability had a slight effect on patterns of taxonomic and phylogenetic dissimilarities. Main conclusions: The Brazilian coastal woody vegetation appears to have emerged through a dynamic of colonisation of evolutionarily distinct but functionally similar lineages that originated from adjacent phytogeographic domains, proportional to their diversity. This is consistent with a combination of both neutral and non‐neutral processes. Our findings underscore the complementary roles of different dimensions of beta diversity in explaining the dynamics of these vegetation communities. [ABSTRACT FROM AUTHOR]

The causes of the gradients in species richness remain contentious because of multiple competing hypotheses, significant knowledge gaps, and regional effects of environmental and historical factors on species pools. Coastal zones are subject to particular sets of environmental constraints, thus identifying the drivers of species richness therein should shed light on the regional gradients of species diversity. Here, we investigate the geographic patterns and drivers of plant diversity across coastal regions while allowing for pervasive sampling deficiencies. Based on 142708 records of flowering plant occurrences, we mapped species richness and estimated the level of knowledge across the coastal zone of Brazil. Based on inventory completeness, we used linear regression models to test the predictive power of environmental variables that represent different environmental hypotheses. Few cells (25%) were well-surveyed, reflecting little knowledge about the distribution and diversity of flowering plants on the highly-populated Brazilian coast. Still, we found support for the habitat heterogeneity hypothesis as the best explanation of the variation in species richness of flowering plants in this region. Soil properties and water constraints are also important factors. Although our work emphasises the paucity of information on plant diversity in tropical and human-dominated areas, we show that knowledge limitations should not curb our capability of addressing hypotheses about species diversity. [ABSTRACT FROM AUTHOR]

Understanding the factors driving assembling structure of ecological communities remains a fundamental problem in ecology, especially when focusing on ecological and evolutionary relatedness among species rather than on their taxonomic identity. It remains critical though to separate the patterns and drivers of phylogenetic and functional structures, because traits are phylogenetically constrained, but phylogeny alone does not fully reflect trait variability among species. Using birds from the Brazilian dry forest as a study case, we employed two different approaches to decompose functional structure into its components that are shared and non‐shared with the phylogenetic structure. We investigated the spatial pattern and environmental hypotheses for these phylogenetically constrained and unconstrained aspects of functional structure, including climate‐induced physiological constraints, historical climatic stability, resource availability and habitat partitioning. We found only partial congruence between the two methods of structure decomposition. Still, we found a differential effect of factors on specific components of functional structure of bird assemblages. While climate affects phylogenetically constrained traits through endurance, habitat partitioning (especially forest cover) affects the functional structure that is independent of phylogeny. With this strategy, we were able to decompose the patterns and drivers of the functional structure of birds along a semiarid gradient and showed that the decomposition of the functional structure into its phylogenetic and non‐phylogenetic counterparts can offer a more complete portrait of the assembling rules in ecological communities. We claim for a further development and use of this sort of strategy to investigate assembling rules in ecological communities. [ABSTRACT FROM AUTHOR]

Geographical gradients of body size express climate-driven constraints on animals, but whether they exist and what causes them in ectotherms remains contentious. For amphibians, the water conservation hypothesis posits that larger bodies reduce evaporative water loss (EWL) along dehydrating gradients. To address this hypothesis mechanistically, we build on well-established biophysical equations of water exchange in anurans to propose a state-transition model that predicts an increase of either body size or resistance to EWL as alternative specialization along dehydrating gradients. The model predicts that species whose water economy is more sensitive to variation in body size than to variation in resistance to EWL should increase in size in response to increasing potential evapotranspiration (PET). To evaluate the model predictions, we combine physiological measurements of resistance to EWL with geographic data of body size for four different anuran species. Only one species, Dendropsophus minutus, was predicted to exhibit a positive body size-PET relationship. Results were as predicted for all cases, with one species-Boana faber-showing a negative relationship. Based on an empirically verified mathematical model, we show that clines of body size among anurans depend on the current values of those traits and emerge as an advantage for water conservation. Our model offers a mechanistic and compelling explanation for the cause and variation of gradients of body size in anurans.