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The dispersal-body mass association has been highlighted as a main determinant of biodiversity patterns in metacommunities. However, less attention has been devoted to other well-recognized determinants of metacommunity diversity: the scaling in density and regional richness with body size. Among active dispersers, the increase in movement with body size may enhance local richness and decrease ß-diversity. Nevertheless, the reduction of population size and regional richness with body mass may determine a negative diversity-body size association. Consequently, metacommunity assembly probably emerges from a balance between the effect of these scalings. We formalize this hypothesis by relating the exponents of size-scaling rules with simulated trends in α-, ß- and γ-diversity with body size. Our results highlight that the diversity-body size relationship in metacommunities may be driven by the combined effect of different scaling rules. Given their ubiquity in most terrestrial and aquatic biotas, these scaling rules may represent the basic determinants-backbone-of biodiversity, over which other mechanisms operate determining metacommunity assembly. Further studies are needed, aimed at explaining biodiversity patterns from functional relationships between biological rates and body size, as well as their association with environmental conditions and species interactions.

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Ecological connectivity depends on key elements within the landscape, which can support ecological fluxes, species richness and long-term viability of a biological community. Landscape planning requires clear aims and quantitative approaches to identify which key elements can reinforce the spatial coherence of protected areas design. We aim to explore the probability of the ecological connectivity of forest remnants and amphibian species distributions for current and future climate scenarios across the Central Corridor of the Brazilian Atlantic Forest. Integrating amphibian conservation, climate change and ecological corridors, we design a landscape ranking based on graph and circuit theories. To identify the sensitivity of connected areas to climate-dependent changes, we use the Model for Interdisciplinary Research on Climate by means of simulations for 2080-2100, representing a moderated emission scenario within an optimistic context. Our findings indicate that more than 70% of forest connectivity loss by climate change may drastically reduce amphibian dispersal in this region. We show that high amphibian turnover rates tend to be greater in the north-eastern edges of the corridor across ensembles of forecasts. Our spatial analysis reveals a general pattern of low-conductance areas in landscape surface, yet with some well-connected patches suggesting potential ecological corridors. Atlantic Forest reserves are expected to be less effective in a near future. For improved conservation outcomes, we recommend some landscape paths with low resistance values across space and time. We highlight the importance of maintaining forest remnants in the southern Bahia region by drafting a blueprint for functional biodiversity corridors.

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BACKGROUND: Geographical patterns and degrees of genetic divergence among populations differ between species, reflecting relative potentials for speciation or cladogenesis and differing capacities for environmental adaptation. Identification of factors that contribute to genetic divergence among populations is important to the understanding of why some species exhibit greater interpopulation genetic divergence. In this study, we calculated the mean pairwise genetic distances among populations as species' average genetic divergence by a phylogeny using nuclear and mitochondrial genes of 303 individuals from 33 Cuban Anolis species and estimated species ages by another phylogeny using nuclear and mitochondrial genes of 51 Cuban and 47 non-Cuban Anolis species. We identified factors that influence species' differences in genetic divergence among 26 species of Anolis lizards from Cuba. Species ages, environmental heterogeneity within species ranges, and ecomorph types were considered as factors affecting average genetic divergences among populations. RESULTS: The phylogenies presented in this study provide the most comprehensive sampling of Cuban Anolis species to date. The phylogeny showed more conservative evolution of Anolis ecomorphs within Cuba and identified twig anoles as a monophyletic group. Subsequent Phylogenetic Generalized Least Squares (PGLS) analyses showed that species age was positively correlated with species' average genetic divergence among populations. CONCLUSION: Although previous studies have focused on factors affecting genetic divergence within species, the present study showed for the first time that species differences in genetic divergence could be largely affected by species age.

RESUMO

Diversity analysis by partition is an approach employed in order to understand how communities spatially structure themselves and the factors that operate in the generation and maintenance of distribution patterns. We examined the spatial structure of species diversity of four taxonomic groups, with different dispersal abilities, in 16 forest fragments in the southern region of the state of Minas Gerais, Brazil. Specifically, we tested: i) if the similarity in species composition would be negatively related to geographical distance between the 16 fragments; and ii) if the beta diversity of the different groups could be negatively related to their dispersal abilities. Alpha diversity and the compositional similarity between localities were both low. Beta diversity was not correlated with distance for any of the groups. Primates, followed by birds, showed a higher tendency of forming similarity groupings, although in a manner that was independent from distance between fragments, as well as showed the lowest beta diversity relative values. Spermatophytes and amphibians did not define groupings and presented the highest values of beta diversity. We interpreted such results as indications that the groups with higher dispersal ability (primates and birds) tend to reach, on average, farther localities and, therefore, to define more similar groupings (low beta diversity). The groups with lower dispersal ability (spermatophytes and amphibians) showed the opposite tendency. Although most of the species were restricted to few localities, contributing to the low similarity, beta and gamma diversity values showed the extent which the localities are, respectively, different and complementary to each other in terms of species composition. Such features reinforce and justify future conservation initiatives, both in local and regional levels.

A análise da diversidade por partição é uma abordagem empregada para tentar compreender como as comunidades se estruturam espacialmente e os fatores que operam na geração e manutenção dos padrões de distribuição das espécies. Nós examinamos a estrutura espacial da diversidade de espécies referente a quatro grupos taxonômicos com diferentes capacidades de dispersão, em 16 fragmentos florestais localizados no sul do Estado de Minas Gerais, Brasil. Especificamente, testamos: i) se a similaridade na composição de espécies estaria relacionada negativamente com a distância geográfica entre os fragmentos e ii) se a diversidade beta apresentada por cada grupo poderia ser negativamente relacionada com as respectivas capacidades de dispersão. Tanto a diversidade alfa quanto a similaridade composicional entre as localidades foram baixas. A diversidade beta não esteve correlacionada com a distância para nenhum dos grupos. Os primatas, seguidos das aves, apresentaram maior tendência em formar agrupamentos de similaridade, embora de maneira independente da distância entre os fragmentos, bem como os menores valores relativos de diversidade beta. Já espermatófitas e anfíbios não definiram agrupamentos e apresentaram relativamente os maiores valores de diversidade beta. Interpretamos tais resultados como indicações de que grupos com maior capacidade de dispersão (primatas e aves) tendem a alcançar, em média, localidades mais distantes e, portanto, a definir agrupamentos mais similares (i.e. baixa diversidade beta). Já os grupos com menor capacidade de dispersão (espermatófitas e anfíbios) apresentaram a tendência oposta. Apesar da maioria das espécies terem apresentado ocorrência restrita a poucas localidades, contribuindo para a baixa similaridade, as altas diversidades beta e gama demonstraram o quanto as localidades são distintas e complementares entre si em termos de composição de espécies. [...]

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RESUMO

ABSTRACT Diversity analysis by partition is an approach employed in order to understand how communities spatially structure themselves and the factors that operate in the generation and maintenance of distribution patterns. We examined the spatial structure of species diversity of four taxonomic groups, with different dispersal abilities, in 16 forest fragments in the southern region of the state of Minas Gerais, Brazil. Specifically, we tested: i) if the similarity in species composition would be negatively related to geographical distance between the 16 fragments; and ii) if the beta diversity of the different groups could be negatively related to their dispersal abilities. Alpha diversity and the compositional similarity between localities were both low. Beta diversity was not correlated with distance for any of the groups. Primates, followed by birds, showed a higher tendency of forming similarity groupings, although in a manner that was independent from distance between fragments, as well as showed the lowest beta diversity relative values. Spermatophytes and amphibians did not define groupings and presented the highest values of beta diversity. We interpreted such results as indications that the groups with higher dispersal ability (primates and birds) tend to reach, on average, farther localities and, therefore, to define more similar groupings (low beta diversity). The groups with lower dispersal ability (spermatophytes and amphibians) showed the opposite tendency. Although most of the species were restricted to few localities, contributing to the low similarity, beta and gamma diversity values showed the extent which the localities are, respectively, different and complementary to each other in terms of species composition. Such features reinforce and justify future conservation initiatives, both in local and regional levels.

RESUMO A análise da diversidade por partição é uma abordagem empregada para tentar compreender como as comunidades se estruturam espacialmente e os fatores que operam na geração e manutenção dos padrões de distribuição das espécies. Nós examinamos a estrutura espacial da diversidade de espécies referente a quatro grupos taxonômicos com diferentes capacidades de dispersão, em 16 fragmentos florestais localizados no sul do Estado de Minas Gerais, Brasil. Especificamente, testamos: i) se a similaridade na composição de espécies estaria relacionada negativamente com a distância geográfica entre os fragmentos e ii) se a diversidade beta apresentada por cada grupo poderia ser negativamente relacionada com as respectivas capacidades de dispersão. Tanto a diversidade alfa quanto a similaridade composicional entre as localidades foram baixas. A diversidade beta não esteve correlacionada com a distância para nenhum dos grupos. Os primatas, seguidos das aves, apresentaram maior tendência em formar agrupamentos de similaridade, embora de maneira independente da distância entre os fragmentos, bem como os menores valores relativos de diversidade beta. Já espermatófitas e anfíbios não definiram agrupamentos e apresentaram relativamente os maiores valores de diversidade beta. Interpretamos tais resultados como indicações de que grupos com maior capacidade de dispersão (primatas e aves) tendem a alcançar, em média, localidades mais distantes e, portanto, a definir agrupamentos mais similares (i.e. baixa diversidade beta). Já os grupos com menor capacidade de dispersão (espermatófitas e anfíbios) apresentaram a tendência oposta. Apesar da maioria das espécies terem apresentado ocorrência restrita a poucas localidades, contribuindo para a baixa similaridade, as altas diversidades beta e gama demonstraram o quanto as localidades são distintas e complementares entre si em termos de composição de espécies. Tais características reforçam e justificam futuras iniciativas de conservação, tanto em âmbito local quanto regional.

RESUMO

Diversity analysis by partition is an approach employed in order to understand how communities spatially structure themselves and the factors that operate in the generation and maintenance of distribution patterns. We examined the spatial structure of species diversity of four taxonomic groups, with different dispersal abilities, in 16 forest fragments in the southern region of the state of Minas Gerais, Brazil. Specifically, we tested: i) if the similarity in species composition would be negatively related to geographical distance between the 16 fragments; and ii) if the beta diversity of the different groups could be negatively related to their dispersal abilities. Alpha diversity and the compositional similarity between localities were both low. Beta diversity was not correlated with distance for any of the groups. Primates, followed by birds, showed a higher tendency of forming similarity groupings, although in a manner that was independent from distance between fragments, as well as showed the lowest beta diversity relative values. Spermatophytes and amphibians did not define groupings and presented the highest values of beta diversity. We interpreted such results as indications that the groups with higher dispersal ability (primates and birds) tend to reach, on average, farther localities and, therefore, to define more similar groupings (low beta diversity). The groups with lower dispersal ability (spermatophytes and amphibians) showed the opposite tendency. Although most of the species were restricted to few localities, contributing to the low similarity, beta and gamma diversity values showed the extent which the localities are, respectively, different and complementary to each other in terms of species composition. Such features reinforce and justify future conservation initiatives, both in local and regional levels.(AU)

A análise da diversidade por partição é uma abordagem empregada para tentar compreender como as comunidades se estruturam espacialmente e os fatores que operam na geração e manutenção dos padrões de distribuição das espécies. Nós examinamos a estrutura espacial da diversidade de espécies referente a quatro grupos taxonômicos com diferentes capacidades de dispersão, em 16 fragmentos florestais localizados no sul do Estado de Minas Gerais, Brasil. Especificamente, testamos: i) se a similaridade na composição de espécies estaria relacionada negativamente com a distância geográfica entre os fragmentos e ii) se a diversidade beta apresentada por cada grupo poderia ser negativamente relacionada com as respectivas capacidades de dispersão. Tanto a diversidade alfa quanto a similaridade composicional entre as localidades foram baixas. A diversidade beta não esteve correlacionada com a distância para nenhum dos grupos. Os primatas, seguidos das aves, apresentaram maior tendência em formar agrupamentos de similaridade, embora de maneira independente da distância entre os fragmentos, bem como os menores valores relativos de diversidade beta. Já espermatófitas e anfíbios não definiram agrupamentos e apresentaram relativamente os maiores valores de diversidade beta. Interpretamos tais resultados como indicações de que grupos com maior capacidade de dispersão (primatas e aves) tendem a alcançar, em média, localidades mais distantes e, portanto, a definir agrupamentos mais similares (i.e. baixa diversidade beta). Já os grupos com menor capacidade de dispersão (espermatófitas e anfíbios) apresentaram a tendência oposta. Apesar da maioria das espécies terem apresentado ocorrência restrita a poucas localidades, contribuindo para a baixa similaridade, as altas diversidades beta e gama demonstraram o quanto as localidades são distintas e complementares entre si em termos de composição de espécies. [...](AU)

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Hypotheses to explain phylogeographic structure traditionally invoke geographic features, but often fail to provide a general explanation for spatial patterns of genetic variation. Organisms' intrinsic characteristics might play more important roles than landscape features in determining phylogeographic structure. We developed a novel comparative approach to explore the role of ecological and life-history variables in determining spatial genetic variation and tested it on frog communities in Panama. We quantified spatial genetic variation within 31 anuran species based on mitochondrial DNA sequences, for which hierarchical approximate Bayesian computation analyses rejected simultaneous divergence over a common landscape. Regressing ecological variables, on genetic divergence allowed us to test the importance of individual variables revealing that body size, current landscape resistance, geographic range, biogeographic origin and reproductive mode were significant predictors of spatial genetic variation. Our results support the idea that phylogeographic structure represents the outcome of an interaction between organisms and their environment, and suggest a conceptual integration we refer to as trait-based phylogeography.

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