Autocorrelação espacial da riqueza e da abundância de mamíferos ao longo do corredor Cerrado-Pantanal, Brasil Central

In this paper, we evaluated spatial patterns in mammalian fauna obtained using 75,000 camera-trap hours in 33 fragments at the Cerrado-Pantanal border, along an east-west axis and flanked by two relatively large preserved areas. This region has been proposed as an ecological corridor, connecting these two large ecosystems. The richness of species obtained (total = 33) was explained by the area and the number of habitats in each fragment. The abundance of small-bodied species tends to have significant spatial patterns, whereas variation in the abundance of large-bodied species is randomly distributed in the geographical space. No faunal transition (changes in species compositions) between the two ecosystems was identified. Key words: camera trap, Cerrado, ecological corridor, Pantanal, mammals.Neste trabalho, avaliamos o padrão espacial da mastofauna através de 75.000 horas de esforço amostral obtidas por armadilhas fotográficas instaladas em 33 fragmentos em uma região de transição entre o Cerrado e o Pantanal, ao longo de um eixo Leste-Oeste, entre duas áreas relativamente grandes e bem preservadas. Esta região tem sido proposta como um corredor ecológico, conectando estes dois grandes ecossistemas. A riqueza de espécies obtida (total de 33 espécies) foi explicada pela área e pelo número de hábitats em cada fragmento. A abundância de espécies de pequeno porte tende a apresentar padrões espaciais significativos, enquanto a variação na abundância de espécies de grande porte é aleatoriamente distribuída no espaço geográfico. Não foi identificada uma transição faunística (mudança na composição de espécies) entre os dois ecossistemas. Palavras-chave: armadilha fotográfica, Cerrado, corredor ecológico, Pantanal, mamíferos

Modeling body size evolution in Felidae under alternative phylogenetic hypotheses

The use of phylogenetic comparative methods in ecological research has advanced during the last twenty years, mainly due to accurate phylogenetic reconstructions based on molecular data and computational and statistical advances. We used phylogenetic correlograms and phylogenetic eigenvector regression (PVR) to model body size evolution in 35 worldwide Felidae (Mammalia, Carnivora) species using two alternative phylogenies and published body size data. The purpose was not to contrast the phylogenetic hypotheses but to evaluate how analyses of body size evolution patterns can be affected by the phylogeny used for comparative analyses (CA). Both phylogenies produced a strong phylogenetic pattern, with closely related species having similar body sizes and the similarity decreasing with increasing distances in time. The PVR explained 65% to 67% of body size variation and all Moran's I values for the PVR residuals were non-significant, indicating that both these models explained phylogenetic structures in trait variation. Even though our results did not suggest that any phylogeny can be used for CA with the same power, or that “good” phylogenies are unnecessary for the correct interpretation of the evolutionary dynamics of ecological, biogeographical, physiological or behavioral patterns, it does suggest that developments in CA can, and indeed should, proceed without waiting for perfect and fully resolved phylogenies

Phylogenetic autocorrelation and evolutionary interpretation of the higher-taxon approach for biodiversity analyses

Although in most recent broad-scale analyses, diversity is measured by counting the number of species in a given area or spatial unity (species richness), a `top-down' approach has been used sometimes, counting higher-taxon (genera, family) instead of species with some advantages. However, this higher-taxon approach is quite empirical and the cut-off level is usually arbitrarily defined. In this work, we show that the higher-taxon approach could be theoretically linked with models of phenotypic diversification by means of phylogenetic autocorrelation analysis in such a way that the taxonomic (or phylogenetic) rank to be used could not be necessarily arbitrary. This rank expresses past time in which taxa became independent for a given phenotypic trait or for the evolution of average phenotypes across different traits. We illustrated the approach by evaluating phylogenetic patches for 23 morphological, ecological and behavioural characters in New World terrestrial Carnivora. The higher-taxon counts at 18.8 mya (S L) defined by phylogenetic correlograms are highly correlated with species richness (r = 0.899; P < 0.001 with ca. 13 degrees of freedom by taking spatial autocorrelation into account). However, S L in North America is usually larger than in South America. Thus, although there are more species in South and Central America, the fast recent diversification that occurred in this region generated species that are "redundant" in relation to lineages that were present at 18.8 my. BP. Therefore, the number of lineages can be comparatively used as a measure of evolutionary diversity under a given model of phenotypic divergence among lower taxonomic units