| Abstract: | We analysed the spatial variation in morphological diversity (MDiv) and speciesrichness (SR) for 91 species of Neotropical Triatominae to determine the ecologicalrelationships between SR and MDiv and to explore the roles that climate,productivity, environmental heterogeneity and the presence of biomes and rivers mayplay in the structuring of species assemblages. For each 110 km x 110 km-cell on agrid map of America, we determined the number of species (SR) and estimated the meanGower index (MDiv) based on 12 morphological attributes. We performed bootstrappinganalyses of species assemblages to identify whether those assemblages were moresimilar or dissimilar in their morphology than expected by chance. We applied amulti-model selection procedure and spatial explicit analyses to account for theassociation of diversity-environment relationships. MDiv and SR both showed alatitudinal gradient, although each peaked at different locations and were thus notstrictly spatially congruent. SR decreased with temperature variability and MDivincreased with mean temperature, suggesting a predominant role for ambient energy indetermining Triatominae diversity. Species that were more similar than expected bychance co-occurred near the limits of the Triatominae distribution in associationwith changes in environmental variables. Environmental filtering may underlie thestructuring of species assemblages near their distributional limits. |
