Efeitos da urbanização na variabilidade intra- e interespecífica de atributos fenotípicos em metacomunidades de anfíbios

Abstract

The conversion of natural landscapes into new urban ecosystems alters various ecological and evolutionary processes and, consequently, community assembly. This not only leads to a change in species identity within communities but also modifies the distribution of phenotypes and the phylogenetic distance among co-occurring species. However, little is known about how city age and size impact the phenotypes of species with limited dispersal ability. In this dissertation, I tested whether urbanization gradients constrain the variation in phenotypic traits in amphibians and the role of trait evolution in community assembly. To this end, we assessed local and landscape environmental variables in 20 ponds in Campo Grande (MS) and 20 others in São José dos Campos (SP). We measured phenotypic traits related to the impact niche, such as head length and width (mm), and to the requirement niche: snout-vent length, thigh length, tibia length, and foot length (mm) for each species in each pond. We partitioned phenotypic variation across hierarchical levels and tested the effect of local and landscape environmental variables on phenotypic traits. Finally, we tested how the inherited and adaptive components of phenotypic variation are influenced by the urban gradient. There was a homogenization of traits within anuran populations at the community scale in both cities. The effect of local and landscape environmental variables and the sources of phenotypic variation differed between cities. Pure functional dissimilarity was higher within cities, but its magnitude varied between them. Only São José dos Campos showed evidence of evolutionary convergence, such as in body size. Our results suggest that not only city age but also the pace of urbanization can alter the magnitude of the effect and the response of anurans, even among tropical cities.