High amphibian diversity throughout urban environmental heterogeneity

Abstract

Urban growth negatively impacts biodiversity through species loss and biotic homogenization. However, cities continue to grow and there are species with certain functional traits that bypass the urban environmental filters persisting in different urban niches. Our objective was to describe taxonomic and functional groups of amphibians and analyze alpha and beta diversity, relating them to environmental variables that characterize fourteen urban green sites with different types and degrees of urbanization, in the metropolitan area of Santa Fe city, Province of Santa Fe, Argentina. We registered 26 species that belong to 13 genera grouped in 5 families: Microhylidae (1), Odontophrynidae (1), Bufonidae (2), Leptodactylidae (10), Hylidae (12). The fourteen surveyed sites were grouped into five categories with similar urbanistic characteristics. Species richness varied from 4 to 15 species per site and between 12 and 19 species per urban green space category. Species corresponded to 10 functional groups and each urban green spaces categories harbor between 7 and 9 functional groups. Beyond the moderate to low beta diversity values, we found that the different urban green spaces categories are complementary as reservoirs of amphibians, since some categories harbor exclusive species or functional groups, while other urban green spaces categories, without exclusive species or functional groups, shelter numerous populations of some species or functional groups.