Unraveling the Taxonomic, Functional, and Phylogenetic Diversity of Lizard Assemblages in Riparian Forest Areas in the Amazon–Pantanal Ecotone

Abstract

Historical, ecological, and biogeographical processes have shaped species distribution and diversity on Earth. However, in ecotonal regions, the action of these processes becomes even more complex. In this study, we analyzed how species richness (SR), as well as functional diversity (standardized functional diversity—SES.FD, functional dispersion—FDis, and functional redundancy—FR), and phylogenetic diversity (phylogenetic species variability – PSV and phylogenetic redundancy – PR) of lizard assemblages varied along riparian forests in the Amazon–Pantanal ecotone. Sampling was carried out at 24 sites distributed along the Paraguay River in Brazil, using pitfall traps and active searches. We recorded 262 lizards from 13 species and 8 families. Species composition differed among the sampled ecoregions. Functional redundancy (FR) and PR were greater in the riparian forest areas of the Amazon; PSV was greater in the assemblages from the Pantanal and Amazon–Pantanal ecotone, while SR, SES.FD, and FDis did not differ among the regions. The variation in the diversity patterns of the lizard assemblages is probably a result of the different environmental conditions and evolutionary histories among these ecoregions and their ecotone. The greater diversity of lineages in the lizard assemblages of the riparian forest areas from the Pantanal was probably influenced by the contact between ecologically and historically distinct regions. However, the lower redundancy in the traits and lineages of these assemblages indicates that they are highly susceptible to disturbances, emphasizing the need for conservation policies and actions to protect the lizard assemblages in the world's largest floodplain area.