Estrutura e papeis topológicos de espécies de serpentes numa rede trófica no cerrado brasileiro

Abstract

Ecological interactions play a key role in shaping biodiversity. Trophic interaction networksrepresent an important link between biodiversity, ecological communities, and ecosystemfunctioning. They allow us to understand the ecosystem-level consequences of biodiversityloss and to identify species and structural characteristics that may confer stabilitytocommunities. Using an ecological networks approach, we structured a trophic networkof asnake assembly in the Brazilian Cerrado, to assess the foodweb structure, the topological roles of the species, and to identify the most central species and those with broader effectsinthe foodweb. The foodweb exhibited a significant modular structure (M= 0.58; p =<0.05, n= 500 randomizations), and encompasses 151 species, including 68 snakes and 83trophiccomponents representing preys at different taxonomic levels. Using the SAalgorithm, weidentified 11 modules. Within these modules, 7 trophic components were module hubs, interacting with several species within the modules, with a pitviper species (Bothropsneuwiedi) being the module hub with the highest number of interactions in the foodweb. Among the species connecting the network modules, the patagonia green racer (Philodryaspatagoniensis) exhibited the highest centrality, representing the species with the greatest influence in the network, both through its direct and indirect interactions. We usedtheJaccard index to explore the dietary similarity of the snakes using the UPGMAmethod. Connector species and module hubs with higher centrality showed lowdietary similarity, suggesting that they may be functionally complementary and connect the trophic networkthrough different pathways via direct and indirect interactions. Additionally, these conectorspecies tend to occupy different modules, suggesting that competition may play an important role in structuring some of these modules. Our results also suggest that there maybeaphylogenetic signal in the structuring of the foodweb. This study provides a useful tool forpredicting impacts on snake assemblages based on trophic data and can aid conservation and management strategies in the face of imminent habitat loss, highlighting the importanceofthe roles of snake species play in the Cerrado biome.