Environmental drivers of Odonate assemblages across biogeographic provinces in the Mexican Transition Zone.

Abstract

This study shows how the different environments and biogeographical provinces in the Mexican Transition Zone influence the structure of odonate communities. Through sampling conducted in 2024 across lentic and lotic habitats in a representative area where four biogeographic provinces converge, habitats were compared by recording physicochemical water parameters and climate conditions. The results revealed that species richness did not vary significantly between habitat types (lentic vs. lotic), but showed marked differences at the biogeographical scale, with the arid and semi-arid zones being the most diverse and high elevations having the lowest species richness. Beta diversity analysis indicated higher turnover than nestedness, suggesting that each region hosts a unique fauna adapted to specific conditions. Environmental variables, such as air and water temperatures and humidity played a crucial role, differentially affecting suborders: Anisoptera showed a greater capacity for dispersal and were more affected by landscape-level, while Zygoptera exhibited higher sensitivity to local factors. We concluded that environmental heterogeneity and biogeographical factors are determinants of odonate biodiversity in the region, with Anisoptera following a classical hierarchical community assembly mechanism and Zygoptera is being influenced and limited by the filter created by environmental factors. It is imperative to implement conservation strategies that protect connectivity and integrity of waterbodies to preserve this unique biological heritage.