Contrasting responses of Odonata diversity to the rainy season in lentic and lotic habitats in Colombia

Abstract

The diversity of adult odonates in two artificial aquatic ecosystems in the Colombian Orinoquía region, a drainage canal and artificial ponds, was assessed in 2020 during both rainy and dry seasons. A total of 66 odonate species were recorded, 15 in the drainage canal and 51 in the artificial ponds. Overall, the assemblage was predominantly composed of common species; however, rare and threatened species (Acanthagrion fluviatile, Agriogomphus jessei) were also documented. Variation in rainfall between the two seasons influenced both species richness and community composition in each aquatic system. Although the ponds maintained higher overall richness, the drainage canal showed a significant increase during the rainy season compared to the dry season, reflecting a positive response to greater water availability and habitat heterogeneity and with a predominance of Zygoptera. In contrast, Anisoptera predominated in the ponds, which exhibited similar richness values between seasons, suggesting greater environmental stability. Despite their artificial origin and human-induced modifications, these water bodies serve as important habitats for various odonate species throughout the year, functioning as temporary refuges that buffer the ecological impacts of seasonal climatic fluctuations.