Odonata in the brazilian Cerrado: Influence of environmental and spatial factors on dragonfly and damselfly assemblages

Abstract

Environmental and spatial variables can act as filters in species distribution, thereby structuring biological communities. Our study aims to analyze the effects of environmental and spatial factors on the structuring of Odonata assemblages in Cerrado. Testing the hypotheses: (1) the structuring of Odonata larvae and adult assemblages is more influenced by the environment than by space; and (2) the structuring of larvae and adult assemblages of the suborder Anisoptera is more influenced by the environment, while Zygoptera is more influenced by space. We measured physicochemical variables (dissolved oxygen, pH, conductivity and temperature) and Habitat Integrity Index. Data analysis involved the coverage-based rarefaction and extrapolation method, Partial Redundancy Analysis (RDAp), and Principal Coordinates of Neighbor Matrices. Thirteen streams were sampled, collecting 1204 specimens. The sampling effort for larvae showed an efficiency of 98 %, and for adults, 85 %. According to RDAp, the composition for larvae was explained solely by environmental factors, while for adults, there was an explanation by the environment for Anisoptera and by both environmental and spatial factors for the order and Zygoptera. The results highlight the joint influence of environmental and spatial factors on the configuration of adult and larval Odonata assemblages in Cerrado streams. A variety of responses, each corresponding to the specific object of analysis, is evident, driven by divergent eco-physiological characteristics among suborders. These nuances reflect the inherent complexity of the ecology of these aquatic insects, emphasizing the importance of considering both environmental and spatial factors when investigating the dynamics of Odonata communities at different developmental stages.