Effects of a Landscape Gradient on the Diversity of Odonates in the Legalamazonia Zone of the Brazilian State of Maranhão

Abstract The various ecosystems of the Amazon biome play a vital role in the maintenance of biodiversity, as well as providing important ecosystem services at local and global levels. Small-bodied generalists include a number of important groups, such as the insects of the order Odonata. Given their sensitivity to environmental alterations, odonates are also valuable bioindicators of environmental quality. In this context, the present study evaluated the distribution of the diversity of adult odonates in the Legal Amazonia zone of the Brazilian state of Maranhão, to verify which environmental variables are the most important drivers of the structure of the local odonate communities. To test these predictions, we sampled 27 streams along a landscape gradient located in the hydrographic basin of the Pindaré River in the Legal Amazonia zone of the Brazilian state of Maranhão. The results of the study indicated that alterations in the environment are reflected in the odonate diversity recorded at each site, with the assemblages of degraded environments having a predominance of more generalist species. However, some of these species are threatened by the loss of habitats, primarily denser vegetation. However, such species are threatened by habitat loss, particularly dense vegetation. Despite this, the discovery of Erythrodiplax unimaculata in Maranhão highlights ongoing biodiversity revelations. The study underscores the urgent need for continuous monitoring to mitigate biodiversity loss in the face of widespread environmental disturbances in the region.