Structuring of Dragonfly Communities (Insecta: Odonata) in Eastern Amazon: Effects of Environmental and Spatial Factors in Preserved and Altered Streams.

Oliveira-Junior Oliveira-Junior,Juen Juen

doi:10.3390/insects10100322

Abstract

The evaluation of the effects of environmental factors on natural communities has been one of the principal approaches in ecology; although, over the past decade, increasing importance has been given to spatial factors. In this context, we evaluated the relative importance of environmental and spatial factors for the structuring of the local odonate communities in preserved and altered streams. Adult Odonata were sampled in 98 streams in eastern Amazonia, Brazil. The physical features of each stream were evaluated and spatial variables were generated. Only environmental factors accounted for the variation in the Odonata community. The same pattern was observed in the suborder Zygoptera. For Anisoptera, environmental factors alone affect the variation in the community, considering all the environments together, and the altered areas on their own. As the two Odonata suborders presented distinct responses to environmental factors, this partitioning may contribute to an improvement in the precision of studies in biomonitoring. We thus suggest that studies would have a greater explanatory potential if additional variables are included, related to biotic interactions (e.g., competition). This will require further investigation on a finer scale of environmental variation to determine how the Odonata fauna of Amazonian streams behaves under this analytical perspective.

Highlights

One of the primary objectives of ecological research has traditionally been the understanding of the factors that determine the distribution of species in natural environments [1]
Most (2415) of the specimens belonged to the suborder Zygoptera, distributed in six families (Calopterygidae, Coenagrionidae, Dicteriadidae, Megapodagrionidae, Perilestidae, and Polythoridae), 20 genera, and 71 species
While some studies have shown that landscape-level factors, such as the geology, area, and other geographic parameters, are at least as important as environmental factors, such as the physical–chemical characteristics of the water [91,92], the present study indicated that these variables have a reduced power of explanation

Summary

Introduction

One of the primary objectives of ecological research has traditionally been the understanding of the factors that determine the distribution of species in natural environments [1]. The variation over time in the composition and abundance of species in a community provides an important parameter for the understanding of the processes that determine its structure [1]. More complex environments would be expected to have a higher species richness due to the greater diversity of ecological niches, related primarily to the availability of feeding resources and environmental conditions [3]. From this perspective, most ecological studies have focused on the environmental factors that determine community structure on a local scale [4].

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Results

Discussion

Conclusion