Spatiotemporal dynamics in caddisfly (Insecta: Trichoptera) of a Cerrado stream, Brazil

Abstract

Knowing the patterns and mechanisms that regulate spatiotemporal dynamics in aquatic communities is a great challenge. Theoretically, the distribution of aquatic insects is related to food and shelter availability, and/or to dispersal. In this perspective, we analyzed the spatiotemporal variation of Trichoptera communities of a Cerrado stream for 3 years. The longitudinal and temporal distribution provided a good explanation of the variation of the Trichoptera species composition. Specifically, 21.4 and 11.5% of the variation in composition was explained by longitudinal and temporal variation, respectively, and 8.3% by the interaction of both factors. The variation of environmental conditions (pH, total dissolved solids and dissolved oxygen) and temporal autocorrelation were the most important predictors for the distribution of Trichoptera communities. Accordingly, it is possible to assume that seasonal variation throughout the year is also an important factor for this aquatic community, in addition to water quality, as is widely known. Therefore, climate change should affect both temporal and spatial patterns of Trichoptera communities present in Cerrado streams. Consequently, such effect should be expected to occur in other regions with more marked seasons.