Influência da conexão sobre as respostas da diversidade local e beta de macroinvertebrados bentônicos para oscilações no nível hidrológico.

Abstract

The hydrological regime is the main driver of ecosystems, as it has strong control over environmental and biological variables. The types of lake systems comprise different, including those sporadically isolated and isolated individuals (LP) to isolated individuals. It is expected that variations in the hydrological level exert different types of habitats on these two types of communities, directly influencing the structure of the communities of these vertebrae, as well as the benthic macroinvertebrates. Evidence of biodiversity from macroinvertebrate communities and LPs to hydrological variations still in LE is scarce and comes from small in spatial and temporal scales. Invest as a richness, density and beta diversity of macroinvertebrates of the community at different hydrological periods (lower, intermediate and high-level periods in LE and LP. A time series of 1 of the hydrological level and biological samples from six lakes were used (LE and 3 LP) from 3 biological years of the upper Paraná River flooding. Richness was obtained in periods of major and minor oscillations and high density in periods of hydrological oscillations. These curvilinear relationships are both LE and for LP, the diversity of benthic macroinvertebrates between periods of low oscillations differed, high beta only in LE. The low regional level periods more for water level beta diversity) the low water level periods BD, the LP higher. According to Redundancy Analysis (RDA), both in LE and macroinvertebrate diversity was mainly structured by environmental factors (ie, oxygen, consonance, turbidity, fish density and macrophyte richness) during periods of low water level. On the other hand, during periods of high hydrological level, the hydrological level was a single structuring forcing of macroinvertebrate diversity. Based on the results obtained, the responses of the macroinvertebrate community to hydrological oscillations tend to be different in LE and LP. Specifically, these are the most pronounced responses in LE, where local environmental factors play a stronger structuring role. The greatest contribution that LE and LP occur to macroinvertebrate diversity in different hydrological periods. Therefore, this evidence that preserves the wide variety of LE and LP in the floodplain is critical to maintaining local and regional biotic communities.