Padrões metacomunitários de insetos aquáticos de riachos florestados da Amazônia

• Autor(a) principal: Nogueira, Denis Silva
• Data de Publicação: 2015
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Repositório Institucional da UFG
• Texto Completo: http://repositorio.bc.ufg.br/tede/handle/tede/5664
• topic: Amazônia; Ecologia de riachos; Metacomunidades; Insetos aquáticos; Seleção de habitats; Interações bióticas; Amazon; Stream ecology; Metacommunity; Aquatic insects; Habitat filters; Biotic interactions; CIENCIAS BIOLOGICAS::ECOLOGIA

Lotic ecosystems are highly complex interacting with acting factors in different spatial and temporal scales. Small forested streams receive direct influence of the surrounding vegetation through the input of organic matter which is the base of the food chain in these ecosystems. I studied the effect of the reduced-impact selective logging on communities of aquatic insects streams to test the hypothesis that communities are affected by their impacts. Despite the metrics used appropriately capture the impact, there were no negative effects on insect communities. However, the results of this study may not be generalizable to other systems because we studied only a fraction of the diversity of Amazonian streams, specifically the insect orders Trichoptera, Plecoptera and Coleoptera. In addition, the absence of the low impact management effects is dependent on the operating system adopted in each enterprise. Another predominant feature in any lotic ecosystem is its directional flow, which consequently affects the distribution of substrates, habitats, and food resources within the streams. I studied the effects of water flow taking it as the main predictor of the selective effect of habitat on the attributes of insect taxa. My hypothesis was confirmed by showing that most rapid flowing streams in Amazon has faunas with morphological and ecological attributes of greater resistance to flow. Environmental factors such as the preference for habitats, dispersive limitation and biotic interactions are among the main mechanisms responsible for structuring communities, and has been widely emphasized in the context of metacommunity theory. A metacommunity is defined as the set of communities in a region which are interconnected by the flow of individuals, which emphasizes the spatial dynamics in structuring the diversity and composition of species in each local community. I tested the effects of environmental factors, spatial filters and biotic interactions in aquatic insects of forested streams of the Amazon, specifically the intraguild segregation and interguild predation effect. My results support the existence of predation effects on the organization of the metacommunity, as evidenced by the exclusive fraction of the predators matrix on prey assemblages of different guilds, and still withstand environmental effects and dispersive limitation in different trophic guilds. The study developed in this thesis help us understand more clearly the effects of the selective logging impacts on aquatic insect communities, assist in understanding about what are the characteristics of the stream habitats filter ecological and morphological attributes of aquatic insects in the Amazon, and advance our understanding of the effects that biotic interactions may have on the structuring streams metacommunities.