Colonização de invertebrados aquáticos e decomposição foliar em tanques de Bromeliaceae em um fragmento florestal de Mata Atlântica

Abstract

The Botanical Garden of the Universidade Federal de Juiz de for a (JB-UFJF) is a fragment of the Atlantic Forest in Minas Gerais, where there are bromeliad species whith rosette-shaped leaves forming a tank that accumulates rainwater and provides a habitat for various arthropods that participate in the degradation of organic matter. This process has extreme importance to the metabolism of aquatic ecosystems. In the first chapter of this dissertation, we evaluated the colonization of invertebrates in the central tank of Aechmea blanchetiana (Baker) bromeliads. The experiment lasted 112 days, and every 14 days, three bromeliad specimens were randomly selected for the removal of the central tank contents. The abundance of organisms and taxonomic richness ranged from 0 to 107 individuals and from 1 to 7 taxa per bromeliad, respectively. In total, 15 taxa were recorded in the bromeliads, with most taxa belonging to the Diptera order. There was no correlation between abundance and richness with colonization time or water volume. Although it was expected that the composition of the invertebrate in the initial colonization periods would be more similar to each other and would differ from the later periods, this was not verified in the cluster analysis. In the second chapter, we evaluated leaf decomposition in tanks of Alcantarea imperialis (Carrière) bromeliads. We used leaf discs from three plant species collected at the JB-UFJF: Alchornea sp. (Euphorbiaceae), Xylopia sp. (Annonaceae) and Piptocarpha sp. (Asteraceae). We also analyzed the chemical composition and physical structure of plant species to assess their nutritional quality. Xylopia sp. presented the highest decomposition rate. In general, our decomposition rate was low, similar to studies that analyzed microbial decomposition. Suggesting that decomposition in the A. imperialis tank was mainly carried out by microorganisms, with weak or absent participation of invertebrates. Studies on invertebrate assemblages that colonize bromeliad tanks and their interactions can help understand the ecological processes that occur in these phytotelmata, such as the decomposition process, contributing to the conservation of Atlantic Forest biodiversity.