Variação sazonal na estrutura de comunidades de drosofilídeos (Insecta; Diptera) em função dos elementos climáticos em remanescente de floresta

Abstract

One of the current issues is to understand how climate change and associated land use change can affect the dynamics of ecosystems. With respect to biodiversity the challenge is primarily to determine your degree of impact, so, estimate their likely response to environmental changes. Among the environmental components that is being investigated are the climatic conditions, which can act as determinant on the structure of communities. The influence of climate variability over the tropical community of frugivorous drosophilids was tested by evaluating the temporal dynamics of species and community structure. The collections were made periodically, from February 2009 to February 2013, in a remnant of primary forest in the metropolitan region of Belém, PA. The drosophilids data were obtained through the method of trap with bait and resource collections (decaying fruits). The weather elements considered were the accumulated rainfall (mm), virtual temperature (° C) and saturation vapour pressure (mb). 34,046 individuals were identified in the Drosophilidae family distributed in 30 species, not all of which associated with the resources. The rainfall was the most important climate variable in the dynamics of the Assembly of drosophilids. The drosophilids responded indirectly to precipitation, reflecting the effects of this variable on the availability and quality of fruit used as place of establishment, and directly through the abundance and species richness collected. The observations indicate the importance of rainfall in providing more appropriate conditions for reproduction, development and survival of the drosophilids, favoring later generations. The assembly of drosophilids presented seasonal behavior in reflection to the local seasonality, conditioned primarily by rainfall. Future climate changes, as announced by IPCC, associated with the reduction of precipitation or change their seasonality can compromise the structure of the community.