Diversidade funcional de abelhas e de plantas em áreas restauradas na parte sul da floresta atlântica, no município de Antonina (PR)

Abstract

Pollination by biotic agents is a key factor for the reproduction and maintenance of most angiosperms, with bees being the main pollinator group. Mutualistic interactions, such as those between bees and plants tend to influence the structure and functioning of both communities involved, as well as their responses to environmental changes. High rates of bee species loss and the steady decline of conserved areas of the Atlantic Forest by anthropic pressure make it urgent to investigate these communities in order to obtain species surveys, to understand the processes that structure their communities, population dynamics and ecosystem services. Functional ecology has been widely used to investigate how communities respond to environmental changes. In this study, restored areas in initial successional stage, in two ecological reserves in Antonina/PR were analyzed. It is premised that environmental factors can promote changes in the proportion of functional traits presented by bee and plant communities, also altering the functional diversity of these groups in space and time. Functional traits were established for 97 species of bees and 56 species of plants. The functional diversity indexes - FDis, FRic, FEve and FDiv - were calculated and then compared using student t test or Kruskal-Wallis between sample months, ecological restoration methods (natural regeneration and reforestation), and restoration time (four and six years). The correlation between the indexes of functional diversity and climatic factors (precipitation, temperature and photoperiod) was tested. With the bees and plants interaction data, it was verified if the functional similarity predicted the similarity of mutualistic partners; also, using method of regression matrices, the most important functional traits in the establishment of the interactions, were analyzed. There was a difference in the bees functional diversity between methods and restoration time, while for plants there was a difference between restoration time and sample months. Functional diversity for both communities was correlated to climatic factors, with warmer months being more heterogeneous in the availability of floral resources, as well as greater bee diversity in activity. In addition, species with similar functional traits tend to interact with the same mutualistic partners. For bees, the most important functional traits in the establishment of interactions were nest location, body size and mouthparts, whereas for plants the most important traits were color and shape of the corolla, and life form. The results showed that small variations in environmental characteristics, as well as climatic factors, can alter functional diversity, although all traits states are generally present in all months, methods and restoration times. Analyzing functional diversity is critical not only to better understand the influence of environmental changes on community structure and functioning, but also to understand how functional attributes affect the establishment of interactions.