Diversidade taxonômica e funcional do zooplâncton em reservatórios tropicais: fatores determinantes das variações nas escalas local e regional

Abstract

A great desire of ecologists is to understand how metacommunities are formed and structures throughout space. Many theories have been created to try to unravel the mysteries of how species are distributed and form communities across geographic space. However, currently, there are two main theories used to explain this phenomenon: the Neutral Theory and the Niche Theory. Today it is known that both theories can influence communities depending on the breadth of the scales being studied. Thus, the objective of this research is to evaluate dissimilarity of taxonomic and functional diversity at different geographical scales, in addition to assessing the relative importance of different processes (environmental, spatial and climatic) in the structuring of the zooplankton community in reservoirs in different climates. For this, we use the additive partition of diversity, evaluating from a local scale (reservoirs-β1) to a more regional scale (climates-β2). In all, collections were made in two sampling campaigns in 79 reservoirs distributed in different climatic zones between August 2019 and March 2020; of which 27 reservoirs belonged to the AS1 climate, 34 to the AS2 climate and 18 to the BsH climate. Chemical and physical samples of the reservoir's local characteristics were sampled, as well as climatic variables such as air temperature and precipitation. To assess the importance of spatial processes, a geographic distance matrix was built and submitted to the Principal Coordinates of Neighboring Matrices (PCNM) using the geographical coordinates of each reservoir. As a result, we observed that the dissimilarity of the zooplankton community is greater at local scales. We also observed that the structuring of this community is influenced mainly by local processes. However, only the local environmental processes alone, were not able to respond to all variation of the community in space, which means that spatial and climatic processes also participated in the assembly of the community. These results can be used for environmental preservation projects, as well as collaborating for works that aim to mitigate the extinction of aquatic species.