Aquatic insects of streams: investigating the role of environmental and spatial factors on beta diversity

Abstract

The search for understanding the role of environmental and spatial factors on the structuring of communities has been a central issue in ecology and evolution. In this context, during the development of this research plan, we will analyze different datasets on metacommunities of aquatic insects in streams in order to answer the following questions: 1) which are the most important factors in structuring the metacommunities of aquatic insects, environmental or spatial factors? 2) do environmental and/or spatial factors explain similarly different components of beta diversity (total beta diversity, species replacement and nestedness) of metacommunities of aquatic insects? 3) do the beta diversity, and the relative importance of environmental and spatial factors change when considering streams with different sizes and in landscapes with different reliefs (hilly or not hilly)? Our hypotheses are: 1) that environmental factors are more relevant than spatial factors; 2) that beta diversity, especially the replacement component, is higher among smaller streams than among larger streams; 3) that beta diversity is higher among streams in landscapes with hilly relief, where a higher environmental gradient (e.g. greater hydraulic variability) is expected to occur, than among streams in not hilly relief. The present plan will be developed together with the research group of Dr. R. D. Holt (Department of Biology, University of Florida). Therefore, in addition to the specific objectives of this research plan, we intend to establish a long-term research partnership between the research group of Dr. Holt and the research group of the Laboratory of Aquatic Biology of UNESP Assis. (AU)