Tropical stream macroalgae: evaluating the effects of environmental and spatial drivers on the distribution of beta diversity at different scales

Abstract

The lotic ecosystems have a very rich biota, formed by organisms with different reproductive strategies and dispersion mechanisms, among which are the macroalgae. Macroalgae have been treated as one of the most important primary producers in tropical streams, since they are at the base of the trophic web of these ecosystems. Recent studies have shown that the structure of tropical lotic macroalgae communities can be strongly influenced by a combination of environmental and spatial factors, as well as the spatial scale of observation. Such information indicate that these organisms may represent a real opportunity to expand the understanding of the influence that the environment and the space have on the distribution patterns of diversity, in its different components. In this context, this research project was established in order to investigate the relative role of local environmental factors and spatial factors on beta diversity (and its components) in tropical lotic macroalgal communities at different spatial scales. Based on available databases, the development of this research project aims, specifically, to address the following issues: i) the beta diversity of the lotic macroalgae communities, and their components (nesting and species substitution), are influenced by the scale of observation and the type of biome?; ii) the components of beta diversity (nesting and species substitution) vary in a similar way regardless of the scale of observation and the type of biome? ; iii) the relative influence of local environmental factors and spatial factors on the components of beta diversity (nesting and species substitution) is similar regardless of the scale of observation and the type of biome?; and iv) there is an effect of taxonomic dependence, considering the algal phyla, on the patterns of beta diversity under different scales and types of biome? Considering that this research project will be developed in collaboration with Dr. Robert D. Holt, Eminent Scholar in Biology, Department of Biology, University of Florida (UF), it is hoped, apart from the specific scientific results, the beginning of a fruitful long-term association between our research group (UNESP/FCL/Assis) and the group led by Dr. Holt. (AU)