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Community Assembly Rules of Fish Assemblages Along a Large Tropical River Catchment: A View from Different Perspectives
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Community ecologist have studied biodiversity worldwide principally focusing on species richness. However, little is known about how species composition varies in space, time and even less about the species role in the ecosystem functioning, which is critical for natural resource management and conservation. In this study, I investigated mechanisms underlying community structure and how environmental and spatial factors influence fish taxonomic and functional (α,β) diversity along a longitudinal gradient in a nearly pristine Neotropical river. Standardized surveys were conducted during the low-water period at 34 sites within the Bita River Basin in the Colombian Llanos. Physical, chemical and landscape parameters were recorded at each site. Asymmetric eigenvector maps were used as spatial variables. To examine the relative influence of spatial and environmental variables on taxonomic and functional diversity, a distance-based redundancy analysis (db-RDA) and variation partitioning analysis were conducted. Results of these two facets of biodiversity showed that environmental filtering and stochastic dynamics might be structuring fish communities in this river system. Variation partitioning analyses for both biodiversity facets revealed that environmental features related to in-stream cover might act as filters structuring fish communities, therefore, in order to preserve fish biodiversity in this diverse river, it is crucial that habitat variability (in-stream cover) and connectivity be preserved.
Lopez Delgado, Edwin Orlando (2019). Community Assembly Rules of Fish Assemblages Along a Large Tropical River Catchment: A View from Different Perspectives. Doctoral dissertation, Texas A & M University. Available electronically from