Drivers of spatio-temporal dissimilarity in community composition: temporal changes in land use and environmental heterogeneity.

Abstract

Biodiversity encompasses multiple aspects or facets changing in space and time. Before a loss of biodiversity in response to anthropogenic impacts it is of the utmost importance to determine what facets of biodiversity are altered and the determinants of such changes. By using information from species abundance, their evolutionary relatedness, and ecological traits we determine how the dissimilarity in composition of fish communities is influenced by temporal changes in land use and changes in environmental heterogeneity across space. In the first approach, we can see that changes in land use over time affected mainly the substitution of evolutionary lineages and functional traits. In the second approach, we find evidence of taxonomic and functional homogenization over time, likely following a decrease in diversity of traits related to habitat use. Furthermore, we found that ecological traits contributed differently to the changes in functional composition as well in their response to environmental heterogeneity. These results support recently evidence showing that anthropogenic impacts are driving changes in biological communities through a taxonomic and functional homogenization.