Spatial autocorrelation signatures of ecological determinants on plant community characteristics in high Andean wetlands

Abstract

Understanding how biological communities are shaped is a central tenet of community ecology. Recent evidence highlights the potential of decoupling diversity spatial autocorrelation into its positive and negative components to reveal community assembly processes that would otherwise remain undetected, as well as to improve understanding of their impacts on different facets of diversity. Yet, such approaches have only been implemented to investigate the effects of a few assembly drivers on a small number of diversity components. Here, we used high Andean wetland plant communities over a strong latitudinal gradient to investigate the effects of various ecological factors on spatial autocorrelation patterns of nine community metrics with different informative values, including measures of richness, dominance, evenness and beta-diversity. By combining Moran’s Eigenvector Maps, partial least squares structural equation modeling, and regression analyses, we revealed two groups of community parameters presenting contrasting spatial patterns due to specific sensitivities to ecological factors. While environmental variation and wetland connectivity increased positive spatial autocorrelation in richness and dominance-related parameters, species co-occurrence promoted negative spatial autocorrelation in evenness-related parameters. These results offer new insights regarding both how ecological processes affect species assembly, as well as the information captured by classical taxonomic parameters.