Hierarchical Analyses Of French Macroinvertebrate Communities' Responses To Anthropogenic Multi-Scale Stressors

Large scale macroecological and metacommunity research is developed to identify patterns and processes of ecosystems and biotic community changes. Too often though, studies of change in the occurrence of species and communities fail to identify the drivers of change, as they often lack the biogeographical context, or the fine-grained data needed to identify the relevant parameters and processes. More specifically they fail to consider or express the hierarchical relationships between the drivers and stressors among the different spatial scales. We couple a large scale biogeographical and metacommunity structure analysis with a fine-grained community analysis, over an extended dataset of macroinvertebrates samples. Hereto we gathered a large river basin dataset of both biotic and environmental data and broke it up in catchment units by specifying a catchment scale of interest for looking at metacommunity patterns. Through statistical analysis we partitioned the total variance between the different scales, with emphasis on differences between catchments of both geographical-climatic and human stressor origin. The identified patterns of response to stressors both in biotic indices and community composition change can furthermore be linked to community trait characteristics to identify drivers of (bio) geographic character and anthropogenic stress gradients.