ARISE: a classification tool for Alpine RIver and Stream Ecosystems

1. Alpine river basins are dynamic and heterogeneous environments both hydrologically and biologically. However, classification approaches that identify structure and patterns in alpine river ecosystems are not well developed or evaluated compared with methods for streams at lower altitude. 2. We undertook field validation of the novel Alpine RIver and Stream Ecosystem classification (ARISE) approach, using data collected from three streams in the French PyrEnEes. Specifically, we evaluated the potential of ARISE to differentiate physicochemical habitat and benthic macroinvertebrate communities between sites in space and time. 3. Using quantitative water source contributions to classify samples, ARISE differentiated streams with contrasting electrical conductivity, water temperature and channel stability. Significant differences were identified between ARISE classifications for selected benthic macroinvertebrate community level descriptors (taxonomic richness, beta diversity, total abundance) and for some individual species. 4. Although ARISE needs to be validated further for other alpine river systems, our results indicate its potential in providing a more objective, quantitative basis to underpin management of alpine stream ecosystems.