Phylogenetic diversity efficiently and accurately prioritizes the conservation of aquatic macroinvertebrate communities

Abstract

131. Land degradation is a leading cause of biodiversity loss yet its consequences on freshwater 14 ecosystems are poorly understood, exacerbating difficulties with assessing ecosystem quality 15 and the effectiveness of restoration practices. 16 2. Many monitoring programs rely on macroinvertebrates to assess the biotic effects of degra-17 dation and/or restoration and management actions on freshwater ecosystems. The ratio of 18 Observed (O) to Expected (E) macroinvertebrate taxa at a given site-O/E-is often used 19 for this purpose, despite the amount of modeling and data required to generate expectations 20 and difficulties quantitatively assessing the degree of degradation at a site.21 3. Despite widespread use in academic biology, phylogenetic diversity is rarely applied in man-22 agement, regardless of empirical correlations between phylogenetic diversity and management 23 targets such as ecosystem structure and function.24 4. We use macroinvertebrate data from 1,400 watersheds to evaluate the potential for phyloge-25 netic metrics to inform evaluations of management practices. These data have been collected 26 since 1998, and have been used to determine the effectiveness of conservation management for 27 the maintenance and restoration of riparian and aquatic systems.28 5. Phylogenetic diversity detected degradation as effectively as O/E, despite not having baseline 29 'expectation' data. Site disturbance, road density, and broader environmental drivers such as 30 mean annual temperature strongly predicted site phylogenetic diversity, providing concrete 31 management objectives to increase site health. 32 6. Synthesis and applications. Management efforts targeted solely at taxonomic metrics, such as 33 O/E, have been successfully used to manage sites. We show here that phylogenetic diversity 34 metrics can support such efforts by providing additional information about the kind of species 35 at sites. Given the ease with which such approaches can be applied, we call on others to use 36 them to supplement existing prioritization schemes.37 38