Linking Climate and Land Use Projections to Stream Habitat: Implications for Brook Trout in the Eastern U.S

Throughout its native range in the Eastern U.S., the brook trout Salvelinus fontinalis is a culturally, economically, and ecologically important species that is sensitive to warming stream temperatures and habitat degradation.  In this assessment we investigate how projected climate and land use changes may alter stream temperature and stream flow, and how these thermal and hydrologic changes might affect the suitability of stream habitat for supporting self-sustaining brook trout populations throughout the Eastern U.S.  We describe water temperature and stream flow models that predict thermal and hydrologic characteristics of all stream reaches of the NHDplus dataset during the warm season. We also describe a model that links predicted stream temperature and flow characteristics with landscape descriptors and recent observations of brook trout to classify current habitat suitability. Finally, we use these models to identify stream habitat suitability changes under climate and land use projections.  We expect that warmer air temperatures and urban land use will result in losses of thermally suitable habitat, while reduced stream flows in the summer may exacerbate temperature increases. Preliminary results suggest that riparian forests may be able to mitigate air temperature increases, maintaining thermal suitability for brook trout in some cases.