Conservation of Populations, Species, and Ecosystems
The Mississippi National River and Recreational Area (MNRRA) is a National Park Service unit comprising a 72-mile stretch of the Mississippi River that flows through the twin cities of Minneapolis and St. Paul, Minnesota, USA. This stretch of river and its floodplain forest is home to 70+ nesting bald eagle pairs and is within the flyway for nearly a third of North American migratory birds. Climate change, invasive species, altered hydrology, urbanization, and herbivory all influence the floodplain forest dynamics in the MNRRA. The relative impact of these factors on key stages of forest development and succession is not well understood.
The ability of beavers to alter habitat via tree felling and dam building is well known, but the potential impact of beaver herbivory on tree regeneration in the MNRRA floodplain forest is undetermined. Anecdotally, managers have noted that beaver forage heavily on the already limited number of eastern cottonwoods, an important nesting tree for bald eagles. The Twin Cities Beaver Project aims to better understand the population biology and functional role of beavers in the MNRRA, with an initial focus on beaver distribution, numbers, and forage selection.