Fish Biologist USDA Forest Service, Pacific Northwest Research Station, Oregon, United States
Abstract: Freshwater aquatic biodiversity is imperiled, highly impacted by human activities, and vulnerable to climate change. Large-scale drivers of aquatic biodiversity such as climate change, interact with ecogeomorphic habitats and zones, that can often be identified by upland vegetation composition such as forests. Different vegetation types also experience different types of anthropogenic land use effects, further complicating assessments of aquatic biodiversity, particularly across diverse species range sizes. Thus, large scale and spatially explicit datasets are needed to evaluate vulnerability and potential resilience in aquatic species in response to current and future ecosystem condition. In this assessment, we focused on forests, whose distribution is responding to climate change, and whose condition is related to anthropogenic land uses such as timber harvest and wildfire management. There are few studies that use large datasets to determine forest association of individual species or groups. We used the ranges of all native species of aquatic-dependent fish, amphibians, reptiles, mussels, and crayfish, and determined their co-occurrence with forested areas. The data used is at the HUC8 scale of the conterminous United States. Areas of high aquatic biodiversity and forest association are clustered in the southeast and along the northern coasts. Aquatic organisms which are associated with low-forested areas are found primarily in the southwestern and central plains. Interaction with climate change in these regions, particularly where forests themselves are shifting their distribution, has important implications for long-term persistence of aquatic biodiversity, particularly related to patterns of habitat connectivity or isolation.
