Multidecadal Response in Soil Carbon and Nitrogen to the Great Fires of 1947 Using Paired Watersheds in Acadia National Park, Maine.

In 1996, Acadia National Park (NP) was chosen as one of fourteen parks to research stressors and ecological effects. This collection of park monitoring sites became known as the Park Research and Intensive Monitoring of Ecosystems Network (PRIMENet). The original PRIMENet program in Acadia determined the response of Hadlock and Cadillac watersheds to an ecosystem-changing disturbance represented by the 1947 wildfire, with particular attention on the fate and cycling of atmospherically derived nitrogen (N) and mercury (Hg) pollutants. The Hadlock and Cadillac forested stream watersheds represent a long-term paired whole-watershed study, with Hadlock as an unburned reference and Cadillac having been severely burned. This research, representing a return campaign to the Acadia PRIMENet watersheds after an approximate 15 year hiatus, focuses on defining current carbon (C), N, and Hg soil burdens. This sampling campaign allows us to evaluate the trajectory of recovery of these two watersheds to atmospheric deposition and fire disturbance. This research will provide insights into the temporal evolution of chemical changes (C, N, Hg) in the soil of these two watersheds, help identify current risks due to pollutant burdens, and inform management considerations of ecosystem resilience to these and other stressors.