Acid Deposition

Atmospheric deposition is a stressor to terrestrial and aquatic systems throughout the eastern United States and has been implicated in the decline or degradation of many ecological systems in the region. Estimates of atmospheric deposition are critical for understanding water chemistry and stress (Likens and Bormann 1974). Swain et al. (1992) estimated that 90% of the mercury entering remote lakes in Voyageurs National Park (Minnesota) was derived from atmospheric deposition. Acidic deposition stresses terrestrial vegetation and alters system functioning and biogeochemical cycles. Compiling acidic deposition data is important for any long-term monitoring program because this stressor has demonstrated negative effects on aquatic systems and can alter wetland function and biogeochemical processes.

The A.T. Environmental Monitoring Program intends to rely on projects such as the Deposition Effects effort, the Baseline Water-Quality Inventory as well as data collected by other agencies and programs to assess resource condition.