High rates of atmospheric deposition of beryllium are toxic biologically and are exacerbated by synergistic interaction with aluminum. The Czech Republic is experiencing growing problems, and similar consequences may well soon be experienced in Maine. An expert international research team would pursue parallel pilot studies into the biogeochemical controls on Be fate and transport by examining beryllium biogeochemistry in forested ecosystems. This project funds the work in Maine and travel for international collaboration; the Czechs are supporting the work in their country. The plan for the pilot study is to develop chemical time series for beryllium fluxes into, through, and out of watersheds in a paired study in the Bear Brook Watershed where one watersheds is being artificially acidified with ammonium sulfate. The study evaluates the fluxes of total BE and 7Be at the forest floor, leaving the watersheds, and in litter fall. Be in stream vegetation and sediment is being evaluated before and after acidic discharge events to assess temporary exchangeable pools