The Oak Ridge National Laboratory's Environmental Sciences Division initiated the Walker Branch Watershed Project on the Oak Ridge Reservation in east Tennessee in 1967, with the support of the U. S. Department of Energy's Office of Health and Environmental Research (DOE/OHER), to quantify land-water interactions in a forested landscape. It was designed to focus on three principal objectives: (1) to develop baseline data on unpolluted ecosystems, (2) to contribute to our knowledge of cycling and loss of chemical elements in natural ecosystems, and (3) to provide the understanding necessary...