Introduction

Abstract

The Walker Branch Watershed Project was initiated in 1967 under sponsorship of the U.S. Atomic Energy Commission with three primary objectives: (1) providing base-line values for unpolluted natural waters, (2) contributing to our knowledge of cycling and loss of chemical elements in natural ecosystems, and (3) enabling the construction of models for predicting the effects of man’s activities on the landscape. Walker Branch Watershed is located in the Ridge and Valley province of east Tennessee on the Oak Ridge Reservation. The initial focus of the project centered primarily on the geologic and hydrologie processes that govern the quantity and quality of water moving through the watershed. The research focus expanded through time as new projects were initiated: intensive ecological process studies under the National Science Foundation (NSF) in 1970, trace contaminant studies under NSF in 1973, forest micrometeorology research jointly under the Department of Energy and the National Oceanic and Atmospheric Administration in 1976, atmospheric deposition studies under the National Atmospheric Deposition Program in 1980, and detailed acidic deposition effects research on canopy processes and soil chemistry in 1981. These studies of varying lengths have all contributed to a more complete understanding of the biological, chemical, geological, and physical processes governing watershed behavior.