1. Department of Chemistry, St. Lawrence University, Canton, New York 13617, U.S. Geological Survey, P.O. Box 628, Montpelier, Vermont 05601, Department of Environmental Conservation, Vermont Agency of Natural Resources, Waterbury, Vermont 05671, Ecosystems Research Group, Ltd., P.O. Box 1227, Norwich, Vermont 05055, Department of Atmospheric, Oceanic and Space Sciences, University of Michigan, Ann Arbor, Michigan 48109, School of Natural Resources, University of Vermont, Burlington, Vermont 05405,...