1. Dep. of Plant & Soil Science, Hills Bldg.; Univ. of Vermont; Burlington VT 05405-0082
2. Dep. of Natural Resources and Environmental Sciences; Univ. of Illinois; W-503 Turner Hall, 1102 South Goodwin Urbana IL 61801
3. U.S. Geological Survey; 425 Jordan Rd. Troy NY 12180