1. The Earth Institute of Columbia University; 61 Route 9W Lamont Hall PO Box 1000 Palisades NY 10964 USA
2. Department of Geological & Mining Engineering & Sciences; Michigan Technological University; 1400 Townsend Drive Houghton MI 49931 USA
3. Now at the School of Forestry and Environmental Studies; Yale University; 195 Prospect St. New Haven CT 06511 USA
4. Department of Civil and Environmental Engineering; Michigan Technological University; 1400 Townsend Drive Houghton MI 49931 USA
5. Millennium Village Project; Milimani Block 10/35 Busia Road PO Box 2389-40100 Kisumu Kenya
6. Cary Institute of Ecosystem Studies; 2801 Sharon Turnpike PO Box AB Millbrook NY 12545 USA
7. City University of New York Advanced Science Research Center and Brooklyn College Department of Earth and Environmental Sciences; 85 St. Nicholas Terrace, 5th Floor New York NY 10031 USA
8. University of Maryland; 2108 Plant Sciences Building College Park MD 20742 USA
9. Now at the University of Florida; P.O. Box 110180 Gainesville FL 32611 USA