Emeritus Scientist, USDA, Forest Service, International Institute of Tropical Forestry

Head of Division, IMK-IFU; Principal Scientist, International Livestock Research Institute

Professor of Oceanography, College of Marine Science, University of South Florida

Professor of Forest Soils, University of Alberta

New South Wales Department of Primary Industries (NSW DPI), Soils

Professor, La Trobe University

Professor of Ecosystem Ecology, University of California, Berkeley

Professor of Biological Sciences, University of Notre Dame

Principal Research Scientist

Cornell University