Karen L. Vaughan, 1000 E University Ave., University of Wyoming, Laramie, WY, US, Patrick J. Drohan, Pennsylvania State University, University Park, PA, John M. Galbraith, School of Plant and Environmental Sciences, Virginia Tech, Blacksburg, VA, Martin C. Rabenhorst, Environmental Science & Technology, University of Maryland-College Park, College Park, MD, US, Lesley A. Spokas, School of Earth and Sustainability, University of Massachusetts, Amherst, MA, Mark Stolt, 112 Kingston Coastal Institute Bldg, University of Rhode Island, Kingston, RI, US, James A. Thompson, 3115 Agricultural Sciences Building, West Virginia University, Morgantown, WV, US and Bruce L. Vasilas, Department of Plant and Soil Sciences, University of Delaware, Newark, DE