Steven R. Radosevich, PHD, is a Professor of Forest Science, Graduate Program Coordinator in the Department of Forest Science, and an Adjunct Professor of Crop Science and Soil Science at Oregon State University. He is the author of Weed Ecology: Implications for Management, the first textbook on the ecology of weedy plants (now in its second edition) and over 100 scientific papers. Jodie S. Holt, PHD, is a Professor of Plant Physiology and Chair of the Department of Botany and Plant Sciences at the University of California, Riverside. She is the coauthor of the first two editions of this book and has authored numerous technical papers. Claudio M. Ghersa, PHD, is an Associate Professor of Ecology in the Department of Natural Resources and Environment at the University of Buenos Aires and Principal Researcher at the National Research Council (CONICET) in Argentina. He has contributed to or coauthored twelve books.