XVI International Botanical Congess

Frederic Clements was the guru of vegetation science in the U.S. from 1905-1945. His view of plant communities was a holistic, almost organismic one, of a group of species acting as a natural unit. In the 1920s, Gleason, Ramensky, and Lenoble independently proposed individualistic" theories in which vegetation is a continuum, each species responding uniquely to environmental factors. In this view, communities are not real, natural units but human constructs. Research, particularly by Curtis and his students and by Whittaker has supported this continuum view. Hutchinson's multidimensional niche model and his concepts of fundamental and realized niches have influenced community studies. Current controversy, and research by Tilman, Grimes, Grace, Austin, Rydin, and others concern the role of competition in determining plant community structure.