Competition in Plant Communities

Paul A. Keddy

in Ecology

ISBN: 9780199830060
Published online May 2012 | | DOI:
Competition in Plant Communities

More Like This

Show all results sharing these subjects:

  • Applied Ecology (Environmental Science)
  • Ecology and Conservation
  • Plant Ecology
  • Zoology and Animal Sciences



Competition is generally understood to refer to the negative effects caused by the presence of neighbors, usually by reducing the availability of resources. Competition is one of the most important factors controlling plant communities, along with resources, disturbance, grazing, and mutualism. Since all plants require a few basic elements, the resource involved is generally light, water, nitrogen, or phosphorus, depending upon the species and the location. The effects of competition are widespread and easily observed in mixtures of crops and managed forests, which is why weeding and thinning are practiced. Competition is also widespread in native habitats, from deserts to wetlands, and is known to have important—indeed crucial—effects upon recruitment, growth, and reproduction. In the late 1800s, Darwin wrote extensively about the importance of competition in nature, particularly its role in driving natural selection. Thereafter, interest in the phenomenon grew. There were many experiments with both crops and wild species, most now overlooked. Models of competitive interactions were also constructed, with the number and size of the models increasing rapidly with the advent of computers in the 1970s. Hence, simple, early models are now often overlooked. Because the word competition has a common usage in English, it is frequently taken for granted, and therefore misunderstood. Care must be taken in using or interpreting the word without specifying what kind of competition is being investigated. For example, competition may be looked at from the perspective of an individual, a population, or a species, and it may be asymmetric or involve multiple species simultaneously. Experimental design carries its own assumptions, which are often not stated in published articles. One of the most difficult tasks in reading the literature is sifting through large numbers of experiments in which investigators have haphazardly selected (a pair of) species and grown them in mixture, without adequately justifying their choice of species and study design. Another difficult task is distinguishing between models that, at least in principle, have measurable inputs or make measurable predictions (or both) and those that do not and cannot be tested. Overall, the very ease of growing plants in mixture, as well as the ease of making models, has made people careless, with the result that basic questions are remaining unaddressed. Ongoing issues of importance include mechanisms of competition, types of competition, and the intensity of competition under different conditions.

Article.  9003 words. 

Subjects: Applied Ecology (Environmental Science) ; Ecology and Conservation ; Plant Ecology ; Zoology and Animal Sciences

Full text: subscription required

How to subscribeRecommend to my Librarian

Buy this work at Oxford University Press »