Measuring the importance of competition: a new formulation of the problem
Article first published online: 28 OCT 2009
© 2009 The Authors. Journal compilation © 2009 British Ecological Society
Journal of Ecology
Volume 98, Issue 1, pages 1–6, January 2010
How to Cite
Damgaard, C. and Fayolle, A. (2010), Measuring the importance of competition: a new formulation of the problem. Journal of Ecology, 98: 1–6. doi: 10.1111/j.1365-2745.2009.01587.x
- Issue published online: 11 DEC 2009
- Article first published online: 28 OCT 2009
- Received 12 May 2009; accepted 3 September 2009 Handling Editor: David Gibson
- ecological success;
- environmental gradient;
- population dynamics
1. Currently, there is a debate among plant ecologists on the concepts of the intensity of competition and the importance of competition, which is central to many issues of modern plant population ecology and plant community ecology.
2. It is problematic that the current measures of intensity and importance of competition, typically, are reported as dimensionless indices because they hide the fact that both indices are functions of plant density and the level of the environmental gradient.
3. Here, a new formulation of the concepts is suggested, which explicitly highlights the functional dependencies on plant density and the level of the environmental gradient. The new measures are a generalization of the previous indices and correspond to the previous indices in the case of a simple experimental design.
4. The suggested measures of the intensity and importance of competition are exemplified using data from a response surface competition experiment between Agrostis capillaris and Festuca ovina along a herbicide gradient, where the expected clear effect of plant density was demonstrated.
5. Synthesis. As the suggested measures of the intensity and importance of competition explicitly highlight the functional dependencies on plant density and the level of the environmental gradient, we think that they will help to ensure a closer connection between experimental plant ecology and the attempts to model plant populations and communities.