So, first off, how do biologists define “competition”?
James B. Grace, ecologist and senior research scientist with the U.S. Geological Survey, says:
Any attempt to define competitive success must begin with a definition of competition. The variety of possible definitions of competition have been discussed numerous times and it is safe to say that there is no universally accepted definition.i
Ok, so we can see right away that this subject is not going to be cut-and-dry.
More helpfully, he then goes on:
Nonetheless, it can be argued that a conventional definition does exist, based on the methodologies used to study competition. Practically speaking, there exists a body of experimental data that constitutes our observational basis for discussing competition. In nearly all cases, these data were collected by allowing plants to grow either with or without neighbors of another species and, in many cases, by demonstrating that the plants were limited by some common set of resources. As a result, it can be argued that there exists a "conventional" definition of interspecific competition that is exemplified by the definition offered by Begon et al. (1986): "an interaction between individuals, brought about by a shared requirement for a resource in limited supply, and leading to a reduction in the survivorship, growth and/or reproduction of the competing individuals concerned.”ii
Paul Keddy, an ecologist who has studied plant population ecology and community ecology, and who literally wrote a book called, Competition, explains:
Definitions of competition present a particular challenge because it is such a widespread phenomenon, and occurs in so many conditions. It may be difficult to find a definition that is sufficiently robust to encompass the riotous display of possibilities in nature, yet precise enough to clarify every particular circumstance where it is applied. Further, we may look for a definition that emphasized the mechanisms of competition, or its measurement by means of experiment, or its long term evolutionary consequences. Recent textbooks of ecology reveal a wide array of attempts to satisfy these conflicting objectives. Some authors even advocate that we no longer use the term.iii [our emphasis]
That being said, Keddy then lets us know that the definition he’ll be using in Competition is: “the negative effects that one organism has upon another by consuming, or controlling, access to a resource that is limited in availability.”iv
We could quote a dozen more definitions, as well as a dozen more reflections from respected biologists on the difficulty of coming up with definitions, but we hope you get the idea: understanding the concept of competition, the ecological process, is not as simple as picturing two boxers in a ring.
Keep reading with a 7-day free trial
Subscribe to Speaking for the Trees, No Matter Where They're From to keep reading this post and get 7 days of free access to the full post archives.