Climax communities are defined by species composition and ecological succession.
In this brief article we examine exactly what climax communities are and why they matter.
What Is An Ecological Community?
An ecological community is a particular collection of species.
They are organized in a similar way to the way that you might find nodes on a spider’s web, with each species being a consumer of other species (resources) and, in turn, each species is also consumed by other species (usually, not the ones that it consumes).
If you were an ecologist, you would call these acts of consumption “trophic interactions” and while there are huge variations in the different types of ecological community they are all linked by trophic interactions.
Climax Community: A Steady State Based On Ecological Succession
A climax community is an ecological community that contains any number of plants, animals, or fungi that have reached a “steady state” by the process of “ecological succession”.
In effect, this means that from an observational point of view primary and secondary succession have reached equilibrium and primary and successional change are no longer taking place.
This is the “final stage” of the evolution of all the species within the climax community. Of course, in reality, animal species, plant species, fungal species, etc. never stop evolving and that means, as many critics point out, that a climax community is more of an “apparent” state rather than an objectively real one.
If you were to observe any kind of climax community and the environmental conditions that it faced over time, you would see that the “final stage of succession” was not a real “final stage” and while plant communities and animals remain stable for a period, eventually change is inevitable.
Thus a “true climax community” cannot exist, except, perhaps, in the dying moments of the universe.
That doesn’t matter, the term “climax community” is a very useful one to those studying and working in ecological professions.
Frederic Clements And The Idea Of “Climax”
Frederic Clements was the guy who coined the idea of “climax community”. He was an ecologist of sorts working around the year 1900 and he saw that the development of a community could be roughly comparable to the primary succession and the secondary succession of a pioneer species. Community succession, if you like.
This has led some ecologists to dub the whole ecological community as a “superorganism”. If you have ever examined Gaia Theory then you will have seen this idea taken to its farthest logical extent and seen that the entire planet can be considered as a superorganism and thus a community might also be seen as equivalent to the most complex organisms on the planet.
The English botanist, Arthur Tansley, took this idea and coined the phrase “polyclimax” which took the idea that many communities could start in a similar position and end in any of a number of different steady-state points, which would be determined by “edaphic” (soil-like) and climate factors. Thus , there would be no predetermined stable equilibrium point but rather sharp boundaries that could be reached via any given intermediate stage. This meant the final stage of succession for any particular community would not be obvious to an observer.
Human interference can, of course, have a huge impact on climax theory and species composition remains particularly vulnerable to outside influence. Think of something as simple as plant succession and the introduction of genetically modified crops.
It is important to note that this idea of Clements’ was never meant to be rigid or used as a predictive tool. He meant for the concept of climax community to provoke discussion around primary succession and further succession rather than for it to define something absolutely.
And, in fact, his own work which focused mainly on vegetation never showed that he expected a “climax” end state and he developed a huge range of new words to describe other possible outcomes.
Sadly, in the 1990s, many ecologists decided to stop using this idea but it has been slowly coming back into fashion as more and more ecologists adapt the term to mean “mature communities” as opposed to “steady-state” ones.
Final Thoughts On Species Composition And Climax Communities
The idea of a climax community is not something that was meant to reflect the real world, but rather to provide a model to explore some of the more peculiar aspects of observed phenomena.
It may not be as popular as it once was in ecology but it certainly helped to develop Gaia Theory.