Monday, August 3, 2009 - 2:30 PM

COS 12-4: CANCELLED - Niche construction from an eco-evolutionary standpoint

Grigoris Kylafis and Michel Loreau. McGill University

Background/Question/Methods

The reflection that the entire evolutionary history of the earth has been partially written by organisms themselves has fascinated many scientists of ecology and evolution. The concept of niche construction captures the idea that organisms are able to shape their own local environment, and thereby become an active subject of their own evolution and of ecosystem organization.

However, a systematic theoretical and experimental investigation of this idea has been lacking so far. The main criticism that has been addressed to the niche construction concept is that it is too ubiquitous and abstract to be useful. The concept has also been implicit, though not explicitly incorporated, in other ecological concepts such as ecosystem engineering, positive interactions, and indirect interactions. This has resulted in a conceptual fragmentation, which now requires integration in a solid eco-evolutionary framework.

We investigate the short- and long-term properties and consequences of niche construction, and present examples that qualify as cases of real niche construction in nature. We present, a simple model of a predator - niche constructing consumer - resource system, and use a graphical mechanistic analysis proposed by Tilman (1982) and Chase & Leibold (2003) to support our suggested conceptual framework. We extend our model to evolutionary time scales, and investigate the properties of niche construction in a changing selective environment. We extend the concept to communities and ecosystems.

Results/Conclusions

An organism engages in niche construction when it is capable of controlling its relationship with its biotic and abiotic environment. The adaptive feedbacks generated by organism-environment interaction are crucial for the success of niche construction. Niche construction can either strengthen or weaken interspecific competition, and hence affect the potential for species coexistence in the short run. Niche construction also counteracts changes in the selective environment of its agent, thereby generating environmental homeostasis in the long run. By modifying and regulating niche parameters, niche-constructing organisms can become “ecosystem managers” that strongly affect the ecology and evolution of an ecosystem’s biotic components. Niche construction accounts for a diverse array of species interactions (positive or negative) that collectively maintain critical ecosystem processes and services.