Abstract

This paper revisits the debate over whether the study of facilitation requires ecologists to revise their understanding of the relationship between realized and fundamental niches as conceptualized by Hutchinson. Following Rodriguez-Cabal et al., I argue against Bruno et al.’s claim that facilitation can make a species’ realized niche larger than its fundamental niche. However, I also maintain that the abstract Hutchinsonian conceptualization of the niche makes a whole range of facilitative interactions—which I propose to call ameliorative facilitation—invisible to niche-based approaches to the study of ecological communities. I propose a way to incorporate ameliorative facilitation into such approaches. My proposal involves supplementing the Hutchinsonian realized/fundamental dyad with a third concept: the potential niche. This concept was introduced by ecologists studying the effects of environmental change on species distributions, but I show how it could also be fruitfully used in facilitation studies. I argue that this proposed solution is more appealing than Stachowicz’s suggestion that Hutchinson’s realized/fundamental contrast be applied to a spatial-geographical, as opposed to an abstract-conceptual, notion of the niche.