Nov 14 2011
Reflection Post Fundamental/Realized/Generalist/Specialist Confusion
Ok, so I get that a fundamental niche is “the suite of ideal environmental conditions for a species” and that a realized niche is “the range of abiotic and biotic conditions under which a species actually lives” but my really quest has to do with niche generalists versus niche specialists. Are generalists found in both fundamental and realized niches or only in various realized niches because they can live with abiotic/biotic conditions variations? And vice versa with specialists. Sorry, I’ve sort of really confused myself on the matter.
I think the one thing that is confusing you is that species do not actually live in their fundamental niche. I fundamental niche, like you said is the set of ideal conditions, so they do not actually live in their fundamental niche because all of the conditions are never perfect all the time. A species lives in a realized niche which is the actual conditions in which they live. So niche generalists and specialists do not live in fundamental niches because no species does. They all live in their realized niche. Notice the definitions say “ideal environmental conditions for a species”(never says they live in these conditions) and “conditions under which a species actually lives”(suggesting that they do live here). At least that is what I thought so some one correct me if I’m wrong.
Good discussion, but I think a fundamental niche is not simply a theoretical ideal. Some species may have little competition and occupy something closer to a fundamental niche. In communities with intense competition for single niche, there may be many species “specialized” into smaller, realized niches. Generalists can certainly tolerate a wider range of abiotic/biotic conditions and would tend to occupy larger realized niches than specialist species.