Definition
Niche
A niche describes the role of a species in its environment, including how it interacts with biotic (living) and abiotic (non-living) factors.
- A niche refers to the ecological role of a species within an ecosystem — how it interacts with both biotic (living) and abiotic (non-living) factors.
- It includes everything that affects the species’ survival and reproduction: habitat, food sources, competition, predators, and environmental conditions.
Fundamental Niche
Definition
Fundamental niche
The fundamental niche is the full range of conditions and resources a species could theoretically use if there were no competition, predators, or other limiting factors.
- The fundamental niche represents the potential ecological space a species could occupy if there were no competitors, predators, or limiting factors.
- It is determined by the species’ physiological tolerance to environmental conditions and the availability of essential resources.
- It is theoretical, describing where a species could live, not necessarily where it does live.
Realized Niche
Definition
Realized niche
A realized niche is the actual conditions in which a species exists due to competition, predation, and environmental constraints.
- The realized niche represents the actual conditions under which a species exists, given biotic interactions (competition, predation, mutualism).
- It is always narrower than the fundamental niche, as species are restricted by the presence of other organisms.
