Ecology Terms Index
The working vocabulary of ecology, defined so that each term can be checked against a field observation.
A glossary is only useful if its definitions draw boundaries. 'Population' is the standard example: the word means all individuals of one species in a stated area at a stated time, and any use that omits the area or the date has quietly stopped meaning anything testable. The entries below keep those boundary conditions attached.
Community is the next level up — every population, of every species, sharing one area. The community is what succession acts on: after a fire, after a field is abandoned, after bare rock is exposed, the community changes in a broadly directional sequence from fast-colonising pioneers toward a more persistent assemblage. The stages are observable, which is why succession earns a definition rather than a slogan.
Habitat and niche are the pair most often confused. A habitat is a place — the physical address where a species lives. A niche is an occupation: the full set of conditions the species tolerates, the resources it uses, and the role it plays. Two species can share one habitat precisely because their niches differ.
Trophic level describes feeding position. Producers fix energy at the base; herbivores, predators, and decomposers occupy the levels above. Because only a fraction of energy crosses each boundary, the levels form a pyramid, and the vocabulary of 'primary' and 'secondary' consumers is really a vocabulary of energy transfer.
Each entry in the full glossary follows the same pattern: a one-sentence definition, the boundary conditions that make it testable, and a note on the confusions most often seen in reports and coursework.
Further reading