Plant communities are typically named for their dominant species (e.g. Monterey Pine Forest), general character (e.g. Coastal Prairie), or habitat (e.g. Coastal Bluff.) Each community exists where it does as a result of interactions among climate, soils, topography, plants, animals, fire, man, and time.

Boundaries of plant communities, called ecotones, can be gradual or abrupt. They are biologically the most productive areas in that animals may find shelter in one area and more abundant food in the other.