Ecological communities are groups of interacting species that occur in the same place at the same time. Ecologists have different ways of describing and delimiting communities. In terrestrial environments, plants are the most obvious, stationary, and identifiable members of communities, so communities are often characterized by their dominant plant species.
Cal Poly Pomona has four ecological communities in its undeveloped areas. The one with the greatest area is coastal sage scrub. Walnut woodland is next, with smaller patches of oak woodland and riparian woodland.
Coastal sage scrub, oak woodland, and walnut woodland are all visible here, along with developed areas. (photo by Tom Zasadzinski)