A large concentration of diverse coniferous species of trees exists in these mountains. Thirty conifer species (or more, depending on where one delineates the region) inhabit the area, including two endemic species, the Brewer's spruce and the Port Orford cedar, making the Klamath Mountains one of the richest coniferous forest regions of the world in terms of concentrated species diversity. The region also has several edaphic plant communities, adapted to specific soil types, notably serpentine outcrops.