 The ability of "Quercus chrysolepis" to compete with other dominant trees within its range has been analyzed from the standpoint of leaf architecture and photosynthetic capability.The study results explain that, in low light environments, "Q. chrysolepis" out-competes species with superior leaf size and crown mass per unit volume by its greater photosynthetic efficiency and leaf lifespan.Canyon live oak gives functional habitat for many fauna by providing perching, nesting, resting, or foraging sites for numerous species of birds, and shade and cover for diverse other mammals.