Elements that allows plants to grow at certain elevations include soil temperature, air temperature, forest diseases and adaptations to soil disturbances. This is about 1200'-1300' elevation and is a oak woodland ecosystem dominated by oaks. Dominance is measured by size of the predominate species and not the amount. Oak woodland is rapidly disappearing because of human development. Plants must go a long time without water.
Color is an adaption also.
Bluer vegetation reflects more energy so the tree doesn't need as much water. Waxy coatings help prevent water molecules from exiting the leaves. Reduced leaf size actually gives more surface area and provides self-shading for the plant. We view a valley oak, the California white oak, Quercus lobata , a deciduous tree. This oak has no prickle on the ends of the leaves.