Forests
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Yellow pine forests found on mountain slopes, mostly between 5000-8000 ft. in Southern California. At higher latitudes, it is found at lower elevations. This is an area where the snow covers the ground for at least part of the year, and there really are four seasons. The mountains often get summer rain, and fall colors can be seen in this habitat as deciduous trees lose their leaves. Still, compared to yellow pine forests further north, ours are drier and more open. Due to the cooler temperatures and lack of moisture, decomposition occurs slowly, so the habitat is less productive than northern forests, the nutrients remaining locked up in the fallen wood for a long time before the trees decompose. The soils tend to be made of decomposed granite, and are thin and acidic. Pine needles as they decompose release weak acid into the soil. These forests are found on the south and west sides of the San Gabriel and San Bernardino Mountains, and at the same elevation on the north and east sides you fine a pinyon-juniper woodland. Typical plants include the ponderosa pine, Jeffrey pine, Coulter pine, incense cedar, sugar pine, big-cone spruce, black oak, white fir, Sierra currant, Sierra gooseberry, thimbleberry, deer brush, and snowbush. Animals include mountain kingsnakes, Stellar’s Jays, white and red-breasted nuthatches, white-headed and acorn woodpeckers, black-headed grosbeaks, western tanagers, mountain chickadees, fox sparrows, mountain quail, olive-sided flycatchers, violet-green swallows, mule deer, coyotes, black bears (introduced into Southern California), mountain lions, western gray squirrels, and deer mice.
Lodgepole-western white pine forest. Further north, this zone is called the lodgepole-red fir forest, but our forests are generally too dry to support red fir. Above 8,000 ft., the yellow pines drop out, and the forest is made up of species which can tolerate longer winters and colder temperatures. Lodgepole pine, western white pine, and white fir are the dominant species. Animals are much the same as those of the yellow pine forest, but Clark’s nutcrackers are also found here.
Subalpine forest is found only near the tops of our tallest Southern California mountains, usually over 9,000 ft. The climate is harsh, and snow may lay on the ground into June, with the first snow falling and freezing temperatures occurring in October. This short growing season favors conifers, which can continue to do photosynthesis even in winter. Prostrate vegetation sometimes forms a ground cover, so it is buried under snow and insulated during the winter. On ridges, parts of trees emerging from the winter’s snow can be wind blasted, desiccated, or frozen, leading to the form of tree known as a krummholtz, or bent wood. Limber pines are found at these high elevations.