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Californian Province
The coastal ranges of California and Oregon, as well as the western slopes of the Sierras, make up this floristic province. The Californian region is distinguished by a Mediterrranean climate with warm, dry summers and cool, moist winters. Late winter is emerald green as grasses emerge and annual wildflowers bloom in response to the 15 to 25 inches of precipitation dropped during the rainy season. Drought-tolerant evergreen oaks such as emory oak (Quercus emoryi) and coast live oak sprout new leaves at this time. As the summer warms and rain becomes scarce to non-existent, native grasses go dormant and the landscape turns russet and brown for the rest of the year.
California's ideal climate has attracted millions of people. Coastal regions as well as the foothills of the Sierra have been radically altered by the burgeoning human population. The fertile valleys, too, have been transformed, converted to agricultural crops. As a result, many species of the unique and diverse flora of this province are endangered.
Chaparral, a community dominated by shrubs and small trees interspersed with grasses, oak woodlands, and grasslands are the major associations of the Californian Floristic Province. They are home to coyotes, foxes, hawks, reptiles, and many songbirds, some of which are endemic to the region, meaning they are found nowhere else - as are an unusually large number of California plants.
California Grassland
The extensive grasslands of central and southern California were once known as the Pacific Prairie. The association is dominated by cool-season bunch grasses that turn golden during the marked summer dry season. Bulbous plants such as onions (Allium species), mariposas (Calochortus species), and blue dicks (Dichelostemma pulchellum) are common in spring. This vast grassland covered over 5 million hectares, much of which is now grazed or has been converted to farmland. Grazing has disturbed the soil, eliminated many native species, and introduced a vast array of exotic weeds. Fires were once common in the grasslands, controlling the spread of trees. Native Americans set many of the fires to improve the habitat for game animals. Oaks and other trees now invade many areas formerly dominated by grasses.
Oak Woodland
Oaks cover the low foothills and line the narrow stream valleys. Moving north in the province, pinyons and junipers intermingle with oaks and come to dominate in the higher elevations and colder areas. Blue oak woodland, also called foothills oak woodland, rings the central valley on the slopes of the Coastal and Sierra Ranges. Blue oak is dominant, but digger pine, interior live oak, and black oak are also common. There is no defined shrub layer, and the ground layer is composed of grasses, bulbs, and annuals. Southern oak woodland occurs mainly on the Pacific side of the Coastal Range, but also on the eastern slope in southern California and Mexico. The structure of this community is similar to that of other oak woodlands. The dominant oak is coast live oak, except on eastern slopes in the south, where it is codominant with Engelmann oak.
Chaparral
Chaparral is a community created by an impenetrable thicket of shrubs. The coastal chaparral is found where the rolling mountain slopes meet the Pacific Ocean, from southern Oregon to Baja. Mountain chaparral is found on the slopes and crests of inland foothills. The coast and mountain chaparral is composed of various shrubs with thick, leathery evergreen leaves, such as manzanitas, which resist drought and salt spray. Many chaparral shrubs rely on fire for renewal and reproduction. The propensity of the chaparral to burn often ends in tragedy for the many Californians who build their homes in the midst of this natural community. Selective, periodic controlled burning is one way to lessen the fire hazard. Reptiles, small mammals, and birds such as the California thrasher are common in chaparral communities.