Los Padres National Forest is one of the most botanically diverse National Forests in the United States. It lies primarily within the Coast and Transverse Mountain Ranges. These mountains have been formed by the intense folding, fracturing, and faulting of the underlying bedrock which has been found to be around 200 million years old, and in some cases, as old as 1.7 billion years. Most of the forest experiences a Mediterranean climate characterized by cool, wet winters and hot, dry summers. Precipitation, consisting of both rain and snow, falls primarily between November and April with annual totals averaging from 8 to 38 inches on the lower four districts and as much as 75 inches on the Monterey District. This climate coupled with elevational changes creates a unique assemblage of plant communities in which chaparral dominates, yet also offers a tremendous diversity ranging from pinyon-juniper woodland to coastal redwood forest. Examples of other plant communities encountered on the forest include conifer forest, riparian woodland, oak woodland, grassland, and sub-alpine fellfield. Of particular interest is a group of specialized plants that grow only on serpentine soils; a nutrient poor substrate not suitable for most plants.
Chaparral is a surprisingly complex plant community. It includes many species of manzanita, chemise, wild lilac, scrub oak, silk-tassel bush, mountain mahogany, islay, monkeyflower, toyon, laurel sumac, current, buckwheat and true sages. Chaparral plants characteristically have moisture conserving leaves, small and thick with either a hairy or waxy covering, and a large root system. They also tend to produce large amounts of terpenes and oils which make them aromatic, and fire prone. Interestingly, chaparral plants actually flourish after fires either by resprouting from basal root burls or growing from seed that germinate only after exposure to high temperatures.
Also noteworthy, chaparral harbors more rare plants than any other plant community found on the forest. The manzanita genus alone accounts for five rare species: Little Sur manzanita, Santa Margarita manzanita, Santa Lucia manzanita, La Cruz manzanita, and Refugio manzanita. Other examples of rare plants include the "late-flowered" mariposa lily", Nuttal's scrub oak, Fort Tejon woolly sunflower, Rockcreek broomrape, Arroyo Seco bush mallow, Carmel Valley cliff-aster, and Ojai fritillary.
Pinyon-juniper woodland occurs primarily on the Mt. Pinos Ranger District. It exists in the most hostile of climates; experiencing snow and bitter cold in the winter, and dry, scorching heat in the summer. In general, pinyon pines occupy the cooler north-facing slopes. Pinyon pines are known for their large flavorful and nutritious nuts which were once a staple food for many Native Americans. Junipers tend to dominate on the south-facing slopes. Other plants found in this woodland include Great Basin sagebrush, rabbitbrush, blackbrush, scrub oak, matchweed, and valley cholla. Although deceptively barren, this community provides abundant food and shelter for many animal species: from the rare blunt-nosed leopard lizard to big horn sheep. (It also provides habitat for many rare plant species including the California jewelflower, Blakley's spineflower, Hoover's eriastrum, Kern mallow, and pale-yellow layia.
Coastal redwoods are the tallest trees in the world, some reaching heights of over 350 ft. Redwood stands occur on the Monterey District and represent the southern extreme of the temperate rain forest that occurs along the coast from Alaska to California. Due to their relative isolation, these stands may possess unique genetic material separate from their more northern counterparts. These southern redwoods appear to be restricted to areas which receive ample rainfall and summer fog, primarily along canyon bottoms and north-facing slopes. Other plants associated with this community include California bay, California huckleberry, tanbark oak, poison oak, redwood sorrel, western trillium, false solomon's seal, California polypody, and sword fern. Rare plants include Hutchinson's larkspur and Dudley's lousewort.
Conifer forests occur on all five Ranger Districts at the higher elevations on cool, wet north-facing slopes and canyon bottoms. This community consists of pure and mixed stands of Jeffrey pines, ponderosa pines, sugar pines, knobcone pines, Coulter pines, white firs, bigcone Douglas firs, and Santa Lucia firs. Coulter pines produce the largest cones with some reportedly bigger than basketballs. Of course, it is best to avoid pitching a tent beneath these trees! It has been postulated that Coulter pines demonstrate less drought tolerance than other conifers in southern California. Consequently, apparently weakened by drought and smog, many Coulter pines have succumbed to bark beetle infestations. Bigcone Douglas firs, while related to the northern Douglas firs, occur only in southern California extending from Santa Barbara to San Diego. They grow in relatively steep inaccessible north-facing drainage.
Santa Lucia firs are the rarest and most unusual firs in North America, existing along the coast only in Monterey County. These beautiful firs grow primarily on steep, rocky slopes and in canyons.
Riparian woodland is one of the most productive and diverse plant communities in the forest. Dense thickets of willows, alders, cottonwoods, sycamores, sedges, and rushes attract a myriad of animals seeking water, food, and shelter. Unfortunately, throughout the west, much riparian woodland has been lost to urban and agricultural development. Consequently, it has become extremely important to protect the riparian woodland still existing on the forest.
Visitors to the forest will observe woodlands composed of pure and mixed stands of blue oaks, valley oaks, coast live oaks, interior live oaks, and canyon live oaks. Blue oaks tend to grow on drier slopes and form a more open canopy. Canyon live oaks grow in moist drainages and form a closed canopy. Valley oaks, coast live oaks, and interior live oaks all grow under a variety of conditions forming both open and closed canopies. Oak acorns once provided a major food source utilized by Native Americans. Deer, squirrels, bears, birds, and other animals also eat acorns and depend on the woodlands for shelter. Unfortunately, much like riparian woodlands, oak woodlands have been lost to urban and agricultural development. To compound the problem, blue oak and valley oak regeneration appears to be declining.
Native grassland once covered California's Central Valley and the valleys of the Coastal Ranges. In fact, the Central Valley was once considered the "Serengetti of North America". However, over the past century, native grasses have been dramatically replaced by farmland and European annual grasses (accidentally and purposely introduced). Some of the native species include needle grass, melic grass, and wild rye. These grasses still exist in scattered locations throughout the forest. Some of the annual species include wild oats, barley, and ripcut brome. These species presently dominate the forest grassland. Wildflowers grow among the grasses, and with the right combination of rain and temperatures, provide exquisite displays of color; attracting many visitors to the forest each Spring.
This community occurs at elevations above 8,000 ft. on the Mt. Pinos Ranger District. Fellfields can be characterized as undulating flats and gentle slopes covered with rock or gravel. Harsh cold winds and snow restrict the majority of plant life to small, ground-hugging perennials. In summer, small flowers bloom in abundance to attract pollinators. Interestingly, because of the short growing season at these high elevations, production of flower buds commences during the year prior to blooming. Limber pines also grow in this community; their gnarled twisted trunks towering above the carpet of perennials.
Serpentine soils occur in scattered locations on the Monterey, Santa Lucia, and Santa Barbara Ranger Districts. These soils have a high magnesium content and a low calcium content. Most plants cannot tolerate this rare chemical composition. Of those plants that have adapted, several grow exclusively on these soils. Examples include Sargent cypress, leather oak, Santa Barbara jewelflower, Cuesta Pass checkerbloom, and Brewer's spineflower. These rare species also appear to be adapted to fire to the extent that fire suppression may actually cause a decline in the number of plants. For the primary purpose of protecting and properly managing this unique plant community, Los Padres National Forest has established three botanical areas (the forest has a total of six botanical areas). The forest welcomes the public to visit, enjoy, and learn about these fascinating areas.