For ease of learning and description, the habitats of San Diego County have been divided into nine distinct types. It is important to remember that habitat boundaries are not well defined. Habitats may overlap and/or grade into one another forming a patchy, “mosaic” of habitats across the landscape.
Sunset at Del Mar beach Photo by Barbarab Barnes
These habitats are found where the ocean meets the land. They are heavily influenced by the ocean's tides. Coastal salt marshes are characterized by flooding by seawater at high tide and exposure to the sun at low tide. Salt water mixes with freshwater in coastal lagoons, creating "brackish" water. These habitats are home to both aquatic (live in the water) and terrestrial (live on land) organisms. Plants living here are able to tolerate high levels of salinity (salt) in the water and soil by excreting their excess salt or by storing large amounts of water for dilution. Some of the characteristic plants found here are Southwestern spiny rush, cordgrass, goldenbush, saltgrass, pickleweed, sea lavender, golden yarrow, and saltbush. Some characteristic animals found here include birds like the great blue heron, osprey, California brown pelican, snowy egret, cormorants, terns, and gulls, and marine animals like crabs, clams, and fish.
Beach, salt marsh and lagoons make up only 2000 acres of San Diego County’s area (0.1%) and none of these habitats were burned in the 2003 Fires.
Coastal Sage Scrub
Coastal sage scrub habitat near San Marcos © 1993 Marc Hoshovsky
Coastal sage scrub is a uniquely southern California habitat. This habitat is found from sea level to 1500 feet in elevation, from the coast to the foothills where coastal fog moderates the climate, and in many inland valleys. This habitat can be described as sparse, low-growing shrubs that are aromatic, soft, and mostly gray-green in color. The foliage is very fragrant. During dry, summer months the shrubs often loose their leaves - a mechanism for drought tolerance. During this time, many of the plants may appear to be dead but they are actually dormant and will become green and vibrant again with the winter rains. One way to tell coastal sage scrub apart from chaparral is that coastal sage shrubs have some-what flexible branches with softer leaves, while chaparral shrubs have stiff, woody braches and 'hard' leaves. As a result, coastal sage scrub is often referred to as "soft chaparral". It originally covered most of what is now the urbanized portion of San Diego. Along the county's north coast (on sandstone cliffs bordering the beach) lies a special strip of coastal sage scrub that is home to one of the rarest pine trees in the country, the Torrey pine. Some of the characteristic plants include California sagebrush, black sage, California buckwheat, monkeyflower, laurel sumac, lemonadeberry, and bush sunflower. Characteristic animals of Coastal Sage Scrub include coyote, Audubon cottontail, red-tailed hawk, road runner, sage sparrow, rosy boa, and horned lizard.
Coastal sage scrub covers 248,000 acres of San Diego County’s area (14.5%). Approximately 81,000 (32.6% of the habitat) of these acres burned in the 2003 Fires.
San Diego backcountry--a patchwork of grasslands, oak woodlands, and chaparral Photo by Barbara Barnes
This habitat is found in interior valleys, often at low elevations but can occur up to 4000 feet elevation. Non-native annual grasses dominate the majority of San Diego’s grasslands, but they also contain a number of native annuals and perennials. Most grassland plant species are annuals that flower in the spring, set seed and die in the early summer months - leaving a golden-brown expanse of dry grass and herbs. This cycle is repeated each year. Grasslands often form a mosaic with coastal sage scrub, chaparral and oak woodlands. Some of the characteristic plants of grasslands include non-native species such as, cheat grass, red brome, ryegrass, deergrass, wild oats, filaree, mustard, and clover. The most common native grass species is purple needlegrass. The characteristic animals are, coyote, golden eagle, burrowing owl, cottontail rabbit, California meadow mouse, and Western meadow lark.
Grasslands cover 144,000 acres (8.4%) of San Diego County’s area. An estimated 17,500 (12.2% of the habitat) of these acres burned in the 2003 Fires.
Mixed chaparral habitat (near Temecula) Photo by Rick Halsey
Chaparral is found inland in the higher, drier foothills in a belt between coastal sage scrub at lower elevations and mixed conifer forest at higher elevations. It often occurs on very steep slopes and is found between 500 and 4,500 feet elevation. Chaparral is the most widespread habitat in the San Diego area. It is characterized by impenetrable thickets of shrubs with a dense canopy five to fifteen feet high. It is an evergreen shrubland, meaning most of the shrubs keep their leaves year-round. The leaves contain oils (resins) that are very flammable, and this along with high plant density and a long, dry season makes chaparral somewhat "fire-prone." Most plant species found in the chaparral are capable of surviving wildfires through a variety of adaptations. Characteristic plants of the chaparral include, chamise, manzanita, ceanothus (wild lilac), scrub oak, toyon, mountain mahogany, and yucca. Characteristic animals of the chaparral include, grey fox, bobcat, brush rabbit, spotted skunk, wood rat, wrentit, scrub jay, California thrasher, alligator lizard, rattlesnake, and gopher snake.
Chaparral covers 775,000 acres (45.4%) of San Diego County’s area. A total of 178,000 (23% of the habitat) of these acres burned in the 2003 Fires.
Black oak on Milk Ranch Road (Cuyamaca Rancho State Park) Photo by Barbara Barnes
Oak Woodlands are found in the inland foothills and canyons between 1,500 and 4,500 feet elevation. This habitat consists of an open, oak woodland carpeted with grasses, wildflowers, and patches of chaparral shrubs. It lines canyons in the inland foothills and can extend into coastal sage scrub habitat in canyons and draws where there is more moisture available. Since the oaks are evergreen - meaning they do not loose their leaves during the winter - they provide year-round protective cover for birds and a cool escape from the intense sun for wildlife. Some characteristic oak woodland plants are, Coast live oak, Engelmann oak, poison oak, elderberry, coffeeberry, and manzanita. The characteristic animals include, mule deer, ground squirrel, woodrat, red-shouldered hawk, acorn woodpecker, and California kingsnake.
Oak Woodlands cover 119,000 acres (7.0%) of San Diego County’s area. There were 34,000 acres (28.6% of the habitat) burned in the 2003 Fires.
Riparian habitat along Santa Margarita River Photo by San Diego State University
Riparian areas or streamsides are found at the bottom of canyons and valleys throughout the county regardless of elevation, wherever a stream is present. Riparian communities are characterized by deciduous trees and shrubs requiring a close source of abundant water. They form dense understories in moist canyons and drainage areas, such as the thickets found along the San Diego, San Louis Rey, and Santa Margarita Rivers (major San Diego County Rivers). While small in total area, riaprian areas are of special value as wildlife habitat. Over 135 species of California birds and 90 species of mammals, reptiles, and amphibians either completely depend upon these habitats or use them preferentially at some stage of their life history. Riparian habitats also provide riverbank protection, erosion control and improved water quality. In Southern California, only 3 to 5% of the pre-settlement riparian forest remains, the rest having been converted primarily to farming or urban uses. The characteristic plants of riparian areas include, sycamore, cottonwood, arroyo willow, and mule fat. Characteristic animals of riparian areas include, raccoon, belted kingfisher, Pacific tree frog, toads, and salamanders.
Riparian areas cover 58,000 acres (3.4%) of San Diego County’s area. An estimated 7,000 acres (12.0% of the habitat) burned in the 2003 Fires.
Freshwater Marsh/Montane (mountain) Meadow/Vernal Pool
Mt. Laguna meadow in late Spring Photo by Barbara Barnes
These habitats occur where soils remain saturated with water for most or all of the year, regardless of elevation. Freshwater marshes form along streamsides and other areas where water collects. Montane (mountain) meadows occur as scattered open areas within the mixed conifer forest where the soil is too moist for trees to grow. Moisture is supplied to meadows primarily by melting snow.
Vernal pools are shallow bodies of water that occur in depressions in grassland and woodland areas. These pools are filled by water from winter storms then dry up during the spring or early summer. Most plant and animal species that occur in vernal pools are endemic (occur only there) and highly specialized or adapted to vernal pool habitats, and some are listed as endangered species.
Some of the characteristic plants of these habitats include, bulrush, spike-rush, cattails, goldenrod, watercress, evening primrose, knotweeds, lupines, mallows, sedges and grasses. The characteristic animals are, mallard, red-winged blackbird, Western meadow lark, and California meadow mouse.
Taken together, these habitats cover 18,500 acres (1.0%) of San Diego County’s area. An estimated 3,300 acres (17.8% of the combined habitats) burned in the 2003 Fires.
Mixed Conifer Forest
Cuyamaca Rancho State Park prior to Cedar Fire Photo by San Diego State University
Mixed conifer forests are found in the mountain ranges above 4,500 feet elevation. Mixed conifer forests range from dense forests of pine, cedar, and fir species to more open forests with oak trees and an understory of chaparral shrubs and pineland herbaceous species. The forest has multiple 'layers' of vegetation: the top layer is called the canopy, and is made up of the tallest pine trees. Below the canopy is a shorter tree layer, then a shrub layer, and finally a ground layer of grasses, ferns and other herbs. Characteristic plants include coulter pine, jeffrey pine, white fir, Incense cedar, black oak, and canyon live oak. The characteristic animals found in mixed conifer forest are, mountain lion, golden eagle, Stellar's jay, woodpeckers, and great horned owl.
Mixed conifer forests cover 78,000 acres (4.6%) of San Diego County’s area. There were 26,000 acres (33.3% of the habitat--mostly Cuyamaca Rancho State Park) burned in the 2003 Fires.
Brittle Bush framed by the Santa Rosa Mts. in Anza-Borrego State Park Photo by Barbara Barnes
Deserts are found east of the Peninsular Mountains (which include Palomar Mountain and the Laguna Mountain range) which rise to an elevation of 6,000 feet. Desert covers most of the eastern quarter of San Diego County. Deserts are found in areas where there is very little rainfall and what rain does fall evaporates quickly. Deserts lose more water per year to evaporation than they receive from rain. The habitat includes rugged peaks at 5800 feet in elevation (e.g., eastern slopes of the Laguna Mountains, Jacumba area, lower slopes of the Santa Rosa Mountains), chaparral in the 3,000-5500 foot elevation range, desert hills and slopes from 3,000 feet, and washes and dry lakes below sea level. This habitat is second only to the rainforest in the variety of plants and animals that live there. It has the most diverse reptile population in North America, with 27 snake and 31 lizard species. There are over 600 species of desert plants, including 22 cacti varieities, and 60 mammal and over 240 different bird species. These generally are associated with specific subhabitats, such as, desert wash, low desert and desert slope, chaparral, and pinyon juniper. Many plants found in the desert store water in their stems and leaves -- plants that do this are called succulents. Some plants found in the desert include, creosote bush, desert willow, agave, indigo bush, chuparosa, beavertail cactus, cholla cacti, barrel cactus, smoke tree, saltbush, ocotillo, palo verde tree, desert fan palm, lupine, primrose, and verbena. Some of the animals are, bighorn sheep, kit fox, blacktailed jackrabbit, kangaroo rat, rattlesnake, spiny lizard, cactus wren, roadrunner, and coyote.
Desert covers 720,000 acres (27%) of San Diego County’s area. The desert was not burned in the 2003 Fires.
Desert agave Photo by Barbara Barnes
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