California montane chaparral and woodlands
The montane habitats of southern California share many species with the Sierras to the north and the lower-elevation Mediterranean woodlands and chaparral. Their communities, however, are distinctive in structure and composition, in addition to supporting a number of endemic and relict species. The ecoregion encompasses most of the Transverse Range that includes the San Bernardino Mountains; San Gabriel Mountains; portions of the Santa Ynez and San Rafael Mountains; Topatopa Mountains; San Jacinto Mountains; the Tehachapi, Greenhorn, Piute, and Kiavah Mountains that extend roughly northeast-southwest from the southern Sierra Nevada; and the Santa Lucia Range (part of the Coast Range) that parallels the coast southward from Monterey Bay to Morro Bay. Several of the mountain ranges in this ecoregion are complex and high, with peaks ranging up to 3500 meters (m) elevation in the Transverse Range. Such topography creates conditions for a wide range of natural communities, ranging from chaparral to mixed-conifer forests and alpine habitats.
The California Montane Chaparral and Woodland ecoregion consists of a complex mosaic of coastal sage scrub, lower chaparral dominated by chamise, upper chaparral dominated by manzanita, desert chaparral, Piñon-juniper woodland, oak woodlands, closed-cone pine forests, yellow pine forests, sugar pine-white fir forests, lodgepole pine forests, and alpine habitats. The prevalence of drought-adapted scrub species in the flora of this ecoregion helps distinguish it from similar communities in the Sierras and other portions of northern California. Many of the shared Sierra Nevadan species typically are adapted to drier habitats in that ecoregion, Jeffrey pine (Pinus jeffrey) being a good example.
Some coastal sage scrub occurs on the southern slopes of the Transverse Range, although chamise (Adenostoma fasciculatum) chaparral and scrub oak chaparral cover most lower habitats. Higher up, cold chaparral dominated by manzanitas are interspersed with closed-cone pine forests, Coulter pine (Pinus coulteri) woodlands, and endemic bigcone Douglas-fir (Pseudotsuga macrocarpa) communities. Oak species are an important component of many chaparral and forest communities throughout the ecoregion. Canyon live oak, interior live oak, tan oak, Engelmann oak, golden-cup oak, and scrub oak are some examples. Mixed-conifer forests are found between 1,371 to 2,896 m (4,500 to 9,500 feet) elevation with various combinations and dominance of incense cedar, sugar pine, and white fir, Jeffrey pine, ponderosa pine, and mountain juniper. Subalpine forests consist of groves of limber pine (Pinus flexilis), lodgepole pine, and Jeffrey pine. Very old individual trees are commonly observed in these relict subalpine forests. Within this zone are subalpine wet meadows, talus slope herbaceous communities, krumholz woodlands, and a few small aspen groves. Herbaceous and shrubby species are very diverse and share affinities with the Sierras, Mojave Desert, and coastal and interior chaparral and woodlands. Numerous endemic plant species occur in many different communities.
In addition to these general vegetation patterns, this ecoregion is noted for a variety of ecologic islands, communities with specialized conditions that are widely scattered and isolated and typically harbor endemic and relict species. Examples include two localities of knobcone pine (Pinus attenuata) on serpentine soils, scattered vernal pools with a number of endemic and relict species, and isolated populations of one of North America’s most diverse cypress floras, including the rare Gowen cypress (Cupressus goveniana goveniana) restricted to two sites on acidic soils in the northern Santa Lucia Range, Monterey cypress (Cupressus macrocarpa) found only at two coastal localities near Monterey Bay, and Sargent cypress (Cupressus sargentii) restricted to serpentine outcrops. Monterey pine (Pinus radiata) is also restricted to three coastal sites near Monterey Bay. The ecoregion supports eight endemic conifer species, the highest number for any ecoregion in the U.S. and Canada along with the Northern California Coastal Forest ecoregion.
The Santa Lucia Range supports scattered populations of redwoods limited to fog-inundated coastal valleys. Coast live oaks and madrone form coastal evergreen communities intermixed with coastal sage and chamise chaparral. Higher up, one finds tan oak and canyon live oak woodlands eventually grading into forests of ponderosa pine, sugar pine, Jeffrey pine, Coulter pine, and serpentine-associated knobcone pine. The range also harbors the unusual and endemic Santa Lucia or bristlecone fir (Abies bracteata) between 610 and 1,525 m (2,000 and 5,000 ft) elevation.
The ecoregion is also home to a few endemic or near-endemic vertebrates, such as the white-eared pocket mouse (Perognathus alticolis) and five endemic and near-endemic amphibians, largely Plethodontid salamanders. California condors once inhabited much of the ecoregion, with the western Transverse Range acting as a refuge for the last wild population. Winter aggregations of monarch butterflies occur at several localities near Monterey Bay and southward along the coast. Some larger vertebrate predators still occur in the ecoregion, including puma (Puma concolor), bobcat (Lynx rufus), coyote (Canis latrans), and ringtails (Bassariscus astutus).
Fire Regime Characteristics
California montane chaparral and woodlands historically have their ecology strongly controlled by natural fires. It is also thought that during the Holocene, Native Americans may have used fire as a means of maximizing game productivity. In any case, prior to the early 1900s the records of fire are not consistent, such that calculations of return frequency is difficult. It is known that the intervention of man starting in the early 20th century has had a profound effect upon the ecology of these systems. While the introduction of staunch fire suppression was well meaning, it now persists in an ever heightened manner due to the desire to protect human lives and buildings that have intruded into this ecosystem.
The problem with heightened fire suppression is twofold. Firstly the ecosystem dynamics are destabilized, since normal succession involves periodic fires, likely on the order of every thirty to fifty years. This destabilization causes changes in species distribution, intrudes on decomposition cycles and alters age distribution and recruitment patterns of flora. For example, fire suppression in many California montane chaparral and woodlands communities in Northern California has led to the advance and dominance of conifers in many of these ecosystems which have been historically dominated by oaks. In extreme cases, large areas have been altered from productive habitats with diverse flora and fauna, to become dense stands of conifer with depauperate forest floors.
The second major consequence of fire suppression is buildup of excessive debris, chiefly from desiccated or dead chaparral species. Thus when a fire arises, it burns hotter and travels more swiftly than historic natural fire regimes. Not only is this an adverse consequence with respect to ultimate control and protection of human lives, but the ecological alteration covers a much wider area than typical historic fires. This outcome has consequences of broader scale erosion and more extensive habitat fragmentation than would historically be the case.
Habitat Loss and Degradation
Approximately thirty percent of the ecoregion is supports relatively intact habitat, with the caveat that virtually all bunchgrass elements have been replaced by introduced annual grasses and fire suppression, grazing, and loss of riparian and aquatic habitats are a major problem everywhere.
Remaining Blocks of Intact Habitat
The Ventana wilderness area in the Santa Lucia Range and the Ventura region of the Transverse Range have some of the larger intact habitat blocks. The northern extension of the ecoregions towards the Sierra Nevada has some large blocks, although much of this region is significantly impacted by grazing, cement mining, cotton, and windmill farms. Some larger, more intact blocks occur on Forest Service lands and the San Emigidio Ranch, recently purchased by the Wildlands Conservancy. The few blocks of conifer forests on the mountain peaks of the Transverse Range are all disturbed by development, grazing, logging, and fire suppression. Most of the designated wilderness areas are small and heavily used. Some of the best examples of native blue and valley oak woodlands occur in the inland valleys of the northern Santa Lucia Range, near Hunter-Leggett and the Ventana Wilderness.
Degree of Fragmentation
Degree of Protection
Much of the ecoregion falls within the Los Padres National Forest. The forests and chaparral of this National Forest suffer from intensive logging of low-productivity ecosystems, overgrazing, air pollution, loss of aquatic habitats, heavy recreational use, and decades of fire suppression intervention by man.
Types and Severity of Threats
Fire suppression is a severe problem throughout the ecoregion, allowing fuel loads to build up and increase the probability of ecologically devastating hot fires. Few large predators remain due to centuries of hunting and predator control. The high densities of deer, rodents, and other herbivores that has resulted from predator extirpation contribute to intensive grazing and seed predation. This effect results in dramatic changes to plant and animal communities throughout the ecoregion. Many springs, streams, rivers, and other aquatic habitats have been highly disturbed through land development, overgrazing, sedimentation, introduced species (18% of the flora), and water diversions. Extensive development around lakes and streams for resorts and vacation homes has altered many montane aquatic systems. The wide range of terrestrial species that depend upon critical water resources to survive, such as amphibians, have been severely impacted by the loss and alteration of aquatic habitats. High-impact recreational activities, such as off-road vehicles and hunting, cause significant damage of plant communities and mortality and disturbance of wildlife.
Mixed conifer and closed-cone pine forests are heavily impacted by air pollution from urban centers. Ozone from smog causes ponderosa pine and other species of conifer, shrubs, and lichen to weaken and die.
Suite of Priority Activities to Enhance Biodiversity Conservation
- Restore fire events to frequencies and intensities within their natural range of variation through management prescriptions such as controlled burns and fuel reduction (not salvage logging).
- Strictly protect ecologic islands and populations of rare species such as Gowen cypress and knobcone pine forests, vernal pools, and bigcone Douglas-fir and Santa Lucia fir groves. For example, strong protection needs to be given to Huckleberry Hill and its environs near Monterey to conserve several rare tree species.
- Protect the last blocks of foothill oak woodlands, a habitat type severely threatened throughout its range.
- Prohibit off-road vehicle use and grazing in fragile and rare serpentine plant communities.
- Prohibit further cutting of the last remaining groves and trees used by overwintering monarchs. These sites may experience rare environmental conditions that are necessary for the butterflies to survive. Some city governments near Monterey Bay recently voted to allow cutting of some of the butterfly trees for development, showing a disregard for the global rarity of this phenomena or the fragile nature of the scattered populations. Multiple butterfly sites may be necessary to allow long-term persistence of the butterflies in the face of natural weather events.
- The U.S. Forest Service must reduce timber harvest in these habitats characterized by low productivity and which experience significant periods of drought. Grazing and continued destruction of riparian and aquatic habitats must be curtailed on both federal and private lands.
- Air pollution is a significant problem, and reduction in smog emissions from Los Angeles and environs is challenging.
- California Native Plant Society
- The Nature Conservancy
- The Nature Conservancy of California
- The Sierra Club
- U.S. Fish and Wildlife Service
- U.S. Forest Service
References and Additional Information
- Taylor H. Ricketts. 1999. Terrestrial ecoregions of North America: a conservation assessment. Island Press. 485 pages
- Michael G.Barbour, Todd Keeler-Wolf, Allan A.Schoenherr. 2007. Terrestrial vegetation of California. University of California Press. 712 pages
- Neil G.Sugihara. 2006. Fire in California's ecosystems. University of California Press. 596 pages
- For a summary of this entry, see the WWF WildWorld profile of this ecoregion.
Disclaimer: This article contains information that was originally published by the World Wildlife Fund. Authors for the Encyclopedia of Earth have edited its content and added new information. The use of information from the World Wildlife Fund should not be construed as support for or endorsement by that organization for any new information added by EoE personnel, or for any editing of the original content.