California chaparral and woodlands

California chaparral and woodlands

Ecology
Realm	Nearctic
Biome	Mediterranean forests, woodlands, and scrub
Geography
Area	121,000 km² (47,000 sq mi)
Countries	United States Mexico
States	Oregon California Baja California
Climate type	Mediterranean

The California chaparral and woodlands is a terrestrial ecoregion of southwestern Oregon, northern, central, and southern California (United States) and northwestern Baja California (Mexico), located on the west coast of North America. It is an ecoregion of the Mediterranean forests, woodlands, and scrub biome, and part of the Nearctic realm.

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When I got my job with the Forest service and started working in the chaparral I knew that was my passion and that’s where I liked to be because it was a stubby shrubby vegetation type and I figured I’m a stubby shrubby person and this is where I think I would want to spend a lot of time. Chaparral is about ten percent of the vegetation cover in the state of California. Most of this ten percent exists in Southern California and since southern California is a biodiversity hotspot, Chaparral is very important for the wildlife in a lot of Southern California ecosystems. Chaparral is a very resilient type of plant community, and it has the ability to re-sprout or reseed itself and grow after fires or severe disturbances. But recently we’ve had this onslaught of people coming into the chaparral and then because of the anthropogenic influence of all this urban blight we have a lot of fires, and the close interval burns are happening more and more frequently and the chaparral is not able to sustain itself with this repeated disturbance. Ninety-five percent of the fires in the chaparral are set, they’re not natural, so one of the problems we’re seeing is along with the close interval fire we’re having invasive plants coming in and using up the resources so you can’t re-establish the native chaparral species. Plus, the invasive species are a smaller fuel type and are easier ignite so we’re finding this new invasion is causing more fires than the chaparral, so getting rid of the chaparral can actually cause a lot more of a fire hazard because of the different fuels that you’re bringing in. There’s a lot of scenarios in ecological recent history which prove that the communities that were here were very important. Chaparral is a large community now but it could be like the Old Growth Forest, when almost all of it was gone we finally realized it had value. There was the tall grass prairie, when it was almost all gone we finally realized it was a problem. I think chaparral communities are very important in a lot of ways that maybe we don’t even understand yet, and it’s time that we start to restore them now, before it becomes urgent and a crisis.

Setting

Three sub-ecoregions

The California chaparral and woodlands ecoregion is subdivided into three smaller ecoregions.^[1]

California coastal sage and chaparral ecoregion: In southern coastal California and northwestern coastal Baja California, as well as all the Channel Islands of California and Guadalupe Island.
California montane chaparral and woodlands: In southern and central coast adjacent and inland California, covering some of the mountains of: the Coast Ranges; the Transverse Ranges; and the western slopes of the northern Peninsular Ranges.
California interior chaparral and woodlands: In central interior California surrounding the California Central Valley cover the foothills and the Transverse Ranges and Sierra Nevada.

Locations

Montane chaparral and woodlands in the Santa Ynez Mountains, near Santa Barbara, California

Most of the population of California and Baja California lives in these ecoregions, which includes the San Francisco Bay Area, Ventura County, the Greater Los Angeles Area, San Diego County, Tijuana, and Ensenada, Baja California.

The California Central Valley grasslands ecoregion, as well as the coniferous Sierra Nevada forests, Northern California coastal forests, and Klamath-Siskiyou forests of northern California and southwestern Oregon, share many plant and animal affinities with the California chaparral and woodlands. Many botanists consider the California chaparral and woodlands, Sierra Nevada forests, Klamath-Siskiyou forests, and Northern California coastal forests as a single California Floristic Province, excluding the deserts of eastern California, which belong to other floristic provinces. Many Bioregionalists, including poet Gary Snyder, identify the central and northern Coast Ranges, Klamath-Siskiyou, the Central Valley, and Sierra Nevada as the Shasta Bioregion or the Alta California Bioregion.

Flora

The ecoregion includes a great variety of plant communities, including grasslands, oak savannas and woodlands, chaparral, and coniferous forests, including southern stands of the tall coast redwood (Sequoia sempervirens). The flora of this ecoregion also includes tree species such as gray or foothill pine (Pinus sabiniana), scrub oak (Quercus dumosa), California buckeye (Aesculus californica), the rare Gowen cypress (Cupressus goveniana), the rare Monterey cypress (Cupressus macrocarpa), and a wealth of endemic plant species, including the extremely rare San Gabriel Mountain liveforever (Dudleya densiflora), Catalina mahogany (Cercocarpus traskiae), and the threatened most beautiful jewel-flower (Streptanthus albidus ssp. Peramoenus).^[1] Hesperoyucca whipplei, colloquially known as Chaparral Yucca, is commonplace throughout the lower elevations of the climate zone.

There are two types of chaparral: soft and hard chaparral. Hard chaparral is usually evergreen, located at higher elevation and is harder to walk through. Soft chaparral tends to be drought deciduous, live at lower elevations and tends to be easier to walk through.^{[citation needed]}

Fauna

Species include the California gnatcatcher (Polioptila californica), Costa's hummingbird (Calypte costae), coast horned lizard (Phrynosoma coronatum), and rosy boa (Lichanura trivirgata). Other animals found here are the Heermann kangaroo rat (Dipodomys heermanni), Santa Cruz kangaroo rat (Dipodomys venustus), and the endangered white-eared pocket mouse (Perognathus alticolus).^[1]

Another notable insect resident of this ecoregion is the rain beetle (Pleocoma sp.) It spends up to several years living underground in a larval stage and emerges only during wet-season rains to mate.

Fire

Chaparral, like most Mediterranean shrublands, is highly fire resilient and historically burned with high-severity, stand replacing events every 30 to 100 years.^[2] Historically, Native Americans burned chaparral to promote grasslands for textiles and food.^[3] Though adapted to infrequent fires, chaparral plant communities can be exterminated by frequent fires especially with climate change induced drought.^[4]^[5] Today, frequent accidental ignitions can convert chaparral from a native shrubland to nonnative annual grassland and drastically reduce species diversity, especially under global-change-type drought.^[4]^[5] The historical fire return interval for chaparral communities used to be 30–50 years, but has now decreased to 5–10 years due to human interference.^{[citation needed]}

Human influence

The region has been heavily affected by grazing, logging, dams and water diversions, and intensive agriculture and urbanization, as well as competition by numerous introduced or exotic plant and animal species. Some unique plant communities, like southern California's Coastal Sage Scrub, have been nearly eradicated by agriculture and urbanization. As a result, the region now has many rare and endangered species, including the California condor (Gymnogyps californianus).^{[citation needed]}

References

^ ^a ^b ^c "California Chaparral & Woodlands". World Wildlife Fund. Archived from the original on October 8, 2012. Retrieved 2012-06-15. (material included verbatim under the CC BY-SA 3.0 license
^ Keeley, JE; Davis, FW (2007). "Chaparral". In Barbour, MG; Keeler-Wolf, T; Schoenherr, AA (eds.). Terrestrial Vegetation of California (PDF). Los Angeles: University of California Press. pp. 339–366.
^ Vale, TR (2002). Fire, Native Peoples, and the Natural Landscape. Washington, DC: Island Press. pp. 269–286.
^ ^a ^b Syphard, AD; Radeloff, VC; Keeley, JE; Hawbaker, TJ; et al. (2007). "Human influence on California fire regimes" (PDF). Ecological Applications. 17 (5): 1388–1402. doi:10.1890/06-1128.1. PMID 17708216.
^ ^a ^b Pratt, RB; Jacobsen, AL; Ramirez, AR; Helms, AM; et al. (2014). "Mortality of resprouting chaparral shrubs after a fire and during a record drought: physiological mechanisms and demographic consequences" (PDF). Global Change Biology. 20 (3): 893–907. Bibcode:2014GCBio..20..893P. doi:10.1111/gcb.12477. PMID 24375846.

Bakker, Elna (1971) An Island Called California. University of California Press; Berkeley.
Dallman, Peter R. (1998). Plant Life in the World's Mediterranean Climates. California Native Plant Society–University of California Press; Berkeley.
Ricketts, Taylor H; Eric Dinerstein; David M. Olson; Colby J. Loucks; et al. (1999). Terrestrial Ecoregions of North America: a Conservation Assessment. Island Press; Washington, DC.
Schoenherr, Allan A. (1992). A Natural History of California. University of California Press; Berkeley.

External links

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California chaparral and woodlands

This page was last edited on 20 April 2024, at 00:38

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