View source for Ecology of California

{{Short description|Environments and natural history of California}}
{{Redirect|Natural history of California|the book, [[A Natural History of California]]|Allan A. Schoenherr}}
{{about|natural biological communities|a description of human habitat adjustments|Environment of California}}
[[File:Joshua trees.jpg|thumb|upright|[[Mojave Desert]] in [[Joshua Tree National Park]]]]
The '''ecology of California''' can be understood by dividing the state into a number of [[ecoregion]]s, which contain distinct [[Ecology|ecological]] [[community (ecology)|communities]] of plants and animals in a contiguous region. The ecoregions of California can be grouped into four major groups: desert ecoregions (such as the [[Mojave Desert]]), Mediterranean ecoregions (such as the [[Central Valley (California)|Central Valley]]), forested mountains (such as the [[Ecology of the Sierra Nevada|Sierra Nevada]]), and coastal forests.<ref>{{Cite book|url=https://archive.org/details/ecologicalregion0000unse|title=Ecological Regions of North America: Toward a Common Perspective|publisher=Commission for Environmental Cooperation|year=1997|isbn=2-922305-18-X|url-access=registration}}</ref>

Different authorities define the boundaries of ecoregions somewhat differently: this article follows the definitions of the [[World Wide Fund for Nature]] (WWF) and the [[United States Environmental Protection Agency]] (EPA)

==Deserts==
{{main|Deserts of California}}
[[California]]'s high mountains block most moisture from reaching the eastern parts of the state, which are home to California's [[Deserts and xeric shrublands|desert and xeric shrub]] ecoregions. The low desert of southeastern California is part of the [[Sonoran Desert]] ecoregion, which extends into [[Arizona]] and parts of northern [[Mexico]].<ref>{{WWF ecoregion|id=na1310|name=Sonoran Desert}}</ref> California has two high deserts: the [[Mojave Desert]] and the [[Great Basin Desert]]. The Mojave Desert ecoregion is marked by the presence of [[Joshua tree]]s.<ref>{{WWF ecoregion|id=na1308|name=Mojave Desert}}</ref> The dry cold Great Basin desert of California consists of the [[Owens Valley]], and is classified into [[Great Basin shrub steppe]] by the WWF,<ref>{{WWF ecoregion|id=na1305|name=Great Basin shrub steppe}}</ref> and into the [[Central Basin and Range ecoregion]] by the [[United States Environmental Protection Agency|EPA]].<ref name=epaMap>{{cite web|url=ftp://ftp.epa.gov/wed/ecoregions/us/Eco_Level_III_US.pdf|archive-url=https://web.archive.org/web/20170525051650/ftp://ftp.epa.gov/wed/ecoregions/us/Eco_Level_III_US.pdf|archive-date=2017-05-25|url-status=dead|title=Level III ecoregions of the United States|access-date=2012-10-24}}</ref>

The deserts in California receive between {{convert|2|and|10|in|mm}} of rain per year.<ref name=ch40>{{cite web|url=http://www.fs.fed.us/land/pubs/ecoregions/ch40.html|title=American Semi-Desert and Desert|work=Ecological Subregions of the United States|publisher=US Forest Service|archive-url=https://web.archive.org/web/20080507203838/http://www.fs.fed.us/land/pubs/ecoregions/ch40.html|archive-date=2008-05-07|url-status=dead}}</ref> Plants in these deserts are brush and scrub, adapted to the low rainfall. Common plant species include [[creosote bush]], [[blackbrush]], [[greasewood]], [[saltbush]], [[big sagebrush]], [[low sagebrush]], and [[shadscale]].<ref name=ch40/> Higher elevations have more precipitation, which allows drought-resistant trees to grow, such as [[western juniper]] and [[pinyon pine]].<ref name=ch40/>

==Mediterranean ecoregions==
[[File:Chaparral1.jpg|thumb|[[California montane chaparral and woodlands]] in the [[Santa Ynez Mountains]]]]
The coast of California from [[Monterey Bay]] south to the Mexican border, and inland from [[San Francisco Bay Area]] to the Sierra Nevada foothills contain California's [[Mediterranean Forests, Woodlands, and Scrub|Mediterranean]] ecoregions. This region is divided by the WWF into three [[California chaparral and woodlands]] ecoregions, plus the Central Valley grasslands.<ref>{{cite web|title=California Chaparral & Woodlands |url=http://wwf.panda.org/about_our_earth/ecoregions/california_chaparral_woodlands.cfm |publisher=World Wildlife Fund |access-date=2012-10-24 |url-status=dead |archive-url=https://web.archive.org/web/20121008083831/http://wwf.panda.org/about_our_earth/ecoregions/california_chaparral_woodlands.cfm |archive-date=2012-10-08 }}</ref> The EPA divides the region between the Central Valley (ecoregion 7), the Southern California chaparral (ecoregion 6), the Southern California mountains (ecoregion 8), and the Southern California coast (ecoregion 85).<ref name=epaMap/>

The WWF distinguishes between different chaparral ecoregions based on species [[endemic (ecology)|endemism]].<ref name=na1201/> In the south, the [[California coastal sage and chaparral]] extends across the Mexican border into northwestern [[Baja California]] and Los Angeles.<ref name=na1201/> The coastal sage ecoregion is notable for having the highest number of native bees in the United States, although much of the ecoregion is now urbanized.<ref name=na1201/> The [[California montane chaparral and woodlands]] include the [[Transverse Ranges]] north of Los Angeles as well as the [[Santa Lucia Range]] on the [[Central Coast of California|Central Coast]].<ref name=na1203>{{WWF ecoregion|name=California montane chaparral and woodlands|id=na1203}}</ref> The montane chaparral consists of a mosaic of sage scrub, chaparral, and montane species, depending on altitude.<ref name=na1203/> The [[California interior chaparral and woodlands]] form a ring around the [[Central Valley (California)|Central Valley]], covering the hills around the Bay Area as well as the foothills of the Sierra Nevada.<ref name=na1202>{{WWF ecoregion|id=na1202|name=California interior chaparral and woodlands}}</ref> The interior woodland ecoregion contains several endemic species, due to unique soil types such as [[serpentine soil|serpentine]].<ref name=na1203/>
[[File:Carizzo plain spring flowers in bloom 1.jpg|thumb|The Carrizo Plain grassland in springtime]]

These chaparral ecoregions contain numerous plant communities, including oak savanna,<ref name=na1202/> oak woodland, conifer woodlands, chamise chaparral, [[coastal sage scrub]], and coastal grassland.<ref name=na1201>{{WWF ecoregion|id=na1201|name=California coastal sage and chaparral}}</ref> These plant communities often occur as a mosaic,<ref name=na1203/> caused by fire.<ref>{{cite book|chapter=Chaparral|last=Keeley|first=JE|title=North American Terrestrial Vegetation|page=209|editor1-first=MG|editor1-last=Barbour|editor2-first=WD|editor2-last=Billings|edition=2nd|year=2000|publisher=Cambridge University Press|isbn=978-0-521-55986-7}}</ref>

California's [[Central Valley (California)|Central Valley]] was once a large [[Temperate grasslands, savannas, and shrublands|temperate grassland]] containing native [[bunchgrass]]es and [[vernal pools]].<ref name=na0801>{{WWF ecoregion|id=na0801|name=California Central Valley grasslands}}</ref> [[Grizzly bear]], [[gray wolf]], [[tule elk]], and [[pronghorn antelope]] used to inhabit the grasslands.<ref>{{cite web|url=http://www.fs.fed.us/land/pubs/ecoregions/ch31.html|title=California Dry Steppe|work=Ecological Subregions of the United States|publisher=US Forest Service|access-date=2012-10-24|archive-url=https://web.archive.org/web/20150221021145/https://www.fs.fed.us/land/pubs/ecoregions/ch31.html|archive-date=2015-02-21|url-status=dead}}</ref> The native grasslands and pools have now been largely replaced by livestock ranches and farms.<ref>{{cite web|publisher=[[United States Department of Agriculture]]|url=https://agresearchmag.ars.usda.gov/2004/may/grass|title=Restoring California's Native Grasses}}</ref> The [[Carrizo Plain]], where the native grass is preserved, is referred to as the "Serengeti of California".<ref>{{cite news|title=Conflicting Visions for 'Serengeti of California'|newspaper=Los Angeles Times|date=2001-05-13|first=John|last=Johnson|url=https://www.latimes.com/archives/la-xpm-2001-may-13-me-62956-story.html}}</ref>

[[File:Post Fire Wildflowers.jpg|thumb|Wildflowers bloom after a wildfire in [[San Diego County]]]]

==Forested mountains==
[[File:Pinus ponderosa Yosemite 2.jpg|thumb|Sierra Nevada lower montane forest in [[Yosemite Valley]]]]
The cooler and wetter mountains of northern California are covered by [[temperate coniferous forest|forest ecoregions]]. Both the WWF and the EPA divide the mountains into three ecoregions: the [[Ecology of the Sierra Nevada|Sierra Nevada]],<ref name=na0527>{{WWF ecoregion|name=Sierra Nevada forests|id=na0527}}</ref> the [[Klamath Mountains (ecoregion)|Klamath Mountains]],<ref name=na0516>{{WWF ecoregion|name=Klamath-Siskiyou forests|id=na0516}}</ref> and the [[Eastern Cascades Slopes and Foothills (ecoregion)|Eastern Cascades Slopes and Foothills]] (occurring on the [[Modoc Plateau]]).<ref name=na0512>{{WWF ecoregion|name=Eastern Cascades forests|id=na0512}}</ref>

The Sierra Nevada are home to half of the [[vascular plant]] species of California, with 400 species that are [[endemic (ecology)|endemic]] to the region.<ref name=na0527/> Like many mountain ranges, the plant communities of the Sierra group into [[biotic zone]]s by altitude, because of the increasingly harsh climate as elevation increases.<ref>{{cite book|title=Sierra Nevada Natural History|url=https://books.google.com/books?id=6h4q4dIcLb4C|page=20|first1=TI|last1=Storer|first2=RL|last2=Usinger|isbn=978-0-520-24096-4|date=2004-09-01| publisher=University of California Press }}</ref> These biotic zones include montane forest dominated by [[conifer]]s such as [[Jeffrey pine]] and [[Lodgepole pine]], [[Sierra Nevada subalpine zone|subalpine forest]] dominated by [[whitebark pine]], up to [[alpine tundra]] which cannot support trees.<ref name=schoenherr>{{cite book|title=[[A Natural History of California]]|first=Allan A.|last=Schoenherr|publisher=University of California Press|isbn=0-520-06922-6|year=1992}}</ref> The Sierra are also notable for [[giant sequoia]] trees: the most massive on earth.<ref>{{cite book|last=Flint|first=WD|year=2002|title=To Find The Biggest Tree|publisher=Sequoia Natural History Association|isbn=1-878441-09-4}}</ref>

The Klamath and Siskiyou Mountains are a notable [[biodiversity hotspot]], containing one of the four most biodiverse temperate forests in the world.<ref name=na0516/> The diversity is caused by the ecoregion being adjacent to a number of other ecoregions, diverse soil, and having [[refugium (population biology)|refugia]] caused by isolation in the last [[ice age]].<ref name=na0516/> Some endemic species in the Klamath mountains are limited to only one mountain or valley.<ref name=na0516/>

The Eastern Cascades slopes of the Modoc Plateau are characterized by a mosaic of open [[ponderosa pine]] forest, grasslands, and shrublands.<ref name=na0512/> Although high, these slopes and mountains are in the rain shadow of the [[Cascade Range]], and hence are drier and more open.<ref name=schoenherr/>

==Coastal forests==
[[File:Redwood and fog.jpg|thumb|right|Fog in [[Redwoods National Park]]]]
The coast of California north of San Francisco contains the [[Northern California coastal forests (WWF ecoregion)|Northern California coastal forests]] (as defined by the WWF) and the southern section of the [[Coast Range (ecoregion)|Coast Range ecoregion]] (as defined by the EPA). This ecoregion is dominated by [[Sequoia sempervirens|redwood forest]], containing the tallest and some of the oldest trees in the world.<ref name=na0519>{{WWF ecoregion|id=na0519|name=Northern California coastal forests}}</ref>

The redwood forests thrive in a thin belt up to {{convert|35|mi|km}} wide next to the coast, where the trees are kept moist by winter rains and summer fog.<ref name=na0519/> The redwood forests are also notable for having the highest forest [[productivity (ecology)|productivity]] in the world.<ref name=na0519/>

==See also==
{{div col|colwidth=21em}}
* {{Portal-inline|Ecology}}
* {{Portal-inline|California}}
*[[List of California birds]]
*[[Fauna of California]]
*[[California Floristic Province]]
*[[Geography of California]]
*[[California native plants]]
*[[Protected areas of California]]
{{div col end}}

==References==
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{{Reflist|33em}}
{{Environment of the United States by political division}}
{{California}}

{{DEFAULTSORT:Ecology Of California}}
[[Category:Environment of California| ]]
[[Category:Natural history of California| ]]
[[Category:Plant communities of California| ]]
[[Category:Regions of California| ]]