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California Chaparral

The chaparral community lies west of the Sierra Nevada summit and Mojave Desert

Between elevations of sea level to around 10,000 feet

Chaparral Area in California by County (in acres)*

San Diego 1,003,441

Los Angeles 553,789

Riverside 499,160

Santa Barbara 440,645

San Luis Obispo 417,718

Monterey 369,345

Ventura 326,447

San Bernardino 276,010

San Benito 246,623

Santa Clara 188,427

Orange 111,550

Marin 37,566

San Mateo 36,152

Santa Cruz 32,328

*From Fried, J.S., C.L. Bosinger, and D. Beardsley. 2004. Chaparal in Southern and Central Coastal California in the Mid-1990's: Area, Ownership, Condition, and Change. USFS Resource Bulletin PNW-RB-240

Chaparral was part of the Madro-Tertiary Geoflora

Beginning about 65 million years ago

  • The Madro-Tertiary Geoflora comprises

  • Semiarid live oak-conifer woodland
  • Chaparral
  • Arid subtropic scrub
  • Desert grassland
  • Desert vegetation

  • The climate of Western North American began to cool and became more arid

  • Partly in response to the initial uplift of the Sierra Nevada and Coast Range.

  • And partly due to falling global temperatures and increasing global aridity.

  • The rainshadow that resulted from these mountain barriers allowed the Madro-Tertiary Geoflora (from the Sierra Madre of Mexico) to expand it's range and replace some of the Arcto-Tertiary plants in California, the Columbia Plateau, and Western Oregon.

Redwood, fir, cedar, spruce, and hemlock trees and their ancestors

  • Subsequent uplift of the Cascades increased the rainshadow effect in the interior PNW especially in the last ~20 million years.

  • Rainshadow effects of the Olympic Mountains and Vancouver Island have created enough aridity for some of the drought-adapted Madro Tertiary Geoflora to extend well into Western Canada.

Most of the plants of Madro-Tertiary Geoflora

  • Are drought adapted with some combination of small, deciduous, or waxy leaves.

  • Some are found in fairly high precipitation zones (such as the coast) if the soils are coarse-grained with minimal moisture holding capacity.

Chaparral borders with several other important CA plant associations:

  • In Southern California- integrates with coastal shrub
  • In Northern California- integrates into grasslands and also xerophytic mixed conifer forests
  • On foothill sites it integrates into oak woodland types
  • Within chaparral community, various forms of riparian woodlands and riparain scrub exists

Chaparral varies greatly in:

  • Species composition
  • Size
  • Cover
  • Appearance

From one area to the next and within the same stand

Chaparral is distinguished by the sclerophyll leaf:

  • Small, thick stiff and usually evergreen

  • Some are moderatly to heavily wax coated

  • Plants have extensive root systems to endure the typical Mediterranean summer of hot, dry conditions
  • Chaparral shrubs have many branches to support the leaf canopy.

  • Stem flow of precipitation is important

  • Through stemflow, water is delivered to the base of each shrub

  • Soils are loose and friable, protected by leaf litter

  • Infiltration is high

  • May recieve up to 30% of total precipitation to the base of plant

Soils

Soils are characterized as being youthful = Entisols

Storie and Harricline (1958) estimated that 85% of chaparral soils are lithosols= physically disentegrated igneous-metamorphic parent rock

Generally the texture is

Sand (40-to 80%)

Silt (20 to 30%)

Clay (<20%)

Soils are highly porous, rocky and low in nutrients

Creates rapid infiltration, but low water holding capacity

Topography

Generally steep and rough resulting in these shallow rocky unstable soils

Surface materials are highly erosive because of coarse texture (sandiness) and steep angle of repose

Slope movement is common both during the wet (erosion) and dry (creep) conditions

Creep may exceed wet erosion rates

  • After a fire dry creep may be 10 to 16 times greater then prefire rates

Vegetation Communities

There are three (3) Major subdivisions covering a combined area of 11 million areas

Kuchler PNV

#29 True Chaparral

#30 Montane Chaparral

#32 Coastal Sagebrush

#29 True Chaparral

Adenostoma/Arctostaphylos/Ceanothus

  • Very dense vegetation of broadleaf evergreen sclerophyll shrubs
  • Largest community
  • 8.5 million acres

Dominates include:

A) Chamise- Adenostoma fasciculatum

B) Manzanita- Arctostaphylos ssp

C) California Lilac- Ceanothus species

#30 Montane Chaparral

Arctostaphylos/Chrysolepis/Ceanothus

  • Dense vegetation of broadleaf evergreen shrubs, occasionally with some some needleleaf evergreen and broadleaf decidious trees
  • .6 million acres

Dominants are:

A) Green leaf manzanita (Arctostaphylos patula)

B) Bush Chinquapin (Chrysolepis sempervirens)

C) Snowbush (Ceanothus velutinus)

Great Chaparralians

California Grizzly Bear

Once the ruler of the chaparral, the last California grizzly was seen in 1924. The last one in Southern California was shot in 1908.

California Condor

Fire

Fire is an important factor in this environment

Axelrod (1958,1977) has shown that fire and summer drought were the major environmental agents that shaped the chaparral over the past 2 million years.

Frequency is 10-40 years

California chaparral is one of the most fire susceptible vegetation types in the world: 1)Shrub density 2)Summer dryness

3) A volatile foliar substance within many of the chaparral plants

Burn to Live & Lives to Burn

But Maybe Not

From the California Chaparral Institute;

  • Old-growth chaparral is a beautiful, healthy ecosystem. It does NOT need fire to "renew" or clean out "built-up" or "over-grown" vegetation.

  • As an ecosystem, old-growth chaparral does not "need" fire to remain healthy.

  • The term "over-grown" is a value judgment that's applicable to our managed backyards and urban parks, not wild plant communities.

  • Old-growth chaparral continues to be a productive ecosystem, growing fresh, new growth in its upper canopy every year.

  • In fact, some chaparral plants require the leaf litter and shade provided by older chaparral stands for their seeds to germinate successfully.

  • Instead of becoming "trashy" or unproductive, as some have claimed, old-growth chaparral (in excess of 40-50 years) is actually just beginning a new cycle of life.

Concern over Fire

Old-growth chaparral being removed by a mechanical "masticator".

  • Will this result in fire risk reduction?
  • Or create additional resource degradation including:

  • Loss of native species
  • Destruction of soil crust
  • Introduction of invasive annual grasses
  • Formation of rills and gullies
  • Sediment delivery to watersheds.

  • "Treatments" near homes is the most effective in protecting structures from ignition.

And one more thing...

Coastal Scrub- PNV #32

Also refered to as soft chaparral, coastal sage scrub, coastal sage brush association

Within Terrestrial Vegetation of California

by Barber and Major

1) Northern Coastal Scrub

2) Coastal Sage Scrub

3) Coastal Sage Succulent Scrub

Extends from Southern Oregon to Baja as follows

1) Northern Coastal Scrub- From southern oregon to Big Sur

2) Coastal Sage Scrub- Big Sur to San Diego

3) Coastal Sage Succulant Scrub-San Diego to Baja

Northern Coastal Scrub

  • The annual rainfall in the Northern Coastal Scrub plant community can vary from 25 to 75 inches.
  • Temperatures remain mild throughout the year because of the proximity to the ocean.
  • Although the temperature is mild here the wind and salt spray make this a harsh environment for plants.
  • Plants remain low forming a dense or open scrub.
  • This cover is home to such birds as the California Thrasher, a species endemic to California.

  • Some common species include
  • California Lilac (Ceanothus thyrsiflorus var. repens)
  • Coyote Brush (Baccharis pilularis)
  • Coastal Golden Yarrow (Eriophyllum staechadifolium)
  • Seaside Daisy (Erigeron glaucus)
  • Sticky Monkey Flower (Mimulus aurantiacus).
  • Thimble berry and black berries are also prevalent in the coastal sage scrub plant community.

Other shrubs include:

  • California yerba santa (Eriodictyon californicum)
  • Coast silk-tassel (Garrya elliptica),
  • Salal (Gaultheria shallon)
  • Yellow bush lupine (Lupinus arboreus).

  • Herbaceous species include Western Blue-eyed Grass (Sisyrinchium bellum), Douglas iris (Iris douglasiana), and grasses.

Coyote brush- Baccharis pilularis

California Yerba Santa- Eriodictyon californicum

Salal- Gaultheria shallon

Coastal Sage Scrub

It is characterized by low-growing aromatic, and drought-deciduous shrubs adapted to the semi-arid Mediterranean climate of the coastal lowlands.

Characteristic plants include:

  • California sagebrush (Artemisia californica)
  • Black sage (Salvia mellifera)
  • White sage (Salvia apiana)
  • California buckwheat (Eriogonum fasciculatum),
  • Coast brittle-bush (Encelia californica)
  • Golden yarrow (Eriophyllum confertifolium)
  • Toyon (Heteromeles arbutifolia)
  • Lemonade berry (Rhus integrifolia)
  • Along with other shrubs and herbaceous plants, grasses, and in some places, cacti and succulents

California sagebrush (Artemisia californica)

Toyon (Heteromeles arbutifolia)

White sage (Salvia apiana)

Black sage (Salvia mellifera)

  • 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.

Endangered in the wild, Torrey pine is planted as an ornamental tree

Torrey Pines State Reserve

Torrey Pines State Natural Reserve is located within San Diego city limits

  • Remains one of the wildest stretches of land on the Southern California coast
  • 2000 acres of land set aside ---- before San Diego was developed
  • The chaparral plant community, the rare and elegant Torrey pine trees, miles of beaches, and a lagoon that is vital to migrating seabirds.

Salt Pruning

  • Salt pruning is the process by which saline mists generated by seawater are driven ashore by winds
  • Alter the shape of trees

  • The process of salt pruning selectively degrades foliage and branches on the windward side of the plant facing the body of saline water.

  • The resultant growth form is an asymmetrical plant form, swept back away from the ocean.

Coastal Sage Succulant

Presumably, colder temperatures, or perhaps increased rainfall limits the northern distribution of many of these succulent species. Some of the succulent species are actually found in San Diego County

Some of the plants characteristic of this community includes:

  • Agave shawii, a large, dark green agave at maturity
  • Coreopis maritima, a member of the sunflower family that dies back to a succulent root during the dry season
  • Fraxinus trifoliata, a small ash native to Baja California
  • Ambrosia chenopodifolia, another member of the sunflower family, but one with wind pollinated flowers.

Agave shawii

Coreopis maritima

Climate

Occupies dry slopes and ridges of thin soils

Temperature of chaparral is moderate but fluctuates considerably

Mean summer temp range from 82 F- 94 F

The overriding abiotic factor of the chaparral is precipitation

Rainfall occurs from October through April

About 85% comes during December through April

The growing season ranges from 340 days to 360 days during normal years

Coastal Scrub

A California condor taking a rest from soaring over the Los Padres National (Chaparral) Forest. Photo: Lane Frank

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