Home/Species/ California Scrub Oak

Quercus dumosa

Nutt.

California Scrub Oak

G3Vulnerable Found in 5 roadless areas NatureServe Explorer →

G3VulnerableGlobal Rank

EndangeredIUCN

HighThreat Impact

Identity

Unique IDELEMENT_GLOBAL.2.154209

Element CodePDFAG050D0

Record TypeSPECIES

ClassificationSpecies

Classification StatusStandard

Name CategoryVascular Plant

IUCNEndangered

Endemicoccurs (regularly, as a native taxon) in multiple nations

KingdomPlantae

PhylumAnthophyta

ClassDicotyledoneae

OrderFagales

FamilyFagaceae

GenusQuercus

Other Common Names

coastal sage scrub oak (EN) Coastal Sage Scrub Oak (EN)

Concept Reference

Kartesz, J.T. 1994. A synonymized checklist of the vascular flora of the United States, Canada, and Greenland. 2nd edition. 2 vols. Timber Press, Portland, OR.

Taxonomic Comments

The name Quercus dumosa was formerly widely applied to material now generally recognized as distinct (Q. cornelius-mulleri, Q. berberidifolia, etc.) This record is for a narrow treatment. The plants treated as var. kinselae by Kartesz (1994 checklist) are now regarded as the interspecific hybrid Quercus x townei (Kartesz 1999); two varieties remain in Q. dumosa (typical var. dumosa and var. elegantula).

Conservation Status

Rank MethodLegacy Rank calculation - Excel v3.1x

Review Date2017-03-07

Change Date2017-03-07

Edition Date2018-04-25

Edition AuthorsD. Gries (1997), rev. L. Morse (1998), rev. A. Olivero (2003), rev. Treher and Bittman (2017), rev. Treher (2018)

Threat ImpactHigh

Range Extent20,000-200,000 square km (about 8000-80,000 square miles)

Number of Occurrences81 - 300

Rank Reasons

Quercus dumosa occurs in Orange, Santa Barbara and San Diego Counties, California. It is also known from Baja California, Mexico. The primary threat ot the species is development which has also caused decline across the species range. Between 100 and 160 extant occurrences. Declines are known but can't be quantified due to lack of data.

Range Extent Comments

Quercus dumosa occurs in southern California and adjacent northern Baja California. It is reported from Sonora by the Sonora Conservation Data Center but there is no mention of Sonora in range cited by Roberts (1995).

Occurrences Comments

There are 162 occurrences that are known to be extant or potentially extant.

Threat Impact Comments

The most serious threat to this species is development, many sites are at risk of development, especially the 39 occurrences on private land. Improper fire regimes, non-native species, and ORV use (CNDDB 2018).

Ecology & Habitat

Habitat

Dry chaparrral and coastal scrub, "almost always within sight of the ocean" (FNA 1997).

Ecology

This species has some tolerance for fire, as it resproutes after fire. However, seedlings are not usually recruite for 10 to 20 years following fire. Therefore, the species requires long fire-free periods (Keeley 1992).

Terrestrial Habitats

Shrubland/chaparralGrassland/herbaceous

Other Nations (1)

United StatesN3

Province	Rank	Native
California	S3	Yes

Threat Assessments

Threat	Scope	Severity	Timing
1 - Residential & commercial development	Large - restricted	Extreme or 71-100% pop. decline	High (continuing)
6 - Human intrusions & disturbance	Unknown	Unknown	High (continuing)
6.1 - Recreational activities	Unknown	Unknown	High (continuing)
7 - Natural system modifications	Unknown	Unknown	High (continuing)
7.1 - Fire & fire suppression	Unknown	Unknown	High (continuing)
8 - Invasive & other problematic species, genes & diseases	Small (1-10%)	Unknown	High (continuing)
8.1 - Invasive non-native/alien species/diseases	Small (1-10%)	Unknown	High (continuing)

Plant Characteristics

DurationPERENNIAL, Long-lived

Economic Value (Genus)No

Roadless Areas (5)

California (5)

Area	Forest	Acres
Dry Lakes	Los Padres National Forest	17,043
Juncal	Los Padres National Forest	12,289
Malduce Buckhorn	Los Padres National Forest	14,177
Matilija	Los Padres National Forest	5,218
White Ledge	Los Padres National Forest	18,632

References (9)

California Department of Fish and Game. 2000. Natural Diversity Database (RareFind 2), Version 2.1.2, January 25, 2000. Downloaded in 2003.
California Native Plant Society (CNPS). 2001. Inventory of Rare and Endangered Plants of California (sixth edition). Rare Plant Scientific Advisory Committee, David P. Tibor, Convening Editor. California Native Plant Society. Sacramento, CA. x + 388pp.
Flora of North America Editorial Committee. 1997. Flora of North America north of Mexico. Vol. 3. Magnoliophyta: Magnoliidae and Hamamelidae. Oxford Univ. Press, New York. xxiii + 590 pp.
Hickman, J. C., ed. 1993. The Jepson manual: Higher plants of California. University of California Press, Berkeley, CA. 1400 pp.
Kartesz, J.T. 1994. A synonymized checklist of the vascular flora of the United States, Canada, and Greenland. 2nd edition. 2 vols. Timber Press, Portland, OR.
Keeley, J.E. 1992. Recruitment of Seedlings and Vegetative Sprouts in Unburned Chaparral. <i>Ecology</i> 73(4): 1194–1208.
Little, E.L., Jr. 1979. Checklist of United States trees (native and naturalized). Agriculture Handbook No. 541. U.S. Forest Service, Washington, D.C. 375 pp.
Roberts, F.M., Jr. 1995. Illustrated guide to the oaks of the Southern Californian Floristic Province. F.M. Roberts Publications, Encinatas, Calif. 112 pp.
Skinner, M.W., and B.M. Pavlik, eds. 1997 (1994). Inventory of rare and endangered vascular plants of California. 1997 Electronic Inventory Update of 1994 5th edition, California Native Plant Society, Special Publication No. 1, Sacramento.

Quercus dumosa

Habitat

Ecology

—