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Home/Species/ Klamath Manzanita

Arctostaphylos klamathensis

S.W. Edwards, Keeler-Wolf & W. Knight

Klamath Manzanita

G2Imperiled Found in 4 roadless areas NatureServe Explorer →
G2ImperiledGlobal Rank
HighThreat Impact
Identity
Unique IDELEMENT_GLOBAL.2.161482
Element CodePDERI041R0
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVascular Plant
Endemicendemic to a single state or province
KingdomPlantae
PhylumAnthophyta
ClassDicotyledoneae
OrderEricales
FamilyEricaceae
GenusArctostaphylos
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.
Conservation Status
Rank Method Rank calculation - Biotics v2
Review Date2021-09-13
Change Date2021-09-13
Edition Date2021-09-14
Edition AuthorsBittman, R.L., rev. D. Gries, rev. L. Oliver, rev. R. Bittman (2005), rev. A. Treher and Bittman (2016), rev. Treher (2021).
Threat ImpactHigh
Range Extent250-1000 square km (about 100-400 square miles)
Number of Occurrences21 - 80
Rank Reasons
As an endemic of California, Arctostaphylos klamathensis is restricted to the Klamath Mountains in Shasta, Siskiyou, and Trinity Counties. It occurs on serpentine and gabbro substrates. This species is on private land, USFS lands, or occurrences occupying both, where logging, clearing, wildfires, trail use and recreation are threats. There are thousands of plants across 48 known occurrences. Historical occurrences should be surveyed to determine if plants are extant and more research is needed to better understand the species response to logging.
Range Extent Comments
Arctostaphylos klamathensis is endemic to California (U.S.A.) where it is known from the Klamath Mountains in Shasta, Siskiyou, and Trinity Counties.
Occurrences Comments
There are forty-eight occurrences in California but eight are historical. It could occur in nearby areas of Oregon, but there are no reports known to date.
Threat Impact Comments
Threats include logging activities, roads, wildfire, biocides, and ORVs at some sites. Impact of logging activities is unclear and may be beneficial in some instances. Many sites are on private land (CNDDB 2021).
Ecology & Habitat

Habitat

This species occurs in open submontane chaparral and open mixed forest of shasta red fir, lodgepole pine, mountain hemlock on shallow rocky, often gabbro but sometimes serpentine soils. The habitat of this consists of areas which have primarily been mapped as Californian Montane Conifer Forest & Woodland (G344), Sierra-Cascade Red Fir - Mountain Hemlock Forest (G749), or Western Montane Chaparral (G282) at the group level of the US National Vegetation Classification (NatureServe 2025).
Terrestrial Habitats
Forest/WoodlandForest - ConiferWoodland - ConiferShrubland/chaparralBarrens
Other Nations (1)
United StatesN2
ProvinceRankNative
CaliforniaS2Yes
Threat Assessments
ThreatScopeSeverityTiming
4 - Transportation & service corridorsRestricted (11-30%)Moderate or 11-30% pop. declineHigh (continuing)
4.1 - Roads & railroadsRestricted (11-30%)Moderate or 11-30% pop. declineHigh (continuing)
5 - Biological resource useLarge (31-70%)Moderate - slightHigh (continuing)
5.3 - Logging & wood harvestingLarge (31-70%)Moderate - slightHigh (continuing)
6 - Human intrusions & disturbanceNegligible (<1%)Slight or 1-10% pop. declineHigh (continuing)
6.1 - Recreational activitiesNegligible (<1%)Slight or 1-10% pop. declineHigh (continuing)
7 - Natural system modificationsLarge (31-70%)Moderate or 11-30% pop. declineHigh (continuing)
7.1 - Fire & fire suppressionLarge (31-70%)Moderate or 11-30% pop. declineHigh (continuing)
7.1.1 - Increase in fire frequency/intensityLarge (31-70%)Moderate or 11-30% pop. declineHigh (continuing)
9 - PollutionRestricted (11-30%)Moderate or 11-30% pop. declineHigh (continuing)
9.3 - Agricultural & forestry effluentsRestricted (11-30%)Moderate or 11-30% pop. declineHigh (continuing)
9.3.3 - Herbicides and pesticidesRestricted (11-30%)Moderate or 11-30% pop. declineHigh (continuing)

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Plant Characteristics
DurationPERENNIAL, EVERGREEN
Economic Value (Genus)No
Roadless Areas (4)
California (4)
AreaForestAcres
Bonanza KingShasta-Trinity National Forest16,402
Lake EleanorShasta-Trinity National Forest397
Orleans Mtn.Klamath National Forest49,090
Slate CreekShasta-Trinity National Forest6,636
References (6)
  1. California Department of Fish and Game. 2000. Natural Diversity Database (RareFind 2), Version 2.1.2, January 25, 2000. Downloaded in 2003.
  2. 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.
  3. Flora of North America Editorial Committee (FNA). 2009. Flora of North America north of Mexico. Vol. 8. Magnoliophyta: Paeoniaceae to Ericaceae. Oxford University Press, New York. xxiv + 585 pp.
  4. 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.
  5. NatureServe. 2025. Ecosystems of the Conterminous US and Adjacent Areas, Version 1.0. NatureServe, Arlington, Virginia. Online. Available: https://natureserve.maps.arcgis.com/home/item.html?id=66c13612635d4ee9bd4d6500cf462e7f (Accessed 2025).
  6. 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.