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Home/Species/ Nissenan Manzanita

Arctostaphylos nissenana

Merriam

Nissenan Manzanita

G1Critically Imperiled Found in 1 roadless area NatureServe Explorer →
G1Critically ImperiledGlobal Rank
Very highThreat Impact
Identity
Unique IDELEMENT_GLOBAL.2.154143
Element CodePDERI040V0
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVascular Plant
Endemicendemic to a single state or province
KingdomPlantae
PhylumAnthophyta
ClassDicotyledoneae
OrderEricales
FamilyEricaceae
GenusArctostaphylos
Synonyms
Arctostaphylos nissenianaMerriam
Other Common Names
Nissenan manzanita (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.
Conservation Status
Rank Method Rank calculation - Biotics v2
Review Date2024-05-30
Change Date2013-12-19
Edition Date2024-05-30
Edition AuthorsBittman, R.L., rev. L. Oliver (2003), rev. A. Treher (2013), rev. Bittman (2013), J. Johnson (2024)
Threat ImpactVery high
Range Extent1000-5000 square km (about 400-2000 square miles)
Number of Occurrences21 - 80
Rank Reasons
Arctostaphylos nissenana is endemic to California and occurs in only three counties. There are about nine extant occurrences of Arctostaphylos nissenana. Development, pathogens, land clearing for livestock grazing, fire, and fire suppression are major threats.
Range Extent Comments
Arctostaphylos nissenana is endemic to California, USA. Most of the populations are found near Placerville in Placer and El Dorado Counties and two are near Sonora in Tuolumne County. Range extent was estimated using photo-based observations and California Natural Diversity Database occurrence data collected between 1993 and 2024 (iNaturalist 2024, CNDDB 2024).
Occurrences Comments
By applying a 1 km separation distance to photo-based observations and California Natural Diversity Database occurrence data documented between 1993 and 2024, it is estimated that there are six occurrences range-wide (iNaturalist 2024, CNDDB 2024).
Threat Impact Comments
Development and pathogens that caused die-offs in two populations pose the largest threats to this species (CNPS 2001, CNDDB 2024). Shade from overstory species and high-intensity wildfires, both caused by long-term fire suppression, are impacting many occurrences. Motorized and non-motorized trail construction, logging, land clearing for livestock grazing, and herbicide use also threaten this species (CNDDB 2024).
Ecology & Habitat

Habitat

Arctostaphylos nissenana grows in open, rocky shale ridges, chaparral, woodland, and sparse coniferous forest from 500 to 1300 m elevation (CNDDB 2024).
Terrestrial Habitats
Forest/WoodlandForest - ConiferShrubland/chaparral
Other Nations (1)
United StatesN1
ProvinceRankNative
CaliforniaS1Yes
Threat Assessments
ThreatScopeSeverityTiming
1 - Residential & commercial developmentRestricted - smallExtreme or 71-100% pop. declineHigh - moderate
2 - Agriculture & aquacultureRestricted (11-30%)Extreme - moderateHigh (continuing)
2.3 - Livestock farming & ranchingRestricted (11-30%)Extreme - moderateHigh (continuing)
4 - Transportation & service corridorsSmall (1-10%)Serious - moderateHigh (continuing)
4.1 - Roads & railroadsSmall (1-10%)Serious - moderateHigh (continuing)
5 - Biological resource useLarge (31-70%)Serious - moderateModerate (short-term)
5.3 - Logging & wood harvestingLarge (31-70%)Serious - moderateModerate (short-term)
6 - Human intrusions & disturbanceRestricted (11-30%)Moderate or 11-30% pop. declineHigh (continuing)
6.1 - Recreational activitiesRestricted (11-30%)Moderate or 11-30% pop. declineHigh (continuing)
7 - Natural system modificationsPervasive (71-100%)Serious or 31-70% pop. declineHigh (continuing)
7.1 - Fire & fire suppressionPervasive (71-100%)Serious or 31-70% pop. declineHigh (continuing)
8 - Invasive & other problematic species, genes & diseasesLarge - restrictedSerious or 31-70% pop. declineHigh (continuing)
9 - PollutionRestricted - smallSerious or 31-70% pop. declineHigh (continuing)
9.3 - Agricultural & forestry effluentsRestricted - smallSerious or 31-70% pop. declineHigh (continuing)
9.3.3 - Herbicides and pesticidesRestricted - smallSerious or 31-70% pop. declineHigh (continuing)

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Plant Characteristics
DurationPERENNIAL, Long-lived
Economic Value (Genus)No
Roadless Areas (1)
California (1)
AreaForestAcres
North Fork Middle Fork American RiverTahoe National Forest11,245
References (9)
  1. Bachman, S., J. Moat, A.W. Hill, J. de la Torre, and B. Scott. Supporting Red List threat assessments with GeoCAT: geospatial conservation assessment tool. In: Smith, V., and L. Penev (Eds). 2011. e-Infrastructures for data publishing in biodiversity science. ZooKeys 150:117-126. Version BETA. Accessed online: http://geocat.kew.org/editor
  2. California Department of Fish and Game. 2000. Natural Diversity Database (RareFind 2), Version 2.1.2, January 25, 2000. Downloaded in 2003.
  3. 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.
  4. California Native Plant Society (CNPS). 2013. Inventory of Rare and Endangered Plants (online edition, v8-01a). California Native Plant Society. Sacramento, CA. Online. Available: www.rareplants.cnps.org (Accessed 2013).
  5. California Natural Diversity Database (CNDDB). 2024. RareFind Version 5.3.0. California Department of Fish and Game, Sacramento.
  6. 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.
  7. iNaturalist. 2024. Online. Available: https://www.inaturalist.org (accessed 2024).
  8. 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.
  9. 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.