Quercus douglasii
Hook. & Arn.
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Pays · région · aire protégée · écorégion · biome
Graphe en cours d’indexation
Calcul du tissu écologique de Quercus douglasii.
Le graphe apparaîtra automatiquement dès que le calcul est terminé (rafraîchissement toutes les 5s).
Liste rouge IUCN
LC · Préoccupation mineure→Stable- Évaluation
- 2016 · v3.1
- Altitude
- 0 – 1200 m
- Profondeur
- – m
État de la populationTexte officiel évaluation IUCNExpert
There is no estimation available for the number of mature Quercus douglasii individuals, but this species' domination of oak woodland in California seems to lead to its secure status, as well as its growth in drought-stricken and sloped environments where pressure from development and agriculture is low (Pavlik et al. 1991). Still, low recruitment rates are a concern and are perpetuated by a variety of factors, including fire suppression, livestock grazing, non-native annual grasses and habitat fragmentation (Tyler et al. 2006).
Menaces identifiées(7 menaces classées CMP-IUCN)
11_2DroughtsUnknownUnknownOngoing1_1Housing & urban areasUnknownUnknownOngoing2_3_2Small-holder grazing, ranching or farmingUnknownMinority (<50%)Ongoing7_1_2Supression in fire frequency/intensityUnknownMajority (50-90%)Ongoing8_1_1Unspecified speciesUnknownUnknownOngoing8_2_2Named speciesUnknownUnknownOngoing8_2_2Named speciesUnknownUnknownOngoing
Description complète des menacesTexte détaillé évaluation IUCNExpert
Although Blue Oak currently seems to have a stable population, there is concern that juvenile replacements will not be present when mature Blue Oaks die. Reduced sapling and pole recruitment has been attributed to livestock, Mule Deer and Pocket Gopher, drought, interference from non-native annual grasses, fire suppression and habitat fragmentation (Pulido et al. 2013, Gordon et al. 1989, Stanford et al. 2015). However, Tyler et al. (2006) found that when regeneration of foothill oaks is examined over longer periods of time, although Q. douglasii shows very limited seedling or sapling recruitment at present, rare recruitment may not lead to decreasing population size due to low rates of mortality of overstory individuals. Recruitment levels are clearly low, but it is yet to be understood if a significant decline in the species will be experienced in the future.
Habitats préférentiels (classification IUCN)
1_4Forest - Temperate★1_5Forest - Subtropical/Tropical Dry★
Mesures de conservation recommandéesStratégies de conservation IUCNExpert
The Integrated Hardwood Range Management Program, a collaborative effort between the University of California and the California Division of Forestry, is monitoring Blue Oak populations at the state level, providing recommendations for future legal protection. Blue Oak woodland is currently owned by approximately 75% private individuals and companies, 14% national (forest system) and 11% various other public ownership (Fryer 2007).
The species is also located in 34 arboreta and botanic garden ex situ sights around the world, according to Botanic Gardens Conservation International (2015).
The species is also located in 34 arboreta and botanic garden ex situ sights around the world, according to Botanic Gardens Conservation International (2015).
Stress écologiques (10)Stresses Classification — IUCNExpert
1_1Ecosystem conversion1_2Ecosystem degradation1_2Ecosystem degradation2_1Species mortality2_1Species mortality2_2Species disturbance2_3_2Competition2_3_7Reduced reproductive success2_3_7Reduced reproductive success2_3_7Reduced reproductive success
Usage & commerce (4)Use & Trade — IUCNExpert
17Other (free text)national2Food - animal7Fuelssubsistance9Construction or structural materialssubsistance
Niche IUCN globaleRealms · Systems · LMEs · Growth forms · FAOs — biogéographie IUCNExpert
Royaumes biogéographiques
Nearctic
Systèmes (terrestre/eau douce/marin)
Terrestrial
Formes de croissance
Tree - largeTree - small
Références bibliographiques (9)Sources scientifiques de l'évaluation IUCNExpert
- BGCI. 2017. PlantSearch. Available at: <a href="www.bgci.org/plant_search.php">www.bgci.org/plant_search.php</a>.
- IUCN. 2016. The IUCN Red List of Threatened Species. Version 2016-1. Available at: <a href="www.iucnredlist.org">www.iucnredlist.org</a>. (Accessed: 30 June 2016).
- Standiford, R.B., Phillips, R.L. and McDougald, N.K. 2015. Thinning – a Tool for Restoration of California’s Southern Sierra Nevada Blue Oak Woodlands. <i>General Technical Report PSW-GTR-19x</i>.
- GBIF. 2015. Global Biodiversity Information Facility (GBIF) Occurrence Download. Available at: <a href="http://www.gbif.org/">http://www.gbif.org/</a>. (Accessed: September 2015).
- Pulido, F., McCreary, D., Cañellas, I., McClaran, M. and Plieninger, T. 2013. Oak Regeneration: Ecological Dynamics and Restoration Techniques. <i>Mediterranean Oak Woodland Working Landscapes</i> 16: 123-144.
- Fryer, J.L. 2007. <i>Quercus douglasii</i>. In: Fire Effects Information System. Available at: <a href="http://www.fs.fed.us/database/feis/">http://www.fs.fed.us/database/feis/</a>. (Accessed: 16 September 2015).
- Tyler, C.M., Kuhn, B. and Davis, F.W. 2006. Demography and Recruitment Limitations of Three Oak Species in California. <i>The Quarterly Review of Biology</i> 81(2).
- Pavlik, B.M., Muick, P.C., Johnson, S.G. and Popper, M. 1991. <i>Oaks of California</i>. Cachuma Press, Inc., Los Olivos.
- Gordon, D.R., Menke, J.M. and Rice, K.J. 1989. Competition for soil water between annual plants and blue oak (<i>Quercus douglasii</i>) seedlings. <i>Oecologia</i> 79(4): 533-541.
Évaluateurs & contributeurs (2)Personnes ayant contribué à l'évaluation IUCNExpert
assessor
Beckman, E.
evaluator
Oldfield, S.
Beckman, E. 2016. Quercus douglasii. The IUCN Red List of Threatened Species 2016: e.T78914533A78914539. Accessed on 05 May 2026.
Distribution mondiale
Calcul de la distribution GBIF· ~10–60 s
Phénologie
Calcul du calendrier d'apparition· ~5–30 s
Consulter sur les bases externes
Observations & statuts
Cartographie
Note nomenclaturale & synonymesDétails taxonomiques + synonymes CoLExpert
Note nomenclaturale
TAXREF v18 — INPN/MNHNSynonymes (4)— redirigent vers cette page
- Quercus gambeliiLiebm.
- Quercus douglasii var. ransomii(Kellogg) Zabel
- Quercus oblongifolia var. brevilobataTorr.
- Quercus ransomiiKellogg
Sources : Catalogue of Life Cross-References (synonymes) · TAXREF v18 INPN/MNHN (commentaires FR).