Pinus monticola Forest & Woodland Alliance
Western white pine forest and woodland
Western white pine forest and woodland
USDA Ecological Section Map
Summary Information
- Primary Life FormTree
- Elevation200-2300 m
- State RarityS4
- Global RarityG5
- DistributionCAN: BC. USA: CA, ID, MT, OR, WA (NatureServe)
- Endemic to CaliforniaNo
- Endemic to California Floristic Province and DesertsNo
- Date Added1995/11/01
Characteristic Species
Pinus monticola is dominant or co-dominant in the tree canopy with Abies concolor, Abies magnifica, Abies ×shastensis, Pinus attenuata, Pinus balfouriana, Pinus contorta ssp. murrayana, Pinus jeffreyi, Pinus ponderosa var. washoensis, Pseudotsuga menziesii and Tsuga mertensiana.
Vegetation Layers
Trees < 70 m; canopy is open to intermittent. Shrub layer is sparse to intermittent. Herbaceous layer is sparse or abundant.
Membership Rules
- Pinus monticola > 30% relative cover in the tree layer (Keeler-Wolf et al. 2003b).
Habitats
Raised stream benches and terraces, all slopes, but most extensive above subalpine lake margins, on plateaus, and on upper elevation slopes and ridgetops. Soils are granitic, ultramafic, or volcanic derived. The USFWS Wetland Inventory (1996 national list) recognizes Pinus monticola as a FACU plant.
Other Habitat, Alliance and Community Groupings
| MCV (1995) | Western white pine series |
| NVCS (2009) | Pinus monticola forest alliance, Pinus monticola woodland alliance |
| Calveg | Western white pine |
| Holland | Ultramafic white pine forest |
| Munz | Subalpine forest |
| WHR | Subalpine conifer |
| CDFW CA Code | 87.170.00 |
National Vegetation Classification Hierarchy
| Formation Class | Mesomorphic Tree Vegetation (Forest and Woodland) |
| Formation Subclass | Temperate Forest |
| Formation | Cool Temperate Forest |
| Division | Western North America Cool Temperate Forest |
| Macro Group | Vancouverian Subalpine Forest |
| Group | Vancouverian mesic montane coniferous forest and woodland |
Remarks
Pinus monticola grows to 60 m in height and attains 400 years in age. Trees develop cones after 7 years. Seeds remain viable in the duff for up to 4 years and germinate after cold stratification. Seedlings germinate on mineral soil and duff. Seedling mortality is high in the first year because of snow mold (Neopeckia coulteri), rodents, late-season drought, and high soil temperatures. On dry sites, partial shade favors seedling establishment. Trees attain their greatest size on deep, fertile soils, but they are more common on unfertile soils. P. monticola is shade intolerant and does not respond after release from 30 years of suppression (Griffith 1992c).
Pinus monticola grows in a wide range of mountain settings throughout the state, and it is a common sec-ondary species in several alliances, especially at subalpine elevations. In the Klamath Mountains, it grows as low as 200 m in elevation on ultramafic substrates, where it associates with P. contorta ssp. contorta (sensu lato) and P. attenuata. See the Pinus contorta ssp. contorta alliance for discussion on the taxonomic status of Pinus contorta in the western Siskiyou Mountains. See also Sawyer (2006, 2007) for a regional description of Klamath Mountains.
Pinus monticola grows in a wide range of mountain settings throughout the state, and it is a common sec-ondary species in several alliances, especially at subalpine elevations. In the Klamath Mountains, it grows as low as 200 m in elevation on ultramafic substrates, where it associates with P. contorta ssp. contorta (sensu lato) and P. attenuata. See the Pinus contorta ssp. contorta alliance for discussion on the taxonomic status of Pinus contorta in the western Siskiyou Mountains. See also Sawyer (2006, 2007) for a regional description of Klamath Mountains.
Life History Traits of the Principal Species
| Pinus monticola | |
|---|---|
| Life forms | Tree; evergreen |
| Seed storage | Soil |
| Seed longevity | Medium |
| Mode of dispersal | Wind |
| Germination agents | Stratification—winter |
| Mode of sprouting | None |
| Survivability after fire/disturbance | Fire-hardy; thick epidermis; canopy architecture resistant |
| Disturbance-stimulated flowering | No |
| Reproductive range | 2-400+ years |
| Recruitment | Low |
| Regional variation | Low |
Fire Characteristics
Trees have thin bark and can be killed or scarred by cool fires. Most open subalpine stands have discontinuous surface fuel, which limits fire spread to a small area. Scars provide vectors for butt rots to enter trees (Sugihara et al. 2007).
| Fire return interval | Long (200+ years) |
| Seasonality | Late summer (short) |
| Size/extent | Small to medium |
| Complexity | Low |
| Intensity | Low |
| Severity | Low |
| Type | Surface to passive crown |
| Regional knowledge | Klamath Mountains; Sierra Nevada |
Regional Status
- Klamath Mountains (M261Aa-b, Ad, Ag, Aj-k, Ap, At). Self-replacing stands occur on deep, partially serpentinized peridotite in western Del Norte Co. (Duebendorfer 1987). These Pinus monticola woodlands, first described by Whittaker (1960), mix in a patchy mosaic with P. jeffreyi woodlands and shrublands. Soil differences and history cause the mosaic. The shrublands occupy forest sites disturbed by fire or white pine bluster rust (Cronartium ribicola) in the 1990s. Less-undisturbed sites find P. monticola mixed with Pseudotsuga menziesii. Stands also occur at subalpine elevations in the Marble, Salmon, and Scott mountains, and in the Trinity Alps. Common associates are Pinus balfouriana, P. contorta ssp. murrayana, and P. jeffreyi (Sawyer 2006, 2007).
- Modoc Plateau (M261Gf). Stands are extensive in the northern Warner Mountains above the Abies concolor zone. Perhaps because of the absence of A. magnifica, this pine may have expanded into ecological conditions normally occupied by other firs elsewhere in northern California’s mountains (Fites-Kaufman et al. 2007).
- Sierra Nevada (M261Ed, Eh, Ej-k, Eo, Eq). Stands exist at subalpine elevations throughout all but the southernmost parts of the section (Fites-Kaufman et al. 2007). Stands described for Yosemite National Park (Keeler-Wolf et al. 2003b) contain A. magnifica and P. contorta. Stands in Babbitt Peak RNA include P. ponderosa var. washoensis. Those in South Mountaineer Creek cRNA represent the southern expression of the alliance (Keeler-Wolf 1991b, see Cheng 2004). Stands appear to be larger and better developed on the eastern side of the central and northern Sierra Nevada, particularly in the Carson Range in both California and adjacent Nevada.
- Southern Cascades (M261Df, Dj, Dm). Stands exist with Tsuga mertensiana at higher subalpine elevations near Mount Lassen and along lake margins in the section (Fites-Kaufman et al. 2007).
Management Considerations
White pine blister rust has affected stands greatly in the wetter climates of the western Klamath Mountains. Disease and fire are less important at subalpine elevations, where stands are commonly small and the trees scattered. Stands in the Sierra Nevada are less affected. Sierra Nevada stands are typically limited to a narrow ecological range between the Abies magnifica alliance and true subalpine alliances. Changing climate may compress and restrict these stands in some parts of this tree’s California range (van Wagtendonk and Fites-Kaufman 2007).
Associations
- Pinus monticola / Achnatherum occidentale [4], [8]
- Pinus monticola / Arctostaphylos nevadensis [5], [7]
- Pinus monticola - Pinus contorta ssp. murrayana [4], [8]
- Pinus monticola - Pinus contorta ssp. murrayana / Notholithocarpus densiflorus var. echinoides [1], [2], [3]
- Pinus monticola - Pseudotsuga menziesii / Quercus vacciniifolia - Notholithocarpus densiflorus var. echinoides [2]
- Pinus monticola / Xerophyllum tenax [6]
References
- [1] Duebendorfer, T.E. 1987
- [2] Jimerson, T.M.;Hoover, L.D.;McGee, E.A.;DeNitto, G.;Creasy, R.M. 1995
- [3] Keeler-Wolf, T. 1986e
- [4] Keeler-Wolf, T.;Schindel, M.;San, S.;Moore, P.;Hickson, D. 2003b
- [5] Sawyer, J.O.;Thornburgh, D.A. 1977
- [6] Simpson, L.G. 1980
- [7] Whipple, J.;Cope, E. 1979
- [8] NPS-SEKI, 2009
- Barry, W.J. 1989a
- Barry, W.J. 1989b
- Boyd, R.J. 1980b
- Cheatham, N.H.;Haller, J.R. 1975
- Fites-Kauffman, J.A.;Rundel, P.;Stephenson, N.;Weixelman, D. 2007
- Graham, R.T. 1990
- Griffin, J.R.;Critchfield, W.B. 1972
- Griffith, R.S. 1992c
- Kruckeberg, A.R. 1984
- Sawyer, J.O. 2006
- Sawyer, J.O. 2007
- van Wagtendonk, J.W.;Fites-Kauffman, J. 2006