Pinus quadrifolia Woodland Alliance
Parry pinyon woodland
Parry pinyon woodland
USDA Ecological Section Map
Summary Information
- Primary Life FormTree
- Elevation900-1800 m
- State RarityS2
- Global RarityG3
- DistributionUSA: CA. Mexico (NatureServe)
- Endemic to CaliforniaNo
- Endemic to California Floristic Province and DesertsNo
- Date Added1995/11/01
Characteristic Species
Pinus quadrifolia is dominant in the tree canopy with Juniperus californica, Pinus jeffreyi, Pinus monophylla and Quercus chrysolepis. Or it is emergent above the shrub canopy with Adenostoma fasciculatum, Adenostoma sparsifolium, Arctostaphylos glandulosa, Arctostaphylos glauca, Ceanothus greggii, Cercocarpus montanus, Eriogonum fasciculatum, Hesperoyucca whipplei, Quercus cornelius-mulleri, Rhus ovata or Yucca schidigera.
Vegetation Layers
Trees < 15 m; canopy is open or intermittent. Shrub layer is usually intermittent. Herbaceous layer is sparse.
Membership Rules
- Pinus quadrifolia > 3% absolute cover of trees over chaparral shrubs with scattered Quercus chrysolepis (Keeler-Wolf et al. 1998b).
- Pinus quadrifolia is > 50% relative cover and > 10% absolute cover in the tree canopy (Klein and Evens 2005).
Habitats
Slopes with north-facing aspects, ridges. Soils are well drained.
Other Habitat, Alliance and Community Groupings
| MCV (1995) | Parry pinyon series |
| NVCS (2009) | Pinus quadrifolia woodland alliance |
| Calveg | Four-needle pinyon pine |
| Holland | Peninsular piñon woodland, Peninsular juniper woodland and scrub |
| Munz | Pinyon-juniper woodland |
| WHR | Pinyon-juniper |
| CDFW CA Code | 87.030.00 |
National Vegetation Classification Hierarchy
| Formation Class | Mesomorphic Tree Vegetation (Forest and Woodland) |
| Formation Subclass | Temperate Forest |
| Formation | Warm Temperate Forest |
| Division | Madrean Forest and Woodland |
| Macro Group | California Forest and Woodland |
| Group | Californian evergreen coniferous forest and woodland |
Remarks
Pinus quadrifolia is a conifer that attains a height of 15 m and an age of 500 years. Trees begin bearing cones by 10-20 years of age. Seed production is heavy every 1-5 years. Animals disperse and cache the seeds. Fresh seeds have high viability and germinate readily with little or no stratification (Esser 1993d). The taxonomic status of P. quadrifolia is controversial (Lanner 1999). Lanner argues for a hybrid origin between the Baja California P. juarezensis and the P. monophylla of the Peninsular Ranges. Kral (1993), in the Flora of North America, places P. juarezensis in synonymy with P. quadrifolia.
The species is more widespread than is the alliance, with individual trees found in stands of other alliances. We include only stands in the alliance where P. quadrifolia is conspicuous over a dense chaparral shrub canopy (Minnich 2007). These stands, although commonly within view of P. monophylla stands, tend to occur in more mesic settings and usually contain cismontane chaparral species rather than transmontane desert species.
The species is more widespread than is the alliance, with individual trees found in stands of other alliances. We include only stands in the alliance where P. quadrifolia is conspicuous over a dense chaparral shrub canopy (Minnich 2007). These stands, although commonly within view of P. monophylla stands, tend to occur in more mesic settings and usually contain cismontane chaparral species rather than transmontane desert species.
Life History Traits of the Principal Species
| Pinus quadrifolia | |
|---|---|
| Life forms | Tree; evergreen |
| Seed storage | Soil |
| Seed longevity | Medium |
| Mode of dispersal | Animal |
| Germination agents | None; stratification—winter |
| Mode of sprouting | None |
| Survivability after fire/disturbance | Fire-sensitive; thin epidermis; high flammability; no/low sprouter; canopy architecture susceptible |
| Disturbance-stimulated flowering | No |
| Reproductive range | 10-500 years |
| Recruitment | Medium to high |
| Regional variation | Low |
Fire Characteristics
Pinus quadrifolia is an obligate seeder without the ability to sprout after fire. Trees are thin barked, and even surface fires kill old trees. Long intervals between fires favor higher densities of P. quadrifolia. Fires are stand replacing, and surviving trees occur on unburned islands (R. A. Minnich pers. comm. 2007). Individual trees in open, rocky sites are more apt to survive (Esser 1993d).
| Fire return interval | Truncated long |
| Seasonality | Summer-early fall |
| Size/extent | Medium to large |
| Complexity | Low to moderate |
| Intensity | Moderate to high |
| Severity | High to very high |
| Type | Passive-active crown fire |
| Regional knowledge | Peninsular Ranges |
Regional Status
- Southern California Mountains and Valleys (M262Bl, Bo-p). Mainly a Baja California species (Minnich and Franco-Vizcaino 1998), Pinus quadrifolia grows in the Laguna, San Jacinto, and Santa Rosa mountains in California (Griffin and Critchfield 1972, Minnich and Everett 2001). Stands on montane slopes south of the San Jacinto Mountains in western Riverside Co. (Klein and Evens 2005) contain an open understory. Stands described for Anza-Borrego Desert State Park occur on the steep eastern escarpment of Mount Laguna between Monument Peak and the north-facing slopes above Potrero Wash (Keeler-Wolf et al. 1998b). These were associated with large shrubs of Cercocarpus montanus and Quercus chrysolepis.
Management Considerations
Pinus quadrifolia often grows on steep, rocky terrain that does not easily carry fire (Griffin and Critchfield 1972). Young trees seen in chaparral and mature stands suggest that its range is increasing, but we do not have sufficient long-term spatial data to evaluate whether fire suppression is contributing to this pattern (R. A. Minnich pers. comm. 2007).
Associations
- Pinus quadrifolia / Quercus cornelius-mulleri [1]
References
- [1] Klein, A.;Evens, J. 2006
- Esser, L.L. 1993d
- Lanner, R.M. 1999
- Minnich, R.A. 1987
- Minnich, R.A. 2007
- Minnich, R.A.;Everett, R.G. 2001
- Minnich, R.;Vizcaino, E.F. 1998
- Paysen, T.E.;Derby, J.A.;Black, H.;Bleich, V.C.;Mincks, J.W. 1980
- Thorne, R.F. 1982
- Thorne, R.F.;Schoenherr, A.;Clements, C.D.;Young., J.A. 2007