Print Report
CEGL000789 Pinus edulis - Juniperus osteosperma / Purshia tridentata Woodland
Type Concept Sentence: No Data Available
Common (Translated Scientific) Name: Two-needle Pinyon - Utah Juniper / Antelope Bitterbrush Woodland
Colloquial Name: No Data Available
Hierarchy Level: Association
Type Concept: This association is common at middle elevations of the pinyon-juniper woodland zone in western Colorado and northwestern New Mexico. Sites occupy ridges, scarps and mesas with generally gentle to moderate slopes. Elevations range from 1800 to 2330 m (5900-7645 feet) and aspect is variable. Soils are often coarse and rocky, may be shallow, and sometimes contain outcrops of the underlying sandstone or limestone. This association is characterized by a mixed canopy of Pinus edulis and Juniperus spp. with a shrub layer dominated by Purshia tridentata. Canopy cover ranges from 10% in the beetle- and fungus-affected woodlands of southwestern Colorado to around 50% in the mountains of northern New Mexico. The canopy sometimes includes arborescent Quercus gambelii in the southern part of the range. The shrub layer may consist almost entirely of Purshia tridentata with between 5 and 25% cover, or more often it is mixed with other shrubs that have at least 1% cover, including Amelanchier utahensis, Artemisia tridentata, Artemisia nova, Cercocarpus montanus, Ephedra viridis, Opuntia polyacantha, Ribes cereum, and Yucca baccata. Graminoids are well-represented to abundant; common species include Pseudoroegneria spicata, Poa fendleriana, Koeleria macrantha, Carex rossii, and Piptatheropsis micrantha. The forb component of the understory is often diverse but rarely contributes significantly to the overall vegetation cover. Species noted as occurring in this community include Astragalus scopulorum, Eriogonum jamesii, Eriogonum racemosum, Penstemon linarioides ssp. coloradoensis, Petradoria pumila, Phlox spp., and Stenotus acaulis.
Diagnostic Characteristics: The overstory consists of Pinus edulis, Juniperus osteosperma, and occasionally Quercus gambelii. The shrubby understory includes Purshia tridentata. Artemisia tridentata is scarce or absent. Usually has a very sparse cover of grasses and forbs.
Rationale for Nominal Species or Physiognomic Features: No Data Available
Classification Comments: Some stands of this association in northwestern Colorado have a shrub layer that is codominated by Artemisia nova and Purshia tridentata. The classification of these stands may need to be revisited to determine whether they are a better fit with the concept of this association or with ~Pinus edulis - Juniperus osteosperma / Artemisia nova Woodland (CEGL002331)$$.
Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: No Data Available
Floristics: This association is characterized by a mixed canopy of Pinus edulis and Juniperus spp. with a shrub layer dominated by Purshia tridentata. Canopy cover ranges from 10% in the beetle- and fungus-affected woodlands of southwestern Colorado to around 50% in the mountains of northern New Mexico. The canopy occasionally includes arborescent Quercus gambelii in the southern part of the range. The shrub layer may consist almost entirely of Purshia tridentata with between 5 and 25% cover, or more often it is mixed with other shrubs that have at least 1% cover, including Amelanchier utahensis, Artemisia tridentata, Artemisia nova, Cercocarpus montanus, Ephedra viridis, Opuntia polyacantha, Ribes cereum, and Yucca baccata. Graminoids are well-represented to abundant; common species include Pseudoroegneria spicata, Poa fendleriana, Koeleria macrantha, Carex rossii, and Piptatheropsis micrantha (= Piptatherum micranthum). The forb component of the understory is often diverse but rarely contributes significantly to the overall vegetation cover. Species noted as occurring in this community include Astragalus scopulorum, Eriogonum jamesii, Eriogonum racemosum, Penstemon linarioides ssp. coloradoensis, Petradoria pumila, Phlox spp., and Stenotus acaulis.
Dynamics: At Mesa Verde National Park, this association is limited to the southern mesatops that have not burned in the last 200 years. Before 1980, it was much more widespread within the park. Blackstain root-rot (a fungus) and a major Ips beetle infestation have devastated pinyon trees in southwestern Colorado and southeastern Utah since 1999, reducing populations in some areas by more than 90%. This has converted some stands of this association to a de facto Juniperus osteosperma / Purshia tridentata woodland association, although Pinus edulis seedlings commonly occur in the herbaceous stratum. Purshia tridentata shrubs are often heavily browsed by deer and elk.
Environmental Description: This association is common at middle elevations of the pinyon-juniper woodland zone in western Colorado and northwestern New Mexico. Sites occur on ridges, scarps and mesas with gentle to moderate slopes, but a few stands have been recorded on slopes approaching 100%. Elevations range from 1800 to 2330 m (5900-7645 feet) and aspect is variable. Soils are often coarse and rocky, may be shallow, and sometimes have outcrops of the underlying sandstone or limestone.
Geographic Range: This association is documented from the Sandia and Jemez ranges in New Mexico, from Mesa Verde in southwestern Colorado, the high plateaus of southern Utah, and from Dinosaur National Monument in northwestern Colorado.
Nations: US
States/Provinces: AZ, CO, NM, UT
Plot Analysis Summary:
http://vegbank.org/natureserve/ELEMENT_GLOBAL.2.687220
Confidence Level: High
Confidence Level Comments: No Data Available
Grank: G5
Greasons: No Data Available
| Type | Name | Database Code | Classification Code |
|---|---|---|---|
| Class | 1 Forest & Woodland Class | C01 | 1 |
| Subclass | 1.B Temperate & Boreal Forest & Woodland Subclass | S15 | 1.B |
| Formation | 1.B.2 Cool Temperate Forest & Woodland Formation | F008 | 1.B.2 |
| Division | 1.B.2.Nc Western North American Pinyon - Juniper Woodland & Scrub Division | D010 | 1.B.2.Nc |
| Macrogroup | 1.B.2.Nc.1 Singleleaf Pinyon - Utah Juniper - Western Juniper Intermountain Woodland Macrogroup | M896 | 1.B.2.Nc.1 |
| Group | 1.B.2.Nc.1.a Two-needle Pinyon - Utah Juniper Woodland Group | G900 | 1.B.2.Nc.1.a |
| Alliance | A3571 Two-needle Pinyon - Utah Juniper / Shrub Understory Foothill & Lower Montane Dry-Mesic Woodland Alliance | A3571 | 1.B.2.Nc.1.a |
| Association | CEGL000789 Two-needle Pinyon - Utah Juniper / Antelope Bitterbrush Woodland | CEGL000789 | 1.B.2.Nc.1.a |
Concept Lineage: No Data Available
Predecessors: No Data Available
Obsolete Names: No Data Available
Obsolete Parents: No Data Available
Synonomy: = Juniperus - Pinus - Purshia (Erdman 1962)
= Pinus edulis - Juniperus osteosperma / Purshia tridentata (Johnston 1987)
= Pinus edulis / Purshia tridentata (Stuever and Hayden 1997b)
= Pinus edulis / Purshia tridentata Plant Association (Larson and Moir 1987)
= Pinus edulis - Juniperus osteosperma / Purshia tridentata (Johnston 1987)
= Pinus edulis / Purshia tridentata (Stuever and Hayden 1997b)
= Pinus edulis / Purshia tridentata Plant Association (Larson and Moir 1987)
- Bourgeron, P. S., and L. D. Engelking, editors. 1994. A preliminary vegetation classification of the western United States. Unpublished report. The Nature Conservancy, Western Heritage Task Force, Boulder, CO. 175 pp. plus appendix.
- Bradley, A. F. 1986c. Purshia tridentata. In: Fire Effects Information System [Online]. USDA Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). [http://www.fs.fed.us/database/feis/]
- CNHP [Colorado Natural Heritage Program]. 2006-2017. Tracked natural plant communities. Colorado Natural Heritage Program, Colorado State University, Fort Collins. [https://cnhp.colostate.edu/ourdata/trackinglist/plant_communities/]
- Clark, D., M. Dela Cruz, T. Clark, J. Coles, S. Topp, A. Evenden, A. Wight, G. Wakefield, and J. Von Loh. 2009. Vegetation classification and mapping project report, Capitol Reef National Park. Natural Resource Report NPS/NCPN/NRTR--2009/187. National Park Service, Fort Collins, CO. 882 pp.
- Coles, J., D. Cogan, D. Salas, A. Wight, G. Wakefield, J. Von Loh, and A. Evenden. 2008a. Vegetation classification and mapping project report, Dinosaur National Monument. Natural Resource Technical Report NPS/NCPN/NRTR-2008/112. National Park Service, Fort Collins, CO. 814 pp.
- Edwards, M. C., G. Miller, J. Redders, R. Stein, and K. Dunstan. 1987. Terrestrial ecosystem survey for the Carson National Forest. USDA Forest Service, Southwestern Region, Albuquerque, NM. 552 pp.
- Erdman, J. A. 1962. Ecology of the pinyon-juniper woodland of Wetherill Mesa, Mesa Verde National Park, Colorado. Unpublished thesis, University of Colorado, Boulder. 109 pp.
- Erdman, J. A. 1970. Pinyon-juniper succession after natural fires on residual soils of Mesa Verde, Colorado. Brigham Young University Science Bulletin, Biological Series 11(2):1-26.
- Erdman, J. A., C. L. Douglas, and J. W. Marr. 1969. Wetherill Mesa Studies, environment of Mesa Verde, Colorado. USDI National Park Service. Archeological Research Series 7-B. Washington, DC. 72 pp.
- Everett, R. L. 1987. Plant response to fire in the pinyon-juniper zone. Pages 152-157 in R. L. Everett, compiler. Proceedings pinyon-juniper conference: 1986 January 13-16, Reno, NV. General Technical Report INT-215. USDA Forest Service, Intermountain Research Station, Ogden, UT.
- Floyd, M. L., editor. 2003. Ancient piñon-juniper woodlands: A natural history of Mesa Verde country. University Press of Colorado, Boulder.
- Johnston, B. C. 1987. Plant associations of Region Two: Potential plant communities of Wyoming, South Dakota, Nebraska, Colorado, and Kansas. R2-ECOL-87-2. USDA Forest Service, Rocky Mountain Region. Lakewood, CO. 429 pp.
- Larson, M., and W. H. Moir. 1987. Forest and woodland habitat types of northern New Mexico and northern Arizona. Edition 2. USDA Forest Service, Southwestern Region, Albuquerque, NM.
- Moir, W. H., and J. O. Carleton. 1987. Classification of pinyon-juniper (P-J) sites on national forests in the Southwest. Pages 216-226 in: R. L. Everett, editor. Proceedings of the Pinyon-Juniper Conference, Reno, NV, 13-16 January 1986. General Technical Report. USDA Forest Service, Intermountain Forest and Range Experiment Station, Ogden, UT. 581 pp.
- Romme, W. H., K. D. Heil, J. M. Porter, and R. Fleming. 1993. Plant communities of Capitol Reef National Park, Utah. USDI National Park Service, Technical Report NPS/NAUCARE/NRTER-93/02. Cooperative Park Studies Unit, Northern Arizona University. 37 pp.
- Salas, D. E., D. Wegner, and C. Bolen. 2010a. Vegetation classification and distribution mapping report: Navajo National Monument. Natural Resource Technical Report NPS/SCPN/NRTR--2010/298. National Park Service, Fort Collins, CO. 160 pp.
- Stuever, M. C., and J. S. Hayden. 1997b. Plant associations of Arizona and New Mexico. Volume 2: Woodlands. USDA Forest Service, Southwestern Region, Habitat Typing Guides. 196 pp.
- Tendick, A., G. Kittel, J. Von Loh, P. Williams, D. Cogan, J. Coles, A. Wight, G. Wakefield, and A. Evenden. 2011b. Vegetation classification and mapping project report, Bryce Canyon National Park. Natural Resource Technical Report NPS/NCPN/NRTR--2011/442. National Park Service, Fort Collins, CO.
- Thomas, K. A., M. L. McTeague, L. Ogden, M. L. Floyd, K. Schulz, B. Friesen, T. Fancher, R. Waltermire, and A. Cully. 2009b. Vegetation classification and distribution mapping report: Mesa Verde National Park. Natural Resource Report NPS/SCPN/NRR--2009/112. National Park Service, Fort Collins, CO. 352 pp.
- USFS [U.S. Forest Service]. 1987a. Forest and woodland habitat types (plant associations) of northern New Mexico and northern Arizona. USDA Forest Service, Southwestern Region, Albuquerque, NM. Second edition, 170 pp. plus insert.
- Western Ecology Working Group of NatureServe. No date. International Ecological Classification Standard: International Vegetation Classification. Terrestrial Vegetation. NatureServe, Boulder, CO.