SOUTHERN ROCKY MOUNTAIN PINYON-JUNIPER WOODLAND S038

Division 306, Forest and Woodland, CES306.835

Spatial Scale & Pattern: Matrix Classification Confidence: medium
Required Classifiers: Natural/Semi-natural, Vegetated (>10% vasc.), Upland
Diagnostic Classifiers: Forest and Woodland (Treed), Very Shallow Soil, Shallow Soil, Mineral: W/ A-Horizon <10 cm, Aridic, Long Disturbance Interval, Needle-Leaved Tree, Pinus edulis, Juniperus monosperma
Non-Diagnostic Classifiers: Lowland [Foothill], Butte, Escarpment, Foothill(s), Midslope, Ridge, Temperate [Temperate Continental], Unglaciated, F-Patch/Medium Intensity, F-Landscape/Medium Intensity

Concept Summary: This southern Rocky Mountain ecological system occurs on dry mountains and foothills in southern Colorado east of the Continental Divide, in mountains and plateaus of northern New Mexico, and extends out onto limestone breaks in the Great Plains. These woodlands occur on warm, dry sites on mountain slopes, mesas, plateaus, and ridges. Severe climatic events occurring during the growing season, such as frosts and drought, are thought to limit the distribution of pinyon-juniper woodlands to relatively narrow altitudinal belts on mountainsides. Soils supporting this system vary in texture ranging from stony, cobbly, gravelly sandy loams to clay loam or clay. Pinus edulis and/or Juniperus monosperma dominate the tree canopy. Juniperus scopulorum may codominate or replace Juniperus monosperma at higher elevations. In transitional areas along the Mogollon Rim and in northern New Mexico, Juniperus deppeana becomes common. Understory layers are variable and may be dominated by shrubs, graminoids, or be absent. Associated species include Artemisia tridentata, Cercocarpus montanus, Quercus gambelii, Achnatherum scribneri, Bouteloua gracilis, Festuca arizonica, or Pleuraphis jamesii.

Distribution:
Range: Occurs on dry mountains and foothills in southern Colorado, in mountains and plateaus of northern New Mexico and Arizona, and extends out onto breaks in the Great Plains.
Ecological Divisions: 303, 304, 306
TNC Ecoregions: 19:C, 20:C, 21:C, 22:P, 27:C, 28:C
Subnations/Nations: AZ:c, CO:c, NM:c, UT:c

CONCEPT
Alliances and Associations:
• JUNIPERUS MONOSPERMA WOODLAND ALLIANCE (A.504) Juniperus monosperma - Rhus trilobata / Schizachyrium scoparium Woodland (CEGL002121)Juniperus monosperma / Agave lechuguilla Woodland (CEGL000703) Juniperus monosperma / Andropogon hallii Woodland (CEGL000704) Juniperus monosperma / Artemisia bigelovii Woodland (CEGL000705) Juniperus monosperma / Artemisia tridentata Woodland (CEGL000706) Juniperus monosperma / Atriplex confertifolia / Achnatherum hymenoides Woodland (CEGL000707) Juniperus monosperma / Bouteloua curtipendula Woodland (CEGL000708) Juniperus monosperma / Bouteloua eriopoda Woodland (CEGL000709) Juniperus monosperma / Bouteloua gracilis Woodland (CEGL000710) Juniperus monosperma / Bouteloua hirsuta Woodland (CEGL000711) Juniperus monosperma / Cercocarpus montanus - Ribes cereum Woodland (CEGL000714) Juniperus monosperma / Cercocarpus montanus Woodland (CEGL000713) Juniperus monosperma / Ericameria nauseosa - Fallugia paradoxa Woodland (CEGL000715) Juniperus monosperma / Fallugia paradoxa / Xanthoparmelia neoconspersa Woodland (CEGL000716) Juniperus monosperma / Hesperostipa neomexicana Woodland (CEGL000722) Juniperus monosperma / Krascheninnikovia lanata Woodland (CEGL000712) Juniperus monosperma / Nolina microcarpa - Agave lechuguilla Woodland (CEGL000718) Juniperus monosperma / Quercus turbinella Woodland (CEGL000720) Juniperus monosperma / Quercus X pauciloba Woodland (CEGL000721)
• PINUS EDULIS - (JUNIPERUS SPP.) WOODLAND ALLIANCE (A.516) Pinus edulis - (Juniperus monosperma) / Bouteloua gracilis Woodland (CEGL002151) Pinus edulis - (Juniperus monosperma, Juniperus osteosperma) / Hesperostipa comata Woodland (CEGL000797) Pinus edulis - Juniperus scopulorum Woodland [Provisional] (CEGL002907) Pinus edulis - Juniperus spp. / Artemisia tridentata Woodland (CEGL000776) Pinus edulis - Juniperus spp. / Cercocarpus montanus Woodland (CEGL000780) Pinus edulis - Juniperus spp. / Quercus gambelii Woodland (CEGL000791) Pinus edulis - Quercus arizonica / Rhus trilobata Woodland (CEGL000790) Pinus edulis / Achnatherum nelsonii ssp. dorei Woodland (CEGL000796) Pinus edulis / Achnatherum scribneri Woodland (CEGL000798) Pinus edulis / Andropogon hallii Woodland (CEGL000774) Pinus edulis / Arctostaphylos pungens Woodland (CEGL000775) Pinus edulis / Bouteloua curtipendula Woodland (CEGL000777) Pinus edulis / Cercocarpus ledifolius Woodland [Provisional] (CEGL002940) Pinus edulis / Festuca arizonica Woodland (CEGL000783) Pinus edulis / Leymus ambiguus Woodland (CEGL002908) Pinus edulis / Muhlenbergia dubia Woodland (CEGL000784) Pinus edulis / Muhlenbergia pauciflora Woodland (CEGL000785) Pinus edulis / Nolina microcarpa Woodland (CEGL000786) Pinus edulis / Poa fendleriana Woodland (CEGL000787) Pinus edulis / Pseudoroegneria spicata Woodland (CEGL000788) Pinus edulis / Purshia tridentata Woodland (CEGL000789) Pinus edulis / Quercus X pauciloba Woodland (CEGL000793) Pinus edulis / Rockland Woodland (CEGL000794)
• PINUS EDULIS FOREST ALLIANCE (A.135) Pinus edulis / Sparse Understory Forest (CEGL000795)

SOURCES
References: Alexander 1981, Barbour and Billings 1988, Blackburn and Tueller 1970, Bradley et al. 1992, Commons et al. 1999, Dwyer and Pieper 1967, Eager 1999, Erdman 1962, Hess and Wasser 1982, Ladyman and Muldavin 1996, Lindauer et al. 1982, Mehl 1992, Muldavin et al. 1992, Muldavin et al. 1996, Neely et al. 2001, Powell 1988b, West 1999, West 1999b, West and Van Pelt 1987, West and Young 2000, Young and Evans 1981
Last updated: 20 Feb 2003
Stakeholders: WCS
Concept Author: NatureServe Western Ecology Team
LeadResp: WCS