Print Report

A3497 Juniperus osteosperma Grassy Open Woodland Alliance

Type Concept Sentence: This juniper woodland and savanna alliance is characterized by an open to moderately dense, short (<15 m) tree canopy strongly dominated by Juniperus osteosperma or Juniperus scopulorum (at higher elevations) with an understory dominated by an open to dense layer of perennial grasses and lacking significant cover of shrubs. It occurs in the Colorado Plateau, but it extends out into adjacent ecoregions primarily west into the Great Basin and north and east into the foothills of the central and southern Rocky Mountains.

Common (Translated Scientific) Name: Utah Juniper Grassy Open Woodland Alliance

Colloquial Name: Utah Juniper Grassy Open Woodland

Hierarchy Level:  Alliance

Type Concept: Stands have a typically open to moderately dense tree canopy with an understory characterized by herbaceous vegetation. Tree canopy is dominated by Juniperus osteosperma with Juniperus scopulorum becoming important at higher elevations and along drainages. Pinus species are absent or accidental. Perennial grasses typically dominate the herbaceous layer although forbs are present and can be diverse. Characteristic species include Achnatherum hymenoides, Bouteloua gracilis, Hesperostipa comata, Hesperostipa neomexicana, Leymus salinus, Pleuraphis jamesii, Pleuraphis mutica, and Pseudoroegneria spicata. The non-native, invasive annual grass Bromus tectorum may be abundant in disturbed stands and dominate the herbaceous layer of highly disturbed stands. The core distribution of this juniper alliance is the Colorado Plateau, but it extends out into adjacent ecoregions primarily west into the Great Basin and north and east into the foothills of the central and southern Rocky Mountains. Stands occur on level to moderately steep alluvial fans and terraces, colluvial slopes, benches, hills, and badlands. Elevation of most stands ranges from 1423 to 1880 m (4670-6165 feet) but may occur as high as 2200 m (7215 feet) on warmer southwest-facing slopes. Sites may be oriented to any aspect. Stands have been observed on north-facing steep slopes along bluffs of the Snake River in southeastern Idaho. Soils are well-drained sands, sandy clays, or clay loams derived from shales, sandstones, or a mix of the two. Less frequently substrates are derived from eolian sands.

Diagnostic Characteristics: Stands have an open to moderately dense tree canopy dominated by Juniperus osteosperma with Juniperus scopulorum present to dominant at higher elevations. Understory is characterized by dominant and diagnostic perennial grass species Bouteloua gracilis, Hesperostipa comata, Hesperostipa neomexicana, Leymus ambiguus, Leymus salinus, Pleuraphis jamesii, Pleuraphis mutica, Poa fendleriana, Poa secunda, and Pseudoroegneria spicata. Shrub cover is sparse and does not form a layer. Forbs are present generally with low cover. This alliance also includes disturbed stands with the understory dominated by introduced annual grass Bromus tectorum.

Rationale for Nominal Species or Physiognomic Features: No Data Available

Classification Comments: This alliance may include stands with Juniperus monosperma present to codominant in northeastern Arizona. There is a transition zone between the ranges of the two species of Juniperus in the southern Colorado Plateau.

Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: These are sparsely to moderate dense (5-30% cover) wooded communities dominated by scale-leaved evergreen trees of low stature (<15 m). Evergreen or cold-deciduous shrubs occupy the interstices between trees, interspersed with cespitose graminoids. In total, the herbaceous layer is usually of moderate cover (25-50%), but may also be low (~5% cover) when it exceeds shrub cover. Occasionally shrubs may be present, but do not form a layer (<10% cover).

Floristics: Stands have a short (<15 m tall), typically open to moderately dense tree canopy with an understory characterized by herbaceous vegetation. Tree canopy is dominated by Juniperus osteosperma with Juniperus scopulorum becoming important at higher elevations and along drainages. Pinus species, such as Pinus monophylla, Pinus edulis, Pinus flexilis, Pinus ponderosa, or Pseudotsuga menziesii are absent or accidental. The open to dense herbaceous layer is typically dominated by perennial grasses. Characteristic species include Achnatherum hymenoides, Bouteloua gracilis, Hesperostipa comata, Hesperostipa neomexicana, Leymus ambiguus, Leymus salinus, Pleuraphis jamesii, Pleuraphis mutica, Poa fendleriana, Poa secunda, and Pseudoroegneria spicata. Forbs are present in the herbaceous layer and can be diverse but contribute little cover, including Arenaria hookeri, Arenaria fendleri, Calochortus gunnisonii, Chaetopappa ericoides, Cymopterus bulbosus, Cymopterus purpureus, Eriogonum umbellatum, Hymenoxys richardsonii, Linanthus pungens (= Leptodactylon pungens), Lepidium montanum, Machaeranthera grindelioides, Mirabilis multiflora, Oenothera pallida, Petradoria pumila, Phlox austromontana, Phlox hoodii, Sphaeralcea coccinea, Streptanthella longirostris, Stenotus acaulis, Tetraneuris acaulis (= Hymenoxys acaulis), and Xylorhiza venusta. The non-native, invasive annual grass Bromus tectorum may be abundant in disturbed stands and dominate the herbaceous layer of highly disturbed stands. Scattered shrubs such as Artemisia tridentata, Artemisia nova, Atriplex spp., Chrysothamnus spp., Cercocarpus spp. (on thin soils near rock outcrops), Gutierrezia sarothrae, Krascheninnikovia lanata, and Opuntia spp. by be present but do not form a layer or exceed the herbaceous cover.

Dynamics:  Within the distribution of Pinus edulis, this alliance typically occurs at lower elevation and on more xeric sites than Pinus edulis - (Juniperus spp.) woodlands. There is elevational overlap between this alliance and Pinus monophylla woodlands as this pinyon can occur on more xeric sites than Pinus edulis. Juniperus osteosperma also occurs on sites outside the ranges of Pinus edulis and Pinus monophylla. There has been significant expansion of this alliance over the last century into sagebrush-dominated shrublands. An altered fire regime (such as fire suppression, thus longer return intervals) is considered a primary cause of this expansion.
Environmental Description:  This savanna and open woodland alliance is distributed across the Intermountain West from the foothills of the eastern Sierra Nevada to the foothills of the central and southern Rocky Mountains. Climate is temperate with freezing temperatures during winter. Distribution of the alliance is often correlated with "thermal belts" which occur above the areas of cold-air drainage in high intermountain basins. Average annual precipitation is between 25 and 50 cm; however, seasonal distribution is variable across the range of the alliance. Stands occur on alluvial fans and terraces, colluvial slopes, benches, hills, and badlands. Sites are on level to moderately steep (3-46% slope) terrain that may be oriented to any aspect. Elevation of most stands ranges from 1423 to 1880 m (4670-6165 feet) but may occur as high as 2200 m (7215 feet). Sites tend to occur on cooler north and east aspects at lower elevations and warmer/drier south and west aspects at higher elevations. Soils are well-drained sands, sandy clays, or clay loams derived from shales, sandstones, or a mix of the two. Less frequently substrates are derived from eolian sands. Parent materials include Mesozoic marine shales of the Morrison Formation, Chinle Formation or Mancos shale, Kayenta Formation and Cedar Mesa sandstone. Colluvium from sandstone cliffs or outcrops upslope is common on the ground surface.
Geographic Range: The core distribution of this juniper alliance is the Colorado Plateau, but it extends out into adjacent ecoregions primarily west into the Great Basin and north and east into the foothills of the central and southern Rocky Mountains.

Nations: US

States/Provinces:  AZ, CA, CO, ID, MT, NM, NV, UT, WY


Confidence Level: Low

Confidence Level Comments: No Data Available
Grank: GNR

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 A3497 Utah Juniper Grassy Open Woodland Alliance A3497 1.B.2.Nc.1.a
Association CEGL000736 Utah Juniper / Tobosa Grass Open Woodland CEGL000736 1.B.2.Nc.1.a
Association CEGL000738 Utah Juniper / Bluebunch Wheatgrass Open Woodland CEGL000738 1.B.2.Nc.1.a
Association CEGL000740 Utah Juniper / New Mexico Feathergrass Open Woodland CEGL000740 1.B.2.Nc.1.a
Association CEGL001488 Utah Juniper / Salmon Wildrye Wooded Grassland CEGL001488 1.B.2.Nc.1.a
Association CEGL001489 Utah Juniper / Needle-and-Thread Wooded Grassland CEGL001489 1.B.2.Nc.1.a
Association CEGL002361 Utah Juniper / Blue Grama Open Woodland CEGL002361 1.B.2.Nc.1.a
Association CEGL002362 Utah Juniper / James'' Galleta Open Woodland CEGL002362 1.B.2.Nc.1.a
Association CEGL002815 Utah Juniper / Needle-and-Thread Open Woodland CEGL002815 1.B.2.Nc.1.a
Association CEGL002817 Utah Juniper / Cheatgrass Ruderal Woodland CEGL002817 1.B.2.Nc.1.a
Association CEGL003109 Utah Juniper / Saline Wildrye Open Woodland CEGL003109 1.B.2.Nc.1.a
Association CEGL005618 Utah Juniper / Idaho Fescue Open Woodland CEGL005618 1.B.2.Nc.1.a
Concept Lineage: This alliance is composed of eight herbaceous understory associations from Old Alliance II.A.4.N.a. Juniperus osteosperma Woodland Alliance (A.536) and two associations from Old Alliance V.A.6.N.f. Juniperus osteosperma Wooded Herbaceous Alliance (A.1502). A.536 (in part) and A.1502.

Predecessors: No Data Available

Obsolete Names: No Data Available

Obsolete Parents: No Data Available
Synonomy: >< Juniperus osteosperma (Utah juniper woodland) Alliance (Sawyer et al. 2009) [89.300.00]
>< Utah Juniper Series (Sawyer and Keeler-Wolf 1995)
Concept Author(s): K.A. Schulz, in Faber-Langendoen et al. (2013)

Author of Description: K.A. Schulz

Acknowledgements: We have incorporated significant descriptive information previously compiled by M. Jennings, M.S. Reid, and D. Sarr.

Version Date: 03-14-14
  • Baker, W. L. 1983b. Some aspects of the presettlement vegetation of the Piceance Basin, Colorado. Great Basin Naturalist 43(4):687-699.
  • Baker, W. L. 1984a. A preliminary classification of the natural vegetation of Colorado. Great Basin Naturalist 44(4):647-676.
  • Baker, W. L., and S. C. Kennedy. 1985. Presettlement vegetation of part of northwestern Moffat County, Colorado, described from remnants. Great Basin Naturalist 45(4):747-777.
  • Barney, M. A., and N. C. Frischknecht. 1974. Vegetation changes following fire in the pinyon-juniper types of west-central Utah. Journal of Range Management 27(2):91-96.
  • Blackburn, W. H. 1967. Plant succession on selected habitat types in Nevada. Unpublished thesis, University of Nevada, Reno. 162 pp.
  • Blackburn, W. H., P. T. Tueller, and R. E. Eckert, Jr. 1968a. Vegetation and soils of the Mill Creek watershed. Nevada Agricultural Experiment Station Bulletin R-43. University of Nevada, Reno. 69 pp.
  • Blackburn, W. H., P. T. Tueller, and R. E. Eckert, Jr. 1968c. Vegetation and soils of the Duckwater watershed. Nevada Agricultural Experiment Station Bulletin R-40. University of Nevada, Reno. 76 pp.
  • Blackburn, W. H., P. T. Tueller, and R. E. Eckert, Jr. 1969a. Vegetation and soils of the Cow Creek watershed. Vegetation and soils of the Mill Creek watershed. In cooperation with USDI Bureau of Land Management. University of Nevada, College of Agriculture, Reno. 71 pp.
  • Blackburn, W. H., P. T. Tueller, and R. E. Eckert, Jr. 1971. Vegetation and soils of the Rock Springs watershed. Nevada Agricultural Experiment Station Bulletin R-83. Reno. 116 pp.
  • Blackburn, W. H., R. E. Eckert, Jr., and P. T. Tueller. 1969e. Vegetation and soils of the Crane Springs watershed. Nevada Agricultural Experiment Station Bulletin R-55. Reno. 63 pp.
  • Brotherson, J. D., and W. E. Evenson. 1982. Vegetation communities surrounding Utah Lake and its bays. Utah Lake Vegetation Studies. Unpublished report done for the Utah Division of Wildlife Resources and USDI Bureau of Reclamation, Provo, UT. 401 pp.
  • Bunting, S. C. 1987. Use of prescribed burning in juniper and pinyon-juniper woodlands. Pages 141-144 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.
  • Caicco, S. L., and C. A. Wellner. 1983c. Research Natural Area recommendation for Southwest Lemhi Range. Unpublished report prepared for USDI Bureau of Land Management, Idaho Falls District, Idaho by Idaho Natural Areas Coordinating Committee. On file at Idaho Conservation Data Center, Boise, ID.
  • Dastrup, B. C. 1963. Vegetational changes of the Uinta Basin since settlement. Unpublished thesis, Brigham Young University, Provo, UT. 118 pp.
  • Despain, D. G. 1973a. Vegetation of the Big Horn Mountains, Wyoming, in relation to substrate and climate. Ecological Monographs 43(3):329-354.
  • Donart, G. B., D. D. Sylvester, and W. C. Hickey. 1978b. Potential natural vegetation-New Mexico. New Mexico Interagency Range Commission Report 11.
  • Everett, R. L., compiler. 1986. Proceedings pinyon-juniper conference: 1986 January 13-16, Reno, NV. General Technical Report INT-215. USDA Forest Service, Intermountain Research Station, Ogden, UT. 581 pp.
  • Faber-Langendoen, D., J. Drake, M. Hall, G. Kittel, S. Menard, C. Nordman, M. Pyne, M. Reid, M. Russo, K. Schulz, L. Sneddon, K. Snow, and J. Teague. 2013-2019b. Screening alliances for induction into the U.S. National Vegetation Classification: Part 1 - Alliance concept review. NatureServe, Arlington, VA.
  • Isaacson, H. E. 1967. Ecological provinces within the pinyon-juniper type of the Great Basin and Colorado Plateau. Unpublished thesis, Utah State University, Logan. 44 pp.
  • Jameson, D. A., J. A. Williams, and E. W. Wilton. 1962. Vegetation and soils of Fishtail Mesa, Arizona. Ecology 43:403-410.
  • Johnsen, T. N., Jr. 1962. One-seed juniper invasion of northern Arizona grasslands. Ecological Monographs 32:187-207.
  • 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.
  • Jones, G. P. 1989b. Survey of plant species and communities of interest in the Beaver Rim Area of Critical Environmental Concern. Report submitted to the Bureau of Land Management, Rawlins District Office, under Work Effort No. WY030-09-4352-06-2512. Wyoming Natural Diversity Database, Laramie, WY.
  • Kline, R. P. 1973. Establishment report for West Fork Mink Creek Research Natural Area within Caribou National Forest, Bannock County, Idaho. Unpublished report. 7 pp. plus maps.
  • Knight, D. H., G. P. Jones, Y. Akashi, and R. W. Myers. 1987. Vegetation ecology in the Bighorn Canyon National Recreation Area. Unpublished report prepared for the USDI National Park Service and University of Wyoming-National Park Service Research.
  • Komarkova, V. K., R. R. Alexander, and B. C. Johnston. 1988b. Forest vegetation of the Gunnison and parts of the Uncompahgre national forests: A preliminary habitat type classification. Research Paper RM-163. USDA Forest Service, Rocky Mountain Forest and Range Experiment Station, Fort Collins, CO. 65 pp.
  • Koniak, S. 1985. Succession in pinyon-juniper woodlands following wildfire in the Great Basin. Great Basin Naturalist 45:556-566.
  • Larson, M., and W. H. Moir. 1986. Forest and woodland habitat types (plant associations) of southern New Mexico and central Arizona (north of the Mogollon Rim). USDA Forest Service, Southwestern Region, Albuquerque, NM. 76 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.
  • Lesica, P., and R. L. DeVelice. 1992. Plant communities of the Pryor Mountains. Preliminary report prepared by the Montana Natural Heritage Program, Helena, MT.
  • Marriott, H. J., and G. P. Jones. 1989. Special status plant surveys and plant community surveys in the Trapper Creek and Medicine Lodge Wilderness Study Areas and the Spanish Point Karst ACEC. Report submitted to the Bureau of Land Management, Worland District Office, under Cooperative Agreement Task Order No. WY910-CA9-001TQE1. Wyoming Natural Diversity Database, Laramie. 42 pp. plus appendices.
  • 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.
  • Sawyer, J. O., T. Keeler-Wolf, and J. Evens. 2009. A manual of California vegetation. Second edition. California Native Plant Society, Sacramento CA. 1300 pp.
  • Sawyer, J. O., and T. Keeler-Wolf. 1995. A manual of California vegetation. California Native Plant Society, Sacramento. 471 pp.
  • USFS [U.S. Forest Service]. 1983a. TES-4, Coyote Ranger District. Unpublished report prepared for USDA Forest Service, Southwestern Region, Albuquerque, NM. Various pages, appendices and maps.
  • USFS [U.S. Forest Service]. 1985c. TES-1, Terrestrial ecosystem survey handbook, appendix B. Unpublished report prepared for USDA Forest Service, Southwestern Region, Albuquerque, NM. Various pages, appendices and maps.
  • West, N. E., R. J. Tausch, K. H. Rea, and A. R. Southard. 1978. Soils associated with pinyon-juniper woodlands of the Great Basin. Pages 68-88 in: C. T. Youngberg, editor. Forest soils and land use, Proceedings of the 5th North American Forest and Soils Conference, Colorado State University, Fort Collins.
  • Wight, J. R. 1965. Site and vegetation characteristics and relationships of juniper communities in northwestern Wyoming Unpublished dissertation, University of Wyoming, Laramie.
  • Wight, J. R., and H. G. Fisser. 1968. Juniperus osteosperma in northwestern Wyoming: Their distribution and ecology. University of Wyoming Agricultural Experiment Station Science Monograph 7. Laramie. 28 pp.
  • Wright, H. A., L. F. Neuenschwander, and C. M. Britton. 1979. The role and use of fire in sagebrush-grass and pinyon-juniper plant communities: A state of the art review. General Technical Report INT-58. USDA Forest Service, Intermountain Forest and Range Experiment Station, Ogden, UT.