Print Report

A3575 Juniperus monosperma Wooded Grassland Alliance

Type Concept Sentence: This juniper woodland and savanna alliance is characterized by an open to moderately dense, short (<15 m) tree canopy and is strongly dominated by Juniperus monosperma 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 on warm, dry mountains and foothills in southern Colorado east of the Continental Divide and in mountains and plateaus of northern and central New Mexico, extending east on breaks in the southeastern Great Plains.

Common (Translated Scientific) Name: One-seed Juniper Wooded Grassland Alliance

Colloquial Name: One-seed Juniper Wooded Grassland

Hierarchy Level:  Alliance

Type Concept: This woodland and savanna alliance is characterized by diagnostic tree species Juniperus monosperma that forms a very open to moderately dense tree layer. At higher elevations and relatively mesic sites, such as along drainages, Juniperus scopulorum may be present and sometimes dominant. In southern transitional areas with ~Madrean Pinyon - Juniper Woodland Group (G200)$$ in central New Mexico, Juniperus deppeana may be present but not dominant. Other conifers, including Pinus edulis, are absent or accidental with very low cover. Scattered shrubs and dwarf-shrubs may be present but do not form a layer. The understory is characterized by an moderate to dense herbaceous layer composed of grasses often with diverse, but low cover of forbs. Characteristic species may include Achnatherum hymenoides, Achnatherum nelsonii, Achnatherum scribneri, Andropogon hallii, Achnatherum hymenoides, Bouteloua eriopoda, Bouteloua gracilis, Bouteloua hirsuta, Hesperostipa comata, Hesperostipa neomexicana, Pleuraphis jamesii, and Schizachyrium scoparium. This alliance occurs on warm, dry mountains and foothills in southern Colorado east of the Continental Divide and in mountains and plateaus of northern and central New Mexico, extending east on breaks in the southeastern Great Plains. Stands occur on nearly level surfaces to steep, rocky slopes in canyons, on hillsides, and on mesatops, but also occur on stream terraces and on deep sands. Elevations range from 1200-2100 m. Aspect does not seem important except in elevational extremes for a given latitude. Sites are typically dry with shallow, rocky, calcareous, alkaline soils. Soil textures range from sandy loam to clay soils typically derived from limestone, sandstone or shale.

Diagnostic Characteristics: This woodland alliance is found in foothills in southern Colorado east of the Continental Divide and in mountains and plateaus of northern and central New Mexico, extending east on breaks in the southeastern Great Plains. These woodlands are characterized by diagnostic tree species Juniperus monosperma that forms an open to dense tree layer. At higher elevations and relatively mesic sites, Juniperus scopulorum may be present and sometimes dominant. In southern transitional areas with ~Madrean Pinyon-Juniper Woodland Group (G200)$$ in central New Mexico, Juniperus deppeana may be present but not dominant. Other conifers, including Pinus edulis, are absent or accidental with very low cover. The understory is characterized by a moderate to dense herbaceous layer composed of grasses often with a diverse but low cover of forbs.

Rationale for Nominal Species or Physiognomic Features: No Data Available

Classification Comments: In northwestern New Mexico, the distributional ranges of Juniperus monosperma and Juniperus osteosperma overlap. This alliance does not occur within the range of Juniperus osteosperma in this transition zone from the southern Rocky Mountain juniper woodland and savanna alliances to the Colorado Plateau juniper woodland and savanna alliances.

Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: Vegetation included in this alliance has a sparse to moderately dense (5-45% cover) tree canopy that is typically 2-10 m tall. Stands are solely dominated by scale-leaved evergreen trees. Broad-leaved and needle-leaved evergreen trees may be present but have low cover (<5%). A sparse to moderate layer that is dominated by perennial graminoids is usually present. Perennial forbs may be scattered. Annual forbs and grasses may be seasonally present. Scattered shrubs may be present with low cover (<10%) and less cover than the herbaceous layer. Cacti and stem succulents are often present.

Floristics: This woodland and savanna alliance is characterized by diagnostic tree species Juniperus monosperma that forms a very open to moderately dense tree layer. At higher elevations and relatively mesic sites, such as along drainages, Juniperus scopulorum may be present and sometimes dominant. In southern transitional areas with ~Madrean Pinyon - Juniper Woodland Group (G200)$$ in central New Mexico, Juniperus deppeana may be present but not dominant. Other conifers, including Pinus edulis, are absent or accidental with very low cover. Scattered shrubs and dwarf-shrubs may be present but do not form a layer. The understory is characterized by an moderate to dense herbaceous layer composed of grasses often with diverse but low cover of forbs. Characteristic graminoids may include Achnatherum hymenoides, Achnatherum nelsonii, Achnatherum scribneri, Achnatherum hymenoides, Aristida spp., Bouteloua eriopoda, Bouteloua gracilis, Bouteloua hirsuta, Hesperostipa comata, Hesperostipa neomexicana, Muhlenbergia spp., Piptatheropsis micrantha (= Piptatherum micranthum), Pleuraphis jamesii, Schizachyrium scoparium, Sporobolus spp., and Andropogon hallii in rare, deep sands habitats. Many forb species can occur, but few have much cover. Commonly present forbs include species of Artemisia, Dalea, Eriogonum, Heterotheca, Hymenoxys, Mirabilis, Penstemon, Phlox, Physalis, Pediomelum (= Psoralea), and Zinnia. Annual grasses and forbs are seasonally present.

Dynamics:  Juniperus monosperma is extremely drought-tolerant. It is also non-sprouting and may be killed by fire (Wright et al. 1979). The effect of fire on a stand is largely dependent on the tree height and density, fine fuel load on the ground, weather conditions, and season (Dwyer and Pieper 1967, Wright et al. 1979). Trees are more vulnerable in open stands where fires frequently occur in the spring, when the relative humidity is low, wind speeds are over 10-20 mph, and there is adequate fine fuels to carry fire (Wright et al. 1979, Fischer and Bradley 1987). Under other conditions, burns tend to be spotty with low tree mortality. Large trees are generally not killed unless fine fuels, such as tumbleweeds, have accumulated beneath the tree to provide ladder fuels for the fire to reach the crown. Closed-canopy stands rarely burn because they typically do not have enough understory or wind to carry a fire. Altered fire regimes, cutting trees for fencing, and improper grazing by livestock have significant impacts on the quality of sites. Grazing by livestock can modify the fire regime by removing the fine fuels that carry fire. Juniperus monosperma invasion into grasslands has occurred in places. Control efforts by chaining and prescribed burning have mixed results. More study is needed to understand and manage these woodlands ecologically.
Environmental Description:  Stands included in this woodland alliance occur from eastern Arizona to western Texas and the Panhandle of Oklahoma and in the foothills in the southern Rocky Mountains. Stands also occur in the mountains, mesas, plateaus, piedmonts, canyons, escarpments, and other geographic breaks in the southern Great Plains. Elevations range from 1200-2100 m. Climate is semi-arid with drought not uncommon. Summers are generally hot, and winters have cold periods and occasional snows with extended periods of freezing temperatures. The mean annual precipitation ranges from 30-48 cm. Stands occur on nearly level surfaces to steep, rocky slopes in canyons, on hillsides, and on mesatops, but also occur on stream terraces and on deep sands. Aspect does not seem important except in elevational extremes for a given latitude. Low-elevation stands are restricted to the more mesic north slopes, whereas high-elevation stands occur on south aspects. Sites are typically dry with shallow, rocky, calcareous, alkaline soils. Soil textures range from sandy loam to clay soils typically derived from limestone, sandstone or shale. Other parent materials include basalt, granite, dolomite, siltstone and mixed alluvium.
Geographic Range: This woodland alliance occurs in foothills in southern Colorado east of the Continental Divide and in mountains and plateaus of northern and central New Mexico, extending east on breaks in the southeastern Great Plains.

Nations: US

States/Provinces:  AZ, CO, NM, OK, TX


Confidence Level: Moderate

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.2 Two-needle Pinyon - One-seed Juniper Southern Rocky Mountain Woodland Macrogroup M897 1.B.2.Nc.2
Group 1.B.2.Nc.2.b One-seed Juniper Open Woodland Group G252 1.B.2.Nc.2.b
Alliance A3575 One-seed Juniper Wooded Grassland Alliance A3575 1.B.2.Nc.2.b
Association CEGL000704 One-seed Juniper / Sand Bluestem Open Woodland CEGL000704 1.B.2.Nc.2.b
Association CEGL000708 One-seed Juniper / Sideoats Grama Open Woodland CEGL000708 1.B.2.Nc.2.b
Association CEGL000709 One-seed Juniper / Black Grama Open Woodland CEGL000709 1.B.2.Nc.2.b
Association CEGL000710 One-seed Juniper / Blue Grama Open Woodland CEGL000710 1.B.2.Nc.2.b
Association CEGL000711 One-seed Juniper / Hairy Grama Open Woodland CEGL000711 1.B.2.Nc.2.b
Association CEGL000722 One-seed Juniper / New Mexico Feathergrass Open Woodland CEGL000722 1.B.2.Nc.2.b
Concept Lineage: This alliance is composed of 6 herbaceous understory associations from Old Alliance II.A.4.N.a. Juniperus monosperma Woodland Alliance (A.504).

Predecessors: No Data Available

Obsolete Names: No Data Available

Obsolete Parents: No Data Available
Synonomy: < Juniperus monosperma woodland alliance (Hoagland 1998a)
< Oneseed Juniper Series (Dick-Peddie 1993) [includes all the Juniperus monosperma stands]
Concept Author(s): K.A. Schulz, in Faber-Langendoen et al. (2013)

Author of Description: K.A. Schulz

Acknowledgements: No Data Available

Version Date: 03-14-14
  • Adams, D. B. 1979. Vegetation-environment relationships in Palo Duro Canyon, West Texas. Ph.D. dissertation, University of Oklahoma, Norman. 123 pp.
  • Baker, W. L. 1984a. A preliminary classification of the natural vegetation of Colorado. Great Basin Naturalist 44(4):647-676.
  • Barnes, F. J. 1987. Carbon and water relations across a pinyon-juniper habitat gradient. Unpublished dissertation, New Mexico State University, Las Cruces.
  • Baxter, C. 1977. A comparison between grazed and ungrazed juniper woodland. Pages 25-27 in: Ecology, uses and management of pinyon-juniper woodlands. General Technical Report RM-39. USDA Forest Service, Rocky Mountain Forest and Range Experiment Station, Fort Collins, CO.
  • Diamond, D. D. 1993. Classification of the plant communities of Texas (series level). Unpublished document. Texas Natural Heritage Program, Austin. 25 pp.
  • Dick-Peddie, W. A. 1987. A vegetation classification system for New Mexico, USA. Pages 488-490 in: Proceedings of the First International Rangeland Congress. Society for Range Management.
  • Dick-Peddie, W. A. 1993. New Mexico vegetation: Past, present, and future. University of New Mexico Press, Albuquerque. 244 pp.
  • Dick-Peddie, W. A., J. K. Meents, and R. Spellenberg. 1984. Vegetation resource analysis for the Velarde Community Ditch Project, Rio Arriba and Santa Fe counties, New Mexico. Unpublished final report prepared for the USDI Bureau of Reclamation, Southwestern Region, Amarillo, TX. 251 pp.
  • Donart, G. B., D. Sylvester, and W. Hickey. 1978a. A vegetation classification system for New Mexico, USA. Pages 488-490 in: Rangeland Congress, Denver, CO, 14-18 August 1978. Society for Range Management, Denver.
  • Dwyer, D. D., and R. D. Pieper. 1967. Fire effects on blue gramma-pinyon-juniper rangeland in New Mexico. Journal of Range Management 20:359-362.
  • 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.
  • Fischer, W. C., and A. F. Bradley. 1987. Fire ecology of western Montana forest habitat types. General Technical Report INT-223. USDA Forest Service, Intermountain Research Station, Ogden, UT. 95 pp.
  • Fitzhugh, E. L., W. H. Moir, J. A. Ludwig, and F. Ronco, Jr. 1987. Forest habitat types in the Apache, Gila, and part of the Cibola national forests. General Technical Report RM-145. USDA Forest Service, Rocky Mountain Forest and Range Experiment Station, Fort Collins, CO. 116 pp.
  • Francis, R. E. 1986. Phyto-edaphic communities of the Upper Rio Puerco Watershed, New Mexico. Research Paper RM-272. USDA Forest Service, Rocky Mountain Forest and Range Experiment Station, Fort Collins, CO. 73 pp.
  • Hoagland, B. W. 1998a. Classification of Oklahoma vegetation types. Working draft. University of Oklahoma, Oklahoma Natural Heritage Inventory, Norman. 43 pp.
  • Johnsen, T. N., Jr. 1962. One-seed juniper invasion of northern Arizona grasslands. Ecological Monographs 32:187-207.
  • Johnston, B. C. 1984. Plant associations of Region Two. Edition 3.5. USDA Forest Service, Rocky Mountain Region. Lakewood, CO.
  • 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.
  • Ladyman, J. A. R., and E. Muldavin. 1996. Terrestrial cryptograms of pinyon-juniper woodlands in the southwestern United States: A review. General Technical Report RM-GTR-280. USDA Forest Service, Rocky Mountain Forest and Range Experiment Station, Fort Collins, CO. 33 pp.
  • 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.
  • Lindsey, A. A. 1951. Vegetation and habitats in a southwestern volcanic area. Ecological Monographs 21(3):227-253.
  • 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.
  • Muldavin, E., and P. Mehlhop. 1992. A preliminary classification and test vegetation map for White Sands Missile Range and San Andreas National Wildlife Refuge, New Mexico. University of New Mexico, New Mexico Natural Heritage Program.
  • Muldavin, E., et al. 1998c. Plant community inventory for Fort Bliss. Unpublished report in preparation by the New Mexico Natural Heritage Program, Albuquerque, NM.
  • Nelson, C. A., and J. S. Redders. 1982. Terrestrial ecosystem inventory, Heber Ranger District, Apache-Sitgreaves national forests. Unpublished report prepared for USDA Forest Service, Southwestern Region, Albuquerque, NM. 240 pp.
  • New Mexico Environmental Institute. 1971. Sevilleta, a socioecological survey of the Sevilleta Land Grant. Unpublished report prepared for Environmental Institute, Las Cruces, NM. 89 pp.
  • Pettit, R., R. S. Sosebee, and W. Dahl 1980. Vegetation support document. McGregor range grazing environmental impact statement. USDI Bureau of Land Management, Las Cruces, NM.
  • Pieper, R. D. 1968. Comparison of vegetation on grazed and ungrazed pinyon-juniper grassland sites in south-central New Mexico. Journal of Range Management 21:51-53.
  • Pieper, R. D., J. R. Montoya, and V. L. Groce. 1971. Site characteristics on pinyon-juniper and blue grama ranges in south-central New Mexico. New Mexico State University Agricultural Experiment Station. Bulletin 573. Las Cruces, NM. 21 pp.
  • Rippel, P., Pieper, R. D., and G. H. Lymbery. 1983. Vegetational evaluations of pinyon-juniper cabling in south-central New Mexico. Journal of Range Management 36:13-15.
  • Rogers, C. M. 1953. The vegetation of the Mesa de Maya region of Colorado, New Mexico, and Oklahoma. Lloydia 16(4):257-290.
  • Soil Conservation Service. 1978. Range site descriptions for Colorado. Technical Guide, Section II-E. USDA Soil Conservation Service, Colorado State Office, Denver.
  • Terwilliger, C., K. Hess, and C. Wasser. 1979a. Key to the preliminary habitat types of Region 2. Addendum to initial progress report for habitat type classification. USDA Forest Service, Rocky Mountain Forest and Range Experiment Station. Fort Collins, CO.
  • USFS [U.S. Forest Service]. 1981a. TES-7, South La Luz grazing allotment. Unpublished report prepared for USDA Forest Service, Southwestern Region, Albuquerque, NM. Various pages, appendices and maps.
  • USFS [U.S. Forest Service]. 1983c. TES-10, Alura Mesa and Strayhorse allotments. Unpublished report prepared for USDA Forest Service, Southwestern Region, Albuquerque, NM. Various pages, appendices and maps.
  • USFS [U.S. Forest Service]. 1985b. TES-5, western portion of the Glenwood 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.
  • USFS [U.S. Forest Service]. 1985e. TES-3, western part Rio Arriba County. Unpublished report prepared for USDA Forest Service, Southwestern Region, Albuquerque, NM. Various pages, appendices and maps.
  • USFS [U.S. Forest Service]. 1985f. TES-8, Smokey Bear District. Unpublished report prepared for USDA Forest Service, Southwestern Region, Albuquerque, NM. Various pages, appendices and maps.
  • USFS [U.S. Forest Service]. 1985g. Key to woodland plant associations and plant communities, Lincoln National Forest. Unpublished materials. USDA Forest Service, Southwestern Region, Albuquerque, NM.
  • Wells, P. V. 1970b. Historical factors controlling vegetation patterns and floristic distributions in the central plains region of North America. Pages 211-221 in: W. Dort and J. D. Jones, editors. Pleistocene and recent environments of the central Great Plains. University of Kansas Press, Lawrence.
  • Woodin, H. E., and A. A. Lindsey. 1954. Juniper-pinyon east of the Continental Divide, as analyzed by the pine-strip method. Ecology 35:473-489.
  • Wright, H. A. 1972. Shrub response to fire. Pages 204-217 in: C. M. McKell, J. P. Blaisdell, and J. R. Goodin, editors. Wildland shrubs: Their biology and utilization. General Technical Report INT-1. USDA Forest Service, Intermountain Forest and Range Experiment Station, Ogden, UT.
  • 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.
  • Wright, H. A., and A. W. Bailey. 1982a. Pinyon-juniper. Pages 195-208 in: Fire ecology: United States and southern Canada. Wiley-Interscience Publication, John Wiley and Sons, New York. 501 pp.
  • Wright, H. E., Jr., A. M. Bent, B. S. Hansen, and L. J. Mahar, Jr. 1973. Present and past vegetation of the Chuska Mountains, northwestern New Mexico. Geological Society of America Bulletin 84:1155-1179.