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CEGL005660 Pinus edulis - Juniperus monosperma / Hesperostipa comata Open Woodland
Type Concept Sentence: This association is represented by woodlands and savannas with grassy understories which are dominated by Pinus edulis and Juniperus monosperma. It occurs in foothills and lower mountain slopes of southern Colorado and northern and central New Mexico, on coarse-sandy, sometimes rocky soils.
Common (Translated Scientific) Name: Two-needle Pinyon - One-seed Juniper / Needle-and-Thread Open Woodland
Colloquial Name: Southern Rockies Pinyon - Juniper / Needle-and-Thread Woodland
Hierarchy Level: Association
Type Concept: This woodland association is known from central New Mexico and southern Colorado. Stands occur on a variety of sites from flat or gentle lower slopes, benches, wash terraces, mesatops to steep colluvial slopes to montane alluvial fans. Parent materials are frequently sandstone or shale. This woodland is characterized by the dominance or codominance of Pinus edulis in an open evergreen tree canopy (5-30% cover). Juniperus monosperma and Juniperus scopulorum may present to codominant. The sparse to moderately dense herbaceous layer is dominated by the perennial bunchgrass Hesperostipa comata, with Achnatherum hymenoides, Koeleria macrantha, Bouteloua gracilis, Pleuraphis jamesii, and Pascopyrum smithii often present to common. Forb cover is generally sparse but may include Heterotheca villosa, Hymenoxys spp., Artemisia dracunculus, Oxytropis lambertii, Castilleja sp., Eriogonum jamesii, and Sphaeralcea coccinea. Scattered shrubs and dwarf-shrubs may also be present, such as Artemisia frigida, Atriplex canescens, Cercocarpus montanus, Quercus gambelii, or Gutierrezia sarothrae. Opuntia polyacantha and Yucca glauca are often present. Diagnostic of this woodland association is the dominance or codominance of Pinus edulis in the tree canopy and a Hesperostipa comata-dominated herbaceous layer.
Diagnostic Characteristics: No Data Available
Rationale for Nominal Species or Physiognomic Features: No Data Available
Classification Comments: This association is currently known from Sevilleta National Wildlife Refuge and Cibola National Forest (USFS 2007) in central New Mexico, and National Forest lands in Rio Grande and Saguache counties in San Luis Valley, Colorado. More survey is needed to understand the full range of this type. Colorado stands have 5-25% tree cover. Stands with <5% cover may better be placed in similar grass associations (e.g., CEGL001703). On New Mexico sites, this type typically has 10-30% tree cover with some communities having over 30% tree cover.
Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: Total vegetation cover ranges between 10% to at least 70%, with an open to somewhat closed canopy of evergreen conifers, typically 2-5 m tall, and an open herb layer with around 15% cover, dominated by bunchgrasses.
Floristics: The canopy layer is characterized by Pinus edulis and Juniperus monosperma trees. Scattered shrubs such as Gutierrezia sarothrae and Chrysothamnus viscidiflorus are present but do not form a layer. The herbaceous layer is dominated by bunchgrasses, is diverse and provides up to 15% cover. Total graminoid cover is 10-40%, with Hesperostipa comata dominating and Achnatherum hymenoides sometimes codominant. Pleuraphis jamesii or Bouteloua gracilis may be present with low cover. Forbs are more diverse but contribute little cover and may include Heterotheca villosa, Hymenoxys spp., Artemisia dracunculus (= Artemisia dracunculoides), Oxytropis lambertii, Castilleja sp., Eriogonum jamesii, and Sphaeralcea coccinea. Biological crusts are present in some stands. The occurrences known from south-central Colorado have total tree cover of <5% and total shrub cover is <5% with scattered Atriplex canescens, Chrysothamnus greenei, and Gutierrezia sarothrae. Opuntia polyacantha and Yucca glauca are often present. Diagnostic of this woodland association is the dominance or codominance of Pinus edulis in the tree canopy and a Hesperostipa comata-dominated herbaceous layer.
Dynamics: When burned, these stands are sometimes converted to Hesperostipa comata-dominated grasslands (e.g., CEGL001703).
Environmental Description: This woodland association occurs on slopes, benches and ridges and wash terraces with coarse-sandy, sometimes rocky soils. Elevations range between 1600 and 2200 m (5250-7200 feet); slopes are level to steep and may be oriented to any aspect. The unvegetated soil surface may be rocky, gravelly, or mostly bare ground, or biological soil crusts can have high cover in areas that have been protected from grazing. The sandy or silty soils are generally derived from sandstone, less often from shale, alluvial or eolian deposits. The Colorado occurrences are located on sandy, cobbly soils at the base of alluvial fans along the Sangre de Cristo Mountains or rocky slopes below mesatops.
Geographic Range: This association is known from Sevilleta National Wildlife Refuge and Cibola National Forest (USFS 2007) in central New Mexico and the San Luis Valley in south-central Colorado.
Nations: US
States/Provinces: CO, NM
Plot Analysis Summary:
http://vegbank.org/natureserve/ELEMENT_GLOBAL.2.959307
Confidence Level: Low - Poorly Documented
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.c Two-needle Pinyon - One-seed Juniper - Rocky Mountain Juniper Woodland Group | G253 | 1.B.2.Nc.2.c |
| Alliance | A3577 Two-needle Pinyon - One-seed Juniper Grassy Woodland Alliance | A3577 | 1.B.2.Nc.2.c |
| Association | CEGL005660 Two-needle Pinyon - One-seed Juniper / Needle-and-Thread Open Woodland | CEGL005660 | 1.B.2.Nc.2.c |
Concept Lineage: No Data Available
Predecessors: No Data Available
Obsolete Names: No Data Available
Obsolete Parents: No Data Available
Synonomy: = Pinus edulis / Stipa comata Plant Association (Muldavin et al. 1998d)
- 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.
- 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/]
- Muldavin, E., G. Shore, K. Taugher, and B. Milne. 1998d. A vegetation map classification and map for the Sevilleta National Wildlife Refuge, New Mexico. Final report submitted to USDI, U.S. Fish and Wildlife Service, Sevilleta National Wildlife Refuge, Socorro, NM, by the New Mexico Natural Heritage Program, University of New Mexico, Albuquerque. 73 pp. + appendices.
- USFS [U.S. Forest Service]. 2007. Terrestrial ecosystem survey of the Cibola National Forest and National Grasslands. Technical report on file. USDA Forest Service, Southwestern Region, Regional Office, Albuquerque, NM.
- Western Ecology Working Group of NatureServe. No date. International Ecological Classification Standard: International Vegetation Classification. Terrestrial Vegetation. NatureServe, Boulder, CO.