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CEGL002343 Achnatherum hymenoides Colorado Plateau Grassland
Type Concept Sentence: No Data Available
Common (Translated Scientific) Name: Indian Ricegrass Colorado Plateau Grassland
Colloquial Name: No Data Available
Hierarchy Level: Association
Type Concept: This herbaceous vegetation association occurs in eastern Utah and northwestern Colorado. It is likely to occur in small patches throughout the Colorado Plateau. Total vegetation cover in upland sites with blowing sand is usually quite sparse, rarely exceeding 10%. Sites on sandy terraces and point bars may have up to 30% cover by vascular plants, with another 25% cover provided by biological soil crusts. Achnatherum hymenoides is the dominant species, ranging in cover between 3 and 15%. A scattering of shrubs may be present, with no species exceeding 1% cover and the total not exceeding 5% cover. Associated shrubs include Amsonia tomentosa, Artemisia filifolia, Atriplex canescens, Ephedra torreyana, Ephedra viridis, Poliomintha incana, Vanclevea stylosa, Gutierrezia sarothrae, and Opuntia polyacantha. Some stands may contain scattered Juniperus osteosperma trees or saplings. Associated graminoids include the short bunchgrasses Aristida purpurea, Sporobolus cryptandrus, and Pleuraphis jamesii. Forbs present include Abronia fragrans and Sphaeralcea parvifolia. Stands usually occur in small patches (<1 hectare) on upland eolian sand deposits, as well as on sandy alluvial terraces and point bars along intermittent washes. Disturbance is usually a factor; upland sites often have blowing sand, and wash sites are subject to periodic flooding. Sites are flat to gently sloping (not exceeding 10%) and between 1108 and 1815 m elevation. The unvegetated surface has high cover by bare soil or sand, low cover by litter, and biological soil crusts may have up to 30% cover. Soils are rapidly drained sands or sandy loams derived from alluvium or eolian deposits.
Diagnostic Characteristics: No Data Available
Rationale for Nominal Species or Physiognomic Features: No Data Available
Classification Comments: This association is largely known and described from National Park Service inventory efforts in the Colorado Plateau.
Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: No Data Available
Floristics: Small patches (usually less than 1 hectare) of this distinctive grassland type occur sporadically in the Colorado Plateau of southeastern Utah. Total vegetation cover in upland sites with blowing sand is usually quite sparse, rarely exceeding 10%. Sites on sandy terraces and point bars may have up to 55% cover by vascular plants, often with another 25% cover provided by biological soil crusts, although crusts can vary from 0-35 % cover. Achnatherum hymenoides is the dominant species, ranging in cover between 3 and 25%. A scattering of shrubs may be present, with no species exceeding 1% cover and the total not exceeding 5% cover. Associated shrubs include Acamptopappus sphaerocephalus, Amsonia tomentosa, Artemisia filifolia, Atriplex canescens, Ephedra cutleri, Ephedra torreyana, Ephedra viridis, Gutierrezia sarothrae, Opuntia polyacantha, Poliomintha incana, and Vanclevea stylosa. Some stands may contain scattered Juniperus osteosperma trees or saplings. Associated graminoids include the short bunchgrasses Aristida purpurea, Pleuraphis jamesii, Sporobolus airoides, and Sporobolus cryptandrus. Forbs present include Abronia fragrans and Sphaeralcea parvifolia.
Dynamics: Most stands are subject to soil movement because of wind erosion or catastrophic flooding. Without periodic disturbance, the community is likely to shift toward a shrubland type, such as ~Ephedra viridis / (Achnatherum hymenoides, Hesperostipa comata) Shrubland (CEGL002354)$$. The bunch grasses are deeply rooted and even intense flooding, such as occurred at Natural Bridges National Monument in September 2003, fails to remove them completely from a point bar at stream level.
Environmental Description: This herbaceous vegetation association occurs on upland eolian sand deposits, as well as on sandy alluvial terraces and point bars along intermittent washes in eastern Utah and northwestern Colorado. It is likely to occur in small patches throughout the Colorado Plateau. Sites are flat to gently sloping (not exceeding 10%), between 1108 and 1815 m elevation and include benches, sand dunes, stream terraces, valley sides and canyon sides. The unvegetated surface has high cover by bare soil or sand, low cover by litter, and biological soil crusts may have up to 30% cover. Soils are rapidly drained sands or sandy loams that are usually derived from alluvium or eolian deposits, but include talus/colluvium below sandstone cliffs.
Geographic Range: This association is documented from eastern Utah and northwestern Colorado. It is likely to occur in small stands, 0.1 to 1 ha in size, scattered throughout the Colorado Plateau.
Nations: US
States/Provinces: AZ, CO, NM?, UT
Plot Analysis Summary:
http://vegbank.org/natureserve/ELEMENT_GLOBAL.2.768815
Confidence Level: High
Confidence Level Comments: No Data Available
Grank: GNR
Greasons: No Data Available
| Type | Name | Database Code | Classification Code |
|---|---|---|---|
| Class | 3 Desert & Semi-Desert Class | C03 | 3 |
| Subclass | 3.B Cool Semi-Desert Scrub & Grassland Subclass | S11 | 3.B |
| Formation | 3.B.1 Cool Semi-Desert Scrub & Grassland Formation | F033 | 3.B.1 |
| Division | 3.B.1.Ne Western North American Cool Semi-Desert Scrub & Grassland Division | D040 | 3.B.1.Ne |
| Macrogroup | 3.B.1.Ne.1 Yellow Rabbitbrush - Blackbrush / Indian Ricegrass Dry Shrubland & Grassland Macrogroup | M171 | 3.B.1.Ne.1 |
| Group | 3.B.1.Ne.1.c James'' Galleta - Indian Ricegrass - Needle-and-Thread Semi-Desert Grassland Group | G311 | 3.B.1.Ne.1.c |
| Alliance | A1262 Indian Ricegrass - Bluebunch Wheatgrass - Sandhill Muhly Grassland Alliance | A1262 | 3.B.1.Ne.1.c |
| Association | CEGL002343 Indian Ricegrass Colorado Plateau Grassland | CEGL002343 | 3.B.1.Ne.1.c |
Concept Lineage: No Data Available
Predecessors: No Data Available
Obsolete Names: No Data Available
Obsolete Parents: No Data Available
Synonomy: = Achnatherum hymenoides Colorado Plateau Herbaceous Vegetation (Clark et al. 2009)
- 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., A. Tendick, G. Manis, A. Wight, G. Wakefield, J. Von Loh, and A. Evenden. 2009a. Vegetation classification and mapping project report, Arches National Park. Natural Resource Technical Report NPS/NCPN/NRTR--2009/253. National Park Service, Fort Collins, CO. 544 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.
- 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.
- Tendick, A., J. Coles, K. Decker, M. Hall, J. Von Loh, T. Belote, A. Wight, G. Wakefield, and A. Evenden. 2012. Vegetation classification and mapping project report, Canyonlands National Park. Natural Resource Technical Report NPS/NCPN/NRTR--2012/577. National Park Service, Fort Collins, CO.
- Tendick, A., J. Spence, M. Reid, K. Shulz, G. Kittel, K. Green, A. Wight, and G. Wakefield. 2017. Vegetation classification and mapping project report, Glen Canyon National Recreation Area and Rainbow Bridge National Monument. Natural Resource Report NPS/NCPN/NRR—2017/1500. National Park Service, Fort Collins, CO. 1464 pp.
- Thomas, K. A., M. L. McTeague, L. Ogden, K. Schulz, T. Fancher, R. Waltermire, and A. Cully. 2010. Vegetation classification and distribution mapping report: Canyon de Chelly National Monument. National Resource Technical Report NPS/SCPN/NRTR-2010/306. National Park Service, Fort Collins, CO. 338 pp.
- Western Ecology Working Group of NatureServe. No date. International Ecological Classification Standard: International Vegetation Classification. Terrestrial Vegetation. NatureServe, Boulder, CO.