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G775 Intermountain Sparsely Vegetated Dune Scrub & Grassland Group
Type Concept Sentence: This shrubby and herbaceous group occurs on sandy sites in the intermountain western U.S. and is characterized by a sparse to open vegetation layer composed of shrubs Ericameria nauseosa, Eriogonum leptocladon, or Tetradymia tetrameres and herbaceous species Achnatherum hymenoides, Leymus flavescens, Psoralidium lanceolatum, and Redfieldia flexuosa, which may dominate solely or in a combination on active and stable dunes and sandsheets.
Common (Translated Scientific) Name: Intermountain Sparsely Vegetated Dune Scrub & Grassland Group
Colloquial Name: Intermountain Sparsely Vegetated Dune Scrub & Grassland
Hierarchy Level: Group
Type Concept: This group occurs on sandy sites in the intermountain western U.S. from the Columbia Basin, Great Basin, and Centennial Valley in Montana, Wyoming Basins, Colorado Plateau and the San Luis Valley of southern Colorado. This group is characterized by open to sparse (<15% total cover) shrub and/or herbaceous vegetation. Characteristic shrubs include Ericameria nauseosa, Eriogonum leptocladon, or Tetradymia tetrameres. Diagnostic herbaceous species are Achnatherum hymenoides, Leymus flavescens, Muhlenbergia pungens, Psoralidium lanceolatum, and Redfieldia flexuosa, which may dominate solely or in a combination. There are several associated species, including graminoids such as Calamovilfa gigantea, Hesperostipa comata, Schizachyrium scoparium, and forbs Heliotropium convolvulaceum, Machaeranthera canescens, Oxytheca dendroidea, Polanisia dodecandra ssp. trachysperma, Polanisia jamesii, Reverchonia arenaria, Sophora stenophylla, Scabrethia scabra, and the annual forb Eriogonum deflexum. Stands occur on active and stable dunes and sandsheets. Elevations range from 1500-2400 m. All sites have cool, semi-arid continental climates. Substrates are eolian sand.
Diagnostic Characteristics: This group is characterized by a sparse to open shrub and/or herbaceous layer composed of shrubs Ericameria nauseosa, Eriogonum leptocladon, Tetradymia tetrameres, and perennial grasses and forbs Achnatherum hymenoides, Leymus flavescens, Psoralidium lanceolatum, and Redfieldia flexuosa, which may dominate solely or in a combination on rapidly drained sands.
Rationale for Nominal Species or Physiognomic Features: No Data Available
Classification Comments: The majority of this group occurs in the intermountain western U.S.; however, two of the associations may extend out into the shortgrass region of the western Great Plains. These associations need further review as far as floristic composition and range such as on "blowout" sites where sandy plains or stabilized dunes have been disturbed (Ramaley 1939b). Shrubby semi-arid dune communities in this group need further review.
Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: Vegetation has a sparse cover of xeromorphic shrubs and dwarf-shrubs less than 2 m tall and/or a short herbaceous layer that is typically sparse and is dominated by perennial graminoids, with ephemeral forbs and grasses present seasonally.
Floristics: This group occurs on sandy sites in the intermountain western U.S. from the Columbia Basin, Great Basin, and Centennial Valley in Montana, Wyoming Basins, Colorado Plateau and the San Luis Valley of southern Colorado. This group is characterized by open to sparse (<15% total cover) shrub and/or herbaceous vegetation. Dominant shrubs include Ericameria nauseosa, Eriogonum leptocladon, or Tetradymia tetrameres. Diagnostic herbaceous species are Achnatherum hymenoides, Leymus flavescens, Muhlenbergia pungens, Psoralidium lanceolatum, and Redfieldia flexuosa, which may dominate solely or in a combination. There are several associated species, including graminoids such as Calamovilfa gigantea, Hesperostipa comata (= Stipa comata), Schizachyrium scoparium, and forbs Heliotropium convolvulaceum, Machaeranthera canescens (= Aster canescens), Oxytheca dendroidea (= Eriogonum dendroideum), Polanisia dodecandra ssp. trachysperma, Polanisia jamesii, Reverchonia arenaria, Sophora stenophylla, Scabrethia scabra (= Wyethia scabra), and the annual forb Eriogonum deflexum. On the Colorado Plateau, active dune sites have codominants such as Calamovilfa gigantea, Psoralidium lanceolatum, Reverchonia arenaria, Sophora stenophylla, and Scabrethia scabra (Castle 1954, Bowers 1982).
Dynamics: Achnatherum hymenoides is one of the most drought-tolerant grasses in the western U.S. and occurs on a variety of xeric sites (USFS 1937). It is also a valuable forage grass in arid and semi-arid regions. Improperly managed livestock grazing could increase soil erosion, decrease cover of this palatable plant species and increase weedy species (USFS 1937).
Dunes gradually become smaller and reach a threshold of size, below which they become stabilized by vegetation. This vegetation occurs on recent sand deposits, but over time, if deposition slows, it will succeed to shrubland or grassland vegetation types.
Dunes gradually become smaller and reach a threshold of size, below which they become stabilized by vegetation. This vegetation occurs on recent sand deposits, but over time, if deposition slows, it will succeed to shrubland or grassland vegetation types.
Environmental Description: This group occurs on sandy sites in the intermountain western U.S. from the Columbia Basin, Great Basin, and Centennial Valley in Montana, Wyoming Basins, Colorado Plateau and the San Luis Valley of southern Colorado. Elevations range from 1500-2400 m. Stands occur on active and stable dunes and sandsheets. In the San Luis Valley in Colorado, at approximately 2400 m elevation, stands occur on a sandsheet on the windward side of dunes (R. Rondeau, CONHP, pers. comm.). In semi-arid dune systems in the Colorado Plateau and Great Basin, stands occur in active dunes (Van Pelt 1978, Bowers 1982). They are early-seral communities that colonize bare sand in interdune valleys. The plants adapt to sand deposition by stem elongation but eventually will be buried or dug up as the dunes move. On dune margins, stabilization may occur as other sand-adapted species colonize, eventually succeeding into the adjacent desert scrub community. In the Colorado Plateau of southeastern Utah and western Colorado, this vegetation is often limited to small stands on sandy point bars, islands or terraces in the beds of intermittent streams. These stands are subject to periodic flooding but are usually isolated from the water table. A few Colorado Plateau stands occupy unconsolidated sands in areas with active dunes. Additional review is needed to characterize the environments in its full range.
Climate: This group occurs in a cool, semi-arid continental climate. Soil/substrate/hydrology: Substrates are eolian sands.
Climate: This group occurs in a cool, semi-arid continental climate. Soil/substrate/hydrology: Substrates are eolian sands.
Geographic Range: This group occurs on sandy sites in the intermountain western U.S. from the Columbia Basin, Great Basin, Centennial Valley in Montana, Wyoming Basins, Colorado Plateau and the San Luis Valley of southern Colorado.
Nations: CA?,US
States/Provinces: AZ, CO, ID, MT, NV, OR, UT, WA, WY
Plot Analysis Summary:
http://vegbank.org/natureserve/ELEMENT_GLOBAL.2.895818
Confidence Level: Moderate
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.e Intermountain Sparsely Vegetated Dune Scrub & Grassland Group | G775 | 3.B.1.Ne.1.e |
| Alliance | A4011 Blowout Grass - Yellow Wildrye - Indian Ricegrass Grassland Alliance | A4011 | 3.B.1.Ne.1.e |
| Alliance | A4149 Rubber Rabbitbrush - Sand Buckwheat - Four-part Horsebrush Sparse Scrub Alliance | A4149 | 3.B.1.Ne.1.e |
Concept Lineage: No Data Available
Predecessors: No Data Available
Obsolete Names: No Data Available
Obsolete Parents: No Data Available
Synonomy: No Data Available
- Faber-Langendoen, D., J. Drake, S. Gawler, M. Hall, C. Josse, G. Kittel, S. Menard, C. Nordman, M. Pyne, M. Reid, L. Sneddon, K. Schulz, J. Teague, M. Russo, K. Snow, and P. Comer, editors. 2010-2019a. Divisions, Macrogroups and Groups for the Revised U.S. National Vegetation Classification. NatureServe, Arlington, VA. plus appendices. [in preparation]