Community Field Guide
Scientific Name:
Calamovilfa longifolia - Hesperostipa comata Herbaceous Vegetation
Common Name:
Prairie sandreed - needle-and-thread Prairie
Community Description
Summary:
The prairie sandreed - needle-and-thread association occurs most abundantly where sandy substrates obtain, the central Great Plains and specifically the Nebraska Sandhills, and becomes less extensive to the north. Stands occur on stabilized sand dunes, interdunal swales and on colluvial sands. Soils are medium to fine sands originating from aeolian or colluvial processes. The vegetation has an open canopy, dominate by mid- to tall grasses. Calamovilfa longifolia is usually the conspicuous dominant, ranging from 30 to 90 % canopy cover, with the shorter Hesperostipa comata somewhat obscured and usually exhibiting less cover (10 to 40%). Accessory graminoids include the high constancy-low coverage Bouteloua gracilis (blue grama), Koeleria macrantha (prairie junegrass) and Carex filifolia (threadleaf sedge) and those with occasionally high cover values, such as Pascopyrum smithii (western wheatgrass), Calamagrostis montanensis (plains reedgrass), Achnatherum hymenoides (indian ricegrass) and Carex inops (sun sedge). Forb diversity and cover is low; Thermopsis rhombifolia (round-leaved thermopsis) is the only forb present whose constancy exceeds 50%. Shrubs cover is also notably depauperate with only Yucca glauca (yucca), Rosa arkansana (prairie rose) and Rhus trilobata (skunkbush sumac) having slightly greater than trace amounts in less than half the examined occurrences. This is one of several upland communities in which Selaginella densa (dense clubmoss) is both uncommon and exhibits low canopy cover as well.
Environment:
Stands occur on stabilized sand dunes, as well as in interdunal valleys or draws, colluvial sands, and less commonly, silty terraces of intermittent streams. Soils are medium to fine sands formed either from aeolian or colluvial processes. For example, in Nebraska stands occur below sandstone outcrops and escarpments. More rarely, stands occur on floodplain terraces of intermittent streams where soils are moderately deep, poorly drained, silty loams and loams (Heerwagen 1958, USDI 1979, Barnes et al. 1984, Steinauer and Rolfsmeier 2000).
Vegetation:
The vegetation has an open canopy, dominated by mid- to tall-grasses. Calamovilfa longifolia is the most conspicuous grass. Other common grasses include Bouteloua gracilis, Bouteloua gracilis, Koeleria macrantha, Achnatherum hymenoides (=Oryzopsis hymenoides), Sporobolus cryptandrus, and Hesperostipa comata (= Stipa comata). Pascopyrum smithii (=Agropyron smithii) and Nassella viridula (=Stipa viridula) may occur on more level sites at the base of slopes (Barnes et al. 1984, Steinauer and Rolfsmeier 2000). Andropogon hallii may also be present. Sedges are rare but could include Carex inops ssp. heliophila. Forb diversity ranges from low to moderate, depending on the site. Dry valley sand prairies may be particularly forb-rich. Silty terraces of intermittent streams may contain Artemisia frigida, Artemisia ludoviciana, Gutierrezia sarothrae, Psoralidium tenuiflorum, and Yucca glauca (Steinauer and Rolfsmeier 2000). Shrubs are scattered and are infrequent to absent, with Rhus trilobata the most common species. These areas are highly susceptible to invasion by exotic brome grasses (Bromus japonicus, Bromus squarrosus, Bromus tectorum) and may be quite weedy (Heerwagen 1958, USDI 1979, Steinauer and Rolfsmeier 2000).
Range:
This prairie sandreed grassland community type occurs in the central and northern Great Plains region of the United States, ranging from Colorado and Nebraska, north to Wyoming and South Dakota.
Dynamics:
Blowouts caused by drought and wind may occur in this type. The type probably represents a later successional stage. Earlier stages may be dominated by Andropogon hallii (e.g., Andropogon hallii - Calamovilfa longifolia Herbaceous Vegetation (CEGL001467)). Heavy grazing may increase the likelihood of blowouts.
Global Rank: G3 State Rank: S3
Global Rank Comments:
No occurrences have been documented, but the community is reported in 2 ecoregional sections in Wyoming, Colorado, and Nebraska. It is restricted primarily to stabilized sand dunes, as well as in interdunal valleys or draws, colluvial sands, and intermittent streams, but it has a moderately wide distribution in the central to northern Great Plains. Stands are typically less than a few hectares in size, but larger stands are found in interdunal valleys in Nebraska, some reaching 100 acres or more (G. Steinauer pers. comm. 1999). In Nebraska, this community can be heavily grazed and subsequently invaded by exotic species (Steinauer and Rolfsmeier 2000).
Community References
Identifier:
CEGL001473
Author:
G. Steinauer and S. Rolfsmeier; mod. D. Faber-Langendoen, WCS; mod. S.V. Cooper & C. Jean, MTNHP
Citations:
Bureau of Land Management 1974, CDM Consultants n.d., Johnston 1987, Mine Reclamation Consultants 1977
View Detailed Citation Information | New Community Search | NatureServe Explorer Community Information
This information is from the:
Montana Natural Heritage Program
Montana State Library--Natural Resource Information System
1515 East Sixth Ave., Helena, MT 59620-1800
406 444-3989
mtnhp.org
mtnhp@mt.gov
