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CEGL001553 Artemisia cana ssp. cana / Hesperostipa comata Shrub Wet Meadow
Type Concept Sentence: No Data Available
Common (Translated Scientific) Name: Plains Silver Sagebrush / Needle-and-Thread Shrub Wet Meadow
Colloquial Name: Silver Sagebrush / Needle-and-Thread Shrub Prairie
Hierarchy Level: Association
Type Concept: This shrub prairie association, which generally occurs in small patches (less than 1 hectare), occurs in the northwestern Great Plains. In Montana, it is found on benches to gently inclined slopes (30% maximum recorded) in the vicinity of breaklands. Similar habitats (old river terraces, badlands, ravine sideslopes and valley walls) support its occurrence in Alberta. Sites occur on various parent materials, but mostly well-drained, often sandy, glacial drift and sandy alluvium. Artemisia cana is decidedly the dominant shrub with canopy coverages to 50%, but averaging around 25%, which places it on the cusp of being a true shrub type. Artemisia frigida is the only shrub/subshrub with greater than 50% constancy and its cover does not exceed 3%. A number of graminoids have high constancy, including Bouteloua gracilis, Carex filifolia, Koeleria macrantha, and Poa secunda, but only Hesperostipa comata exhibits both 100% constancy and the highest cover values (averaging 38%). Forbs constitute an insignificant component, virtually none occurring in greater than trace amounts. Those exceeding 50% constancy are Sphaeralcea coccinea, Pediomelum argophyllum, and Gaura coccinea. This association is hypothesized to represent the driest environment capable of supporting Artemisia cana. Occasional fire probably has reduced Artemisia spp. cover and density to low levels and maintains the shrub herbaceous community structure.
Diagnostic Characteristics: No Data Available
Rationale for Nominal Species or Physiognomic Features: No Data Available
Classification Comments: In their vegetation key to this type, DeVelice et al. (1995) allow for the occasional dominance of Bouteloua gracilis and/or Calamovilfa longifolia, in lieu of Hesperostipa comata (which is by far the usual case), to be indicative of the association. The cover of Artemisia cana ranges widely, spanning the values defining shrub herbaceous and shrubland categories. The type is described as shrub herbaceous because the preponderance of stands had cover of less than 25%, though the average cover just exceeded this value. This type could probably be combined with ~Artemisia cana ssp. cana / Calamovilfa longifolia Shrub Wet Meadow (CEGL001555)$$ without compromising the ecological information embedded in either type. This type is less moist than ~Artemisia cana ssp. cana / Pascopyrum smithii Shrub Wet Meadow (CEGL001556)$$, which contains rhizomatous wheatgrasses and/or Nassella viridula as dominants. In Wyoming''s Cheyenne River Basin, stands of Artemisia cana / Bouteloua gracilis - Calamovilfa longifolia Shrub Herbaceous Vegetation (not in the USNVC) (renamed Artemisia cana ssp. cana / Calamovilfa longifolia association by Thilenius et al. (1995), G.P. Jones pers. comm.) occur on well-drained sand dunes and lack, or have low coverages of, Pascopyrum smithii, but support Hesperostipa comata as 100% constant; Hesperostipa comata coverages approach those of the named diagnostic grasses. At least two plots of the this association (CEGL001553) having Calamovilfa longifolia dominant could be allocated to (CEGL001555).
Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: No Data Available
Floristics: Artemisia cana (probably Artemisia cana ssp. cana) is decidedly the dominant shrub with canopy coverages ranging to 50% on heavily grazed sites, but averaging 27%; Artemisia frigida is the only shrub/subshrub with greater than 50% constancy and its cover did not exceed 3%. A number of graminoids have high constancy, including Bouteloua gracilis, Carex filifolia, Koeleria macrantha, and Poa secunda (= Poa sandbergii), but only Hesperostipa comata (= Stipa comata) exhibits both 100% constancy and the highest cover values (averaging 38%). Muhlenbergia cuspidata and Calamovilfa longifolia had rather high cover on some sites. Forbs constitute an insignificant component, occurring in trace amounts; those exceeding 50% constancy are Sphaeralcea coccinea, Pediomelum argophyllum (= Psoralea argophylla) and Gaura coccinea. This association is hypothesized to represent the driest environment capable of supporting Artemisia cana; most often this association grades to upland range sites dominated by Hesperostipa comata and Bouteloua gracilis and to the Artemisia cana / Pascopyrum smithii association that occupies more mesic positions on lower floodplain terraces.
Dynamics: The relatively high cover of Artemisia cana may be the result of an altered fire regime. During presettlement time, when fires were more frequent, this type might not have attained these shrub densities. It is conceivable that this type (or portions thereof) could be interpreted as a grazing disclimax resulting from the overgrazing of ~Artemisia cana / Pascopyrum smithii Wet Shrubland (CEGL001072)$$. However, given that most occurrences of this type (CEGL001553) in Montana were associated with (or in close physical proximity to) Artemisia cana / Pascopyrum smithii Wet Shrubland, which occurred lower on the soil catena, there is evidence that this type is in relatively good condition, representing a particular topo-edaphic, not a grazing-induced, condition.
Environmental Description: This type is found on benches to gently inclined slopes (30% maximum recorded value) of rolling prairie, steeper ravine slopes, and all manner of topography in the vicinity of breaklands. It occurs on various parent materials but mostly well-drained, often sandy, glacial drift. The ground cover is highly variable with some sites (putatively overgrazed) having a sward of Selaginella densa and lichens, while others have 70% litter and trace amounts of Selaginella densa; only one plot had as much as 10% exposed soil, gravel and rock (combined cover).
Geographic Range: This association is well-documented from Montana and Alberta, Canada. The same or a closely analogous type occurs in Wyoming, and some permutation of the type is to be expected in northwestern North Dakota and Saskatchewan.
Nations: CA,US
States/Provinces: AB, MT, ND, SK?, WY?
Plot Analysis Summary:
http://vegbank.org/natureserve/ELEMENT_GLOBAL.2.683570
Confidence Level: Low - Poorly Documented
Confidence Level Comments: No Data Available
Grank: G3
Greasons: No Data Available
| Type | Name | Database Code | Classification Code |
|---|---|---|---|
| Class | 2 Shrub & Herb Vegetation Class | C02 | 2 |
| Subclass | 2.C Shrub & Herb Wetland Subclass | S44 | 2.C |
| Formation | 2.C.4 Temperate to Polar Freshwater Marsh, Wet Meadow & Shrubland Formation | F013 | 2.C.4 |
| Division | 2.C.4.Nd Eastern North American Temperate Freshwater Marsh, Wet Meadow & Shrubland Division | D323 | 2.C.4.Nd |
| Macrogroup | 2.C.4.Nd.5 Prairie Cordgrass - Cattail species - Bulrush species Great Plains Marsh, Wet Meadow, Shrubland & Playa Macrogroup | M071 | 2.C.4.Nd.5 |
| Group | 2.C.4.Nd.5.c Dogwood species - Chokecherry / Western Wheatgrass Great Plains Riparian Wet Meadow & Shrubland Group | G337 | 2.C.4.Nd.5.c |
| Alliance | A3586 Plains Silver Sagebrush Wet Shrubland Alliance | A3586 | 2.C.4.Nd.5.c |
| Association | CEGL001553 Plains Silver Sagebrush / Needle-and-Thread Shrub Wet Meadow | CEGL001553 | 2.C.4.Nd.5.c |
Concept Lineage: No Data Available
Predecessors: No Data Available
Obsolete Names: No Data Available
Obsolete Parents: No Data Available
Synonomy: = Artemisia cana - Stipa comata community type (DeVelice et al. 1995)
< Artemisia cana / Bouteloua gracilis - Calamovilfa longifolia (Thilenius et al. 1995)
= Artemisia cana / Hesperostipa comata Shrub Herbaceous Vegetation (Faber-Langendoen 2001)
= Artemisia cana / Hesperostipa comata Shrub Herbaceous Vegetation (Cooper et al. 2001)
= Artemisia cana / Stipa comata (Allen 2005) [S2S3]
< Artemisia cana / Bouteloua gracilis - Calamovilfa longifolia (Thilenius et al. 1995)
= Artemisia cana / Hesperostipa comata Shrub Herbaceous Vegetation (Faber-Langendoen 2001)
= Artemisia cana / Hesperostipa comata Shrub Herbaceous Vegetation (Cooper et al. 2001)
= Artemisia cana / Stipa comata (Allen 2005) [S2S3]
- Allen, L. 2005. Alberta Natural Heritage Information Centre Preliminary Plant Community Tracking List. Alberta Community Development, Edmonton, Alberta. 94 pp.
- 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.
- Cooper, S. V., C. Jean, and P. Hendricks. 2001. Biological survey of a prairie landscape in Montana''s glaciated plains. Report to State Office, Bureau of Land Management. Montana Natural Heritage Program, Helena. 24 pp. plus appendices.
- DeVelice, R. L., J. Lichthardt, and P. S. Bourgeron. 1991. A preliminary classification of the plant communities of northeastern Montana. Prepared for the Montana Natural Heritage Program. Helena, MT. 144 pp.
- DeVelice, R. L., S. V. Cooper, J. T. McGarvey, J. Lichthardt, and P. S. Bourgeron. 1995. Plant communities of northeastern Montana: A first approximation. Montana Natural Heritage Program, Helena, MT. 116 pp.
- Erixson, J., and D. Cogan. 2012c. Vegetation inventory project report: Nez Perce National Historical Park. Natural Resource Report NPS/UCBN/NRR--2012/531. National Park Service, Fort Collins, CO. 380 pp.
- Faber-Langendoen, D., editor. 2001. Plant communities of the Midwest: Classification in an ecological context. Association for Biodiversity Information, Arlington, VA. 61 pp. plus appendix (705 pp.).
- MTNHP [Montana Natural Heritage Program]. 2002b. List of ecological communities for Montana. Montana Natural Heritage Program, Montana State Library, Helena, MT.
- Thilenius, J. F., G. R. Brown, and A. L. Medina. 1995. Vegetation on semi-arid rangelands, Cheyenne River Basin, Wyoming. General Technical Report RM-GTR-263. USDA Forest Service, Rocky Mountain Forest and Range Experiment Station, Fort Collins, CO. 60 pp.
- WNDD [Wyoming Natural Diversity Database]. No date. Unpublished data on file. Wyoming Natural Diversity Database, University of Wyoming, Laramie, WY.
- Western Ecology Working Group of NatureServe. No date. International Ecological Classification Standard: International Vegetation Classification. Terrestrial Vegetation. NatureServe, Boulder, CO.