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CEGL000841 Pinus ponderosa / (Andropogon gerardii, Schizachyrium scoparium) Open Woodland
Type Concept Sentence: No Data Available
Common (Translated Scientific) Name: Ponderosa Pine / (Big Bluestem, Little Bluestem) Open Woodland
Colloquial Name: No Data Available
Hierarchy Level: Association
Type Concept: This woodland occurs in the western Black Hills of South Dakota and in the Powder River Basin and Little Missouri drainage of Wyoming and Montana. Pinus ponderosa is the only tree in the overstory. Shrubby Juniperus scopulorum may occur in the understory. The ground layer is dominated by Schizachyrium scoparium with Andropogon gerardii and/or Bouteloua curtipendula. This type occurs on warm slopes in Montana, but more mesic sites in drier portions of the Black Hills and Wyoming. Soils are well-drained and often derived from sandstone.
Diagnostic Characteristics: No Data Available
Rationale for Nominal Species or Physiognomic Features: No Data Available
Classification Comments: The description of this community for Montana is based on one stand and reports by Pfister et al. (1977) and by Cooper and Pfister (1985). The lack of data makes it difficult to make comparisons with other descriptions. However, this type appears to be identical to ~Pinus ponderosa / Schizachyrium scoparium Open Woodland (CEGL000201)$$.
Jones (1992b) describes similar vegetation in his Pinus ponderosa / Schizachyrium scoparium community. His type differs from the Montana descriptions as follows: Pinus ponderosa canopy is "relatively dense"; a shrub layer is sometimes present; and there is no mention of Andropogon gerardii. The absence of Andropogon gerardii may be caused by more arid conditions found in Wyoming. The presence of shrubs and a denser tree canopy could result from sampling of stands that have been without fire for longer periods of time. Both the Wyoming and Montana types occur in the Powder River Basin, probably on soils derived from similar parent materials. For this reason they may be considered to be the same.
Thilenius (1972) describes a Pinus ponderosa / Andropogon scoparius habitat unit from the southwestern portion of the Black Hills. It is similar to the Jones type mentioned above and should be considered synonymous. Thilenius (1972) also describes a Pinus ponderosa / Prunus virginiana / Andropogon scoparius habitat unit with more shrub species present; Jones (1992b) considers this to also be synonymous with his Pinus ponderosa / Schizachyrium scoparium Community.
Jones (1992b) describes similar vegetation in his Pinus ponderosa / Schizachyrium scoparium community. His type differs from the Montana descriptions as follows: Pinus ponderosa canopy is "relatively dense"; a shrub layer is sometimes present; and there is no mention of Andropogon gerardii. The absence of Andropogon gerardii may be caused by more arid conditions found in Wyoming. The presence of shrubs and a denser tree canopy could result from sampling of stands that have been without fire for longer periods of time. Both the Wyoming and Montana types occur in the Powder River Basin, probably on soils derived from similar parent materials. For this reason they may be considered to be the same.
Thilenius (1972) describes a Pinus ponderosa / Andropogon scoparius habitat unit from the southwestern portion of the Black Hills. It is similar to the Jones type mentioned above and should be considered synonymous. Thilenius (1972) also describes a Pinus ponderosa / Prunus virginiana / Andropogon scoparius habitat unit with more shrub species present; Jones (1992b) considers this to also be synonymous with his Pinus ponderosa / Schizachyrium scoparium Community.
Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: No Data Available
Floristics: Pinus ponderosa is the only overstory tree species, and canopies may be open (Pfister et al. 1977) or more closed (Jones 1992b, Thilenius 1972). The understory may have scattered shrubs such as Juniperus scopulorum, Prunus virginiana, Symphoricarpos albus, and Rosa woodsii (Thilenius 1972, Jones 1992b). Schizachyrium scoparium, Bouteloua curtipendula, and Pascopyrum smithii dominate the ground layer. Andropogon gerardii may be important in Montana representations (Pfister et al. 1977).
Dynamics: Fire undoubtedly plays an important role in the dynamics of these dry forest communities. Ground layer species composition has much in common with grasslands (Thilenius 1972). Forests vary widely in canopy closure. Understory vegetation may change if canopy closure is allowed to proceed without fire (Hansen and Hoffman 1988).
Hansen and Hoffman (1988) state that Pinus ponderosa / Andropogon spp. community is a seral stage of the Pinus ponderosa / Carex heliophila Habitat Type and predict that, as stands become older and canopies close, Schizachyrium scoparium is replaced by Carex heliophila. However, they present no evidence to support their conclusions, and closed-canopy forests described by Thilenius (1972) and Jones (1992) suggest that Schizachyrium scoparium is not lost with canopy closure.
Hansen and Hoffman (1988) state that Pinus ponderosa / Andropogon spp. community is a seral stage of the Pinus ponderosa / Carex heliophila Habitat Type and predict that, as stands become older and canopies close, Schizachyrium scoparium is replaced by Carex heliophila. However, they present no evidence to support their conclusions, and closed-canopy forests described by Thilenius (1972) and Jones (1992) suggest that Schizachyrium scoparium is not lost with canopy closure.
Environmental Description: This type occurs in the foothills of the Black Hills and adjacent uplands. It is found on warm exposures in the northern portion of its range in southeastern Montana (Pfister et al. 1977), but is found on cool slopes and canyons in the drier portions of the Black Hills (Thilenius 1972) and in the Powder River Basin of Wyoming (Jones 1992b). Elevations are about 1220 m (4000 feet) in Montana, but 1460-1675 m (4800-5500 feet) in South Dakota. Thilenius (1972) reports that stands are in a 45- to 50-cm annual precipitation zone in the Black Hills. Stands in the Black Hills occur on "relatively deep" soils with near-neutral reaction (Thilenius 1972). Montana stands more likely occur on soils derived from sandstone.
Geographic Range: This woodland occurs in the western Black Hills of South Dakota and in the Powder River Basin and Little Missouri drainage of Wyoming and Montana.
Nations: US
States/Provinces: MT, WY
Plot Analysis Summary:
http://vegbank.org/natureserve/ELEMENT_GLOBAL.2.686468
Confidence Level: Low
Confidence Level Comments: No Data Available
Grank: G2Q
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.Nb Rocky Mountain Forest & Woodland Division | D194 | 1.B.2.Nb |
| Macrogroup | 1.B.2.Nb.2 Ponderosa Pine - Douglas-fir - Limber Pine Central Rocky Mountain Dry Forest Macrogroup | M501 | 1.B.2.Nb.2 |
| Group | 1.B.2.Nb.2.e Ponderosa Pine Northwestern Great Plains Forest & Woodland Group | G216 | 1.B.2.Nb.2.e |
| Alliance | A3466 Ponderosa Pine Northwest Great Plains Open Woodland Alliance | A3466 | 1.B.2.Nb.2.e |
| Association | CEGL000841 Ponderosa Pine / (Big Bluestem, Little Bluestem) Open Woodland | CEGL000841 | 1.B.2.Nb.2.e |
Concept Lineage: No Data Available
Predecessors: No Data Available
Obsolete Names: No Data Available
Obsolete Parents: No Data Available
Synonomy: > Pinus ponderosa - Schizachyrium scoparium - Elytrigia smithii Plant Association (Johnston 1987)
> Pinus ponderosa / Andropogon scoparius habitat unit (Thilenius 1972)
= Pinus ponderosa / Andropogon spp. Habitat Type (Pfister et al. 1977)
= Pinus ponderosa / Andropogon spp. Habitat Type (Cooper and Pfister 1985)
> Pinus ponderosa / Schizachyrium scoparium Community (Jones 1992b)
> Pinus ponderosa / Andropogon scoparius habitat unit (Thilenius 1972)
= Pinus ponderosa / Andropogon spp. Habitat Type (Pfister et al. 1977)
= Pinus ponderosa / Andropogon spp. Habitat Type (Cooper and Pfister 1985)
> Pinus ponderosa / Schizachyrium scoparium Community (Jones 1992b)
- 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., and R. D. Pfister. 1985. Forest habitat types of the Crow and Northern Cheyenne Indian Reservations. Unpublished termination report prepared for Bureau of Indian Affairs, Billings Area Office by USDA Forest Service, Intermountain Forest and Range Experiment Station, Ogden, UT. 118 pp.
- Hansen, P. L., G. R. Hoffman, and A. J. Bjugstad. 1984. The vegetation of Theodore Roosevelt National Park, North Dakota: A habitat type classification. General Technical Report RM-113. USDA Forest Service, Rocky Mountain Forest and Range Experiment Station, Fort Collins, CO. 35 pp.
- Hansen, P. L., and G. R. Hoffman. 1988. The vegetation of the Grand River/Cedar River, Sioux, and Ashland districts of the Custer National Forest: A habitat type classification. General Technical Report RM-157. USDA Forest Service, Rocky Mountain Forest and Range Experiment Station, Fort Collins, CO. 68 pp.
- Hoffman, G. R., and R. R. Alexander. 1987. Forest vegetation of the Black Hills National Forest of South Dakota and Wyoming: A habitat type classification. Research Paper RM-276. USDA Forest Service, Rocky Mountain Forest and Range Experiment Station, Fort Collins, CO. 48 pp.
- Johnston, B. C. 1987. Plant associations of Region Two: Potential plant communities of Wyoming, South Dakota, Nebraska, Colorado, and Kansas. R2-ECOL-87-2. USDA Forest Service, Rocky Mountain Region. Lakewood, CO. 429 pp.
- Jones, G. 1992b. Wyoming plant community classification (Draft). Wyoming Natural Diversity Database, Laramie, WY. 183 pp.
- MTNHP [Montana Natural Heritage Program]. 2002b. List of ecological communities for Montana. Montana Natural Heritage Program, Montana State Library, Helena, MT.
- Pfister, R. D., B. L. Kovalchik, S. F. Arno, and R. C. Presby. 1977. Forest habitat types of Montana. General Technical Report INT-34. USDA Forest Service, Intermountain Forest and Range Experiment Station, Ogden, UT. 174 pp.
- Thilenius, J. F. 1972. Classification of the deer habitat in the ponderosa pine forest of the Black Hills, South Dakota. Research Paper RM-91. USDA Forest Service, Rocky Mountain Forest and Range Experiment Station, Fort Collins, CO. 28 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.