Print Report
A1568 Eriogonum spp. / Poa secunda Dwarf-shrub Steppe Alliance
Type Concept Sentence: Grasslands included in this alliance occur in the Columbia Basin of eastern Washington, eastern Oregon, Idaho and into western Wyoming. The herbaceous layer is dominated or codominated by the cool-season, perennial bunchgrass Poa secunda. Codominant species may include one or more Eriogonum dwarf-shrub species.
Common (Translated Scientific) Name: Buckwheat species / Sandberg Bluegrass Dwarf-shrub Steppe Alliance
Colloquial Name: Buckwheat / Sandberg Bluegrass Dwarf-shrub Steppe
Hierarchy Level: Alliance
Type Concept: Stands have a sparse to moderately dense, short herbaceous layer (10-60% cover) with a very sparse to moderately dense dwarf-shrub layer (2-40% cover). The herbaceous layer is dominated or codominated by the cool-season, perennial bunchgrass Poa secunda. Codominant species may include one or more Eriogonum dwarf-shrub species. Associates include perennial graminoids such as Elymus elymoides and Pseudoroegneria spicata and perennial forbs. Scattered dwarf-shrubs and shrubs such as Artemisia rigida, Ericameria nauseosa, and Nestotus stenophyllus may be present. Moss and lichen cover in undisturbed stands is often high and ranges from 5-60% cover. Adjacent stands include other grasslands dominated by Festuca idahoensis, Pseudoroegneria spicata, or other perennial grasses, shrublands dominated by Artemisia tridentata or woodlands dominated by Pinus ponderosa. Grasslands included in this alliance occur in the Columbia Basin of eastern Washington, eastern Oregon, Idaho and into western Wyoming. Stands also likely occur in northeastern California. These grasslands are characteristic of the scablands in the Columbia Basin and portions of the Snake River plain, but extend east into Wyoming. Elevations range from 280-1650 m. Climate is temperate and continental, with mean annual precipitation ranging from 33-60 cm. Precipitation primarily occurs in the winter as snow or rain. Stands are found on flat to undulating ridgetops, plateaus, plains, and benches on steep canyon slopes. Sites are nearly level to moderately sloping (to 15%), but these communities may also occur in soil pockets between rocks on cliffs lining the sides of ravines. They occur on all aspects, but are more common on southern slopes. Soils are shallow with a high percentage of rock fragments and exposed rock (lithic soil). They are moderately to well-drained, sandy to clay loams, non-calcareous, and derived from alluvium, colluvium, residuum or loess. Parent materials include basalt lava.
Diagnostic Characteristics: Sparse to dense herbaceous layer dominated by Poa secunda with a sparse to moderately dense layer of Eriogonum sp. occurring in the Columbia Basin steppe.
Rationale for Nominal Species or Physiognomic Features: No Data Available
Classification Comments: No Data Available
Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: Vegetation in this alliance is characterized by a very sparse to moderately dense dwarf-shrub layer (2-40% cover) and a sparse to moderately dense herbaceous layer (10-60% cover). The herbaceous layer is dominated by perennial bunch grasses less than 0.5 m tall. There is also a sparse to moderate cover of perennial forbs. Scattered shrubs may be present. Annual forbs and grasses are seasonally present. Moss and lichen cover in undisturbed stands is often high and ranges from 5-60% cover.
Floristics: Stands have a sparse to moderately dense, short herbaceous layer (10-60% cover) with a very sparse to moderately dense dwarf-shrub layer (2-40% cover). The herbaceous layer is dominated or codominated by the cool-season, perennial bunchgrass Poa secunda. Codominant species may include one or more Eriogonum dwarf-shrub species such as Eriogonum compositum, Eriogonum douglasii, Eriogonum niveum, Eriogonum sphaerocephalum, Eriogonum strictum, and Eriogonum thymoides. Scattered dwarf-shrubs and shrubs such as Artemisia rigida, Ericameria nauseosa (= Chrysothamnus nauseosus), and Nestotus stenophyllus (= Stenotus stenophyllus) may be present. Associates include perennial graminoids such as Elymus elymoides and Pseudoroegneria spicata; perennial forbs such as Achillea millefolium, Antennaria dimorpha, Antennaria luzuloides, Balsamorhiza incana, Erigeron chrysopsidis, Erigeron disparipilus, Lomatium cous, Lomatium bicolor var. leptocarpum (= Lomatium leptocarpum), Phlox hoodii, Sedum lanceolatum, Sedum stenopetalum; and the annual forbs Collinsia parviflora, Epilobium brachycarpum (= Epilobium paniculatum), Idahoa scapigera, Microsteris gracilis, and Plantago patagonica. Moss and lichen cover in undisturbed stands is often high and ranges from 5-60% cover.
Dynamics: Stands in this alliance are generally considered to be late-seral with species composition controlled by the harsh edaphic conditions of the site (Daubenmire 1970, Johnson and Simon 1987). With disturbance comes an increase in erosion pavement and bare ground, and a decrease in moss cover (Daubenmire 1970, Johnson and Simon 1987). These xeric grasslands have shallow rocky soils with limited water-holding capacity. The winter precipitation wets these soils, but they typically dry out completely to bedrock by mid-summer (Daubenmire 1970, 1992, Johnson and Simon 1987). Poa secunda is well-adapted to these conditions, initiating growth early in the spring and completing its reproductive cycle early while there is still moisture in the soil (Daubenmire 1970, 1992, Johnson and Simon 1987). If there is late-summer or fall precipitation, Poa secunda can respond quickly and green up (Daubenmire 1970). Johnson and Simon (1987) suggest that basalt bedrock present under these dwarf-shrub/grassland stands is fractured enough to support deeper-rooted dwarf-shrubs. In addition to drought tolerance, Poa secunda is also tolerant of grazing and trampling by livestock (Daubenmire 1970, Ganskopp 1979). Other disturbances include frost heaving and exotic species invasion. Frost heaving causes local soil disturbance in the winter when these thin, saturated soils freeze and push soil and plants up out of the ground. Exotic plants have invaded many stands especially where disturbed. Common exotics include annual grasses such as Bromus tectorum, Bromus arvensis, and Bromus briziformis, which may be abundant during wet years, and annual forbs such as Epilobium brachycarpum, Erodium cicutarium, Lactuca serriola, Tragopogon dubius, and the perennial forb Hypericum perforatum. Fire is thought to be unimportant because it is unlikely that the sparse vegetation in these stands could carry a fire.
Environmental Description: These grasslands are characteristic of the scablands in the Columbia Basin and portions of the Snake River plain, but extend east into Wyoming. Elevations range from 280-1650 m. Climate is temperate continental, with mean annual precipitation ranging from 33-60 cm. Precipitation primarily occurs in the winter as snow or rain. This moisture is stored in the soil profile and utilized during the typically dry summers. Stands are found on flat to undulating ridgetops, plateaus, plains, and benches on steep canyon slopes. Sites are nearly level to moderately sloping (to 15%), but these communities may also occur in soil pockets between rocks on cliffs lining the sides of ravines. They occur on all aspects, but are more common on southern slopes. Soils are shallow (less than 30 cm deep) with a high percentage of rock fragments (approximately 35%) and exposed rock (10-90%) (lithic soil). They are moderately to well-drained, sandy to clay loams, and non-calcareous, with pH of 5.9-7.4. They are derived from alluvium, colluvium, residuum or loess. Parent materials include basalt lava.
Geographic Range: This alliance occurs in the Columbia Basin of eastern Washington, eastern Oregon, Idaho and into western Wyoming. Stands also likely occur in northeastern California.
Nations: US
States/Provinces: CA?, ID, OR, WA, WY
Plot Analysis Summary:
http://vegbank.org/natureserve/ELEMENT_GLOBAL.2.899153
Confidence Level: Moderate
Confidence Level Comments: No Data Available
Grank: GNR
Greasons: No Data Available
Concept Lineage: equivalent to A.1568
Predecessors: No Data Available
Obsolete Names: No Data Available
Obsolete Parents: No Data Available
Synonomy: >< One-sided Bluegrass Series (Sawyer and Keeler-Wolf 1995)
- Daubenmire, R. F. 1970. Steppe vegetation of Washington. Washington State University Agricultural Experiment Station Technical Bulletin No. 62. 131 pp.
- Daubenmire, R. F. 1992. Palouse prairie. Pages 297-312 in: R. T. Coupland, editor. Natural grasslands introduction and Western Hemisphere. Ecosystems of the world, Volume 8A. Elsevier Publishing Company, Amsterdam.
- Faber-Langendoen, D., J. Drake, M. Hall, G. Kittel, S. Menard, C. Nordman, M. Pyne, M. Reid, M. Russo, K. Schulz, L. Sneddon, K. Snow, and J. Teague. 2013-2019b. Screening alliances for induction into the U.S. National Vegetation Classification: Part 1 - Alliance concept review. NatureServe, Arlington, VA.
- Ganskopp, D. C. 1979. Plant communities and habitat types of the Meadow Creek Experimental Watershed. Unpublished thesis, Oregon State University, Corvallis. 162 pp.
- Johnson, C. G., Jr., and S. A. Simon. 1987. Plant associations of the Wallowa-Snake Province Wallowa-Whitman National Forest. Technical Paper R6-ECOL-TP-255A-86. USDA Forest Service, Pacific Northwest Region, Wallowa-Whitman National Forest. 399 pp. plus appendices.
- Sawyer, J. O., and T. Keeler-Wolf. 1995. A manual of California vegetation. California Native Plant Society, Sacramento. 471 pp.