Print Report
A1109 Atriplex corrugata Low Scrub Alliance
Type Concept Sentence: Shrublands in this alliance are dominated by the halophytic, evergreen dwarf-shrub Atriplex corrugata and found on lower hillslopes and alkaline flats on the Colorado Plateau portions of northwestern New Mexico, western Colorado and Utah.
Common (Translated Scientific) Name: Mat Saltbush Low Scrub Alliance
Colloquial Name: Mat Saltbush Low Scrub
Hierarchy Level: Alliance
Type Concept: Stands have very sparse to moderate cover (5-30%) of woody vegetation that is dominated by the halophytic, evergreen dwarf-shrub Atriplex corrugata. Sparse stands are often completely dominated by this plant. Stands typically have very low species diversity. Depending on soil salinity and moisture, other plants may be present, including the shrubs Krascheninnikovia lanata, Picrothamnus desertorum, and Tetradymia spinosa. The herbaceous layer is very sparse. Scattered perennial forbs, such as Sphaeralcea grossulariifolia and Xylorhiza glabriuscula, and the perennial grass Achnatherum hymenoides have been reported. Annuals are seasonally present and may include Eriogonum inflatum, Plantago tweedyi, and the exotics Bromus tectorum, Malcolmia africana, and Salsola kali. Shrublands in this alliance are found on lower hillslopes and alkaline flats on the Colorado Plateau portions of northwestern New Mexico, western Colorado and Utah. Climate is semi-arid with most of the highly variable precipitation falling in July and August as high-intensity thunderstorms. Mean annual precipitation is approximately 23 cm. Elevation ranges from 1300-1820 m. Sites are nearly flat to moderately steep, and have soils typically derived from Mancos shale. Soils are moderately deep, strongly saline, moderately alkaline, fine-textured (clayey), poorly developed and typically have high erosion rates.
Diagnostic Characteristics: Sparse to open dwarf-shrublands (5-30%) of alkaline flats in the Colorado Plateau portions of northwestern New Mexico, western Colorado and Utah dominated by Atriplex corrugata occupying substrates typically derived from Mancos shale.
Rationale for Nominal Species or Physiognomic Features: No Data Available
Classification Comments: Vegetation cover in this alliance may vary greatly depending on soil chemistry and slope. Some stands should be classified as shrublands with 25-30% shrub cover (Branson et al. 1976, Potter et al. 1985). Most stands are in the 3-20% shrub cover range and should be classified in a sparsely vegetated alliance (West and Ibrahim 1968, Ibrahim et al. 1972, Harper and Jaynes 1986). Further investigation is needed throughout its range.
Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: Vegetation in this alliance is characterized by sparse to moderate cover of xeromorphic evergreen dwarf-shrubs (<0.3 m tall). A sparse herbaceous layer may be present that is dominated by perennial graminoids with scattered perennial forbs. Annual forbs and grasses are seasonally present.
Floristics: Stands have very sparse to moderate cover (5-30%) of woody vegetation that is dominated by the halophytic evergreen dwarf-shrub Atriplex corrugata. Sparse stands are often completely dominated by this plant. Stands typically have very low species diversity. Depending on soil salinity and moisture, other plants may be present, including the shrubs Krascheninnikovia lanata, Picrothamnus desertorum (= Artemisia spinescens), and Tetradymia spinosa. The herbaceous layer is very sparse. Scattered perennial forbs, such as Xylorhiza glabriuscula and Sphaeralcea grossulariifolia, and the perennial grass Achnatherum hymenoides (= Oryzopsis hymenoides) have been reported. Annuals are seasonally present and may include Eriogonum inflatum, Plantago tweedyi, and the exotics Bromus tectorum, Malcolmia africana, and Salsola kali.
Dynamics: Atriplex corrugata-dominated shrublands are the most saline-tolerant of the Mancos shale plant communities studied by Branson et al. (1976). Although very slow-growing, Atriplex corrugata can completely dominate these extremely saline sites (Branson et al. 1976). It is a true evergreen dwarf-shrub retaining leaves for several years. This plant utilizes winter soil moisture, beginning new growth in March when the soils are relatively warm and moist. It flowers in April and by mid-July fruits are shattered (Branson et al. 1976). If the soils dry out in mid-summer, it can go dormant until the late-summer monsoon rains begin.
Environmental Description: Shrublands included in this alliance are found on the lower slopes of shale outcrops and alkaline flats on the Colorado Plateau portions of northwestern New Mexico, western Colorado and Utah. Climate is semi-arid with most of the highly variable precipitation falling in July and August as high-intensity thunderstorms. Mean annual precipitation is approximately 23 cm. Elevation ranges from 1300-1700 m. Sites are nearly flat to moderately steep. Soils are typically derived from Mancos shale. They are moderately deep, strongly saline, moderately alkaline, fine-textured (clayey), poorly developed and typically have high erosion rates. The soil surface is mostly barren.
Geographic Range: Dwarf-shrublands included in this alliance occur on lower slopes and in basins in western Colorado, northwestern New Mexico and Utah, on Mancos shale.
Nations: US
States/Provinces: CO, NM, UT
Plot Analysis Summary:
http://vegbank.org/natureserve/ELEMENT_GLOBAL.2.899075
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.5 Shadscale Saltbush - Fourwing Saltbush - Mat Saltbush Great Basin Scrub Macrogroup | M093 | 3.B.1.Ne.5 |
| Group | 3.B.1.Ne.5.a Mat Saltbush - Gardner''s Saltbush - Birdfoot Sagebrush Dwarf-Scrub Group | G301 | 3.B.1.Ne.5.a |
| Alliance | A1109 Mat Saltbush Low Scrub Alliance | A1109 | 3.B.1.Ne.5.a |
| Association | CEGL001437 Mat Saltbush Dwarf-shrubland | CEGL001437 | 3.B.1.Ne.5.a |
Concept Lineage: equivalent to A.1109
Predecessors: No Data Available
Obsolete Names: No Data Available
Obsolete Parents: No Data Available
Synonomy: ? Atriplex corrugata Shrub Association (Baker 1984b) [Atriplex corrugata Shale Barren is listed as a synonym.]
? Badlands (Dastrup 1963) [Atriplex corrugata can be found on the "buckskin" knolls in the Uinta Basin of Utah.]
? Mat Atriplex-Hilaria Community (Dastrup 1963) [includes two other species of Atriplex plus significant Artemisia nova cover]
? Mat Atriplex Association (Graham 1937)
? Mat saltbush association (Shantz 1925)
? Badlands (Dastrup 1963) [Atriplex corrugata can be found on the "buckskin" knolls in the Uinta Basin of Utah.]
? Mat Atriplex-Hilaria Community (Dastrup 1963) [includes two other species of Atriplex plus significant Artemisia nova cover]
? Mat Atriplex Association (Graham 1937)
? Mat saltbush association (Shantz 1925)
- Baker, W. L. 1984b. Additions to a bibliography of Colorado vegetation description. Great Basin Naturalist 44(4):677-680.
- Branson, F. A., R. F. Miller, and I. S. McQueen. 1976. Moisture relationships in twelve northern desert shrub communities near Grand Junction, Colorado. Ecology 57:1104-1124.
- Dastrup, B. C. 1963. Vegetational changes of the Uinta Basin since settlement. Unpublished thesis, Brigham Young University, Provo, UT. 118 pp.
- 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.
- Graham, E. H. 1937. Botanical studies in the Uinta Basin of Utah and Colorado. Annals of the Carnegie Museum 26:28-432.
- Harper, K. T., and R. A. Jaynes. 1986. Some edaphic and compositional characteristics of Artemisia tridentata and associated plant communities in southeastern Utah. Pages 265-272 in: E. D. McArthur and B. L. Welch, compilers. Proceedings-Symposium on the Biology of Artemisia and Chrysothamnus, 9-13 July, Provo, UT. General Technical Report INT-200. USDA Forest Service, Intermountain Research Station, Ogden, UT.
- Ibrahim, K. M., N. E. West, and D. L. Goodwin. 1972. Phytosociological characteristics of perennial Atriplex-dominated vegetation of southeastern Utah. Vegetatio 24:13-22.
- Potter, L. D., R. C. Reynolds, Jr., and E. T. Louderbough. 1985. Mancos shale and plant community relationships: Analysis of shale, soil, and vegetation transects. Journal of Arid Environments 9:147-165.
- Shantz, H. L. 1925. Plant communities in Utah and Nevada. Pages 15-23 in: I. Tidestrom. Flora of Utah and Nevada. Contributions of the U.S. National Herbarium 25, Washington, DC.
- West, N. E., and K. I. Ibrahim. 1968. Soil-vegetation relationships in the shadscale zone of southeastern Utah. Ecology 49(3):445-456.