Print Report
A3203 Gutierrezia sarothrae - Gutierrezia microcephala Dwarf-shrubland Alliance
Type Concept Sentence: This alliance represents shrub and shrub herbaceous vegetation of the Colorado Plateau and southern Rocky Mountains with shrub layers most often dominated by Gutierrezia sarothrae with an open to dense herbaceous layer composed of perennial graminoids.
Common (Translated Scientific) Name: Broom Snakeweed - Threadleaf Snakeweed Dwarf-shrubland Alliance
Colloquial Name: Snakeweed Dwarf-shrubland
Hierarchy Level: Alliance
Type Concept: The vegetation is characterized by an open (10-30% cover) woody layer dominated by Gutierrezia sarothrae with a sparse to luxuriant perennial graminoid layer. Atriplex canescens and Krascheninnikovia lanata may codominate the shrub layer in some stands. Other shrub associates may include Artemisia tridentata, Ephedra viridis, Eriogonum corymbosum, Ericameria nauseosa, Fallugia paradoxa, Isocoma drummondii, and Opuntia spp. Trees are absent or represented by scattered individuals of Juniperus monosperma or Pinus edulis, mostly as seedlings or saplings. The most common dominant graminoids include Bouteloua gracilis, Bouteloua eriopoda, Elymus elymoides, Pleuraphis jamesii, and Sporobolus airoides. Other herbaceous associates include Aristida purpurea, Hesperostipa comata, Muhlenbergia porteri, Pleuraphis rigida, Sphaeralcea coccinea, and Sporobolus cryptandrus. Introduced species such as Bromus tectorum or Salsola kali may dominate the herbaceous layer of some disturbed stands. This alliance represents shrub and shrub herbaceous vegetation of the Colorado Plateau and southern Rocky Mountains. It most commonly occurs on level to gently sloping sites, including gently rolling mesatops, terraces, hillslopes, plateaus, sand deposits, bluffs and occasionally along canyon footslopes on sites with moderate solar exposure. Elevation ranges from 1300 to 2230 m.
Diagnostic Characteristics: Gutierrezia sarothrae or Atriplex obovata have 10-25% cover with an herbaceous layer composed of Bouteloua gracilis, Pleuraphis jamesii, Sporobolus airoides, or Sporobolus cryptandrus.
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 has a sparse to dense layer of microphyllous evergreen shrubs (<2 m tall) with a sparse to moderately dense herbaceous layer dominated by perennial medium-tall and short grasses. Perennial forbs are sparse. Annual forbs and grasses may be present seasonally.
Floristics: The vegetation is characterized by an open (10-30% cover) woody layer dominated by Gutierrezia sarothrae with a sparse to luxuriant perennial graminoid layer. Atriplex canescens and Krascheninnikovia lanata may codominate the shrub layer in some stands. Other shrub associates may include Artemisia tridentata, Ephedra viridis, Eriogonum corymbosum, Ericameria nauseosa, Fallugia paradoxa, Isocoma drummondii, and Opuntia spp. Trees are absent or represented by scattered individuals of Juniperus monosperma or Pinus edulis, mostly as seedlings or saplings. The most common dominant graminoids include Bouteloua gracilis, Bouteloua eriopoda, Elymus elymoides, Pleuraphis jamesii, and Sporobolus airoides. Other graminoids may include Aristida purpurea, Hesperostipa comata, Muhlenbergia porteri, Pleuraphis rigida (= Hilaria rigida), and Sporobolus cryptandrus. Introduced species such as Bromus tectorum or Salsola kali may dominate the herbaceous layer of some disturbed stands. Other types of herbaceous species are not consistent, but may include Chamaesyce spp., Opuntia phaeacantha, Opuntia polyacantha, and Sphaeralcea coccinea.
Dynamics: Grazing has significantly impacted much of the vegetation in this region, which has had a long history of settlement and heavy livestock use. With proper livestock management and time, palatable species such as Krascheninnikovia lanata and Sporobolus airoides may increase, and Gutierrezia sarothrae and Opuntia spp. may decline in abundance (Francis 1986).
Environmental Description: This alliance most commonly occurs on level to gently sloping sites, including gently rolling mesatops, terraces, hillslopes, plateaus, sand deposits, bluffs and occasionally along canyon footslopes on sites with moderate solar exposure. Elevation ranges from 1300 to 2230 m. Aspects are reported from the southeast, south and southwest. Soils are variable and range from sandy to clayey texture and may occur over gravel, cinders and cobbles or talus.
Geographic Range: This alliance is known from the Colorado Plateau and southern Rocky Mountains.
Nations: US
States/Provinces: AZ, CA, NM, UT
Plot Analysis Summary:
http://vegbank.org/natureserve/ELEMENT_GLOBAL.2.899327
Confidence Level: Low
Confidence Level Comments: No Data Available
Grank: GNR
Greasons: No Data Available
Concept Lineage: This alliance is a combination of Sporobolus airoides - (Pleuraphis jamesii) Shrub Herbaceous Alliance (A.1532), Bouteloua eriopoda Microphyllous Evergreen Shrub Herbaceous Alliance (A.1545) Gutierrezia (microcephala, sarothrae) Dwarf-shrubland Alliance, and Bouteloua gracilis Dwarf-shrub Herbaceous Alliance (A.1571).
Predecessors: No Data Available
Obsolete Names: No Data Available
Obsolete Parents: No Data Available
Synonomy: = Gutierrezia (microcephala, sarothrae) Shrubland Alliance (Evens et al. 2014)
= Gutierrezia sarothrae (Broom snake weed scrub) Provisional Alliance (Sawyer et al. 2009) [32.043.00]
? Grama Grass - Scrub Series (Warren et al. 1982)
= Gutierrezia sarothrae (Broom snake weed scrub) Provisional Alliance (Sawyer et al. 2009) [32.043.00]
? Grama Grass - Scrub Series (Warren et al. 1982)
- Evens, J. M., K. Sikes, D. Hastings, and J. Ratchford. 2014. Vegetation alliance descriptions for Lake Mead National Recreation Area, Death Valley National Park and Mojave National Preserve. Unpublished report submitted to USDI National Park Service, Mojave Desert Network Inventory and Monitoring Program. California Native Plant Society, Sacramento, CA.
- 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.
- Francis, R. E. 1986. Phyto-edaphic communities of the Upper Rio Puerco Watershed, New Mexico. Research Paper RM-272. USDA Forest Service, Rocky Mountain Forest and Range Experiment Station, Fort Collins, CO. 73 pp.
- Sawyer, J. O., T. Keeler-Wolf, and J. Evens. 2009. A manual of California vegetation. Second edition. California Native Plant Society, Sacramento CA. 1300 pp.
- Warren, P. L., K. L. Reichhardt, D. A. Mouat, B. T. Brown, and R. R. Johnson. 1982. Vegetation of Grand Canyon National Park. Cooperative National Park Resources Studies Unit Technical Report 9. Tucson, AZ. 140 pp.