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A3139 Ephedra aspera Scrub Alliance
Type Concept Sentence: These sparse semi-desert shrublands are dominated by a short-shrub layer of Ephedra aspera often with an herbaceous layer consisting of mixed grasses. They occur in Grand Canyon National Park in Arizona south to the Sonoran Desert.
Common (Translated Scientific) Name: Rough Joint-fir Scrub Alliance
Colloquial Name: Arizona Joint-fir Scrub
Hierarchy Level: Alliance
Type Concept: Vegetation in this shrubland alliance is characterized by a sparse to moderate cover of xeromorphic short shrubs and sparse to moderately dense herbaceous cover. The shrub layer is dominated by Ephedra aspera often with Encelia farinosa and Gutierrezia sarothrae and less commonly with Acacia greggii, Bernardia myricifolia, and Ferocactus cylindraceus. The sparse to moderately dense understory is dominated by graminoids such as Muhlenbergia porteri, Pleuraphis jamesii, Achnatherum speciosum, Aristida purpurea, Dasyochloa pulchella, and annual Vulpia octoflora. Acourtia wrightii, Artemisia ludoviciana, Galium stellatum, Machaeranthera pinnatifida, and Sphaeralcea grossulariifolia are common forbs. Exotic species such as Erodium cicutarium and Bromus rubens occur in many stands. This semi-arid shrubland alliance occurs in Arizona in the Grand Canyon National Park and likely in the Sonoran Desert. Stands most typically occur on sideslopes at 600 to 1100 m elevation, but can be found as high as 1650 m, or rarely in drainages and valley bottoms at 675 to 950 m. It is primarily found on moderate to steep (15-40°), north- to east-facing slopes, but also occasionally occurs on gentler slopes (8-15°). Soils are well- to rapidly-drained silty or sandy loams that occasionally contain clay. The soils typically obscure various underlying bedrock types. The diagnostic and dominant species Ephedra aspera occurs in the Sonoran, Colorado, and Chihuahuan deserts, but the alliance has not been reported from there. Additional survey and classification work are needed to fully characterize this alliance across its full range.
Diagnostic Characteristics: Diagnostic of this shrubland alliance is total vegetation cover over 25% that is dominated by Ephedra aspera.
Rationale for Nominal Species or Physiognomic Features: No Data Available
Classification Comments: This alliance concept was split from the former Ephedra (fasciculata, nevadensis) Shrubland Alliance (A.857). Ephedra fasciculata is being considered as its own alliance now under the currently accepted name of Ephedra aspera Engelm. ex S. Watson, which according to USDA Plants includes Ephedra clokeyi Cutler, Ephedra fasciculata A. Nelson, Ephedra nevadensis S. Watson var. aspera (Engelm. ex S. Watson) L.D. Benson, and Ephedra reedii Cory (USDA NRCS 2014). Ephedra aspera occurs on dry rocky slopes, ravines, and fans at 500-1800 m in Arizona, southern California, southern New Mexico, west Texas; and northern Mexico in the Sonoran, Colorado and Chihuahuan deserts (FNA Editorial Committee 1993). The related shrub Ephedra nevadensis is prominent in the Mojave Desert and Great Basin.
Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: Stands in this shrubland alliance are dominated by sparse to moderate cover of xeromorphic evergreen, microphyllous and broad-leaved shrubs.
Floristics: Vegetation in this shrubland alliance is characterized by a sparse to moderate cover of xeromorphic short shrubs and sparse to moderately dense herbaceous cover. The shrub layer is dominated by Ephedra aspera (= Ephedra fasciculata) often with Encelia farinosa and Gutierrezia sarothrae and less commonly with Acacia greggii, Bernardia myricifolia, and Ferocactus cylindraceus (Reid and Hall 2010). The sparse to moderately dense understory is dominated by graminoids such as Muhlenbergia porteri, Pleuraphis jamesii, Achnatherum speciosum, Aristida purpurea, Dasyochloa pulchella, and annual Vulpia octoflora. Acourtia wrightii, Artemisia ludoviciana, Galium stellatum, Machaeranthera pinnatifida, and Sphaeralcea grossulariifolia are common forbs. Exotic species such as Erodium cicutarium and Bromus rubens occur in many stands.
Dynamics: No Data Available
Environmental Description: This semi-arid shrubland alliance occurs in Arizona in the Grand Canyon National Park and likely in the Sonoran Desert. Stands most typically occurs on sideslopes at 600 to 1100 m elevation, but can be found as high as 1650 m., or rarely in drainages and valley bottoms at 675 to 950 m (Reid and Hall 2010). It is primarily found on moderate to steep (15-40°), north- to east-facing slopes, but also occasionally occurs on gentler slopes (8-15°). Soils are well- to rapidly-drained silty or sandy loams that occasionally contain clay (Reid and Hall 2010). The soils typically obscure various underlying bedrock types. The diagnostic and dominant species Ephedra aspera occurs in the Sonoran, Colorado, and Chihuahuan deserts, but the alliance has not been reported from there. Additional survey and classification work are needed to fully characterize this alliance across its full range.
Geographic Range: This alliance is documented only from Grand Canyon National Park, but it likely occurs in the Sonoran, Colorado, and Chihuahuan deserts.
Nations: US
States/Provinces: AZ
Plot Analysis Summary:
http://vegbank.org/natureserve/ELEMENT_GLOBAL.2.899264
Confidence Level: Low
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.1 Yellow Rabbitbrush - Blackbrush / Indian Ricegrass Dry Shrubland & Grassland Macrogroup | M171 | 3.B.1.Ne.1 |
| Group | 3.B.1.Ne.1.a Joshua Tree - Eastern Mojave Buckwheat - Rough Joint-fir Mixed Desert Scrub Group | G296 | 3.B.1.Ne.1.a |
| Alliance | A3139 Rough Joint-fir Scrub Alliance | A3139 | 3.B.1.Ne.1.a |
| Association | CEGL005084 Rough Joint-fir / Mixed Semi-Desert Grasses Shrubland | CEGL005084 | 3.B.1.Ne.1.a |
| Association | CEGL005090 Rough Joint-fir Shrubland | CEGL005090 | 3.B.1.Ne.1.a |
Concept Lineage: This alliance concept was split from the former Ephedra (fasciculata, nevadensis) Shrubland Alliance (A857).
Predecessors: No Data Available
Obsolete Names: No Data Available
Obsolete Parents: No Data Available
Synonomy: > Ephedra fasciculata / Mixed Semi-Desert Grasses Shrubland (CEGL005084) (Reid and Hall 2010)
> Ephedra fasciculata Shrubland (CEGL005090) (Reid and Hall 2010)
= Ephedra fasciculata Shrubland Alliance (Reid and Hall 2010) [Alliance is based of the two Ephedra aspera shrublands]
> Ephedra fasciculata Shrubland (CEGL005090) (Reid and Hall 2010)
= Ephedra fasciculata Shrubland Alliance (Reid and Hall 2010) [Alliance is based of the two Ephedra aspera shrublands]
- FNA Editorial Committee [Flora of North America Editorial Committee], editors. 1993. Flora of North America, north of Mexico. Volume 2. Pteridophytes and gymnosperms. Oxford University Press, New York. xvi plus 475 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.
- Reid, M. S., and M. E. Hall. 2010. Vegetation classification of Grand Canyon National Park. Draft report submitted to National Park Service, Fort Collins, CO.
- USDA NRCS [Natural Resources Conservation Service]. No date. The PLANTS Database. USDA Natural Resources Conservation Service, National Plant Data Center, Baton Rouge, LA. [http://plants.usda.gov/]