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CEGL001271 Grayia spinosa - Larrea tridentata Shrubland
Type Concept Sentence: No Data Available
Common (Translated Scientific) Name: Spiny Hopsage - Creosotebush Shrubland
Colloquial Name: No Data Available
Hierarchy Level: Association
Type Concept: This association is found in the central Mojave Desert, including southeastern California and central-southern Nevada, and forms an open shrub canopy (10-23% cover) that is codominated by Grayia spinosa and Larrea tridentata along with characteristic shrubs Ephedra nevadensis and Lycium andersonii. Other shrubs often present in stands include Ambrosia dumosa, Hymenoclea salsola, Krameria erecta, Krascheninnikovia lanata, Menodora scabra, Cylindropuntia acanthocarpa, Cylindropuntia ramosissima, Ericameria cooperi, Thamnosma montana, and Yucca schidigera. Herb cover is sparse (3-6% cover) with commonly associated species Achnatherum speciosum, Muhlenbergia porteri, Pleuraphis jamesii, Sphaeralcea ambigua, Sporobolus spp., and invasive exotic Bromus rubens. Occasional emergent Yucca brevifolia trees may be present with low cover (<1%). Stands are found along upper alluvial fans to rolling hillslopes in a transition zone from Larrea tridentata shrublands to mixed desert scrub at mid to upper elevations (1000-1300 m). Sites occur on flat to moderate slopes (0-11°) on variable aspects. Substrates are often gravelly with rock fragments and coarse-textured soils derived from various substrates, including basalt and rhyolite.
Diagnostic Characteristics: No Data Available
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: No Data Available
Floristics: This association forms an open shrub canopy (10-15% cover) that is codominated by Grayia spinosa and Larrea tridentata along with characteristic shrubs Ephedra nevadensis and Lycium andersonii (Evens et al. 2014). Other shrubs often present in stands include Ambrosia dumosa, Ericameria cooperi, Hymenoclea salsola, Krameria erecta, Krascheninnikovia lanata, Menodora scabra, Cylindropuntia acanthocarpa, Cylindropuntia ramosissima, Psorothamnus fremontii, Thamnosma montana, and Yucca schidigera (Ostler et al. 2000, Evens et al. 2014). Herb cover is typically sparse (3-6% cover) with commonly associated species Achnatherum speciosum, Muhlenbergia porteri, Pleuraphis jamesii, Sphaeralcea ambigua, Sporobolus spp., (Evens et al. 2014), and invasive exotic Bromus rubens. Occasional emergent Yucca brevifolia trees may be present with low cover (<1%).
Dynamics: No Data Available
Environmental Description: This shrubland association is found in the central Mojave Desert, including southeastern California and central-southern Nevada. Climate is hot and dry, although nights with temperatures below freezing do occur during winter. Stands typically receive less than 15 cm of precipitation annually, most of it occurring during winter and early spring. However, precipitation is highly variable year to year with drought common. Most of the rain falls between November and April. There is, however, a summer thunderstorm season from July to September with violent and heavy rainstorms possible. Stands are found along upper alluvial fans to rolling hillslopes in a transition zone from Larrea tridentata shrublands to mixed desert scrub at mid to upper elevations (1000-1300 m) (Evens et al. 2014). Sites occur on flat to moderate slopes (0-11°) on variable aspects. Substrates are often gravelly with rock fragments and coarse-textured soils derived from various substrates, including basalt and rhyolite (Ostler et al. 2000, Evens et al. 2014).
Geographic Range: This association is found in the central Mojave Desert and southern Great Basin in southeastern California and southern Nevada.
Nations: US
States/Provinces: CA, NV
Plot Analysis Summary:
http://vegbank.org/natureserve/ELEMENT_GLOBAL.2.686128
Confidence Level: Low - Poorly Documented
Confidence Level Comments: No Data Available
Grank: G5
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 | A4245 Nevada Joint-fir - Water Jacket - Spiny Hopsage Scrub Alliance | A4245 | 3.B.1.Ne.1.a |
| Association | CEGL001271 Spiny Hopsage - Creosotebush Shrubland | CEGL001271 | 3.B.1.Ne.1.a |
Concept Lineage: No Data Available
Predecessors: No Data Available
Obsolete Names: No Data Available
Obsolete Parents: No Data Available
Synonomy: = Grayia spinosa - Larrea tridentata (Keeler-Wolf and Thomas 2000) [deep well-drained soils versus shallow, less alkaline soils.]
= Grayia spinosa - Larrea tridentata (Sawyer et al. 2009) [33.180.03]
= Grayia spinosa - Larrea tridentata Shrubland (Evens et al. 2014)
>< Larrea - Grayia - Lycium plant association (Beatley 1976) [occurs on upper bajadas in Desert Transition Region.]
= Larrea - Lycium - Grayia plant association (Beatley 1976) [occurs on bajadas in Mojave Desert Region.]
= Larrea - Lycium - Grayia plant association (Ostler et al. 2000)
= Grayia spinosa - Larrea tridentata (Sawyer et al. 2009) [33.180.03]
= Grayia spinosa - Larrea tridentata Shrubland (Evens et al. 2014)
>< Larrea - Grayia - Lycium plant association (Beatley 1976) [occurs on upper bajadas in Desert Transition Region.]
= Larrea - Lycium - Grayia plant association (Beatley 1976) [occurs on bajadas in Mojave Desert Region.]
= Larrea - Lycium - Grayia plant association (Ostler et al. 2000)
- Beatley, J. C. 1976. Vascular plants of the Nevada Test Site and central-southern Nevada: Ecological and geographic distributions. Technical Information Center, Energy Research and Development Administration. TID-26881. Prepared for Division of Biomedical and Environmental Research. 297 pp.
- 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.
- Bradley, W. G. 1967. A geographical analysis of the flora of Clark County, Nevada. Journal of the Arizona Academy of Science 4(3):151-162.
- 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.
- Keeler-Wolf, T., and K. Thomas. 2000. Draft descriptions of vegetation alliances for the Mojave Ecosystem Mapping project. California Natural Diversity Database, California Department of Fish and Game, Sacramento.
- Ostler, W. K., D. J. Hansen, D. C. Anderson, and D. B. Hall. 2000. Classification of vegetation on the Nevada Test Site. DOE/NV/11718-477. U.S. Department of Energy, Bechtel Nevada Ecological Services, Las Vegas, NV. 102 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.
- Western Ecology Working Group of NatureServe. No date. International Ecological Classification Standard: International Vegetation Classification. Terrestrial Vegetation. NatureServe, Boulder, CO.