Print Report
A1247 Nassella cernua Grassland Alliance
Type Concept Sentence: This native California bunchgrass alliance is dominated by Nassella cernua. This once-extensive bunchgrass occurs in California''s valleys and foothills on deep soils with a high clay content. Stands typically include many exotic annual grasses.
Common (Translated Scientific) Name: Nodding Needlegrass Grassland Alliance
Colloquial Name: Californian Nodding Needlegrass Grassland
Hierarchy Level: Alliance
Type Concept: This native California bunchgrass alliance is dominated by Nassella cernua. Other graminoids present may include Aristida ternipes, Elymus glaucus, Festuca californica, Koeleria macrantha, Leymus triticoides, Melica californica, and Poa secunda. Stands typically include many exotic annuals, such as Avena barbata, Avena fatua, Bromus diandrus, Bromus madritensis, Bromus hordeaceus, and Lolium perenne ssp. multiflorum. Emergent trees and shrubs may be present, particularly the oak Quercus douglasii. Plant cover tends to be open. Nassella cernua tends to occur in drier areas than does Nassella pulchra. Stands appear more commonly in the transition between coastal/valley grasslands and inland/desert steppes. This once-extensive bunchgrass alliance of California''s valleys and foothills occurs on deep soils with a high clay content. It does not occur above 1400 m of elevation. The native California bunchgrasses are adapted to a Mediterranean climate with moist, cool winters and long, dry summers. Precipitation varies from 25-70 cm per year, and falls mostly between November and April.
Diagnostic Characteristics: No Data Available
Rationale for Nominal Species or Physiognomic Features: No Data Available
Classification Comments: This alliance is based on the Sawyer et al. (2009) alliance of the same name, and much of the material is drawn from their description. Stands appear more commonly in the transition between coastal/valley grasslands and inland/desert steppes. For example, Nassella cernua and Achnatherum speciosum replace Nassella pulchra and Leymus triticoides in the transition between the eastern desert slopes of southern California mountains and the valley grassland (Bartolome et al. 2007).
Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: This medium-tall, temperate or subpolar, bunch grassland forms an open canopy less than 1 m in height. Emergent trees and shrubs may be present.
Floristics: This native California bunchgrass alliance is dominated by Nassella cernua. Other graminoids present may include Aristida ternipes, Elymus glaucus, Festuca californica, Koeleria macrantha, Leymus triticoides, Melica californica, Nassella lepida, Nassella pulchra, and Poa secunda. Many exotic annuals, such as Avena barbata, Avena fatua, Bromus diandrus, Bromus madritensis, Bromus hordeaceus, and Lolium perenne ssp. multiflorum (= Lolium multiflorum), have invaded stands of this alliance. Emergent trees and shrubs may be present, particularly the oak Quercus douglasii. Plant cover tends to be open.
Dynamics: Grazing and fire are important in maintaining these grassland communities, though uncertainty still exists concerning the optimum grazing type and intensity. Reduction in fire frequency has favored introduced annual grasses over native perennial bunchgrasses.
Environmental Description: This once-extensive bunchgrass alliance of California''s valleys and foothills occurs on deep soils with a high clay content. Stands can occur on all topographic positions, but due to climatic factors, they do not occur over 1400 m elevation. Stands now typically include many exotic annual grasses. The native California bunchgrasses are adapted to a Mediterranean climate with moist, cool winters and long, dry summers. Precipitation varies from 25 to 70 cm per year, and falls mostly between November and April.
Geographic Range: This alliance occurs in northern, central, and southern California, and into Baja California, Mexico.
Nations: MX,US
States/Provinces: CA, MXBCN
Plot Analysis Summary:
http://vegbank.org/natureserve/ELEMENT_GLOBAL.2.899093
Confidence Level: Moderate
Confidence Level Comments: No Data Available
Grank: G4
Greasons: No Data Available
| Type | Name | Database Code | Classification Code |
|---|---|---|---|
| Class | 2 Shrub & Herb Vegetation Class | C02 | 2 |
| Subclass | 2.B Temperate & Boreal Grassland & Shrubland Subclass | S18 | 2.B |
| Formation | 2.B.1 Mediterranean Scrub & Grassland Formation | F038 | 2.B.1 |
| Division | 2.B.1.Na Californian Scrub & Grassland Division | D327 | 2.B.1.Na |
| Macrogroup | 2.B.1.Na.3 Purple Needlegrass - Harvest Brodiaea - Rusty Popcorn-flower Native Grassland Macrogroup | M045 | 2.B.1.Na.3 |
| Group | 2.B.1.Na.3.b Purple Needlegrass - California Melicgrass - Giant Wildrye Grassland Group | G496 | 2.B.1.Na.3.b |
| Alliance | A1247 Nodding Needlegrass Grassland Alliance | A1247 | 2.B.1.Na.3.b |
| Association | CEGL003121 Nodding Needlegrass Grassland | CEGL003121 | 2.B.1.Na.3.b |
Concept Lineage: A.1247
Predecessors: No Data Available
Obsolete Names: No Data Available
Obsolete Parents: No Data Available
Synonomy: = Nassella cernua (Nodding needle grass grassland) Provisional Alliance (Sawyer et al. 2009) [41.140.00]
= Nassella cernua Provisional Alliance (Nodding needle grass grassland) (Buck-Diaz et al. 2012)
= Nassella cernua Provisional Herbaceous Alliance (CNPS 2017) [41.140.00]
= Nodding needlegrass series (Sawyer and Keeler-Wolf 1995)
>< Valley Needlegrass Grassland (#42110) (Holland 1986b)
= Nassella cernua Provisional Alliance (Nodding needle grass grassland) (Buck-Diaz et al. 2012)
= Nassella cernua Provisional Herbaceous Alliance (CNPS 2017) [41.140.00]
= Nodding needlegrass series (Sawyer and Keeler-Wolf 1995)
>< Valley Needlegrass Grassland (#42110) (Holland 1986b)
- Bartolome, J. W. W. J. Barry, T. Griggs, and P. Hopkinson. 2007. Valley grassland. Pages 367-393 in: M. G. Barbour, T. Keeler-Wolf and A. A. Schoenherr. Terrestrial vegetation of California, 3rd ed. University of California Press, Berkeley.
- Buck-Diaz, J., S. Batiuk, and J. M. Evens. 2012. Vegetation alliances and associations of the Great Valley ecoregion, California. California Native Society, Sacramento, CA. [http://cnps.org/cnps/vegetation/pdf/great_valley_eco-vegclass2012.pdf]
- CNPS [California Native Plant Society]. 2015-2017. A manual of California vegetation [online]. California Native Plant Society, Sacramento, CA. [http://vegetation.cnps.org/].
- 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.
- Hamilton, J. G., J. R. Griffin, and M. R. Stromberg. 2002. Long-term population dynamics of native Nassella (Poaceae) bunchgrasses in central California. Madroño 49:274-284.
- Heady, H. F. 1988. Valley grassland. Pages 491-514 in: M. G. Barbour and J. Major, editors. Terrestrial vegetation of California. John Wiley and Sons, New York. 1002 pp.
- Holland, R. F. 1986b. Preliminary descriptions of the terrestrial natural communities of California. Unpublished report prepared for the California Department of Fish and Game, Nongame-Heritage Program and Natural Diversity Database, Sacramento. 156 pp.
- Magney, D. L. 1992. Descriptions of three new southern California vegetation types: Southern cactus scrub, southern coastal needle grass grassland, and scale-broom scrub. Crossosoma 18:1-9.
- Moran, V. 2004a. Rare plant and vegetation surveys 2002 and 2003, Santa Ysabel Ranch Open Space Preserve. Unpublished report for the County of San Diego Department of Parks and Recreation and The Nature Conservancy, San Diego, CA.
- Moran, V. 2004b. Post-cedar ecosystem and rare plant impact survey 2004, Santa Ysabel Ranch Open Space Preserve. Unpublished report for The Nature Conservancy and the County of San Diego, Grass Valley, CA.
- Paysen, T. E., J. A. Derby, H. Black, Jr., V. C. Bleich, and J. W. Mincks. 1980. A vegetation classification system applied to southern California. General Technical Report PSW-45. USDA Forest Service, USDA Forest Service, Pacific Southwest Research Station, Berkeley, CA.
- 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.
- Sawyer, J. O., and T. Keeler-Wolf. 1995. A manual of California vegetation. California Native Plant Society, Sacramento. 471 pp.
- Stoddart, L. A., A. D. Smith, and T. W. Box. 1975. Range management. McGraw-Hill Book Company, New York, NY.