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Hordeum brachyantherum

meadow barley

Vegetation Composition: Hordeum brachyantherum typically forms a continuous layer with cover ranging from 25% to near 100%. Cover of graminoid associates varies and may include Carex douglasii, C. microptera, C. athrostachya, Agropyron trachycaulum, Deschampsia cespitosa, Poa nevadensis, Eleocharis palustris, and/or Poa pratensis. The forb cover is very sparse and is characterized by Aster spp., Epilobium spp., Mimulus guttatus, Iris missouriensis, and Rumex crispus (Manning and Padgett 1995).

Classification Comments: This association has been quantitatively defined by Manning and Padgett (1995) from eastern and northern Nevada, supplemented with one plot and one observation from southern Idaho. The Poa nevadensis plant association is closely related to this plant association. According to Manning and Padgett (1995), if a stand in which both species occur is clearly dominated by Poa nevadensis it is placed in the Poa nevadensis plant association. If they have more or less equivalent cover, the stand is placed in the Hordeum brachyantherum plant association. Their observations suggest that the site conditions must be fairly moist for the Hordeum brachyantherum type, while they are usually much drier for the Poa nevadensis type.

Environment: This plant association is known from the mountains, where it occurs at elevations ranging from 5,600 to 8,800 feet. It occurs along streams or in meadows (mostly), in valley bottoms that range from very narrow to very wide and have low to moderate gradients. Two sites in Nevada were along C3 and B3 stream channels (Manning and Padgett 1995). The Idaho sites are near headwater springs.

Soils: All soils sampled in Nevada had thick mollic epipedons and, therefore, were all Mollisols. Soil particle size classes were clayey, silty, or fine-loamy. The depth to the water table in Nevada was greater than three feet (Manning and Padgett 1995). Soils at the Idaho site were seasonally to semi-permanently saturated.

Management Considerations: Hordeum brachyantherum has low to moderate resource value rating for all livestock and a high rating for mule deer in the spring. Because of its tufted habit, H. brachyantherum has a low to moderate potential for streambank stabilization. Heavy livestock grazing will result in the replacement of this type with other less desirable types. In addition, surface soil compaction from livestock is probable in this association due to the typically fine-textured particle size and moist condition (Manning and Padgett 1995).

Successional Dynamics: Manning and Padgett (1995) suggest that Hordeum brachyantherum is an early seral species that can be replaced by other native mesic graminoids if left undisturbed. However, one of the stands sampled in Idaho is within an exclosure that has been in place from between 30 and 50 years. It can maintain dominance with grazing, although excessive use will lower vigor and cover, and increase cover of various Aster spp., Potentilla gracilis, and/or Juncus balticus. The H. brachyantherum plant association typically occurs on sites similar to the Agrostis stolonifera type and has seral status similar to the Poa nevadensis plant association. Poa nevadensis and H. brachyantherum are often present together and may codominate in some places in Nevada (Manning and Padgett 1995).

Wildlife Functions: Hordeum brachyantherum is only moderately palatable to livestock and big game with palatability declining in the latter part of the growing season. Small mammals and waterfowl may make limited use of H. brachyantherum leaves and seeds for food (Elzinga and Rosentreter 1998).

Distribution: Manning and Padgett (1995) described this association from widely scattered locations in western, central, and northern Nevada. It has been sampled in the Owyhee Mountains of southwestern Idaho, at a spring fed wetland on a terrace above the middle Snake River of central Idaho, and in a spring fed meadow in the Sublette Range of southeast Idaho.

References:

Elzinga, C., and R. Rosentreter. 1998. Draft Riparian and wetland plants of the Intermountain West. Unpublished draft distributed for review by Alderspring Ecological Consulting. Tendoy, ID.

Manning, M. E., and W. G. Padgett. 1995. Riparian community type classification for the Humboldt and Toiyabe National Forests, Nevada and eastern California. USDA Forest Service R4-ECOL-89-01. Intermountain Region, Ogden, UT. 274 pp.

Author/Date(Update): R. K. Moseley/1998-12-08(2001-01-05)