Name:
A.947
Reference:
EcoArt 2002
Description:
Plant associations within this temporarily flooded shrubland alliance are located on floodplains and gravel bars between 780-1760 m in the western U.S., and at lower elevations (to below 100 m) in the midwestern and southeastern U.S. Stands may be dominated either by ~Salix exigua$ (in the West) or ~Salix interior$ (in the Midwest and East). Both species or intermediates may occur in stands in the region where the range of the two species overlap. These shrublands are found on open sandbars without canopy shading on larger, well-developed drainages and along larger sandy rivers, or on coarser-textured substrates. They are associated with annual flooding and inundation and will grow well into the channel, where it is flooded, even in drier years. Even though flooding is frequent, surface water is not present for much of the growing season, and the water table is well below the surface. Some stands form large, wide stands on mid-channel islands on larger rivers, or narrow stringer bands on small, rocky tributaries. Stream reaches range widely from moderately sinuous and moderate-gradient reaches to broad, meandering rivers with wide floodplains or broad, braided channels. Many stands also occur within highly entrenched or eroding gullies. Soils of this alliance are typically coarse alluvial deposits of sand, silt and cobbles that are highly stratified with depth from flooding scour and deposition. The stratified profiles consist of alternating layers of clay loam and organic material with coarser sand or thin layers of sandy loam over very coarse alluvium. Occasionally, stands may occur on deep pockets of sand. The pH of the substrate ranges from 6.0-6.8. The canopy is dominated by a tall, 2- to 5-m, broad-leaved deciduous shrub that is typically many-branched with continuous cover of 60-100%. The herbaceous stratum has sparse to moderate cover including a variety of pioneering species. Plant associations within this alliance are characterized as temporarily flooded, cold-deciduous shrubland dominated by ~Salix exigua$ or ~Salix interior$. The tall-shrub layer has 15-90% cover, ranging in height between 2-5 m. Other willows can occur in the canopy including ~Salix eriocephala, Salix lutea, Salix ligulifolia$, and/or ~Salix monticola$. Occasionally taller ~Salix amygdaloides$ or ~Populus deltoides$ occur within the tree subcanopy. The herbaceous layer varies greatly over the broad range of the alliance. It typically has at least 20-35% cover of various graminoid species including ~Carex nebrascensis, Carex pellita (= Carex lanuginosa), Spartina pectinata, Phalaris arundinacea, Equisetum arvense, Panicum bulbosum$, and ~Muhlenbergia rigens$. The forb cover is usually sparse. The understory can be dominated by barren ground or gravel bar. This alliance represents an early seral, primary successional stage on newly deposited sediments that may persist under a regime of repeated fluvial disturbance. ~Salix exigua$ and ~Salix interior$ are highly adapted to most forms of disturbance. Both species are prolific sprouters and will reestablish themselves on sites dominated by other disturbance-associated species, e.g., ~Glycyrrhiza lepidota$ and ~Pascopyrum smithii (= Agropyron smithii)$. Associations in this shrubland alliance are common and widespread. ^Shrublands dominated solely by ~Salix exigua$ (~sensu stricto$) extend from the Pacific Northwest and California east into the Rocky Mountains and onto the Great Plains. Stands of possibly mixed or ambiguous composition may occur from the northern Great Plains south to the Colorado plains, possibly extending into northeastern New Mexico and the western portions of the Dakotas, Nebraska, Kansas, and Oklahoma. Examples dominated by ~Salix interior$ occur in the Midwest in Iowa, Illinois, Indiana, Ohio, and the eastern portions of North Dakota, South Dakota, Nebraska, and Kansas. They also extend into Arkansas, Tennessee, Kentucky, Texas, and eastern Oklahoma, and possibly in Pennsylvania and West Virginia, as well as in Manitoba and other provinces of Canada. In western Oklahoma and throughout the Ozarks the associations are local along major streams. In the West, adjacent upland plains communities include agricultural fields and rolling hills of ~Artemisia filifolia$, xeric tallgrass prairies, and ~Bouteloua gracilis$ shortgrass prairies. In the steep canyons of the foothills, upslope vegetation includes ~Pseudotsuga menziesii$ and ~Pinus ponderosa$ forests, ~Pinus edulis$ and ~Juniperus$ spp. woodlands, oak, sagebrush, and greasewood scrub. In the lower montane, upslope vegetation includes ~Pinus contorta$ and ~Populus tremuloides$ forests.
Accession Code:
VB.CC.2573.A947
Plot-observations of this Community Concept:
0
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