Common (Translated Scientific) Name: Bebb''s Willow / Mesic Graminoids Wet Shrubland

Colloquial Name: No Data Available

Hierarchy Level:  Association

Type Concept: This shrubland is a broadly distributed but infrequently occurring association confirmed from high plateaus and canyonlands of southern Utah, central Nevada, and both the northern panhandle and southern Idaho. It occurs in western Montana and in lower elevation valleys of western and central Colorado, and in other areas where Salix bebbiana-dominated stands form (e.g., Arizona, New Mexico, Washington, and Wyoming). Because of this broad distribution, elevations for this occurrence range from as low as 640 m (2100 feet) in northern Idaho to at least 2805 m (9200 feet) in the southern Rocky Mountains. This association often occurs on well-developed alluvial soils found along low- to moderate-gradient streams, ranging from intermittent streams to broad valley floodplains of higher order systems. Landforms are also variable, including alluvial terraces, subirrigated lower slopes (e.g., springs), and abandoned oxbows. Stands are typically characterized by an open to dense overstory of mature Salix bebbiana, occasionally mixed with other Salix spp., with shorter Ribes inerme frequently present at the bases of willow clumps. The herbaceous understory is dominated by a mixture of at least several native mesic graminoids, often in combination with some exotic grasses and various mesic forbs. The most frequently occurring and often also the most abundant native mesic graminoids include Bromus ciliatus, Calamagrostis canadensis, several Carex species, including Carex nebrascensis, Carex praegracilis, and Carex utriculata, Eleocharis palustris, and several Juncus species, such as Juncus arcticus ssp. littoralis and Juncus ensifolius. Exotic grasses, especially Agrostis stolonifera and Poa pratensis, are nearly always present with variable cover. Forb species cover ranges from low to high with the most common species being Aconitum columbianum, Actaea rubra, Asteraceae spp., Equisetum arvense, Galium triflorum, Geranium richardsonii, Taraxacum officinale, and Trifolium spp.

Diagnostic Characteristics: No Data Available

Rationale for Nominal Species or Physiognomic Features: No Data Available

Classification Comments: Classification of this association is based on only 8 stands sampled in Utah (Padgett et al. 1989). Stands of this association are likely included within the broader Salix bebbiana association described by Hansen et al. (1995) in Montana, Hansen and Hall (2002) in eastern Idaho, and Carsey et al. (2003a) in Colorado. In Nevada, stands matching this type have been lumped within a general Salix / Mesic graminoid association in which various Salix species, including Salix bebbiana, are all common (Manning and Padgett 1995, Weixelman et al. 1996). These broader types are very similar to Salix bebbiana / Mesic graminoids in both understory shrub composition and the high cover of exotic grass species in the herbaceous layer. However, the broader Salix bebbiana association has much higher shrub cover and diversity, as well as a more variable mix of exotic grass species, combined with native mesic graminoids, compared to the Salix bebbiana / Mesic graminoids association. It also seems to have higher forb cover than Salix bebbiana / Mesic graminoids. The break between these two associations is not always clear and seems to be based on the judgment of those classifying stands. For example, in Idaho, stands of Salix bebbiana dominated by exotic grasses and inclusive of higher cover of other shrubs (e.g., Cornus sericea) were included under the broader Salix bebbiana type, while stands dominated by a mix of native mesic graminoids were considered Salix bebbiana / Mesic graminoids. On-going classification work in Idaho may provide additional information regarding classification of Salix bebbiana associations.

Similar NVC Types: No Data Available

note: No Data Available