Common (Translated Scientific) Name: Quaking Aspen / Slough Sedge Riparian Forest

Colloquial Name: No Data Available

Hierarchy Level:  Association

Type Concept: The single known occurrence of this association in Oregon is in a seasonally flooded depression on shallow-soiled basalt scabland. It may be a relict of a type that was more widespread historically. Seasonal flooding is from precipitation, but summer drying precludes formation of peat. The tree layer is dominated by Populus tremuloides with up to 50% cover. The shrub layer includes Spiraea douglasii and Salix hookeriana with covers of 80 and 10%, respectively. The sparse herb layer is dominated by only Carex obnupta with very low cover. The moss layer has up to 98% cover by Sphagnum mendocinum. Large expanses of swamp vegetation once occurred in the northern Willamette and Tualatin valleys, and this association may have been part of it. Populus tremuloides still occurs in a number of low-elevation sites in Clackamas, Multnomah and Washington counties, Oregon, but most are on uplands that do not support wetland vegetation; it becomes very rare at low elevations south of Clackamas County. These wetlands are thought to be more frequent in western Washington and perhaps extend to southwestern British Columbia but have not been sampled adequately. Spiraea douglasii and other species of Sphagnum have been observed in some stands in Washington. Despite the abundance of Spiraea douglasii in this association, Carex obnupta is used here to distinguish these low-elevation occurrences west of the Cascade Range from some Populus tremuloides / Spiraea douglasii stands reported from east of the Cascades.

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