Physiognomy and Structure: No Data Available

Floristics: Tall Salix boothii (usually with between 20 and 50% cover) dominates this association, and Salix geyeriana (with cover less than that of Salix boothii) is often subdominant. Various conifers, Alnus incana, Salix drummondiana, Salix lemmonii, or other tall shrubs are occasionally present with low cover. There is usually a low-shrub understory composed of Betula glandulosa and Lonicera involucrata, with Salix wolfii or Ribes spp. also sometimes present with low cover. Carex aquatilis clearly dominates the herbaceous understory, usually with between 30 and 60% cover. Other graminoid species are intermixed, each with low constancy and low cover, including Calamagrostis canadensis, Carex microptera, Carex utriculata, Deschampsia cespitosa, Juncus arcticus ssp. littoralis (= Juncus balticus), and Scirpus microcarpus. Forbs are diverse, but generally low in cover, the most common including Aconitum columbianum, Geum macrophyllum, and Polemonium occidentale.

Dynamics:  Grazing must be light and prevented until late summer to avoid compacting and damaging wet organic soils (Kovalchik 1987, Crowe and Clausnitzer 1997). Overgrazing reduces cover and vigor of both Salix boothii and Carex aquatilis and promotes other graminoids (Juncus spp., Poa pratensis) and unpalatable mesic forbs. Overgrazing tramples and breaks the soil, reduces roots and rhizomes that anchor streambanks, and allows erosional downcutting or overwidening of streams (Kovalchik 1987, Crowe and Clausnitzer 1997). Salix boothii and Carex aquatilis growth can be rejuvenated with a rest from grazing and by burning with quick, moderate-intensity fires in late summer and fall (Hansen et al. 1995). Both Salix boothii and Carex aquatilis readily resprout from roots and rhizomes, however, it takes about 5 years for the community to grow large enough to withstand grazing. These species also produce large amounts of seeds that quickly colonize fine and moist, disturbed mineral soil (Kovalchik 1987, Crowe and Clausnitzer 1997). These species are adapted to cold and flooding, though too much inundation or drought will kill them. The association is stable unless overgrazing or other disturbance reduces willow and sedge cover allowing weeds, forbs, and less palatable graminoids to increase. As disturbance-induced species, including Poa pratensis, invade, streambanks lose stability and streams downcut. The water table eventually lowers causing further changes in community composition toward drier types (Kovalchik 1987, Crowe and Clausnitzer 1997).