Physiognomy and Structure: No Data Available

Floristics: This is a riparian forest association characterized by an open to moderately dense (20-60% cover), mixed deciduous-evergreen tree canopy with Populus angustifolia and Picea pungens codominant. Populus tremuloides, Picea engelmannii, Pseudotsuga menziesii, and Juniperus scopulorum are occasionally present in small amounts. The broad-leaved deciduous Populus angustifolia has 5-50% cover, and the needle-leaved evergreen tree Picea pungens has 7-50% canopy cover in most stands. The shrub layer is well-developed and is composed primarily of broad-leaved deciduous species, mostly over 2 m tall. Cornus sericea often dominates as a dense layer under the tree canopy, while Alnus incana and Betula occidentalis are abundant along streambanks (Baker 1989b, Kittel et al. 1999b, Carsey et al. 2003a). These three shrubs together consistently have 25% to over 60% cover. Other common shrubs may include Amelanchier alnifolia, Cornus sericea, Lonicera involucrata, Mahonia repens, Prunus virginiana, Rosa woodsii, Rubus idaeus ssp. strigosus, Ribes inerme, Salix monticola, and Symphoricarpos rotundifolius. Several species of Salix may occasionally be common, such as Salix ligulifolia and Salix exigua. The herbaceous layer is not as lush as some other riparian forest types, perhaps due to the dense canopy of shrubs. The most common species include the perennial forbs Actaea rubra, Equisetum arvense, Epilobium brachycarpum, Galium triflorum, Geranium richardsonii, Maianthemum stellatum (= Smilacina stellata), Heracleum maximum (= Heracleum lanatum), and Solidago canadensis. Graminoids are sparse and include Bromus ciliatus, Carex geyeri, Elymus glaucus, Glyceria striata, and Poa pratensis. Total herbaceous cover is typically less than 20%.

Dynamics:  Many stands have been altered by livestock grazing which decreases the shrub layer and increases cover of introduced plant species such as Poa pratensis and Taraxacum officinale (Baker 1986).