Physiognomy and Structure: No Data Available

Floristics: This association is characterized by a moderately open to closed, mixed evergreen-deciduous tree canopy that is codominated by Populus tremuloides and Pinus ponderosa, but may include occasional Pinus flexilis or Pseudotsuga menziesii. Young stands typically have dense Populus tremuloides with Pinus ponderosa mixed in. As the stands age, Populus tremuloides cover is slowly reduced and Pinus ponderosa becomes dominant. The sparse to moderately dense understory may be complex and include tall-shrub, short-shrub and herbaceous layers. Because of the open growth form of Populus tremuloides, more light can penetrate the tree canopy than in a pure conifer forest. Typically the understory is denser in younger stands that are dominated by Populus tremuloides, more mesic sites and in stands with more open canopies. Conifer-dominated stands typically have sparser understories. If present, shrub layers are open to moderately dense. Juniperus communis is typically the most frequent shrub species; however, Artemisia tridentata, Mahonia repens, Prunus virginiana, Quercus gambelii, Ribes spp., Rosa woodsii, and Symphoricarpos oreophilus may be present to abundant. The sparse to moderately dense herbaceous layer is often a relatively even mixture of graminoid species, such as Bromus anomalus, Bromus porteri, Carex geyeri, Carex rossii, Elymus elymoides, Festuca idahoensis, Koeleria macrantha, Poa fendleriana, and Hesperostipa comata, and forb species such as Achillea millefolium, Astragalus miser, Erigeron speciosus, Geranium viscosissimum, Lathyrus lanszwertii var. leucanthus (= Lathyrus leucanthus), Lupinus argenteus, Penstemon watsonii, Thermopsis divaricarpa, Thermopsis montana, and Vicia americana. Introduced species Poa pratensis and Taraxacum officinale are common on disturbed sites. Annuals are typically uncommon except in heavily grazed areas.

Dynamics:  No Data Available