Physiognomy and Structure: Vegetation included in this alliance has an open to moderately dense tree canopy that is typically 2-5 m tall. Stands are solely dominated by evergreen scale-leaved trees. Scattered evergreen needle-leaved or deciduous broad-leaved trees may be present, but they never codominate. An open to moderately dense herbaceous layer dominated by perennial graminoids is present. Perennial forbs may be scattered. Annual forbs and grasses may be seasonally present.

Floristics: This alliance occurs in foothill and lower montane zones in the Rocky Mountains and extends out into the western Great Plains on escarpments. The vegetation is characterized by a patchy or open to moderately dense tree canopy 2-8 m tall that is dominated by either Juniperus scopulorum or, less commonly, Juniperus osteosperma. Scattered individuals of Pinus ponderosa or Pseudotsuga menziesii may be present in the tree canopy, but have low cover (<5%) and are never codominant. In the plains stands the deciduous broad-leaved tree Fraxinus pennsylvanica may be present. Herbaceous layers range from low to moderately dense, and are typically dominated by perennial graminoids such as Bouteloua gracilis, Hesperostipa comata, Koeleria macrantha, Piptatheropsis micrantha (= Piptatherum micranthum), Poa secunda, or Pseudoroegneria spicata. Other graminoids include Achnatherum hymenoides (= Oryzopsis hymenoides), Carex rossii, Festuca idahoensis, Leucopoa kingii (= Festuca kingii), Leymus ambiguus, and Muhlenbergia montana. Perennial forbs are sparse but may be fairly diverse. The most common forbs are Achillea millefolium, Artemisia ludoviciana, Campanula rotundifolia, Eriogonum umbellatum, Galium boreale, Helianthus pumilus, Heterotheca villosa, Heuchera bracteata, Maianthemum stellatum, Penstemon virens, Potentilla fissa, and Senecio integerrimus. The cactus Opuntia polyacantha is often present. In some stands mosses and lichens provide significant ground cover. Annual grasses and forbs are seasonally present. If shrubs are present, then cover is low (<10%) and perennial grass cover exceeds shrub cover.

Dynamics:  Woodlands in this alliance are considered to be edaphic or topographic climax communities (Hansen et al. 1984, Tiedemann et al. 1987). Juniperus scopulorum is a long-lived species. Hansen and Hoffman (1988) found most trees in stands they sampled to be over 120 years, with some individuals older than 360 years. Fire can be used to control Juniperus scopulorum stands on rangeland because the species will not resprout after being burned (Wright et al. 1979, Fischer and Bradley 1987). Young individuals are most vulnerable to fire (Wright et al. 1979, Fischer and Bradley 1987). The effect of fire on a stand is largely dependent on the tree height and density, fine fuel load on the ground, weather conditions, and season (Wright et al. 1979). Trees are more vulnerable in open stands where fires frequently occur in the spring, the humidity is low, wind speeds are over 10-20 mph, and there are adequate fine fuels to carry fire (Wright et al. 1979, Fischer and Bradley 1987). Under other conditions, burns tend to be spotty with low tree mortality. Large trees are generally not killed unless fine fuels, such as tumbleweeds, have accumulated beneath the tree to provide fuel ladders for the fire to reach the crown. Closed-canopy stands rarely burn because they typically do not have enough understory or wind to carry a fire. Altered fire regimes, cutting trees for fencing, and improper grazing by livestock have significant impacts on the quality of sites. Grazing by livestock can modify the fire regime by removing the fine fuels that carry fire. Fire, livestock grazing, and trampling by hikers and vehicles disturb cryptogamic soil crusts that help maintain soil structure, reduce soil erosion, provide habitat for plants and preserve biological diversity. More study is needed to understand and manage these woodlands.