In Utah, the mountain-shrub landscape consists primarily of Gambel oak (Querqus gambelii, Nutt.), curlleaf mountain-mahogany (Cercocarpus ledifolius, Nutt.), true or alderleaf mountain-mahogany (C. montanus, Raf.), littleleaf mountain-mahogany (C. intricatus, S. Wats.), and bigtooth maple (Acer grandidentatum, Nutt.). The maple-oak woodlands usually occur between 5,500 and 7,800 feet elevation in Utah while the mountain-shrub group grades into coniferous forest types between 6,200 and 9,400 feet. Gambel oak can occur as a small tree, a dense shrub thicket, a clump of shrubs, or as a low shrub under another association, such as ponderosa pine. It usually occurs as a low growing tree, and these oak woodlands provide wildlife habitat and protection from soil erosion. The mountain-mahoganies exist as shrubs or small trees and they occupy the drier, steeper slopes of the interior west. The mountain-shrub type occupies approximately 1.2 million acres in Utah.

Gambel oak, true mountain-mahogany, and bigtooth maple zones are considered pretty much fire resistant. However, because many dead branches persist in the crown and its leaves are slightly resinous, curlleaf mountain-mahogany is considered flammable. Fire history studies for mountain-shrub communities are lacking; however, the effect of fire on the various species is known. Historically fire was an integral part of the maintenance and function for the majority of ecosystems in Utah. In the mountain-shrub types, fires probably spread from adjacent communities during dry years. Although mountain-shrub sites are productive and frequently have large amounts of live and woody fuels, moist conditions generally inhibit fire spread.

The mountain-shrub group is very important to wildlife species, in the form of browse, mast or forage, and cover. The range of mountain-shrub has been shrinking due to fire exclusion and overgrazing by both wild and domestic ungulates. The pinyon-juniper and sagebrush types have encroached into the mountain-shrub communities where historically, fires would have prevented their spread. From historical to current values, there has been a decrease in mountain-shrub communities in Utah. Estimates for this decrease range from 3-17%.

1. Ecologist, USDA Forest Service, Fishlake National Forest, Richfield, UT. Brown is located at the Tonto N.F., Mesa Ranger District. 5140 E. Ingram St., Mesa, AZ 85205.
2. Research Ecologist, USDA Forest Service, Rocky Mountain Research Station, Ft. Collins, CO. Bartos is located at the Forestry Science Lab. 860 N. 1200 E., Logan, UT 84321.