Skip to main content

U.S. Forest Service

Douglas-fir - Mixed Conifer Forests

Douglas-fir – mixed conifer forest. Douglas-fir – mixed conifer forests will form closed canopy stands in areas with no recent disturbance. Photo by Charlie McDonald.

Forest openings. Forest openings are a sign of past disturbance or perhaps areas like bogs that will not support trees. Photo by Charlie McDonald.

These forests occur at elevations of 6,000-8,800 feet. The species have strong connections with the Rocky Mountains. Tree cover is at least 50 percent, but often 80 percent in favorable habitats. As the name implies, this community seldom forms stands of a single species. Douglas-fir (Pseudotsuga menziesii), white fir (Abies concolor), New Mexico locust (Robinia neomexicana), Bigtooth maple (Acer grandidentatum), and southwestern white pine (Pinus strobiformis) are the most important species in mature stands. Arizona pine (Pinus arizonica), Gambel oak (Quercus gambelii), silverleaf oak (Q. hypoleucoides), hoptree (Ptelea trifoliata), aspen (Populus tremuloides), and pointleaf manzanita (Arctostaphylos pungens) occur in stands with past disturbance. These forests are found most extensively in the Pinaleno, Chiricahua, Santa Catalina, and Huachuca mountains, with isolated stands in some of the other higher mountain ranges.

typical mixed conifer understory. This is typical mixed conifer understory. Photo by Charlie McDonald.

small patch of old growth ponderosa pines within a mixed conifer forest. This is a small patch of old growth ponderosa pines within a mixed conifer forest. Photo by Charlie McDonald.

This mixed conifer forest burned in 2003. This mixed conifer forest burned in 2003. Aspens that can regenerate from root sprouts are replacing the dead conifers. Photo by Charlie McDonald.

This mixed conifer forest burned in 2004.. This mixed conifer forest burned in 2004. Shrubs like beechleaf buckthorn (Frangula betulifolia) are filling the open space. It will probably be many decades before the conifers return. Photo by Charlie McDonald.

bigtooth maple. Hardwood trees like bigtooth maple are more prominent in cool damp canyons than on exposed hillsides. Photo by Charlie McDonald.

Douglas-fir cones. Douglas-fir cones are very distinctive. They have bracts that look like the back legs and tails of little mice sticking out between the cone scales. Photo by Charlie McDonald.

Further Reading

Bennett, P.S., M.R. Kunzmann and L.A. Graham. 2004. Descriptions of Arizona vegetation represented on the gap vegetation map. (PDF)