The Upper Sevier Watershed Assessment for Major Vegetation Types, January 2000, estimates that, when compared to historical vegetation patterns, 60% of quaking aspen within the watershed has been replaced with mixed conifer vegetation types. In a proper functioning aspen structure there are grasses/forbs, saplings and young aspen; whereas an old aspen stand is dominated by mixed conifer, with little or no understory. While it is obvious that a lack of grasses/forbs results in less forage for wildlife and livestock, and increased erosion within the watershed, it is not so obvious that such conditions result in greater susceptibility to insects and disease, reducing tree vigor and causing tree mortality.

As forest resource personnel study and analyze these changes, they find that the normal fire return interval of 20 to 100 years in aspen communities, has been interrupted by fire suppression efforts throughout much of the western United States *(Bartos, 1988). The fact that fire is an important disturbance factor in aspen and is necessary for aspen regeneration, as well as to keep mixed conifer communities in check, is a large problem now being addressed by various land management agencies.

*Bartos, Dale L. and Campbel, R.B. (1988). Decline of Quaking Aspen in the Interior West – Examples from Utah, Rangelands, 20(1): 17-24. (As cited in: 1999. Natural Inquirer. Quaking in Their Roots: The Decline of Quaking Aspen, 2(1): 5-9). [Online]. Available: at the Natural Inquirer. [September 24, 2002].

Land management agencies are concerned about the loss of historic aspen stands, and have implemented prescribed fire projects like the Mt. Dutton prescribed burn, to improve wildlife forage and habitat.