Aspen Restoration in the Western United States

Aspen Restoration in the Western United States
USDA Forest Service - Rocky Mountain Research Station

Dale Bartos
Program: RWU RMRS-4301
Logan, UT

Wayne Shepperd
Program: RWU RMRS-4451
Fort Collins, CO

* * * Special Video: Fading Gold * * *

Quaking Aspen (Populus tremuloides) communities are the most widespread, tree dominated communities in North America. Aspen ecosystems in the West produce numerous products including:

- Watershed Protection
- Water for Downstream Users
- Forage for Livestock
- Habitat for Wildlife
- Aesthetics
- Sites for Recreational Opportunities
- Wood Fiber
- Landscape Diversity

Loss , or potential loss, of aspen on these lands can be attributed primarily to successional process that occurs with the reduction (or Elimination) of fire and excessive use by ungulates.

Western aspen forests are unique because they reproduce primarily by suckering from the parent root systems with successful sexual reproduction being extremely rare.

Given a continuation of conditions (e.g. lack of fire, deer and elk use, and livestock grazing) that have prevailed for the past 100 to 150 years in the interior West, most aspen stands will be eventually be replaced by conifers, sagebrush, or possibly other tall shrub communities. Numerous areas throughout the West that were once dominated by aspen are in a late successional stage, and if treatment is going to be successful, something needs to be done soon. Many treatment alternatives (such as burning, cutting, fencing, spraying, ripping, chaining,) exist that can be used by land managers to restore aspen. In certain areas, treatments need to be pursued with caution. Excessive animal pressure must be considered in the West. Clones treated by burning and then repeatedly browsed usually only hasten their demise. Treatments to induce suckering, therefore must not be initiated before relief from excessive browsing is obtained.

Aspen dominated lands in the West have diminished from approximately 9.6 million acres since settlement. With this decline there are associated losses (e.g. water depletion - conifers use more water than aspen; less undergrowth vegetation as sites convert to conifer; changes in biodiversity such as birds, plant species, etc.) These aspen dominated regions not only provide socially acceptable landscapes, but they also hold values within ecosystems.

Given a Continuation of Conditions Such as...

Considerable wildlife use

Excessive livestock grazing

And Lack of...

Small prescribed burn at base of aspen stand

Prescribed Burning

Results in...

Conifer Invasion of Aspen

Sparse aspen stand surrounded by grassland

Grassland Invasion of Aspen

Research from a combination of research work units have provided much information needed by natural resource managers to restore aspen communities. However, it has been difficult for managers to apply that knowledge fast enough to begin the reversing the trend in loss of aspen communities.

Quaking Aspen Throughout the West Provide:

Aesthetics...
Aspen stands lining the sides of a mountain valley

Watershed Protection...
Aspen stand at the base of a mountain side covered with snow

Ecosystem Preservation...
Healthy aspen stand

For more information regarding the need for aspen restoration in the Western U.S., see these current publications, or for a more complete list from the Rocky Mountain Research Station.