Shrub-steppe early succession following invasive juniper cutting and prescribed fire

Authors: Bates, Jonathan - Jon; Davies, Kirk; SHARP, ROBERT - Bureau Of Land Management

Submitted to: Environmental Management
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/24/2011
Publication Date: 3/1/2011
Citation: Bates, J.D., Davies, K.W., Sharp, R.N. 2011. Shrub-steppe early succession following invasive juniper cutting and prescribed fire. Environmental Management. 47:468-481.

Interpretive Summary: Piñon-juniper woodland dominance of sagebrush steppe has several negative consequences including reductions in herbaceous production and diversity, decreased wildlife habitat, higher erosion and runoff potentials, and become difficult to prescribe burn because of the lack of understory fuel load. We evaluated partial cutting of the woodlands (cutting 25-50% of the trees), to increase surface fuel loads, followed by prescribed fire treatments in late successional western juniper woodlands of southwest Idaho to evaluate understory recovery. The study demonstrated that; 1) late successional western juniper woodlands can be burned after pre-cutting a portion of the trees, 2) early succession in the cut-and-burn treatments were dominated by native annual and perennial forbs, in part due to high mortality of perennial bunchgrasses, and 3) by the third year after fire the number of perennial grass seedlings establishing indicated both associations would achieve full recovery. Cutting-prescribed fire combinations are an effective means for controlling invasive juniper and restoring herbaceous plant communities, however, land managers should recognize that there are potential problems associated with cutting-prescribed fire applications when invasive weeds are present.

Technical Abstract: Piñon-juniper woodlands of the western United States have expanded in area nearly 10-fold since the late 1800’s. Woodland dominance in sagebrush steppe has several negative consequences including reductions in herbaceous production and diversity, decreased wildlife habitat, higher erosion and runoff potentials, and become difficult to prescribe burn because of the lack of understory fuels. We evaluated partial cutting of the woodlands (cutting 25-50% of the trees), to increase surface fuels, followed by prescribed fire treatments in late successional western juniper woodlands of southwest Idaho to assess understory recovery. The study was conducted in two different plant associations and evaluated what percentage of the woodland required preparatory cutting to eliminate remaining juniper by prescribed fire, determined the impacts of fire to understory species, and examined early post-fire successional dynamics. The study demonstrated that late successional western juniper woodlands can be burned after pre-cutting only a portion of the trees. Early succession in the cut-and-burn treatments were dominated by native annual and perennial forbs; in part due to high mortality of perennial bunchgrasses. By the third year after fire the number of perennial grass seedlings establishing indicated both associations would achieve full recovery. Cutting-prescribed fire combinations are an effective means for controlling invasive late successional juniper and restoring herbaceous plant communities. However land managers should recognize that there are potential problems associated with cutting-prescribed fire applications when invasive weeds are present.