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Juniper Control Aspen Restoration
Aspen, Northern Great Basin
Location; Steens Mountain, Oregon
Cutting Treatment – 1/3 of mature junipers cut for developing fuels base in spring 2001.
Fall Burns – applied October 2001Spring Burn – applied April 2002
Cooperators; Bureau of Land Management, Burns, Oregon Otley Brothers, Inc., Diamond, Oregon
Aspen Restoration: Selective Juniper Cutting and Prescribed Fire
Experimental Design
5 treatment replications.
3 treatments (Control (no treatment), cut & fall burn, cut & spring burn).
ControlCut &
fall burnCut &
spring burn
Measurements:
Project has evaluated …
- Effectiveness of treatments at removing all juniper, from seedling to mature age classes.
- Aspen recruitment
- Shrub cover and density
- Understory cover, density, and diversity
Selective Cut and Fall Fire
Intense fire
September or October burns
Burned with soils dry
Higher risk of fire escape
Selective Cut and Spring Fire
Less intense fire
Late April burn
Burned with soils frozen and at field capacity
No risk of fire escape
Results
FALL BURNS
- 99.9% juniper kill
- increased aspen suckering 6 fold (10,000 ha in 2004)
- sagebrush lost, most other shrubs resprouted.
- increased bareground.
- lost most of the perennial understory except for plants with growth points below ground and with fire resistant seed.
- stimulated T&E species
Results
SPRING BURNS
- 10% of mature juniper remain.
- 50% of juniper seedlings survived. Enough to fully restock site in 70-80 years.
- Increased aspen to 5,000 ha
- Sagebrush lost only under burned trees, other shrubs resprouted or not effected.
- Understory remained largely intact. Understory cover and diversity increased 300%.
Conclusions
• Cut and Fall Burn
– most effective method for removing juniper.– greatest aspen recruitment– greater disturbance severity
• understory• hydrology
Conclusions
• Cut and Spring Burn
– less effective method for removing subcanopy and seedling juniper.
– increased aspen recruitment . . . but . . .– reduced disturbance severity
• understory• hydrology• aspen