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 Fall Burns – applied October 2001 Spring 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). Control Cut & fall burn Cut & 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 % 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 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