What approach best prepares forest ecosystems for climate change? Adaptation options occupy a continuum of management goals related to their levels of desired change. A team of natural resource specialists and researchers developed a set of desired future conditions, objectives, and tactics for the San Juan National Forest based on three climate adaptation approaches:
RESISTANCE
maintain relatively unchanged conditions over time
Management Goal: Retain the same species composition as in pre-harvest stand, with slight reductions in white fir, and maintain all species, especially if poorly represented
Strategies & Approaches:
- thin to 60-90 ft2/acre
- maintain even and consistent spacing
- retain the same species composition as in pre-harvest stand of ponderosa pine, Douglas-fir, and aspen, with a slight reduction in white fir
- retain stand structure to resist the increase of growing space for shrub components and the likelihood of creating a new cohort of conifers that would act as ladder fuels to the existing co-dominants and dominants in the stands
RESILIENCE
allow some change in current conditions, but encourage eventual return to original conditions
Management Goal: Heavily favor fire-adapted and drought tolerant species across all size classes and create openings in the stand
Strategies & Approaches:
- thin to 60-80 ft2/acre
- create high variability in spacing with openings up to 1 acre
- expand openings off of existing natural openings in the stand structure
- retain trees in closely spaced legacy groups with multiple size classes and species
- increase drought-tolerant and fire-adapted species (ponderosa pine and Douglas-fir)
TRANSITION
actively facilitate change to encourage adaptive responses
Management Goal: Retain the most fire-adapted and drought tolerant species
Strategies & Approaches:
- create high variability in spacing with a canopy openness target of 30-40%, average 40 ft2/acre of basal area
- increase drought-tolerant and fire-adapted species (ponderosa pine and Douglas-fir)
- maintain aspen in swales on north slopes
- remove all white fir
Each of these treatments are currently being applied and replicated 3 times across a 400-acre landscape on the San Juan National Forest. Treatments are currently marked, and harvest of the treatment units is anticipated for 2017.