San Juan National Forest

The San Juan National Forest is participating in a study called the Adaptive Silviculture for Climate Change (ASCC) Network. The goals of this project are to test different silvicultural approaches to climate change and forest health adaptation that will also serve as useful examples across the U.S. and Canada.

The San Juan National Forest ASCC study site was established on Jackson Mountain in Southwestern Colorado, ranging in elevation from 7,400 to 8,600 feet. The site has deep, well-drained, loamy soils, and variability in aspect with deep drainages and slopes from 0 to 35%. 

The San Juan ASCC project is located within a dry mixed conifer forest type, containing various tree species including ponderosa pine, Douglas-fir, white fir, aspen, and a shrubby component of Gambel oak. Each species has specific strategies and tolerances to cope with drought, fire, insects, and disease, and provides an excellent opportunity to test various management treatment strategies to inform future management of these forests.

Prior to 1880, the mean fire return interval for this particular site was about 24 years, and ranged from about 10-30 years for this particular forest type on the San Juan National Forest. The area was lightly logged over 50 years ago as indicated by large ponderosa pine stumps. In the mid-1970s through early 1980s, a prep cut of a two-stage shelterwood was implemented removing mainly large diameter ponderosa pine and Douglas-fir. Over the past several decades, the area has been subjected to a range of insects such as western pine beetle, fir engraver, and Douglas-fir beetle, as well as root diseases and dwarf mistletoe.

Dry-mixed conifer forest
The San Juan National Forest ASCC site is a dry mixed-conifer forest type located in southwest Colorado. Photo Credit: Mike Battaglia, USDA Forest Service, Rocky Mountain Research Station

Key Projected

Climate Change Impacts

Key projected climate change impacts that the project team considered for the San Juan National Forest include: 

  • A warming trend and increased average annual temperatures 
  • Variable precipitation patterns with decreased snowpack and earlier snowmelt and peak runoffs 
  • Increased drought that may drive fires and insect outbreaks 
  • The relative proportions of component species may change 

Climate change will present challenges and opportunities for accomplishing the management objectives of the San Juan National Forest, including:

Key projected climate change impacts were identified by the project team for the San Juan National Forest ASCC site. Photo Credit: Courtney Peterson

Challenges

  • The dense understory of white fir and Gambel oak currently acts as ladder fuels contributing to wildfire hazard in the area 
  • The forest has been subjected to a range of insects and diseases, such as western pine beetle, fir engraver, Douglas-fir beetle, root disease, and dwarf mistletoe 

Opportunities

  • Interactions of climate change, fire, drought, and insect outbreaks may lead to changes in species dominance for novel species 
  • Increasing structural heterogeneity will break up fuels and reduce the chance of large, catastrophic wildfires

Management Goals & Treatments

Resistance

Resilience

Transition

Implementation

A team of natural resource specialists from the San Juan National Forest, regional managers, and scientists came together for a three-day workshop to develop the study design for the ASCC project site. The team developed a set of Desired Future Condition statements, Objectives, and Tactics for each major climate adaptation trajectory (resistance, resilience, transition). These three trajectories are briefly summarized below:

Monitoring

Monitoring is an essential component of the ASCC study. Research partners from several institutions are working together to investigate the effectiveness of different silvicultural treatments aimed at creating adaptive ecosystems. Some of the monitoring items include: 

  • Natural regeneration in gaps and harvest areas 
  • Soil nutrients and microclimate sampling 
  • Inventory of fuels and understory plants
    Research partners are working together to investigate the effectiveness of different silvicultural treatments at the San Juan National Forest. Photo Credit: Mike Battaglia, USDA Forest Service, Rocky Mountain Research Station
    Research partners are working together to investigate the effectiveness of different silvicultural treatments at the San Juan National Forest. Photo Credit: Mike Battaglia, USDA Forest Service, Rocky Mountain Research Station

Progress & Next Steps

Each of the adaptation treatments is replicated 4 times across a 400-acre area on the San Juan National Forest. Pre-treatment forest inventory data has been collected on the study site. The treatment units have been marked for harvest and are scheduled to be cut. Future data collection will focus on tree regeneration, forest growth, and forest health. 

Site Leads & Partners

Mike Battaglia (USDA Forest Service Rocky Mountain Research Station, RMRS) is the site lead for the San Juan National Forest project and Adam Tlachac (San Juan National Forest) and Kevin Emde (San Juan National Forest) are the local site managers. Key partners include Lance Asherin (RMRS), Matt Tuten (USDA Forest Service State and Private Forestry), Paula Fornwalt (RMRS), Chuck Rhoades (RMRS), Wade Tinkham (RMRS), Zach Stell (RMRS), Anthony Culpepper (Mountain Studies Institute), and Jake Kurzweil (Mountain Studies Institute), who are working with us to complete monitoring and outreach goals. ​​​​​​​Linda Joyce (Retired, USDA Forest Service Rocky Mountain Research Station) was a key thought-leader in the development of the San Juan ASCC site.

Mike Battaglia
Site Lead

Research Forester, Rocky Mountain Research Station, USDA Forest Service Forest and Woodland Ecosystems Science Program 240 West Prospect Road Fort Collins, CO 80526 Phone: 970-498-1286 [email protected]

Adam Tlachac
Manager Lead

San Juan National Forest, USDA Forest Service 180 Pagosa Street P.O. Box 310 Pagosa Springs, CO 81147 Phone: 970-264-1513 [email protected]

Kevin Emde
Manager Lead

San Juan National Forest, USDA Forest Service 180 Pagosa Street P.O. Box 310 Pagosa Springs, CO 81147 Phone: 970-264-1510 [email protected]