• Start-up
  • Planning
  • Action
  • Evaluation
The Flathead National Forest/Coram Experimental 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.

Project Area

Flathead National Forest/Coram Experimental Forest overlook. Photo Credit: Molly Roske, MN Department of Natural Resources.
The Flathead National Forest/Coram Experimental Forest is located in northwestern Montana. This Northern Rockies ASCC site is influenced by the warm, wet maritime airflows from the Pacific Ocean and the cooler, drier airflows from Canada. The study site consists of second-growth western larch-mixed conifer forests that regenerated after clearcutting in the 1960s, and provides habitat for lynx, grizzly bear, and many bird species. The Flathead/Coram ASCC site is part of the “Crown of the Continent,” a unique and diverse ecosystem whose rivers feed the Pacific Ocean, Hudson Bay, and the Gulf of Mexico.

Management Goals

Natural Resource Specialist in Flathead National Forest. Photo Credit: Justin Crotteau, USDA Forest Service Rocky Mountain Research Station.

A team of natural resource specialist from the Flathead National Forest/Coram Experimental Forest and regional scientists came together for a three-day workshop in the summer of 2016 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 climate adaptation trajectory (resistance, resilience, transition). These three treatments are summarized briefly below: 

 

Resistance: 

  • Maintain pre-treatment species composition and structure of western larch and mixed conifer, but with slightly decreased representation of shade-intolerant species 
  • Sustain vigor of existing desirable trees 
  • Maintain fire-resistant trees with thick bark, high crowns, and low canopy bulk density
  • Maintain low surface fuels
  • Maintain tree health with low incidence of insects and diseases 

Resilience:

  • Increase proportion and development of long-lived, fire-adapted species 
  • Maintain genetic diversity via large diameter, long-lived trees, and planting tree improvement seed
  • Enhance spatial and structural heterogeneity 
  • Maintain high productivity and supply of wood products at regular intervals
  • Promote development of large-diameter, long-lived trees to promote old-growth characteristics 
  • Reduce hazard of crown fire 
  • Promote same low surface fuel and low levels of insects and disease as Resistance treatment 
  • Maintain and improve forage production 

Transition: 

  • Increase proportion and development of the most fire-adapted and drought-tolerant species and genotypes (30% western larch, 25% western white pine, 35% ponderosa pine, and 10% other (i.e., Douglas-fir, aspen, paper birch))
  • Continue to enhance spatial and structural heterogeneity; low surface fuels; low level of insects and disease
  • Maintain high productivity and supply of timber products at regular intervals 
  • Maintain and improve forage production 
  • Promote development of large-diameter long-lived trees (average 10-16 trees per acre) in clumps with scattered trees 
  • Reduce hazard of crown fire and spread by reducing ladder fuels 

Climate Change Impacts

Key climate change impacts that the project team considered for the Flathead National Forest/Coram Experimental Forest included:
Increased frequency and severity of wildfires due to warmer temperatures, widespread drought conditions, greater fuel density, and high wind events
Increasing insect & disease outbreaks
More precipitation in the winter and spring leading to flooding and erosion
Decreasing snowpacks - earlier melting

Challenges and Opportunities

Climate change will present challenges and opportunities for accomplishing the management objectives of this project, including:

Challenges

Greater surface and canopy fuel accumulation in areas experiencing fire exclusion has led to increased vulnerability to wildfire and high crown fire hazard
Potential for increased mountain pine beetle outbreaks due to stand homogeneity, ample host species, and favorable weather
Northern species on site are expected to have reduced habitat suitability under climate change
Western larch may decline in areas with lower water availability and declining groundwater flows

Opportunities

Growth rates in western larch may increase if warmer temperatures coincide with more growing season precipitation
Possible changes in desirable species distribution due to an increase in the number of frost-free days and warmer conditions

Adaptation Actions

The ASCC project was designed to explicitly test three different adaptation options: resistance, resilience, and transition. A detailed silvicultural prescription was designed for each adaptation option, which was replicated several times across the study site. Detailed silvicultural prescriptions can be found in the Adaptation Workbook. The study site also includes several no-action "control" stands for comparison. Some of the adaptation tactics employed in this project include:

Area/Topic
Approach
Tactics
Resilience
Use group selection to create 2-4 acre openings with feathered edges, retaining 6-8 seed tree clumps per acre in openings, favoring retention of western larch and western white pine
Uniform thinning to 75-85 ft2/acre in the matrix
Plant western larch and western white pine in group openings (2-4 acre)
Slash and/or remove damaged trees to facilitate site preparation
Reduce ladder fuels and burn slash piles

Monitoring

Project participants identified several monitoring items that could help inform future management, including:
Natural regeneration survival and growth
Growth of tree improvement seed of western larch and ponderosa pine from high and low elevations
Inventories of fuels and understory plants

Next Steps

The Flathead National Forest/Coram Experimental Forest ASCC workshop took place in June 2016. Measurement plots have been installed and pre-treatment data has been collected. Harvesting was completed in winter 2021-2022. Plantings will take place in 2024. Future data collection will focus on residual trees, forest regeneration, and understory and shrub development.

Keywords

Forest types
Management plan
Planting
Research
Water resources
Wildlife habitat

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