Assessing Vulnerability to Climatic Changes on the Lolo National Forest
We partnered with the Lolo National Forest (LNF) to understand and conceptualize the magnitude of potential climatic change and the relative vulnerability of three forest resources on the LNF. Specifically, we focused on the vulnerability of bull trout, water supply, and forest infrastructure (recreation sites, trails and roads). Our shared goal: to help managers prioritize actions for maintaining or improving resiliency in the face of climate change. Following is a very brief summary, see the full report here.
Our study area included the Lolo National Forest plus lands in-between and the headwaters of Rock Creek.
“The degree to which a system is susceptible to, or unable to cope with, adverse effects of climate change” (IPCC 2007)
From a watershed perspective, it’s a function of exposure (physical change in climate), sensitivity (likelihood of adverse impact given the current or inherent condition), and adaptive capacity (the ability of the ecosystem to adapt). The USFS has the ability reduce vulnerability to some extent through management actions that reduce sensitivity. Our study deals only with exposure and sensitivity, since intrinsic adaptive capacity is largely unknown.
Metrics Used to Determine Vulnerability
These are the metrics we used for assessing exposure and sensitivity of bull trout. They are based on readily available information or proxy measures.
- Reduction in thermally suitable habitat patch
- Winter flood scour
- Reduced summer mean flow
- Low population size/viability
- Low stream connectivity
- Increased sediment
- Road crossings
- Parallel roads near streams
- Low channel complexity
- Riparian cover
- Roads near streams (2 metrics)
- Grazing allotments near streams
- Water diversions
- Low stream-floodplain connection (valley confinement)
- Presence of brook trout
Projected change in stream temperature: baseline, 2040s and 2080s
Projected change in mean summer low flow: baseline, 2040s and 2080s
Modeled Bull Trout Vulnerability to Projected Changes in Temperature in 2040
Modeled Bull Trout Vulnerability to Projected Changes in Flow in 2040
How to use this analysis:
- Identification of data gaps
- Development of monitoring programs
- Integration with existing prioritization programs
- Identify strategies to increase resilience of the resource where it is likely to have the most benefit
- Development of education and outreach materials
- Collaboration with other agencies and local communities
Wade, A.A., C. Brick, S. Spaulding, T. Sylte, and J. Louie. April 2016. Watershed Climate Change Vulnerability Assessment: Lolo National Forest. Publication Number R1-16-05. Missoula, MT: U.S. Department of Agriculture, Forest Service, Northern Region and Lolo National Forest. 132 p.