Forest/District Level Planning: Bitterroot National Forest
Overview:
The Fire Effects Planning Framework (FEPF) was developed to aid resource managers and line officers in determining where and under what conditions fire may create benefits or pose threats to identified ecological conditions or management targets. This spatially explicit representation of potential fire effects will allow for further functional integration of resource and fire management goals by providing information to be used at a variety of scales from long-range planning to current fire incident decision-making.
This example shows how the Bitterroot National Forest (BRF) developed datasets for Lynx foraging habitat, a key criteria for the long-term survival of Lynx:
Resource Objectives:
- Lynx (Lynx canadensis) are key management species on the BRF. To support management decisions, we wanted to know when and where fire might benefit or threaten Lynx habitat.
- Lynx require a variety of habitats within close proximity: late-successional, closed forests are used for denning, while early or mid-successional forests provide foraging opportunities. Winter foraging needs are the focus of this example.
- Key Lynx foraging habitat was determined to consist of elevations above 6200 feet and dense young forest stands between 15-39 years post fire (Figure 1). (more info)
Figure 1: Potential Lynx Foraging Habitat in the West Fork Ranger District.
Basic Fire Behavior Map
We used FlamMap (more info) to model fire behavior under low, moderate and extreme fire weather conditions. We used 80th, 90th, and 99th % Energy Release Component (ERC) for these respectively.
FlamMap Inputs
FlamMap requires elevation, slope, aspect, fuel type and loading, wind, weather, and fuel moisture files. We obtained the first four of these from the Missoula Fire Lab as a Farsite landscape file (more info). We calculated wind, weather and fuel moisture for each ERC from a FireFamilyPlus dataset obtained from the Forest (more info).
FlamMap Outputs
We modeled Crown Fire Activity (CFA) under each weather condition (Figure 2 & 3). (more info).
Figure 2: 80th percentile crown fire activity West Fork Ranger District.
Figure 3: 99th percentile crown fire activity West Fork Ranger District.
Crosswalk to Fire Effects
Next, we developed a rule-based crosswalk between crown fire activity and effect on Lynx foraging habitat (Table 1). (more info)
The crosswalk captures predicted effects over time. During the first 14 years post-fire, there may not be enough re-growth to rise above the winter snow pack and, therefore, be available for snowshoe hares.15-39 years post-fire, forage may be available above the snow pack and provide hare habitat. After 40 years, the forest may no longer have sufficient under-story vegetation to provide hare forage.
In this example we use a numeric coding, -10 to +10, to represent type of change. We could have used a textual description just as easily.
Table 1: Shows benefit/risk multipliers used to crosswalk lynx foraging habitat back to fire severity by forest type., where pre-fire "good" foraging habitat becomes "poor" = -10, "good" remains "good" = +1, "poor" remains "poor" = -1, "poor" becomes "good" = +10 and all non-habitat = 0. WB=whitebark pine, DF=Douglas-fir, L=larch, PP=ponderosa pine, LP=lodgepole, ES=Engelmann spruce, AF=subalpine fir, AL=alpine larch, GF=grand fir, C=cedar, QA=quaking aspen, WH=western hemlock, MH=mountain hemlock, and CW=cottonwood.
Results
The results show that under all fire weather conditions, fire effects are predicted to either improve or cause no change in foraging habitat quality for Lynx immediately following fire and remain good or improve in many areas 15-39 years post-fire (Figure 4 & 5). However, because snowshoe hares prefer a post-fire habitat that is relatively short-lived on the landscape, a landscape with no fire will surely provide little habitat, as evidenced by the 40+ years post-fire time period maps (Figure 6).
Figure 4: Potential effects for 80th percentile ERC conditions, 0-14 yrs post-fire.
Figure 5: Potential effects for 99th percentile ERC conditions, 15-39 yrs post-fire.
Figure 6: Potential effects for 90th percentile ERC conditions, 40+ yrs post-fire in the absence of additional disturbances.
Distribution of the Map Library
The Bitterroot National Forest houses all datasets on their main forest server. In addition, the Forest has created a PDF of the inputs, crosswalks and outputs and mailed these to each district ranger, fuels and fire management officers. A presentation was also made to the Forest Leadership Team.
Map Library: http://leopold.wilderness.net/research/fprojects/pdfs/district_map_library_web.pdf
Use of the Map Library
The map library has been used for initial size-up, referenced for WFIP documentation and as input for a hazardous fuels treatment project. For the latter, effects were summed across GIS datasets for all three ERC conditions to determine where there are always benefits or risks and where they vary by condition. This information was used to help make decisions about where and how to implement fuel treatments. For example, areas where risks always occur may be scrutinized for possible mechanical treatment, if appropriate, or noted as a fire management priority.
For article on size-up:http://leopold.wilderness.net/pubs/540.pdf
Detailed instructions for creating a Map Library (User's Guide)
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