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Boise-Payette-Sawtooth National Forest Plan

National forests are required to update their management plans every 10–15 years. The adjacent Boise, Payette, and Sawtooth National Forests in southern Idaho and northern Utah decided to update their plans together in order to better understand larger landscape issues and to address their many common concerns more efficiently. National forest plans do not make specific decisions about timber harvesting or other activities, but rather have been described as more akin to land use zoning in determining overall rules and activities appropriate for certain areas. As part of planning, forests are required to calculate an “Allowable Sale Quantity” (ASQ) of timber, which led the forest to use Spectrum, a linear optimization DSS developed by the Forest Service. The Forests soon realized that the basic forest growth and harvesting model could be expanded to help evaluate other effects of the different possible management alternatives. The model was expanded to include 120 vegetation classes (combinations of vegetation types, successional stages, and canopy closures) that were distributed across seven land allocation zones over 50 years for each of seven broad management alternatives. To get a more detailed view of the feasibility of these alternatives, the RELM DSS was used to take these Spectrum outputs and distribute them further down to 6th field watersheds (about 200 per forest). Because fire is an important influence in the region that was not explicitly modeled by Spectrum and because there was some suspicion of inherent biases in optimization modeling, a parallel modeling exercise using the VDDT DSS was also undertaken near the end of the planning process. (VDDT is a state-transition simulation model that had also been used to model the unforested parts of the planning area).

Lessons Learned

Johnson, K.N.; Gordon, S.; Duncan, S.; Lach, D.; McComb, B.; Reynolds, K. 2007. Conserving creatures of the forest: A guide to decision making and decision models for forest biodiversity. Corvallis, OR : Oregon State University, College of Forestry. 88 pp.

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Idaho, USA

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Regional Ecosystem And Land Management Decision Support System (RELM)


Vegetation Dynamic Development Tool (VDDT)

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Multiple DSS are often needed to meet complex needs: separate models were needed to handle the strategic (Spectrum) and tactical (RELM) aspects of planning; a simulation approach (VDDT) was also done to provide an alternative view.

The kinds of DSS traditionally used to calculate timber harvest levels are now being used to model more complex vegetation dynamics over time for a variety of resource outputs.

The scope of the modeling project can change significantly during the project; initial calls for “back of the envelope” analyses for ASQ eventually evolved into a model with 120 vegetation classes.

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Sean Gordon

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