Finding uses for millions of tons of beetle-killed trees as a way to offset forestland restoration costs and developing market-oriented ways to use the biomass is a priority for the U.S. Forest Service. The Forest Products Laboratory (FPL) has developed a new strategic framework for approaching these issues in a new report titled: Economic Use of Beetle-Killed Trees. This framework is supported by decades of FPL research in the sustainable and economically viable use of beetle-killed trees.
Out of a total 749 million acres of forest in the United States, 9.2 million acres of trees were killed by insects and disease in 2010. Various beetles, including mountain pine, western bark, southern pine, and spruce, will continue to kill millions of trees across North America every year. The mountain pine beetle (Dendroctonus ponderosae), a native insect found in the western United States, kills about 74% of these trees, nearly seven million forested acres annually.
Mountain pine beetles have a one?year life cycle and spend most of their life feeding on conductive tissues between bark and wood. Trees are killed by the destructive galleries mined by the beetles and the blue stain fungus carried by the insects. This fungus decreases the wood moisture content and weakens the tree defense mechanisms. Blue stain carries over into products made from the stained logs and the physical condition of the wood affects how it can be processed. As such, profitability and usefulness of stained wood can be adversely affected. Infested trees also dry and develop splits and checks as the drying stresses are relieved.
Challenges associated with manufacturing wood products from beetle?killed timber stands exist through all phases of production, including harvesting, transportation, log storage, processing, and end-product marketing. Timber stands left in the wake of the current mountain pine beetle outbreak, however, represent a significant economic resource.
A key issue in this complex problem is the amount of time, or shelf life, associated with capturing economic values and how this may vary between locations. Where current local infrastructure exists to produce value?added products, the FPL provides a framework for overcoming technical and economic barriers to using beetle?killed trees. Where local infrastructure is inadequate or completely lacking, FPL seeks to develop and help commercialize new value?added uses for the wood. Best-use scenarios have economic and market potential on a scale matching the degree of forest biomass available and justifies the capital investment required.
In carrying out this type of work, FPL routinely seeks to develop public–private partnerships with an array of organizations and forestland managers. Diversifying inputs and partnerships helps to overcome technical and economic barriers and can promote the commercial use of beetle killed trees in producing traditional and non?traditional forest products and bioenergy. FPL seeks to involve itself in research, development, and deployment of new and improved technologies to the greatest degree that its expertise and capabilities can benefit private sector partners to ensure successful commercialization.