Moisture content of lumber produced from dead western white pine and lodgepole pine trees /

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Within recent years, disease and insects have killed numerous western white pine (Pinus monticola Dougl.) and lodgepole (Pinus contorta Dougl.) trees in the timber stands of Idaho and Montana. The Intermountain Region of the Forest Service, made up of southern Idaho, western Wyoming, Utah, and Nevada, estimates that it has 800 million cubic feet of dead lodgepole pine, practically all of which is in the area surrounding Yellowstone Park. Most of this dead timber is the result of a mountain pine beetle epidemic. The white pine species in western Montana and northern Idaho has also been severely hit by this insect and by the white pine blister rust. One National Forest in north Idaho has an estimated 1.2 billion cubic feet of dead standing and down timber, most of which is western white pine. Eastern Oregon and Washington have an estimated 227 million cubic feet of dead lodgepole pine. The current practice is to salvage and utilize as much of this dead timber as possible. About 10 percent of the annual mortality is salvaged as part of ongoing timber sales. The logs from these dead trees are normally processed with green logs, and the lumber is intermixed for drying and surfacing. This practice is not the best since the lumber from dead trees usually has a much lower moisture content than the lumber from green trees. With ever-increasing energy costs, the present procedure is also uneconomical due to longer kiln dwell time than is necessary for the lumber from the dead logs and excessive degrade of this material by overdrying. Because initial moisture content is one of the more critical factors used in selecting a drying schedule and determining the drying conditions, we studied this characteristic on samples of western white pine and lodgepole pine lumber cut from dead trees. The moisture content was measured using both a moisture meter and the standard ovendry test. The results were compared to determine the accuracy and consistency between the two methods. Small sections cut from the sample lumber were tested for moisture gradient and drying stress. In addition, a few moisture meter readings were obtained from the lodgepole pine studs after kiln drying. This information was then used to evaluate drying methods and determine if changes would be desirable. Each of the study species was processed at a single mill and the results are discussed separately.