Berguson, William E2023-09-132023-09-131992https://hdl.handle.net/11299/256833This project has five primary research tasks related to the determination of growth and yield of aspen in response to mechanical strip thinning; analysis of disease incidence in thinned and unthinned stands and determination of the costs and economic feasibility of mechanical stripthinning of aspen. Work done during the current reporting period concentrated on detailed characterization of sites as outlined under Task II of the project workplan. Studies of stand density showed that sites in the experiment network differ statistically in average stocking density with more heavily-stocked stands found in Koochiching County and less dense stands located in Cass County. Direct measurement of canopy density was done using a light meter to determine light penetration through canopies in thinned and unthinned stands. This information will be used to track the development of thinned stands over time and project future growth rates. Soil sampling was done at all sites to characterize site quality. Soil samples will be analyzed for texture, water. holding capacity and nutrient status during the coming reporting period. Data collection activities related to Task I and III (evaluation of growth response to strip-thinning) is nearly complete for all sites. Collection of tree growth data will be completed in early December. An inventory of disease, insect and mechanical damage in thinned and unthinned stands was completed for those sites not inventoried in 1991. Economic analyses were expanded to evaluate the effects of assumptions about rotation age on the economic feasibility of strip-thinning. Rotation age is shown to have a large effect on economic performance of an investment in thinning with net present value decreasing by six percent for every year increase in rotation age. Plans for the next reporting period include summary and analysis of growth data for the 1992 growing season, analysis of foliage and soil samples and integration of economic analyses with tree growth data.enNatural Resources Research InstituteUniversity of Minnesota DuluthIncreasing Aspen Production through Mechanical Strip-Thinning (June 1, 1992-November 30, 1992): Monitoring ReportTechnical Report