Increasing Aspen Production through Mechanical Strip-Thinning (June 1, 1994-November 30, 1994): Monitoring Report

Abstract

This 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. All data collection activities for the 1994 growing season are complete and data are currently being entered into computer format in preparation for statistical analysis. Annual incremental basal area growth over the past four years is 15 percent higher on average in thinned stands compared to unthinned stands in the network of experiments established at the start of this project. Tree growth data collected on older previously-thinned stands on the Chippewa National Forest show that thinned stands have approximately 20 merchantable cords standing volume per acre compared to an adjacent unthinned area which has 11 cords per acre. Disease incidence data were collected on all of the research sites during 1994. No difference in the incidence of Hypoxylon, Nectria, Cytospora, and Saperda was observed between thinned and unthinned treatments. Economic analyses (Task V) were done using a range of aspen stumpage prices currently received at auctions in the region. These analyses show that absolute financial returns and differences in returns between thinned and unthinned scenarios continue to increase, primarily a result of increasing stumpage prices.