Thinnin g and Harvesting Regimesf or Yellow- Poplar

Grade I yellow-poplar logs were recently selling for $150/mbf, three t•mes the price for grade 2 logs in North Carolina. A computerized stand development model was used to examine the profitability of thinning and holding yellowpoplar standz for increased diameter and grade. Analyses were done over wide ranges in stand age, site quality, and stocking, at 5% and 10% discount rates. At a 5% dizcount rate, the maximum net present stumpage value was obtained by thinning in most regimes. Lower stand age, higher initial stocking, and higher site indices favored thin-clearcut regimes over egimes with no initial thinning. At a 10% discount rate, thinning was optimal only at •nitial age 30 on the highest quality sites at the highest initial stockings. All other combinations of variables favored clearcutting •mmediately or with a 1 O-year delay. Thinning options with net values within 50% of maximum were numerous at a 5% discount rate in younger stands but decreased rap•dly as initial age increased. Only a few such options were available at the 10% dizcount rate. South. J. Appl. For. 14(3):101-103. Yellow-poplar (Li iodendron tulipifera L.) is an important eastern hardwood that regenerates readily from seeds and sprouts, grows rapidly, and responds well to intermediate thinnings. Increasing demand for yellow-poplar in • Funding for this study was provided by the Southeastern Forest Experiment Stauon, USDA Forest Service, Clemson, SC. We gratefully acknowledge the support and guidance of Doug Phillips (deceased) on this study in his role as project leader at that time. North Carolina Agricultural Research Service Journal Series Paper No. 10554. highly valued wood products such as face veneer has increased prices for higher grade logs. An economic consequence of this relative price increase may be to increase the attractiveness of thinning and holding growing stock to allow it to reach larger diameters.