Abstract
Providing economic incentives to landholders is an effective way of promoting sustainable forest management, conservation and restoration. In Hawaii, the main native hardwood species with commercial value is Acacia koa (koa), but lack of successful examples of koa plantation forestry hinders private investment. Financial models, which have been offered to encourage investment, assume that a particular minimum volume of merchantable wood will be harvested at rotation age. No studies have been done to determine the appropriateness of the assumed volumes for koa plantations. Three 18- to 28-year-old koa plantations were studied to determine butt-log size, crown class and crop tree potential. Estimates of present and future merchantable sawtimber volume were made for each plantation. Results indicate that most existing plantation koa trees fork so close to the ground that they will produce little to no merchantable wood. Projected sawtimber yields from crop trees in these plantations at age 45 years are 10, 15 and 90 m3/ha, which are below the 135 m3/ha yield used in the most recent financial analysis of returns on investment in koa forestry. Relaxing the crop tree criteria gives higher volume yields, but two plantations still fall short of the assumed target yield by 43 and 52%.
Citation
Scowcroft, Paul G.; Friday, James B.; Haraguchi , Janis; Idol , Travis ; Dudley, Nicklos S. 2010. Poor stem form as a potential limitation to private investment in koa plantation forestry in Hawaii. Small-scale Forestry 9:243-262.
