ABSTRACT

Sustainable forest management requires tools to guide optimal silvicultural treatments. Timing and intensity of thinnings and timing of final harvest are key decisions. An Optimized Reforestation Management (herein, an ORM) model was developed to reach the optimal combination of thinning times, thinning intensities and rotation periods for Ecuadorian forest plantations of Alnus acuminata, Kunth and Pinus patula Schltdl. & Cham. The ORM model uses non-linear programing to simultaneously optimize the number of trees to harvest in a certain period in order to maximize the plantations’ annualized net present values (annuities). Results obtained for optimal silvicultural interventions were compared to current management practices in Ecuador, one with no interventions, and a second with a treatment schedule promoted by the Ecuadorian Ministry of Agriculture. ORM model delivered better financial performance for both species, compared to both alternative scenarios, in terms of annuities and payback periods. Thinnings scheduled by ORM tend to be later than recommended by existing schedules. For Alnus, only one thinning was optimal, independent of the discount rate, while for Pinus two thinnings were optimal for higher levels of the discount rate considered. It is recommended for private and public actors to consider these findings for future management of reforestation areas.

摘要

可持续森林管理需要工具来指导最佳造林方法。间伐的时间和强度以及最终收获的时间是关键的决定。开发了一种优化的造林管理模型（在此为ORM），以达到对Alnus acuminata，Kunth和Pinus patula Schltdl的厄瓜多尔人工林间伐时间，间伐强度和轮伐期的最佳组合。和湛 在ORM该模型使用非线性程序来同时优化某个时期内要采伐的树木数量，以使人工林的年度净现值（年金）最大化。将最佳造林干预措施获得的结果与厄瓜多尔目前的管理实践进行了比较，一种没有干预措施，另一种则是由厄瓜多尔农业部推广的治疗计划。与两种替代方案相比，ORM模型在年金和投资回收期方面都为这两种物种提供了更好的财务绩效。ORM计划的细化往往比现有计划建议的更晚。对于Alnus而言，与折价率无关，只有一个细化是最佳的，而对于Pinus对于较高的折现率水平，两个细化是最佳的。建议私人和公共行为者考虑这些发现，以便将来对造林区进行管理。