Feasibility of wood production according to productivity class and rotation criteria

Abstract: The objective of this work was to evaluate the effect of forest rotation on the technical and economic feasibility of eucalyptus wood production for charcoal, in different productivity classes. Data came from Eucalyptus stands whose area was stratified into three classes of productivity: high, medium, and low. To each class, a different criterion of forest rotation was applied, as follows: age of maximum productivity, economic rotation age, single harvest age, and no technical parameter. Analyses of economic feasibility and production were performed for a 21-year planning horizon. For rotation without a technical parameter, a simulation by the Monte Carlo method was performed. For all rotation criteria, feasibility was observed for high- and medium-productivity classes, and unfeasibility for the low-productivity class. For rotation without a technical parameter, there is no chance for the project to be unfeasible. Wood production viability for charcoal under the studied conditions depends on the productivity class, for any rotation criterion adopted. Rotation criterion influences profitability, whose definition, according to productivity class, contributes to forest production maximization and to the economic return of the project, under the studied conditions.摘要：本研究旨在评估森林轮伐期对不同生产力等级下用于木炭生产的桉木生产技术与经济可行性的影响。本研究数据源自桉树林分，其种植区域按生产力水平划分为高、中、低三个等级。针对每个生产力等级，分别采用四种不同的森林轮伐期判定标准，具体如下：最高生产力轮伐龄、经济轮伐龄、单次采伐龄以及无技术参数约束。本研究以21年为规划周期，开展了经济可行性与生产情况分析。针对无技术参数约束的轮伐方案，采用蒙特卡洛方法进行模拟分析。所有轮伐判定标准下，高、中生产力等级的桉木生产均具备经济可行性，而低生产力等级则不具备可行性。采用无技术参数约束的轮伐方案时，项目不存在不可行的可能。在本研究设定的条件下，无论采用何种轮伐判定标准，用于木炭生产的桉木生产可行性均取决于生产力等级。轮伐判定标准会影响项目盈利能力；结合生产力等级确定轮伐期，可在本研究设定的条件下实现林木生产最大化与项目经济收益最大化。