ABSTRACT

We study the effect of forest stand growth models on the economically optimal management of boreal mixed-species forests. Our size-structured economic–ecological model includes the optimization of harvest timing, harvesting intensities, rotation periods, and the choice between rotation forestry and continuous cover forestry. We carry out a systemic comparison of economically optimal solutions obtained with three statistical–empirical stand growth models for both single- and mixed-species stands with up to four tree species. Given a 1% interest rate, the optimal choice between continuous cover and rotation forestry depends on the applied growth model. However, under a 3% interest rate, the optimal management regime is always continuous cover forestry. The optimal solution details are highly dependent on the growth models. With a 1% interest rate, it may become optimal to apply intensive close-to-clearcut harvesting that results in a dominant species change via natural regeneration. However, the level of natural regeneration varies strongly between the growth models. The economic superiority of a species mixture cannot be determined from overyielding differences. Mixed-species stands have higher maximum sustainable yields, bare land values, and average net revenues compared with monocultures.

摘要

我们研究林分生长模型对北方混交林经济优化管理的影响。我们的规模结构经济生态模型包括采伐时机、采伐强度、轮作周期的优化以及轮作林业和连续覆盖林业之间的选择。我们对最多四种树种的单树种和混合树种林分的三种统计经验林分生长模型获得的经济最佳解决方案进行了系统比较。给定 1% 的利率，连续覆盖林业和轮作林业之间的最佳选择取决于所应用的生长模型。然而，在3%的利率下，最优的管理制度始终是连续覆盖林业。最佳解决方案的细节高度依赖于增长模型。以1%的利率计算，通过自然再生。然而，不同生长模型的自然再生水平差异很大。物种混合物的经济优势不能通过产量差异来确定。与单一种植相比，混合品种林分具有更高的最大可持续产量、裸地价值和平均净收入。