Optimal Harvesting of Timber: Valuing Timberland with Stochastically Evolving Timber Volume and Prices Using Linked Biological/Geographical Data from British Columbia

木材的最佳采伐：利用不列颠哥伦比亚省的相关生物/地理数据，通过随机变化的木材数量和价格来评估林地价值

• 批准号: 0241509
• 负责人: John Rust
• 金额: $ 21.94万
• 依托单位: National Bureau of Economic Research Inc
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-07-01 至 2007-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0241509&HistoricalAwards=false
• 关键词: Optimal; Harvesting; Timber; Valuing; Timberland

In environmental and natural resource economics, the management of renewable natural resources is of considerable interest to economists because the prospect of stewarding a resource forever has practical importance and real-world relevance. Moreover, because past failures in managing certain renewable natural resources properly have lead to the extinction of several species, developing practical strategies for managing remaining renewable natural resources is both timely and useful. This project investigates in detail the management of one renewable natural resource, timber, in the province of British Columbia, Canada. For a Timber Supply Area (TSA) in British Columbia the investigators have obtained unique access to extremely detailed site-level data, which are used by timber-supply managers in the British Columbia Ministry of Forests when making harvesting decisions. In particular, they have access to elaborate linked biological and geographical data in the form of a Geographical Information System (GIS) at the grid level which, in this case, is a hectare or 100 meters square. Thus, for every hectare in the Fraser TSA, which is located near Vancouver, British Columbia and contains several hundreds of thousands hectares, officials at the Ministry of Forests provide the investigators with a wide variety of biological, engineering, and geographical information relevant to harvesting timber. In addition, they also have access to the harvesting strategies proposed and, in some cases, the decisions implemented by the Minister of Forests, so they can compare our estimated decisions with actual ones. In developing practical harvesting solutions for timber, they apply the method of stochastic dynamic programming. The goal of the project is to make the following contributions: First, this project takes geography seriously, both in the planar sense and in the three-dimensional sense. Second, it takes site-specific heterogeneity seriously both on the cost side in terms of felling and transportation and on the growth and yield side in terms of heterogeneous stands of timber. Third, it models initial conditions. In particular, it does not take as the starting point a steady-state allocation, or even an optimal allocation. Instead, it takes the existing uneven-aged timber stand as given and derives the optimal policy function, the optimal timber-harvesting profile, in terms of this age distribution. Fourth, this project uses best-practice biological methods to model the dynamics of uneven-aged forest growth and yield. Fifth, in the past economists and foresters have typically demonstrated their methods by making extremely simple assumptions concerning the stochastic nature of timber prices and volumes so that closed-form examples could be solved. This research implements recent developments in computational methods so that practitioners can solve numerically for the optimal policy function in realistic biological, economic, and spatial environments.

在环境和自然资源经济学中，可再生自然资源的管理引起了经济学家的极大兴趣，因为永久管理资源的前景具有实际重要性和现实世界的相关性。此外，由于过去在适当管理某些可再生自然资源方面的失败导致了一些物种的灭绝，因此制定管理剩余可再生自然资源的实用战略既及时又有用。 该项目详细调查了加拿大不列颠哥伦比亚省对一种可再生自然资源——木材的管理。 对于不列颠哥伦比亚省的木材供应区 (TSA)，调查人员获得了极其详细的现场数据的独特访问权限，不列颠哥伦比亚省森林部的木材供应经理在做出采伐决策时使用这些数据。特别是，他们可以以网格级别的地理信息系统 (GIS) 的形式访问详细的链接生物和地理数据，在本例中，网格级别为一公顷或 100 平方米。因此，弗雷泽 TSA 位于不列颠哥伦比亚省温哥华附近，占地数十万公顷，林业部官员为调查人员提供与采伐相关的各种生物、工程和地理信息。木材。此外，他们还可以了解拟议的采伐策略，在某些情况下，还可以了解森林部长实施的决定，以便他们可以将我们的估计决定与实际决定进行比较。在开发实用的木材采伐解决方案时，他们应用了随机动态规划方法。 该项目的目标是做出以下贡献：首先，该项目认真对待地理，无论是在平面意义上还是在三维意义上。其次，它认真对待特定地点的异质性，无论是在砍伐和运输方面的成本方面，还是在木材异质林分的生长和产量方面。第三，它对初始条件进行建模。特别是，它不以稳态分配为起点，甚至不以最优分配为起点。相反，它以现有的不均匀年龄木材林为给定，并根据该年龄分布得出最佳政策函数，即最佳木材采伐概况。第四，该项目使用最佳实践生物学方法来模拟不同年龄森林生长和产量的动态。第五，过去经济学家和林业工作者通常通过对木材价格和数量的随机性质做出极其简单的假设来证明他们的方法，以便解决封闭式的例子。 这项研究实现了计算方法的最新发展，以便从业者能够在现实的生物、经济和空间环境中数值求解最优政策函数。