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Optimal Landscape Management in Farm Woodlands

农场林地的优化景观管理

基本信息

批准号：
09041071
负责人：
YOSHIMOTO Atsushi
金额：
$ 9.41万
依托单位：
MIYAZAKI UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (A).
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1999
项目状态：
已结题

项目摘要

The objective of the project was to seek an optimal landscape management scheme from upper to lower lands in mountainous areas. Our results are:I. With use of a spatially constrained forest landscape management model, the more exclusion periods, the less the harvest flow level and the total present net value were derived and the more heterogeneous forests became in terms of the forest stand age distribution. In plantation forests, our analysis indicated 1). No obvious edge effect in small compartments, 2). High dependence of species richness on stand age and topographic heterogeneity, 3). Variation of biodiversity of ground vegetation with light environments, 4). Inter-catchment differences in tree density reflected by variations of slope length and soil moisture of forest stands, and 5). A high risk of species disappearance by logging from valleys.II. Two stochastic models in forest management were constructed with application to capture stochastic behavior of forest owners and optimal decision under stochastic environments. A technical challenge on stochastic modeling with nonlinear stochastic differential equation was presented.III. Introducing the free market policy to the rice market was analyzed with conclusions that increasing price volatility by the free market policy could lower the minimum threshold rice price for producers to continue production.IV. A program to create new woodlands in farmlands in UK was evaluated. Given the limited benefits to society, it appeared that the FWPS offers poor value for money and that the new woods created will remain small-scale, underexploited and ad-hoc, until the advent of better targeting policies. As for location of woodlands, the incentives currently favor the random placement of woods in the landscape, significant gains for conservation might be achieved by adopting simple targeting strategies such as devising envelopes based on dusters of ancient woodland habitat.

该项目的目标是寻求山区从上到下的最佳景观管理方案。我们的结果是：1。利用空间约束的森林景观管理模型，排除期越多，获得的采伐流量水平和总现值越少，林分年龄分布异质性越强。在人工林中，我们的分析表明：1)。在小隔间中没有明显的边缘效应，2)。物种丰富度对林龄和地形异质性的高度依赖，3)。光照环境下地面植被生物多样性的变化[j]。林分坡长和土壤湿度变化反映的流域间树木密度差异；从山谷伐木导致物种灭绝的高风险。建立了森林经营中的两个随机模型，并应用于捕获森林所有者的随机行为和随机环境下的最优决策。提出了非线性随机微分方程随机建模的一个技术难题。对大米市场引入自由市场政策进行了分析，结论是自由市场政策增加价格波动可以降低生产者继续生产的最低门槛大米价格。对英国一个在农田中创造新林地的项目进行了评估。考虑到对社会的有限好处，FWPS似乎物有所值，而且在更好的目标政策出现之前，新创造的森林将保持小规模、未充分开发和临时的状态。至于林地的位置，目前的激励措施倾向于在景观中随机放置树木，通过采用简单的目标策略，例如根据古代林地栖息地的尘埃设计围护结构，可以实现显著的保护效果。