Optimal Landscape Management in Farm Woodlands

该项目的目标是寻求一个最佳的景观管理方案，从上到下的土地在山区。我们的结果是：I.利用空间约束的森林景观管理模型，排除期越长，收获流量水平和总现值越低，森林林龄分布越异质。在种植园林中，我们的分析表明：1）。在小隔室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;地表植被生物多样性随光环境的变化。林分的坡长和土壤水分变化反映了流域间林木密度的差异。从山谷伐木造成物种消失的高风险。建立了森林经营中的两个随机模型，并将其应用于描述森林所有者的随机行为和随机环境下的最优决策。提出了用非线性随机微分方程进行随机建模的技术挑战.将自由市场政策引入稻米市场进行了分析，结论是通过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稻米价格。对英国一项在农田中创造新林地的计划进行了评价。鉴于对社会的好处有限，看来FWPS提供的资金价值很低，而且在更好的目标政策出现之前，所创造的新森林将仍然是小规模、开发不足和临时性的。至于林地的位置，目前的激励措施倾向于随机放置的树木在景观中，显着的收益，保护可能会实现通过采用简单的目标策略，如设计信封的基础上，古老的林地栖息地的除尘器。

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.