Transect relascope sampling for assessing coarse woody debris: The case of a π/2 relascope angle

In transect relascope sampling, a wide‐angle relascope is used along survey lines for selecting a sample of objects that extend linearly in the plane, e.g. downed logs. The method is closely related to line intersect (intercept) sampling. In this article, a special case of the transect relascope technique is studied. Using a π/2 radian relascope angle, the method becomes invariant to the orientation of the line objects in the population. The reason is that the area of inclusion around objects, through which a survey line should pass for an object to be included, turns out to be circular. In analytical studies and Monte Carlo simulations, the cost‐efficiency of transect relascope and line intersect sampling is evaluated. It is found that transect relascope sampling is a competitive alternative to line intersect sampling in inventories of the total volume of coarse woody debris (in the form of downed logs) in forest compartments.     

Spatial optimization by simulated annealing and linear programming

Forest management planning comprises selection among treatment alternatives in management units. A traditional linear programming (LP) approach may effectively account for a profit maximization objective combined with sustainability constraints, e.g. on the temporal distribution of harvest volume flows, cash‐flow, and net present value development, but it fails to account for spatial constraints, especially those associated with final felling. By applying a simulated annealing adjacency model based on net present value maximization and combined with an LP consequence computation model, it is possible to delineate optimal strategies of final felling scheduling. Evaluation is made of the trade‐off between (1) the incremental cost (determined by use of the LP model) of an optimal adjacency model solution, and (2) the potential damage cost resulting from adjacency characteristics such as windthrow and bark injuries. The decision support system may contribute significantly to reduce damage costs and may improve the reliability of forest management planning.     

新疆乌什县国家级公益林分级区划落界浅析

分析新疆鸟什县国家级公益林分级区划界定情况，总结取得的成就，并就分级区划界定过程中存在的问题，提出对策和建议。     

通河县林地保护规划落界数据说明

林地图斑落界是林地保护利用规划编制工作的主要环节,是落实林地图斑空间位置、核实资源基数,查清森林资源现状的基础性工作。笔者详细论述了通河县林地保护规划落界数据的基本情况、图斑落界方法和结果比较,对林地保护利用规划编制工作具有参考价值。     

Forest soil chemical changes following fire

Abstract

Prescribed fire to remove residue in a pine plantation on a sandy soil resulted in increases in pH, P, K and Ca in the top 20 cm of soil during the first 15 months following treatment.     

落叶松规格材加工利用技术研究

介绍"十一五"国家科技支撑计划"高强度结构材加工利用技术"课题中,对我国主要的商品林树种之一——落叶松,在规格材的优化加工、分级、无损检测、强度性能测试及木构件连接等关键技术研究方面,取得的重点创新成果。这些成果开创性地解决了我国利用国产资源加工结构用规格材的关键性和共性技术问题,并且为我国落叶松资源的高效利用,提供了新的技术途径。     

Testing Stewardship Concepts on Federal Land

Summary

The goal of this paper is to describe recent attempts to define the stewardship concept and to translate it into action on the ground. The focus is on national forest lands and the unique challenges federal land managers face in working with the public to implement a concept that has different meanings to a variety of stakeholders. Stewardship requires more flexibility than is often found under existing administrative authorities. Large, bureaucratic agencies face many barriers in applying creative and innovative solutions to existing problems, not the least of which are internal and external reward structures. While there exist some authorities that allow for the creative testing of stewardship contracting projects on the ground, a number of challenges remain. Two significant ones are: (1) the need for a clearer, consistent understanding (by both Forest Service employees and constituents) of the authorities that can be used to test stewardship concepts; and (2) a more broad-based agreement on the desired outcome of stewardship projects. Given the current lack of understanding and agreement on how to implement stewardship concepts, the most effective means of moving the issue forward will be to apply innovative tests of contracting methods under current or new temporary authorities. These tests should be designed, implemented, monitored, and evaluated using broad-based, inclusive, on-the-ground coalitions that create effective ties and linkages between local and national levels.     

加格达奇林业局森林经营中采伐方式的探讨

加格达奇林业局根据本局森林资源状况,在2001年停止了木材主伐生产,森林经营由以木材生产为主,向以发挥森林生态功能为主的方向转变。本文通过分析该局森林资源现状、管理方式的变迁、经营思路的转变,以提高森林资源质量,改变林分结构,恢复原有植被群落为方向,探讨了森林经营中的采伐方式,以实现森林资源的稳定增长和可持续发展的目标。     

三种地板类型对母猪肢蹄健康的影响

为探索饲养母猪适宜的地板类型,跟踪分析3 600头母猪在3种地板模式下肢蹄部健康状况的影响。结果表明:使用新型复合材料开放式地板的母猪肢蹄健康状态最好,母猪肢蹄部病变比例为17.87%;半开放式混凝土地板加三合土地板次之,母猪肢蹄部病变为23.67%;限位饲养全混凝土地板较差,母猪肢蹄部病变为30.44%。试验数据说明,利用全漏缝新材料复合地板在自由采食饲养管理方式作用下,能够改善母猪肢蹄部健康状况的新思路、新方法是有效的、可行的。     

贵州省黔南州森林环境氧气含量分析

在对黔南州林区氧气含量进行实测基础上,运用科学的分析方法,全面评价了黔南州林区森林释氧功能及其对空气质量状况的改善。研究表明:黔南州森林环境空气中氧气平均含量为21.19%,超出正常空气中氧气浓度0.24%,氧气浓度最高的达到21.54%,超出正常水平0.59个百分点;森林公园中的氧含量明显高于其他森林环境,平均值高达21.32%,超出正常水平0.37个百分点;针阔混交林空气中氧气浓度最高,为21.26%,其次是针叶林,氧气含量最低的是阔叶林;森林环境中的氧气浓度随着林龄的增长而增加,林木成熟后,氧气浓度随着树木年龄的增长而逐渐下降。