查询词典 index forest

Although forest insects and pathogens cause various detriments,they also make positive contributions to forest succession,material cycling and energy flow,a food source,creating wildlife habitat,etc.,and further,in an ecosystem perspective their contributions are critical to forest biodiversity,soil fertility and long-term forest health and sustainability,so forest managers must consider both the detrimental and beneficial functions of insects and pathogens.

森林昆虫和病原物虽然能引起林木损伤与死亡，但它们在森林演替、物质循环和能量流动、食物来源、创造野生动物生境等方面都作出了积极的贡献，而且在一个生态系统发展前景中，对于森林生物多样性、土壤肥力、森林的长时期健康和稳定性等方面，它们的促成作用也是必不可少的。因此，森林经营者应当考虑昆虫和病原物的害与益的两方面作用。

By the analysis of the dead leaves and branches and the holding water contents of five type standing forests—birch and larch mixed forest, larch planted forest, Chinese pine planted forest, birch natural forest and shrub forest in Wutai Mountain area, central Asia alpine region, the water conservation benefit among them was compared.

为了探讨不同林分水源涵养功能，为地域林业发展树种规划提供技术依据，该研究以中亚高山区五台山林区内五种不同类型林分为试材，调查分析了不同林分的枯落物及其持水量，比较了不同林分类型的涵养水源效益。

The water conservation benefit of soil for different forests was 277.28%-173.67% higher than that of grass slope, among them, the highest one was birch and larch mixed forest, the followings were larch planted forest, Chinese pine planted forest, birch natural forest, and the lowest one was natural shrub forest.

林地土壤的涵养水源效益比荒草坡高277.28%~173.67%，其中白桦落叶松混交林最高，落叶松人工林、油松人工林、白桦天然林次之，灌木林最低。

In this paper,based mainly on the heights above sea level of the upper limits of the modern dark coniferous forest zones in some mountainous regions and the climatic data obtained from 102 meteorological stations in China,the theoretic altitude of the forest line has been calculated and maps showing the altitude isolines of the forest line,the isolines of height differences between the permafrost limits and the forest line and the isolines of height differences between the modern climatic snowline and the forest line in China have been constructed respectively.

本文主要根据我国一些地区现代暗针叶林带上限的海拔高程和102个气象台站的气象资料，计算出我国的森林线的理论海拔高度，并编绘出我国的森林线高程等值线图以及多年冻土线与森林线高差等值线图和现代气候雪线与森林线高差等值线图。

Firstly, according to study dynamic changes of the elements structures in succession about natural and artificial forest, then summarized regular patterns;at the same time.based on the study of Coupling Relationship between structure and function of water conservation forest established the ideal structures from the stand level and the watershed level. The ideal structures from the stand level: uneven-aged, double layer and mixed structure, and trend to natural forest. The watershed level followed the same principle, that is double layer patches, uneven-aged forest well-distributed and to build up different forest patches in watershed.

首先，经过对北京山区水源林天然林和人工林结构要素的演替动态研究，提出其发展规律，同时依据水源林结构与功能耦合关系研究，从林分层次和流域层次上分别构建了水源林的理想结构，其中，林分层次上水源林的理想结构为：异龄、复层、混交的结构状态，林分结构趋于天然林结构的特征；在流域层次上水源林的理想结构为也应形成&复层&、&异龄&、&混交&的结构，即：在流域各水源林斑块间形成林冠层复层、斑块内部乔木、灌木、草本层的复层；不同水源林年龄面积上的均匀分布；形成不同水源林斑块间的镶嵌分布。

The system implemented forest fire model selection automatically and intelligently. BP artificial neural network model of forest fire model selection was build by treating forest fire environment data as inputting variable and treating appropriate forest fire model as outputting variable. At the same time, we studied the methods of acquiring and calculating data of inputting and outputting. The system implemented machine of model selection automatically based on dynamic data driven technology. We selected 72 items experimental data from historical forest fire records in Beijing to experiment and confirm the validity of model selection. It turned out that the reliability of model selection is more than 80 percent.

3基于BP人工神经网络方法设计了林火模型适宜性选择技术框架结构，通过神经网络形成林火模型选择知识，实现了林火模型的自动化和智能化选择；以火场环境因子为输入变量，以适宜火场环境模拟的林火蔓延模型作为输出变量，构建了林火模型选择神经网络模型；研究了输入、输出因子数据的获取与计算方式，实现了动态数据驱动的林火模型自动选择机制；以本京市为例，选择了有详细火场情况记录的72场林火作为实验样本，其中60条记录作为学习样本集，12条记录作为验证样本，对神经网络进行了学习和验证，实验结果表明，模型选择精度可达到80%以上。

Protecting forest biodiversity is one standard of sustainable forest management, and it is an advanced subject to develop forest biodiversity index system based on forest management unit level and its assessment method in the study of SFM at home and abroad.

保护森林生物多样性是森林可持续经营的主要标准，研建森林经营单位级的森林生物多样性指标体系及评价方法是国内外森林可持续经营研究及实践的前沿课题。

On the basis of it, eight suggestions are put forward to evaluate the forestry ecological benefits:(1) it is an inevitable trend to carry out the comprehensive evaluation of the multifold forest ecological benefits;(2) upbuilding the theoretical frame of ecological benefits according to the situation of our country;(3) conducting the subarea case research based on the way of creativity accountment;(4) to set up the locating monitoring system of subarea forestry ecology profits to provide the reliable reference for the research;(5) studying the measuring estimate index more comprehensively to make it more self_contained and self_governed;(6) establishing the standards of the forest ecological benefit evaluation so that the evaluation could provide rational evidence for the establishment of the forestry compensation law and so on;(7) upbuilding economic accountment system of forest ecological benefits;(8) establishing economic compensation system of forest ecological benefits.

并且在此基础上提出了对今后森林生态效益评价研究的八点建议：(1)进行森林多种生态效益的综合评价是今后发展的必然趋势；(2)从国情出发建立我国森林生态效益评价理论框架；(3)在创新核算方法的基础上开展分区案例研究；(4)建立区域性森林生态效益定位监测系统，为研究提供真实可靠的数据资料；(5)更全面地研究生态效益计量评价指标，使之既具完备性又具独立性；(6)建立森林生态效益评价标准，使评价结果能为林业补偿等法律政策制定提供科学的依据；(7)建立森林生态效益经济核算制度；(8)建立森林生态效益的经济补偿制度。

The main results are: construction of Tarim desert highway shelter-forest promoted soil microbial development, and with increase of plantation time of the shelter-forest, the quantity, fatty acid diversity index of soil microbe and diversity index of bacterial DNA segment enhanced notably. As to soil microbial community structure, bacteria are dominant population with amounting for over 80% of total soil microbe, and fungi is not more than 1% of total soil microbe, but soil microbial community structure was different among three soil layers. The conclusions from study methods of conventional culture, biological marker and molecule biology were almost identical, which illuminates that construction of Tarim desert highway made soil microbial activity enhance and so promote nutrient cycle and utilization of Tarim desert highway shelter-forest land.

结果表明，塔里木沙漠公路防护林的建设促进了风沙土土壤微生物的发育，随着防护林定植年限的增加，土壤微生物数量、脂肪酸和细菌DNA片段的多样性指数明显增大；土壤微生物区系组成中，细菌是优势类群，占微生物总数80%以上，而真菌很少，不到微生物总数1%，但在不同土层间有所差异；传统培养法与现代生物标记和分子生物学方法对塔里木沙漠公路防护林地土壤微生物多样性的研究结果基本一致，说明塔里木沙漠公路防护林的建设使林地土壤生物活性有所增强，有利于林地土壤养分循环与利用。

Based on the theories of sustainable development,index system of forest resources sustainable management and comprehensive evaluation of urban forest,the index system of measure the urban forest sustainable development have been put forward.

在可持续发展理论、森林资源可持续经营指标体系研究及城市森林综合评价指标体系研究的基础上，提出衡量城市森林可持续发展的指标体系框架，设计城市森林可持续发展的综合评价方法。

In the days of sailing vessels the crew were afraid they would be becalmed on the ocean.

在使用帆船的时代，船员们担心他们会因为无风而无法在海洋上航行。

As long as foreign donors pay the PA's salary bill, few expect a new intifada.

只要外国继续为巴权力机构的薪水买单，希望发动新暴动的人便寥寥无几。