查询词典 selection forest

The species belongs to DCZM-H Pattern, can be seen in the sub-stratum of the Decidural forest, Tsuga forest and Mixed Forest often.

属于滇西及滇西北、川西南、藏东南和缅甸东北部横断山区特有分布。常见于落叶阔叶林、铁杉林和针阔叶混交林下亚层。

These pollen maps show significant vegetation changes during the past 10 000 years in the current forest regions of Northeast China, with the early Holocene characterized by the widely distributed Birch, the mid-Holocene by the development of temperate deciduous forest mainly consisting of Quercus and Ulmus, and the late Holocene by the marked increase in Pinus abun dance and the development of temperate mixed conifer and deciduous forest.

花粉图展示了东北地区植被演化的主要特征。桦树在全新世初期遍布从三江平原到辽东半岛南端的东北东部地区，在森林中占据绝对优势地位；榆属和栎属等阔叶乔木在早中全新世的大部分时间内是东部森林中的主要种类；在大约5kaBP以后，松属在东北现在的森林地区开始增加，云、冷杉属也表现出较明显扩大，中北部地区的森林覆盖度可能比原来增大了。

The result pointed out that the vertical distribution of foliage for each species was different,however,generally speaking,the foliage in upper crown (0.3CL) for broad-leaved species in natural secondary forest took a small percentage,about 10%;in middle or middle lower of the crown(0.4CL to 0.8CL) the branches here took the majority percentage of whole foliage,almost 60%to 75%;but in lower crown(0.8CL),there was about 10%of whole foliage.(5)The interspecies competition of trees in secondary forest was expressed by Hegyi competitioin index,and the active competitor was calculated by the competition zone radius and the tree position,DBH,and distance in the zone,it was not all competitors in tranditional calculation.The study introduced crown area overlap index to describe the crown competition between subject tree and its competitors,furthermore,the crown area was classified into 5 levels with a method of equal crown projection area,therefor,the resulting crown area overlap index showed more realities of existing stand conditons.(6)Based on the theoretics of multiply divide,the spatial strcture optimizing model of secondary forest stand selective thinning was developed by diversity mingling,aggregation index,competition index and crown area overlap index,also designed 10 constraint conditions which were related to forestry meanings,the objective function was solved by the implicit enumeration method with LINGO 9.0,using 0-1 integer programming.

并且得出，每个树种在树冠内相对高度上的叶量的垂直分布是不同的，天然次生林阔叶树种的叶量在树冠的上部(0.3CL以下)所占比例很小，约占10%左右；在树冠的中部以及中下部(0.4CL～0.8CL)，叶量所占比例最大，几乎集中了整个树冠60%～75%的叶量；而在树冠的下部(0.8CL以下)，几乎占很少的叶量，大约10%左右。5、采用Hegyi竞争指数来表现次生林内林木的竞争关系，并且根据竞争圈的大小和林木在竞争圈内的分布位置、大小与距离来计算有效的竞争木，并不是传统意义上的全部竞争木；本研究提出用树冠叠加指数来表示林木与周围树木的树冠竞争情况，并采用等树冠投影面积法把树冠分为5级，这样计算的树冠叠加指数更加与现实林分相符。6、本研究基于乘除法的思想，用多样性混交度、聚集指数、竞争指数和树冠叠加指数构建了天然次生林择伐空间优化模型，设计了10个与林学意义相一致的约束条件，并采用0-1整数规划的思路，在LINGO9.0软件中使用了隐枚举法对目标函数求得最优解。7、以M702标准地为应用实例，具体计算出了每株采伐木，经过择伐后，目标函数值按模型设计的要求发生了极大的改变，增加了5倍多，说明了最后这个解的优良性，满足了设计的要求。

The paper , taking forest parks in the pearl river delta as an example , expounds several problems in forest park planning area , and principles and methods on delimitating the boundary of urban forest parks

摘要以珠江三角洲的部分森林公园为例，剖析城市地区森林公园规划区存在的主要问题，并提出合理勘界的工作原则和方法。

With thick forest and sound vegetation it is one of the forest treasure houses in central China and is also eulogized as immense forest of the west Hubei.

它还是华中地区重要的洁净能源基地。特别是&全国沼气第一州&的建成，使得恩施州的能源开发具有更大的开发前景。

The main content of studying in this dissertation are as follows: First, the dissertation defines the concept and intension that state- owned forest resources assets owned, sets up state- owned forest reserves goal system that assets run, and orientates the operation objective of state- owned forest resources assets according to the classified management of forestry .

第一，界定了国有森林资源资产运营的概念及其内涵，建立了国有森林资源资产运营的目标体系，并按林业分类经营的要求对国有森林资源资产运营目际进行了定位。

On the basis of the analysis of physicochemical properties of soil, analyzes variance characters of soil physical properties and nutrient properties in different land use ways and slope locations in the western edge mountains of Sichuan basin, and the results indicate that, in the respect of soil physical properties, it is either the soil structure coefficient or the degree of aggregation that is contained in farm land is obviously less than that is contained in reforested land and waste land, and because of the effects that forest crop root system and forest floor take, the soil physical properties of forest plantation is far better.

在土壤理化指标测定基础上，分析了四川盆地西缘中低山坡地不同土地利用方式和坡位下土壤物理性质与养分性质的分异特征，结果表明：土壤物理性质方面，耕作土壤的结构系数和团聚度明显低于人工林和荒草地，人工林由于林木根系和枯枝落叶层的作用，土壤物理性状明显较好。

The result indicated that other shrubberies, the land where the forest had not been grown up and the land being suitable for forest growing were the dominant styles of the forest resource landscape of the whole county.

结果表明，其他灌木林、未成林造林地和宜林地是全县森林资源景观的主导类型；当地造林力度大；林业发展空间广阔；景观生态系统不稳定。

People who live outside the forest need not in future appearbefore the royal justices of the forest in answer to general summonses,unless they are actually involved in proceedings or are sureties forsomeone who has been seized for a forest offence.

居住在森林外的人将来不需要在一般森林的王室审判传唤时到庭，除非他们涉入诉讼或者作为侵犯森林的嫌疑人的担保人。

Shen Nong top mist throughout the year the vast, bare rock, there is a long moss and ferns, are located halfway up on the bamboo forest, alpine fir forest and rhododendron forest.

神农顶终年雾霭茫茫，岩石裸露，长有苔藓和蕨类植物，山腰上则分布着箭竹林带、冷杉林带和高山杜鹃林带。

The system can be widely used in belt weighing and batching process control,etc.

介绍了基于智能模糊控制的嵌入式配料系统的设计方法，对模糊PID控制过程和系统调零作了重点的讨论，同时给出了PID控制的程序流程图和系统定长调零子程序。

"I dunno," she answered,"but if you show me aroun', I'll recognize it from the lighthouse just outside the porthole."

"我不知道，"她回答说，"如果你能带我转转，我能认出来的，因为灯塔就在舷窗外。"