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1.
INTRODUCTION Because China is deficient in forest resources, and the forest has the characteristics of low quality, uneven distribution, slow growth and severe situation of ecological environment, the ecology construction has become the first requirement in society and with the implementation of the “Natural Forest Conservation Program”, Chinese forestry is in the historic transition from timber production to ecological construction. Therefore, the timber production in China increases…  相似文献   

2.
The paper studies ten major tree species occupying the space in naturalsecondary forests in Mao Er mountain area.The space is divided into horizon,elevation,slope,aspect and topographic position layer.The features of the species of trees areexamined using the concept of distribution width and the method of space statistics.Theconclusions of analysis indicate that Aspen and Asian White Birch community of forests inthe area would become failing,and the distribution of Mongolian Oak and Mongolian Lidenand Manchurian Walnut are Limited by the slope and aspect and topographic position.Elm,Maple,Manchurian Ash would become the major species constituting naturalsecondary forests in future in this area.  相似文献   

3.
Urban forestry, which rose in the west in the latter half of the 20th century, is a type of forestry serving for city. Its important characteristic is that it makes through its narrow sense, or "urban afforestation", whose objective is to make city green and beautiful, and develops into a forestry system serving for the urban system. The consequence of rapid modern civilization is that skyscrapers concentrate in urban district and green space become narrower, resulting that green  相似文献   

4.
China is a country with an ancient civilization; its backward agriculture is not only a development issue but also a long-standing problem perplexing all levels of governments. More than 90% of the country's population live in rural areas and are mainly engaged in agriculture, they occupy over 90% of all resources (land included) in the country. Continuous increase of the rural population (farmers), low productivity and high use of inputs in farming, as well as some other ecological causes have led to rapid degradation of natural resources which has now become the focus of attention throughout the country. Even  相似文献   

5.
INTRODUCTIONUrban greenbelt is an important component of theurban eco-system. Presently the ecological functionand effect are drawing more and more attention fromenvironmental protective department, gardeningdepartment and all of the citizens. Because it has theefficacy of sterilization, cleaning the air, improvingthe immunity and balancing the functions, the air ionis also hailed as the air vitamin or the air hormone. Asit is vital to human health, it has become one of theimportant stand…  相似文献   

6.
The importance of ecological benefit analyses about green space systems has been widely discussed on the basis of a per-ceived bias towards the landscaping effect of green spaces to be built in urban areas as opposed to the perception of comprehensive ecological benefits of designed plant communities. Given the basic principle of ecological benefit analyses and evaluation methods widely applied today, the methodology to calculate ecological benefits and to model the expansion of urban green spaces by CITY-green 5.0 and its conditions for application were explored. We propose that aerial images can be substituted by AutoCAD graphics of a green space containing detailed information of plant dispositions by digitizing the key features during the working process in order to evaluate the ecological benefits quickly and to offer proper guidance to the establishment of small scale green spaces in urban areas. The theoretical foundation, potential application range and prospects for extension of the method are introduced by using the analysis of ecological benefits of the green spaces on the campus of Southwest Forestry College, Kunming, as an example.  相似文献   

7.
The tree specie selection is the critical part in the process of vegetation restoration and reconstruction in arid and semi-arid areas.As a reliable indicator of drought resistance and water use characteristics of tree species,water use efficiency(WUE) has become a hotspot in the research on tree specie selection.This paper introduced the concept and correspondingly research method of leaf WUE and summarized the research progress of leaf WUE in terms of the variation in leaf WUE between species,positions in the canopy,and characteristics of temporal and spatial variation,its influence on environmental factors like illumination,moisture,temperature, CO2 and O3 concentrations.Furthermore,it put forward the problems currently existing in the research and prospected the trend of future research on leaf WUE.  相似文献   

8.
1 INTRODUCTIONGLOBALURBANISATIONUrbanisation is a worldwide phenomenon; the WorldResource Institute (2001) estimated that in 2025 morethan 50% of the African and Asian populations wouldbe living in urban areas. In Central and South Americathese figures will be between 75% and 85%. Urbanareas in developing countries will account fornearly 90% of the projected world populationincrease of 2.700 million people between 1995 and2030 (Figure 1) .Managing urban population change will b…  相似文献   

9.
As a result of the rapid economic development, China will be confronted with severe energy crisis and environmental protection problem in future decades. As of 2003, China has become the second largest energy consumer in the world. The overall energy structure in China is characterized by abundance of coal and deficiency in crude oil and natural gas. Concerns about energy security paired with the need to tackle climate change lead to increasing support for the development of new domestic sources of renewabl...  相似文献   

10.
With rapid urbanization inChina, cities/towns continueto expand in size, ecological and environmentalproblems emerging during the process of urbanizationare becoming increasinglyevident.Urbanization movesforward rapidly, and any mistake in the design ofurban development would cause irreversible loss tothe country because of large investment in urbanenvironment development. According to the currentstatus of urban environment development in China,the available technical resources are far from me…  相似文献   

11.
Feng S  Hao J  Xu Z  Chen T  Qiu SX 《Fitoterapia》2012,83(1):161-165
A rare naturally-occurring polyprenylated isoflavanone, designated ormosinol (1), and a new isoflavonoid glycoside, named ormosinoside (2), along with 21 known compounds were isolated from the root bark of Ormosia henryi Prain. The structures of compounds 1 and 2 were determined as 5,7,2′,4′-tetrahydroxyl-6,8,5′-tri-(γ,γ-dimethylallyl)isoflavanone and isoprunetin-7-O-β-d-xylopyranosyl-(1 → 6)-β-d-glucopyranoside on the basis of a combination of 1D-, 2D-NMR and mass spectroscopic measurements. Compound 1 showed significant anti-oxidation activity against DPPH radicals (IC50 28.5 μM) and cancer cell line (A549, LAC, and HepG2) growth inhibitory activity with IC50 ranging from 4.25 to 7.09 μM, while compound 2 found to be inactive to both testing systems.  相似文献   

12.
生态经济林与可持续发展   总被引:11,自引:0,他引:11  
通过实地调查与资料收集,对生态经济树种及生态经济林进行了定义,分析了我国经济林的生产现状及发展生态经济林的意义。介绍了浙江省杨梅、山核桃、山茱萸、香榧等主要生态经济树种的经济效益与生态效益,并探讨了生态经济林纯林、混交林、立体经营及散生庭院式的栽培模式及规范化栽培,指出山地或坡地发展生态经济林应以混交林和立体经营为主,减少纯林栽培,提倡四旁、宅院种植经济林以增加收入、美化环境。同时指出生态经济林也是经济林生存和持续发展的根本问题。  相似文献   

13.
城市森林与城市绿化可持续发展   总被引:14,自引:0,他引:14  
针对目前城市绿化中存在的生态环境效能低下 ;绿化维护成本高 ;绿化的社会价值未能充分体现等主要问题 ,提出将城市森林建设作为城市绿化可持续发展的立足点。在阐明城市森林概念和范围的基础上 ,论述了城市森林的主要生态作用。并提出了城市森林建设的思路。  相似文献   

14.
巴东县水土流失现状、成因及治理对策   总被引:1,自引:0,他引:1  
笔者阐述了巴东县水土流失现状及其危害,从自然和人为两个方面分析了水土流失成因,并从技术和政策层面提出了治理对策。  相似文献   

15.
温州名木古树资源及其开发利用价值   总被引:4,自引:0,他引:4  
温州名木古树资源极为丰富,据调查已鉴定名木古树有104种,隶属40科75属;地理成份复杂、热带、亚热带成份占优势;并拥有较多的孑遗种、特有种、单种属;具有古、稀、奇特色;同时还拥有较多的国家级保护树种、创分布新记录和温州特有种。为温州市现代林业的发展提供了科学的依据和丰富的物种基因库,为温州市旅游风景资源展示了自然美的珍贵价值,又是为研究温州古代原始森林植被起源、演替、树种组成、结构特征和历史各进  相似文献   

16.
生态城市与城市绿化   总被引:22,自引:0,他引:22  
良好地反映人与自然和谐发展关系 ,各项规划建设能以不使环境遭到破坏为标准 ,行为主体的活动能自觉地朝利于维护周围环境并融于自然的天然群落即为生态城市。城市绿化的作用在于改善气候、改善环境卫生、蓄水防洪、防灾减灾、美化环境、节约能源等。目前在我国城市绿化方面存在着以下问题 :①都市规划缺乏宏观性、全面性和远见性 ;②绿色城市观念没有在大多数市民中形成 ;③缺乏硬性绿化指标 ;④绿化模式脱离国情、市情 ;⑤园林水平与国外相比有较大差距 ;⑥修建大草坪热温度居高不下 ;⑦城市绿化简单化 ;⑧应该绿化可以绿化的地方尚未绿化 ;⑨绿化布局、比例不尽合理与和谐 ;⑩重种植轻管护。针对以上问题 ,提出了创建生态城市的建议  相似文献   

17.
浅谈园林树种的选择配置与病虫害防治   总被引:7,自引:0,他引:7  
在园林绿化工作中,园林树种的选择搭配与病虫害的发生有一定的必然联系。文章从不同侧面阐述了二者的关系,并提出了通过合理选择配置园林树种防治和减少病虫害的措施。  相似文献   

18.
喷播绿化与喷播机械的技术概况   总被引:4,自引:0,他引:4  
介绍了喷播绿化种植技术及部分国外喷播机械,分析了喷播机械的结构特征及应用范围,论述了喷播设备的国产化现状及存在的问题。  相似文献   

19.
市场导致竞争,建筑师的创作必须与市场经济相结合,市场经济改变了过去对于建筑师职能的理解,给建筑师提示了新要求。  相似文献   

20.
古树名木的养护与管理初探   总被引:3,自引:1,他引:2  
分析了古树名木的衰败原因,并针对衰败原因提出古树养护管理的措施和方法。  相似文献   

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