首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   254篇
  免费   11篇
  国内免费   7篇
废物处理   1篇
环保管理   97篇
综合类   62篇
基础理论   47篇
污染及防治   46篇
评价与监测   13篇
社会与环境   6篇
  2023年   4篇
  2022年   4篇
  2021年   16篇
  2019年   1篇
  2018年   2篇
  2017年   11篇
  2016年   15篇
  2015年   19篇
  2014年   8篇
  2013年   12篇
  2012年   8篇
  2011年   22篇
  2010年   7篇
  2009年   20篇
  2008年   18篇
  2007年   18篇
  2006年   8篇
  2005年   4篇
  2004年   9篇
  2003年   5篇
  2002年   7篇
  2001年   1篇
  2000年   14篇
  1999年   4篇
  1998年   3篇
  1997年   2篇
  1996年   16篇
  1995年   7篇
  1994年   3篇
  1993年   1篇
  1992年   1篇
  1988年   2篇
排序方式: 共有272条查询结果,搜索用时 15 毫秒
91.
This paper explains briefly the conceptual framework of an ecosystem-based multiple-use forest management planning focusing on biodiversity conservation and participation. Some results from a case study were documented to realize the implementation of the concept. A strong liaison between the related institutions and major stakeholders and the effective use of Geographic Information System (GIS) and Remote Sensing (RS) are necessary. Effective participation is evident only with the involvement of enthusiastic and skillful stakeholders. A case study of ??neada, Turkey, supported the idea that participation as communication has better possibilities to promote multiple-use forest management than participation as information gathering. Primary challenges relate to the effectiveness of conservation program, availability of coherent biodiversity data, capacity building; awareness, training, and common understanding of biodiversity and protected area concept; coordination among the related institutions and stakeholders; and willingness and enthusiasm of authorities to accept and implement the concept.  相似文献   
92.
Urban Domestic Gardens (XIV): The Characteristics of Gardens in Five Cities   总被引:1,自引:0,他引:1  
Domestic gardens make substantial contributions to the provision of green space in urban areas. However, the ecological functions provided by such gardens depend critically on their configuration and composition. Here, we present the first detailed analysis of variation in the composition of urban gardens, in relation to housing characteristics and the nature of the surrounding landscape, across different cities in the United Kingdom. In all five cities studied (Belfast, Cardiff, Edinburgh, Leicester, and Oxford), garden size had an overwhelming influence on garden composition. Larger gardens supported more of the land-use types recorded, in greater extents, and were more likely to contain particular features, including tall trees and mature shrubs, areas of unmown grass and uncultivated land, vegetable patches, ponds, and composting sites. The proportional contribution of non-vegetated land-uses decreased as garden area increased. House age was less significant in determining the land-use within gardens, although older houses, which were more likely to be found further from the urban edge of the city, contained fewer hedges and greater areas of vegetation canopy >2 m in height. Current UK government planning recommendations will ultimately reduce the area of individual gardens and are thus predicted to result in fewer tall trees and, in particular, less vegetation canopy >2 m. This might be detrimental from ecological, aesthetic, social, and economic stand points.  相似文献   
93.
Biodiversity is essential for multiple aspects of human life and well-being, but many current assessments of the functioning of biodiversity and ecosystems, understanding of risks posed by environmental change and the best practice of their management of ecosystems are lacking a unified scientific and conceptual basis. Methods such as scenario analysis, and terms such as ecosystem services, are widely used, but their meaning is understood in many different ways depending on context, user needs and experience of researchers. In order to advance the conceptual basis for ecosystem analysis and management in a rapidly changing world, as well as the ability of young scientists to reflect upon these concepts, we have organised five 2-week-long summer schools in Peyresq, a remote village in the Southern French Alps. In total 173 participants have worked intensively with 69 experienced researchers and a team of conveners and tutors in order to discuss a broad range of views on topics on ecosystem analysis and functioning. Topics ranged from conditions of and threats to various ecosystems due to environmental change, models and scenarios for assessment, stakeholder perceptions and needs for information, to the social and economic contexts for biodiversity. We report our experience from these schools, present the training concept which has emerged from them and suggest lines of further development.
Wolfgang CramerEmail:
  相似文献   
94.
洞庭湖区湿地生物多样性保护及其可持续利用   总被引:9,自引:0,他引:9  
洞庭湖区是我国最大的淡水湖泊湿地之一,复杂多样的湿地类型和生态环境蕴含了丰富的生物资源,但长期以来由于人类不合理的开放利用,导致了洞庭湖区湿地面积和景观结构发生了很大变化,湿地生态功能也遭到严重破坏,生物多样性不断减少,本文分析了洞庭湖区湿地生物多样性现状及保护的意义,湿地生物多样性面临的威胁,并提出了洞庭湖区湿地生物多样性保护及其可持续利用的主要对策。  相似文献   
95.
鄱阳湖湿地植被的生物多样性及其保护和利用   总被引:6,自引:0,他引:6  
鄱阳湖是我国最大的天然淡水湖泊,湖区湿地面积2698km^2,是我国湿地生态系统中植物资源及植被类型最丰富的地区之一。该处分布高等植物75科200余属350余种,湿地植被依其生态环境和群落特征可划分为水生群落、沼泽、草甸、沙洲4类型60余个群系,保护与合理地持续利用这些植物群落是有效的保护和发展鄱阳湖湿地生态环境的根本途径。为些就切实制定鄱阳湖湿地总体规划,建立包括整个湖区面积在内的湿地生态系统自  相似文献   
96.
洪泽湖湿地资源保护与可持续利用研究   总被引:20,自引:0,他引:20  
洪泽湖湿地生物多样性比较丰富,湿地植被群丛多样,重点保护鸟类种类众多,种群数量大。调查结果显示:洪泽湖湿地共鉴定出浮游植物165种、水生高等植物81种、浮游动物91种、底栖动物69种、鱼类102种、鸟类194种。我们研究了洪泽湖湿地的大气、河流、湖泊环境质量,在分析洪泽湖湿地的破坏程度和原因后,提出了洪泽湖湿地保护对策和可持续利用途径。  相似文献   
97.
Biological benthic tools as indicators of coastal marine ecosystems health   总被引:1,自引:0,他引:1  
Coastal marine ecosystems are increasingly subjected to environmental stress and degradation due to pollution. Several research programmes have addressed this problem and produced relevant data sets for specific areas, often including consistent sets of environmental and biological variables. The value of existing information gathered from these types of data can be largely increased by combining them into a common data set to determine globally applicable relationships. To perform this exercise, the Intergovernmental Oceanographic Commission (IOC) of UNESCO has recently formed the Ad hoc Study Group on Benthic Indicators (http://www.ioc.unesco.org/benthicindicators) with the aim of developing robust indicators of benthic health. In this paper, initial products and ongoing activities of this international initiative are described and discussed. An expansion of initial IOC/UNESCO research on benthic fauna-organic carbon relationships is also presented. As part of this follow-up research, the relationship between total organic carbon concentrations of sediment and abundance, biomass and species diversity of benthic macrofauna was evaluated using data sets from 2 different regions of the world comprising 3 different coastal marine environments. The ability of identifying threshold levels in selected variables that could serve as indicators of related adverse environmental conditions leading to stress in the benthos is envisaged within the frame of a larger joint analysis, carried out by the IOC/UNESCO Study Group on Benthic Indicators, of merged data sets from several coastal regions worldwide.  相似文献   
98.
Since 1994 data on fungal fruiting have been gathered in the Dawyck Botanic Garden outside Edinburgh, including that for eight plots within a 7.5 ha wood, which has been left unmanaged in order to investigate relationships amongst fungal succession, habitat characteristics and local weather patterns. The climatic data are provided by a small meteorological station situated on site. To handle nearly 4000 entries of data so far collected a computer database was constructed. This assists querying of the information so that changes in fungal communities and patterns of succession can be observed, and the relevant data extracted for further analysis. To aid in this analysis, and to give the user full control over editing, updating and querying the database, a special computer program was compiled.Analysis of the database records revealed that the currently known Dawyck fungal community comprises over 620 different taxa, and the species list increases every year. Although some species of mycorrhizal fungi showed high specificity towards their preferred host either at species (e.g. Lactarius blennius with beech, Lactarius quietus with oak, Russula fellea and Russula mairei with beech), or at genus level (e.g. Suillus spp. with Pinaceae), some other common fungi (e.g. of the genus Amanita) were found to have very wide host ranges. In addition, unusual mycorrhizal associations have also been recorded. A lime tree (Tilia), which is supposedly primarily endomycorrhizal, has been found regularly associated with Russula cyanoxantha, Russula parazurea, Russula pectinata and Inocybe fastigiata. Many common Scottish fungi were found to be associated with introduced exotic trees, which is illustrated on the example of Pseudotsuga menziesii (Douglas Fir).The software created utilises the Microsoft Office suite of programs. Microsoft Access was used to construct the database, and Microsoft Excel was used for statistical investigations. The software was programmed using Microsoft Visual Basic, and provided a means of extracting the necessary data stored in Access and controlling the formulae used in Excel for their analysis. The recorded seasonal patterns of fungal fruiting was successfully described by a simulation mathematical model comprising differential and algebraic equations. This model may now be used as a submodel within more complex models describing terrestrial ecosystem processes. Examples of model simulations and sensitivity analysis are given and implications for future research discussed.  相似文献   
99.
Summary This contribution presents an attempt to measure the path of habitat and vegetation succession in a coastal dune system (Kenfig Burrows, South Wales) using remote sensing and GIS. The loss of slack habitats associated with the continuing stabilization of this dune system is a major cause for concern. These habitats support a range of plant species, including the rare fen orchid,Liparis loeselii, as well as other hydrophytes. A decrease in their areal extent implies a reduction in biodiversity. To quantify the overall rate and spatial dimension of these changes, a series of aerial photographs dating from 1962 to 1994 were digitized and analysed in an image processing system. The resultant maps. transferred to a vector-based GIS, were used to derive a transition matrix for the dune system over this period of time. The results indicate that there has been a marked reduction in the total area of bare sand (19.6% of the dune system in 1962, but only 1.5% in 1994) and a decline in both the areal extent and the number of dune slacks. Over the same period of time, there has been an increase inSalix repens dominated habitats, at the expense of pioneer species. Analysis of the habitat maps, together with hydrological data, within the GIS suggests that even the dry slacks have the potential for further greening and to support invasive species. In terms of habitat management however, there is still scope to restore many of the slacks to their original state. It is estimated that at least 24% of the area occupied by partially and moderately vegetated slacks could be rehabilitated.  相似文献   
100.
生物多样性保护成为当前国际社会普遍关注的焦点问题之一,是因为生物多样性的急剧丧失已在削弱未来人类持续发展的基础。本文从基因、物种和生态系统三个层次分析了生物多样性的性质和价值以及人类生存与发展的意义。指出生物多样性丧失的主要推动力是人类所采取的非持续的生活方式和发展模式,生物多样性的丧失已成为人类持续发展的主要障碍。在分析、总结我国生物多样性保护的成就与问题的基础上,提出了中国生物多样性保护战略。  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号