全文获取类型
收费全文 | 566篇 |
免费 | 9篇 |
国内免费 | 9篇 |
专业分类
安全科学 | 2篇 |
废物处理 | 1篇 |
环保管理 | 240篇 |
综合类 | 97篇 |
基础理论 | 123篇 |
污染及防治 | 91篇 |
评价与监测 | 16篇 |
社会与环境 | 13篇 |
灾害及防治 | 1篇 |
出版年
2023年 | 4篇 |
2022年 | 14篇 |
2021年 | 28篇 |
2020年 | 1篇 |
2019年 | 5篇 |
2018年 | 4篇 |
2017年 | 16篇 |
2016年 | 31篇 |
2015年 | 25篇 |
2014年 | 15篇 |
2013年 | 28篇 |
2012年 | 13篇 |
2011年 | 44篇 |
2010年 | 16篇 |
2009年 | 51篇 |
2008年 | 34篇 |
2007年 | 41篇 |
2006年 | 19篇 |
2005年 | 12篇 |
2004年 | 14篇 |
2003年 | 18篇 |
2002年 | 13篇 |
2001年 | 12篇 |
2000年 | 22篇 |
1999年 | 10篇 |
1998年 | 5篇 |
1997年 | 8篇 |
1996年 | 22篇 |
1995年 | 11篇 |
1994年 | 4篇 |
1993年 | 4篇 |
1992年 | 7篇 |
1991年 | 1篇 |
1990年 | 2篇 |
1989年 | 2篇 |
1988年 | 4篇 |
1987年 | 2篇 |
1986年 | 5篇 |
1985年 | 3篇 |
1984年 | 3篇 |
1983年 | 3篇 |
1982年 | 1篇 |
1981年 | 2篇 |
1979年 | 3篇 |
1978年 | 1篇 |
1977年 | 1篇 |
排序方式: 共有584条查询结果,搜索用时 312 毫秒
91.
We examine the role of spatial interactions in conservation easements placed on prairie pothole habitat in western Canada. One of the goals of the conservation easement program we study is to protect contiguous habitat. We identify endogenous spatial interactions among conservation easements and government protected land, independent of spatially correlated landscape features and local economic shocks that influence easement enrollment. We present evidence that easements increase the likelihood of subsequent easements on neighboring land. Government-protected land appears to have little effect on the location of conservation easements. These results imply that conservation agencies have leveraged past conservation investment to enroll more contiguous habitat in permanent easements through a combination of targeting and positive social interactions among neighboring landowners. 相似文献
92.
Reductions in global bee populations are threatening the pollination benefits to both the planet and people. Whilst the contribution of bee pollination in promoting sustainable development goals through food security and biodiversity is widely acknowledged, a range of other benefits provided by bees has yet to be fully recognised. We explore the contributions of bees towards achieving the United Nation’s Sustainable Development Goals (SDGs). Our insights suggest that bees potentially contribute towards 15 of the 17 SDGs and a minimum of 30 SDG targets. We identify common themes in which bees play an essential role, and suggest that improved understanding of bee contributions to sustainable development is crucial for ensuring viable bee systems. 相似文献
93.
Apps are small task-orientated programs with the potential to integrate the computational and sensing capacities of smartphones with the power of cloud computing, social networking, and crowdsourcing. They have the potential to transform how humans interact with nature, cause a step change in the quantity and resolution of biodiversity data, democratize access to environmental knowledge, and reinvigorate ways of enjoying nature. To assess the extent to which this potential is being exploited in relation to nature, we conducted an automated search of the Google Play Store using 96 nature-related terms. This returned data on ~36 304 apps, of which ~6301 were nature-themed. We found that few of these fully exploit the full range of capabilities inherent in the technology and/or have successfully captured the public imagination. Such breakthroughs will only be achieved by increasing the frequency and quality of collaboration between environmental scientists, information engineers, computer scientists, and interested publics. 相似文献
94.
Adam Erickson 《Ambio》2015,44(5):343-352
New institutions are critically needed to improve the resilience of social–ecological systems globally. Watershed management offers an important model due to its ability to govern mixed-ownership landscapes through common property regimes, translating national goals into local action. Here, I assess the efficacy of state watershed management institutions in the Pacific Northwest, based on their ability to support local watershed groups. I use document analysis to describe and compare state institutions in Washington, Oregon, Idaho, and California. Results indicate that state institutional efficiency and resilience are the key factors determining watershed group activity and stability. The primary drivers of institutional efficiency and resilience were institutional unification, robust funding portfolios, low agency conflict, and strong support for economic multiplier effects, creative partnerships, and scholarly research. My findings elucidate the critical role of institutional efficiency and resilience in governing dynamic and complex social–ecological systems, enabling the flexibility to address emergent transformations. 相似文献
95.
The Global Strategy for Plant Conservation (GSPC) set an ambitious target to achieve a conservation assessment for all known plant species by 2020. We consolidated digitally available plant conservation assessments and reconciled their scientific names and assessment status to predefined standards to provide a quantitative measure of progress toward this target. The 241,919 plant conservation assessments generated represent 111,824 accepted land plant species (vascular plants and bryophytes, not algae). At least 73,081 and up to 90,321 species have been assessed at the global scale, representing 21–26% of known plant species. Of these plant species, at least 27,148 and up to 32,542 are threatened. Eighty plant families, including some of the largest, such as Asteraceae, Orchidaceae, and Rubiaceae, are underassessed and should be the focus of assessment effort if the GSPC target is to be met by 2020. Our data set is accessible online (ThreatSearch) and is a baseline that can be used to directly support other GSPC targets and plant conservation action. Although around one‐quarter of a million plant assessments have been compiled, the majority of plants are still unassessed. The challenge now is to build on this progress and redouble efforts to document conservation status of unassessed plants to better inform conservation decisions and conserve the most threatened species. 相似文献
96.
Sam Provoost Carole Ampe Dries Bonte Eric Cosyns Maurice Hoffmann 《Journal of Coastal Conservation》2004,10(1):33-42
Grey dunes are a priority habitat type of the European Union Habitats Directive and demand special attention for conservation
and management. Knowledge of the ecology of coastal grey dunes can contribute to this policy. Dune grassland succession is
initiated by fixation and driven by the complex of soil formation (humus accumulation) and vegetation development. Leaching
and mobilization of CaCO3. which are important in nutrient dynamics, complicate the picture. At present, grass- and scrub encroachment greatly overrules
these fine scaled soil processes and causes substantial loss of regional biodiversity. Belgium has an international responsibility
in grey dune conservation because of the limited range of its characteristic vegetation, flora and fauna. As biomass removal
seems essential in grassland preservation, grazing is an important management tool. Evaluation of management measures focuses
on biodiversity measurements on the levels of landscape, community and species. 相似文献
97.
The macro-algae communities observed in the south lake of Tunis are characterized by the predominance of nitrophilous algae
which are in the order of biomass importance:Ulva, Cladophora andEnteromorpha. We have noted seasonal changes of alga distribution. The wind appears to be one of the most important factors influencing
this distribution. The total biomass reaches a maximum in the spring. Rapid decomposition of the biomass leads to a severe
ecological imbalance, resulting in crises of anoxia and fish death.
A restoration project has already started. It aims at removal of contaminated muds and the introduction of a new circulation
system.
The main objectives of this work were to collect information on the distribution and biomass of the phytobenthic communities
as a first step in the constitution of a database for further comparison. 相似文献
98.
In the asperillo dune system, Southwest Spain, lichen vegetation covering the dune sand, has a low species diversity but is
an important component of the perennial vegetation, providing stability, nutrients, and moisture to the soil layer. The Asperillo
dunes harbour (1) natural ecosystems, (2) disturbed systems affected by forestry activities where the natural vegetation is
eliminated, and (3) pine forest resulting from afforestation withPinus pinea since the end of the 1940s where the composition and abundance of the lichen flora has been drastically changed.
Our hypothesis was that the lichen species composition and distribution are influenced by the type and period of human intervention.
To test this hypothesis a 1.2 km × 1.1 km area, which includes zones with different degrees of conservation and perturbation,
consisting of five different habitats, was selected: well preservedJuniperus woodland,Pinus pinea plantations with dense scrub, dense scrub,P. pinea plantations cleared from scrub, and pioneer scrub in recent pine afforestation. In each area, randomly located 5m × 5 m homogeneous
plots were sampled. In each plot the cover of shrub and lichen species was recorded.
The first results show that lichen cover is higher in the most preserved areas,Cladonia mediterranea being the dominant species under theJuniperus phoenicea canopy. The lichen community changes in composition and abundance depending on the time elapsed since the last perturbation. 相似文献
99.
/ Public contact is a vital component of any program to manage natural resources. A well-planned public contact program uses a variety of strategies to create a sympathetic and environmentally aware public and to meet specific management-related objectives. A methodology is proposed that can be applied to planning public contact at any level, from media design for a specific project to corporate strategies for communication. The methodology integrates management-driven, client-driven and resource-driven planning to provide the connections essential to effective communication.KEY WORDS: Planning; Public contact; Interpretation; Conservation; Management 相似文献
100.
松山自然保护区的生态评价 总被引:14,自引:0,他引:14
松山国家级自然保护区是华北地区自然生态环境保存比较完好的暖温带山地生态系统其组成结构复杂,类型多样,面积4150.3hm^2,拥有高等植物783种,高等动物184种,本研究通过建立3个层次的生态评价指标体系,运用指标赋分和加权平均法,对松山自然保护区进行了生态评价,结果认为,该保护区的保护价值较高,在华北地区乃至全国均有典型的代表意义,目前保护区的面积,结构及经营管理可以满足保护区持续发展要求。 相似文献