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   5篇
  免费   0篇
环保管理   1篇
综合类   1篇
基础理论   2篇
社会与环境   1篇
  2020年   1篇
  2018年   1篇
  2009年   1篇
  1984年   1篇
  1968年   1篇
排序方式: 共有5条查询结果,搜索用时 15 毫秒
1
1.
Wildlife corridors aim to promote species’ persistence by connecting habitat patches across fragmented landscapes. Their implementation is limited by patterns of land ownership and complicated by differences in the jurisdictional and regulatory authorities under which lands are managed. Terrestrial corridor conservation requires coordination across jurisdictions and sectors subject to site-specific overlapping sources of legal authority. Mapping spatial patterns of legal authority concurrent with habitat condition can illustrate opportunities to build or leverage capacity for connectivity conservation. Streamside areas provide pragmatic opportunities to leverage existing policy mechanisms for riverine and terrestrial habitat connectivity across boundaries. Conservation planners and practitioners can make use of these opportunities by harmonizing actions for multiple conservation outcomes. We formulated an integrative, data-driven method for mapping multiple sources of legal authority weighted by capacity for coordinating terrestrial habitat conservation along streams. We generated a map of capacity to coordinate streamside corridor protections across a wildlife habitat gap to demonstrate this approach. We combined values representing coordination capacity and naturalness to generate an integrated legal-ecological resistance map for connectivity modeling. We then computed least-cost corridors across the integrated map, masking the terrestrial landscape to focus on streamside areas. Streamside least-cost corridors in the integrated, local-scale model diverged (∼25 km) from national-scale least-cost corridors based on naturalness. Spatial categories comparing legal- and naturalness-based resistance values by stream reach highlighted potential locations for building or leveraging existing capacity through spatial coordination of policy mechanisms or restoration actions. Agencies or nongovernmental organizations intending to restore or maintain habitat connectivity across fragmented landscapes can use this approach to inform spatial prioritization and build coordination capacity. Article impact statement: Combined mapping of legal authority and habitat condition reveals capacity to coordinate actions along streams for clean water and wildlife.  相似文献   
2.
Summary Attenuation of pure tones was measured in marsh and grassland habitat. At surface level, in grassland, the ground effect strongly attenuated frequencies below 2.0 kHz (Fig. 2). The ground effect was reduced by increasing source-receiver elevation. In marsh habitat the ground effect did not occur, and low frequencies were optimal for sound propagation (Fig. 3). As predicted from sound propagation tests, analysis of recorded songs of seven grassland and six marsh species indicated that minimum and emphasized frequency were significantly lower in songs of marsh birds. Maximum frequency did not differ between habitats (Table 4). Buzzing songs of yellow-headed blackbirds were broadcast and re-recorded at 1 and 50 m from the speaker in marsh and grassland habitats. Low frequency components attenuated more rapidly than higher frequency components in grassland, and the reverse occurred in marsh. Results suggested that the ground effect restricts the use of low frequencies by grassland birds. This evidence is consistent with the sound window hypothesis of Morton.  相似文献   
3.
Perchlorate, an anion that originates as a contaminant in ground and surface waters, is both naturally occurring and manmade. Because of its toxicity, there has been increased interest in setting drinking water safety standards and in health effects when perchlorate is present at low (parts per billion (ppb)) levels. In January 2009, the EPA issued a heath advisory to assist state and local officials in addressing local contamination of perchlorate in drinking water. The interim health advisory level of 15 micrograms per liter (μg/L), or ppb, is based on the reference dose recommended by the National Research Council (NRC) of the National Academy of Sciences (NAS). This paper describes scope and extent of contaminant issues and a legal process of setting standards for perchlorate concentration in drinking water in the United States of America.  相似文献   
4.
5.
Regional Environmental Change - This article explores the emergence of formal and informal bridging organizations to facilitate solutions to water conflict at the scale of the water resource. This...  相似文献   
1
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