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451.
JONATHAN R. THOMPSON‡ MARK D. ANDERSON† K. NORMAN JOHNSON 《Conservation biology》2004,18(6):1475-1481
Abstract: Cross-boundary ecosystem management is increasingly being advocated to address large-scale ecological issues on forested landscapes. Such management requires information about the age, composition, and distribution of trees and other vegetation in addition to the ability to coordinate management over large areas. In the United States, the forest industry owns and manages a large quantity of biologically productive forest land, and these forests are crucial to the success of regional ecosystem planning. Antitrust laws, such as the Sherman Antitrust Act of 1890, limit the industry's ability to participate in regional ecosystem planning because they restrict the ability of competing firms to coordinate activities and share information. Because antitrust courts do not consider the intentions of violators, achieving conservation or other public policy goals, even when working with government agencies, is not a sufficient defense. Therefore, the real and perceived threat of antitrust litigation is a disincentive to the forest industry's participation in large-scale ecosystem management. Potential solutions to this problem include state immunity statutes and third-party data aggregation. 相似文献
452.
我国农业自然资源法的问题与改善途径初探 总被引:6,自引:0,他引:6
在介绍我国农业自然资源基本法律体系的基础上,分析了现行法律存在的主要问题,提出了强化农业资源管理的若干建议:①制定农业自然资源综合法律,完善农业自然资源法律体系;②更新充实现行农业自然资源法,以适应社会主义市场经济的要求;③从机制和手段两方面革新管理体制,强化农业自然资源相对统一的综合管理。 相似文献
453.
454.
2020年4月29日,第十三届全国人民代表大会常务委员会第十七次会议表决通过了新修订的《中华人民共和国固体废物污染环境防治法》(以下简称《固废法》)。此次修订,进一步巩固并完善了固体废物污染环境防治的基本原则。笔者从法律原则自身的变化和指导法律制度设计2个层面,对几项原则进行深入分析:在减量化、资源化和无害化原则方面,强化固体废物污染防治减量化和资源化的约束性规定同时,突出无害化底线要求;在污染担责原则方面,进一步明确"污染者"内涵和其应承担的责任;在生产者责任延伸原则方面,明确了电器电子、铅蓄电池、车用动力电池等产品实施生产者责任延伸制度的法律地位;在全过程管理原则方面,强化了对工业固废、建筑垃圾等固体废物的全过程监管及信息化监控的要求。还介绍了固体废物污染环境防治原则在发达国家和地区的立法情况,以及在中国的实践情况。 相似文献
455.
本文初探了干旱的榆林地区大气污染物浓度变化规律。指出悬浮微粒污染最严重,SO_2次之,NO_x最轻,描述了各种污染物季节变化规律。 相似文献
456.
Willem Salet 《Journal of Environmental Planning and Management》2019,62(2):189-204
The old tension between planning and law is revived in current practices of sustainable development. Urban professionals often blame central regulation for frustrating an inventive integration of local initiatives and policies. Against this background, the authors focus on the potential of ‘legal contextualisation’: the challenge of how to improve on regulation in such a way that it guides local practices in a normative sense but simultaneously enables optimal use of local – context bounded – option space. In order to make legal contextualisation researchable, the next four operational avenues of analysis are constructed in this paper: the normative dimension (requiring quality of legal norms); the relational dimension (studying the alignment of norms in different positions, such as the legislation, the court, and social compliance); the temporal dimension (searching the alignment of different moments of legal validation); and the functional dimension (making transparent the different roles that government agencies may take). 相似文献
457.
由于储煤仓结构设计较为封闭,通风效果较差,导致煤仓内部残存瓦斯不能有效地排放,极易造成煤仓内瓦斯超限。通过对原煤仓内部空气渗流规律进行研究,可以对其进行合理地通风,从而有效地治理瓦斯超限问题。实验采用玻璃球体和碎石子作为填充介质,采用单一变量法研究了非均质各向同性多孔介质的渗流规律,以及非均质各向异性多孔介质的渗流规律。在此基础上得出,随着粒径和渗流速度的增加,渗透压力梯度也在增加;同时,随着粒径的增大,渗流状态由线性渗流转变为非线性渗流,渗流速度不断地减小,其渗流速度与压力梯度均呈现非线性变化规律。 相似文献
458.
459.
Historical and Future Stream Temperature Change Predicted by a Lidar‐Based Assessment of Riparian Condition and Channel Width
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Gustav B. Seixas Timothy J. Beechie Caleb Fogel Peter M. Kiffney 《Journal of the American Water Resources Association》2018,54(4):974-991
Riparian forests attenuate solar radiation, thereby mediating an important component of the thermal budget of streams. Here, we investigate the relationship between riparian degradation, stream temperature, and channel width in the Chehalis River Basin, Washington State. We used lidar data to measure canopy opening angle, the angle formed between the channel center and trees on both banks; we assumed historical tree heights and calculated the change in canopy angle relative to historical conditions. We then developed an empirical relationship between canopy angle and water temperature using existing data, and simulated temperatures between 2002 and 2080 by combining a tree growth model with climate change scenarios from the NorWeST regional prediction. The greatest change between historical and current conditions (~7°C) occurred in developed portions of the river network, with the highest values of change predicted at channel widths less than ~40 m. Tree growth lessened climate change increases in maximum temperature and the length of river exceeding biologically critical thresholds by ~50%–60%. Moreover, the maximum temperature of channels with bankfull widths less than ~50 m remained similar to current conditions, despite climate change increases. Our findings are consistent with a possible role for the riparian landscape in explaining the low sensitivity of stream temperatures to air temperatures observed in some small mountain streams. 相似文献
460.
Connectivity of Streams and Wetlands to Downstream Waters: An Integrated Systems Framework 总被引:1,自引:0,他引:1
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Scott G. Leibowitz Parker J. Wigington Jr. Kate A. Schofield Laurie C. Alexander Melanie K. Vanderhoof Heather E. Golden 《Journal of the American Water Resources Association》2018,54(2):298-322
Interest in connectivity has increased in the aquatic sciences, partly because of its relevance to the Clean Water Act. This paper has two objectives: (1) provide a framework to understand hydrological, chemical, and biological connectivity, focusing on how headwater streams and wetlands connect to and contribute to rivers; and (2) briefly review methods to quantify hydrological and chemical connectivity. Streams and wetlands affect river structure and function by altering material and biological fluxes to the river; this depends on two factors: (1) functions within streams and wetlands that affect material fluxes; and (2) connectivity (or isolation) from streams and wetlands to rivers that allows (or prevents) material transport between systems. Connectivity can be described in terms of frequency, magnitude, duration, timing, and rate of change. It results from physical characteristics of a system, e.g., climate, soils, geology, topography, and the spatial distribution of aquatic components. Biological connectivity is also affected by traits and behavior of the biota. Connectivity can be altered by human impacts, often in complex ways. Because of variability in these factors, connectivity is not constant but varies over time and space. Connectivity can be quantified with field‐based methods, modeling, and remote sensing. Further studies using these methods are needed to classify and quantify connectivity of aquatic ecosystems and to understand how impacts affect connectivity. 相似文献