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641.
Matthew F. Child S. A. Jeanetta Selier Frans G. T. Radloff W. Andrew Taylor Michael Hoffmann Lizanne Nel R. John Power Coral Birss Nicola C. Okes Michael J. Peel David Mallon Harriet Davies-Mostert 《Conservation biology》2019,33(5):1106-1119
As landscapes continue to fall under human influence through habitat loss and fragmentation, fencing is increasingly being used to mitigate anthropogenic threats and enhance the commercial value of wildlife. Subsequent intensification of management potentially erodes wildness by disembodying populations from landscape-level processes, thereby disconnecting species from natural selection. Tools are needed to measure the degree to which populations of large vertebrate species in formally protected and privately owned wildlife areas are self-sustaining and free to adapt. We devised a framework to measure such wildness based on 6 attributes relating to the evolutionary and ecological dynamics of vertebrates (space, disease and parasite resistance, exposure to predation, exposure to limitations and fluctuations of food and water supply, and reproduction). For each attribute, we set empirical, species-specific thresholds between 5 wildness states based on quantifiable management interventions. We analysed data from 205 private wildlife properties with management objectives spanning ecotourism to consumptive utilization to test the framework on 6 herbivore species representing a range of conservation statuses and commercial values. Wildness scores among species differed significantly, and the proportion of populations identified as wild ranged from 12% to 84%, which indicates the tool detected site-scale differences both among populations of different species and populations of the same species under different management regimes. By quantifying wildness, this framework provides practitioners with standardized measurement units that link biodiversity with the sustainable use of wildlife. Applications include informing species management plans at local scales; standardizing the inclusion of managed populations in red-list assessments; and providing a platform for certification and regulation of wildlife-based economies. Applying this framework may help embed wildness as a normative value in policy and mitigate the shifting baseline of what it means to truly conserve a species. 相似文献
642.
More than half of all energy produced by electric utilities is lost in the form of waste heat. However, when manufacturing facilities choose to produce their own electricity, this waste heat is captured by Combined Heating and Power (CHP) technologies and used in the production process. As a result, manufacturers' pollution footprint can be dramatically reduced by choosing to produce electricity onsite rather than purchasing it from a utility. This paper uses Census microdata to study manufacturers’ decision to produce electricity onsite and examines how plants adjust onsite generation when they are subject to environmental regulations. Environmental regulations will backfire if they cause manufacturers to produce less electricity onsite and shift to electricity from less efficient, offsite electric utilities. We find that manufacturing plants subject to NOx command-and-control regulations decrease onsite electricity generation, increase electricity purchases from off-site utilities and see declines in their energy efficiency. However, manufacturers subject to cap-and-trade see no decline in onsite generation and experience improvements in energy efficiency. These findings demonstrate the importance of instrument selection and identify a new pathway through which emissions leakage may occur. 相似文献
643.
Land and water resource development can independently eliminate riparian plant communities, including Fremont cottonwood forest (CF), a major contributor to ecosystem structure and functioning in semiarid portions of the American Southwest. We tested whether floodplain development was linked to river regulation in the Upper Colorado River Basin (UCRB) by relating the extent of five developed land-cover categories as well as CF and other natural vegetation to catchment reservoir capacity, changes in total annual and annual peak discharge, and overall level of mainstem hydrologic alteration (small, moderate, or large) in 26 fourth-order subbasins. We also asked whether CF appeared to be in jeopardy at a regional level. We classified 51% of the 57,000 ha of alluvial floodplain examined along >2600 km of mainstem rivers as CF and 36% as developed. The proportion developed was unrelated to the level of mainstem hydrologic alteration. The proportion classified as CF was also independent of the level of hydrologic alteration, a result we attribute to confounding effects from development, the presence of time lags, and contrasting effects from flow alteration in different subbasins. Most CF (68% by area) had a sparse canopy (50% canopy cover occupied <1% of the floodplain in 15 subbasins. We suggest that CF extent in the UCRB will decline markedly in the future, when the old trees on floodplains now disconnected from the river die and large areas change from CF to non-CF categories. Attention at a basinwide scale to the multiple factors affecting cottonwood patch dynamics is needed to assure conservation of these riparian forests. 相似文献
644.
旱作小麦─玉米垅种沟盖地膜带田集水调水与增产效应研究 总被引:2,自引:0,他引:2
旱作垅种(小麦)沟盖(玉米)地膜带田优于目前推广的沟种(小麦)垅盖(玉米)带田种植形式。在作物共生期相互调水作用更趋合理,平衡了小麦、玉米不同生育阶段对水分的供需矛盾,作物的生态条件更加适宜,群体结构更加协调,提高了作物的生产量,前者比后者增产90%~125%。 相似文献
645.
"罐中罐"技术在炼油废水处理中的工业应用 总被引:4,自引:0,他引:4
介绍了具有复合功能的水力旋液型均质、除油、沉淀、调节罐(WS-Ⅱ型、简称“罐中罐”)技术和设备的开发和工业应用的情况,通过生产实践和现场标定,显现了该设备具有较高的除油能力和缓冲调节能力。其可靠的收油、排泥设施使得运行稳定。基本上解决了现存污水调节罐的问题。设计思想独特新颖,操作简便可靠,值得推广和应用。 相似文献
646.
The paper reviews various policy tools that have been discussed in the literature, including legal, administrative and fiscal
(tax) schemes, as well as tradeable emission permits, and concludes that none of them are really suitable for dealing with
global problems. An alternative is suggested, namely the use of tradeable individual consumption quotas for traded commodities
at the national level, to be extended later to the global level by trading quotas among nations (assuming agreement can be
reached on the basis for determining quotas).
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
647.
我国排污收费制度评析 总被引:3,自引:0,他引:3
我国排污收费制度大体经历了4个发展阶段,形成了由国家法律、行政法规、地方法规等5个层次组成的政策体系。针对其存在的问题,建议明确“排污收费,超标处罚”为基本原则.扩大征收范围,加强税费改革,加强环境执法队伍建设。 相似文献
648.
Inefficient environmental instruments and the gains from trade 总被引:1,自引:0,他引:1
The primary result from the trade and environment literature is that countries never lose from trade liberalization as long as they implement optimal pollution targets or if they hold emissions constant. These results are derived in models where the regulators use efficient instruments such as tradable permits or emission taxes. Regulators, however, continue to prefer command and control instruments. I show that regulation under these inefficient instruments (such as design standards or concentration standards) can lead to net losses under trade liberalization even if emissions are optimally adjusted for trade. Furthermore, holding the line on emissions need not guarantee welfare improvements either. The problem is that institutional distortions, the excess costs of inefficient instruments, can rise with trade and offset the material gains from trade. Hence the presumption that we can achieve gains from trade by considering only the level of emissions fails to recognize that the mode of regulation also matters. 相似文献
649.
Plant vintage, technology, and environmental regulation 总被引:4,自引:0,他引:4
Wayne B. Gray Ronald J. Shadbegian 《Journal of Environmental Economics and Management》2003,46(3):384-402
We use data on productivity and pollution abatement costs at individual pulp and paper mills to test whether the impact of environmental regulation on productivity differs by plant vintage and technology. Plants with higher pollution abatement costs have significantly lower productivity levels. This relationship differs greatly based on a plant's technology, with productivity at integrated mills being greatly affected by abatement costs, while the impact at non-integrated mills is negligible. Plant vintage does not seem to matter, with older and newer plants showing similar impacts. Reported abatement costs appear to substantially understate the true costs of abatement. Accounting for the impact of technology differences makes some difference in the estimated overall impact of environmental regulation. 相似文献
650.
王充 《城市环境与城市生态》1997,10(1):25-28
本文介绍了干熄焦环境除尘系统的基本构成形式和工艺烟法特点。针对现有聊尘系统存在的一些缺欠,提出了四条相应的改进措施,并结合除尘系统实际运行情况,通过不同方式的风量调节对比,从理论上阐明了对风机进行调速设计才是达到调节风量和节能的最佳方式。 相似文献