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101.
Effective environmental management requires documentation of ecosystem status and changes to that status. Without long-term data, short-term natural variability can mask chronic and/or cumulative impacts, often until critical levels are reached. However, a trade-off generally occurs between sampling in space and time. This study analyses a spatially and temporally nested long-term (12 years) monitoring programme conducted on benthic macrofauna in a large harbour. Sampling was carried out at six sites for 5.5 years, after which only two sites were sampled for the next 5 years. After this period, all six sites were sampled for another 2 years. While ecology is frequently thought of being highly variable, this design was able to detect trends, and cycles, in abundance, with only around 10% of species at each site exhibiting unpredictable temporal variability. Sites exhibiting similar trends in the abundance of a species over the 12.5-year period were generally spatially contiguous, and the spatial scale of change could be assessed. Continuous sampling at two sites identified whether changes in unsampled sites were related to long-term cycles. Moreover, this sampling provided a long-term background of temporal fluctuations against which to assess the ecological significance of observed changes.  相似文献   
102.
Abstract:  In the first comprehensive reviews since 1969, two high-level reports on the status of U.S. marine ecosystems and resources have been released: that of the nongovernmental Pew Oceans Commission in 2003 and that of the congressionally mandated U.S. Commission on Ocean Policy in 2004 . Although the two commissions differed in the breadth and depth of their mandates, their findings on the state of our oceans and need for new management approaches are similar, and their major recommendations for science, governance, management and conservation, and education echo and reinforce each other. The history behind the two commissions and the structure and objectives of each remind us of the crucial roles conservation practitioners and scientists must play in the implementation of report recommendations. The reports suggest priorities for conservation practitioners to improve science, management, conservation, governance, and education to better manage and protect ocean resources and ecosystems. To redirect activities affecting the state of global marine resources, integrated research; education and outreach by terrestrial, aquatic, and marine conservation practitioners; and a clear definition of their roles in the implementation of recommendations is essential. Marine ecosystems provide a test case of society's ability to manage complexity in human and natural systems in an integrated manner, with extensive opportunities for participation by conservation practitioners from all disciplines.  相似文献   
103.
A combination of in-situ PM2.5, sunphotometers, upward pointing lidar and satellite aerosol optical depth (AOD) instruments have been employed to better understand variability in the correlation between AOD and PM2.5 at the surface. Previous studies have shown good correlation between these measures, especially in the US east, and encouraged the use of satellite data for spatially interpolating between ground sensors. This work shows that cases of weak correlation can be better understood with knowledge of whether the aerosol is confined to the surface planetary boundary layer (PBL) or aloft. Lidar apportionment of the fraction of aerosol optical depth that is within the PBL can be scaled to give better agreement with surface PM2.5 than does the total column amount. The study has shown that lidar combined with surface and remotely sensed data might be strategically used to improve our understanding of long-range or regionally transported pollutants in multiple dimensions.  相似文献   
104.
The rapid growth of rural enterprises has transformed the Chinese countryside. Although rural industrialisation has resulted in increased financial well-being, it has also contributed to decreased environmental quality. While China has strong environmental protection laws, this paper will demonstrate that they are not being effectively implemented in a rural region in Zhejiang Province. This is due to a number of social, political, and economic barriers that prevent agencies from effectively enforcing environmental policies and regulatory mechanisms. This paper investigates the implementation of China's environmental policies through a case study in Yuhang County, Zhejiang Province. It demonstrates that the implementation of environmental impact assessment, discharge fees, and limited time treatment is limited by inadequate technology, low finances, limited human resources, poor public environmental awareness, faulty data, inferior agency reports, organizational conflict, relations based on guanxi, and low discharge fee prices.  相似文献   
105.
The Seine River is a highly artificialised catchment in Europe, comprising both productive agricultural areas and intense industrial and commercial activity. Due to its strategic importance, monitoring programs in the river started as early as the 1970s. The present study compiles and analyses this valuable data set (1970–2014), thoroughly describing the riverine section downstream of Paris and the estuary. We identify long-term trends and shifting patterns in nutrients and oxygen, and pay special attention to the river’s evolution after the year 2000, when the European Water Framework Directive came into force. The study has a manifest management perspective, and the results are discussed on the basis of the environmental quality standards proposed in current environmental regulations. The data show that water quality has improved remarkably over the past two decades, with sharp reductions of ammonium and phosphate and a progressive increase of dissolved oxygen levels. The amelioration is prominent in the estuary, where summer anoxic episodes have nearly disappeared. As a result, these three parameters are nowadays in good or very good condition throughout the year. The successful abatement of point sources contrasts, however, with the low effectiveness of the measures provided for the control of nutrients from diffuse sources. Nitrate concentration has increased by 150% since the early 1980s, and only very recently has the upward trend been reversed. Bold agri-environmental management measures are required if we are to prevent chronic pollution problems and truly restore the good ecological status of rivers.  相似文献   
106.
Handmer JW 《Disasters》1985,9(4):279-285
In 1977 the Government of New South Wales introduced a flood prone lands policy which attempted to break with the past emphasis on structural works. Cornerstones of the policy were the preparation of floodplain maps, and use of the 1:100 (100 year or 1%) flood to delineate floodplains and 1:20 flood for floodway definition. The fiscal and regulatory elements of the policy were to be applied more or less uniformly within the two zones. At first there was little effective opposition to the program, but this changed when large areas of Sydney, which had not been inundated since development, were mapped. Local government concern over issues of legal liability led to decisions which in turn prompted opposition to the policy from residents' action groups and property development interests. A perceived drop in property values provided the main motivation for action by residents. This pressure for change, which intensified just before the 1984 state election, saw the policy overturned.
The new policy gives local government greater responsibility for floodplain management. State authorities have withdrawn from floodplain mapping, although technical advice will continue to be provided, and there are no longer any uniform floodplain or floodway definitions. Policy implementation is to be guided by a Manual which attempts to define flood hazard in terms of both physical and social criteria.  相似文献   
107.
The Common Agricultural Policy (CAP) is the European Union's main instrument for agricultural planning, with a new reform approved for 2023–2027. The CAP intends to align with the European Green Deal (EGD), a set of policy initiatives underpinning sustainable development and climate neutrality in the European Union (EU), but several flaws cast doubts about the compatibility of the objectives of these 2 policies. We reviewed recent literature on the potential of CAP environmental objectives for integration with the EGD: protection of biodiversity, climate change mitigation and adaptation, and sustainable management of natural resources. The CAP lacks appropriate planning measures, furthering instead risks to biodiversity and ecosystem services driven by landscape and biotic homogenization. Funding allocation mechanisms are not tailored to mitigate agricultural emissions, decreasing the efficiency of climate mitigation actions. The legislation subsidies farmers making extensive use of synthetic inputs without adequately supporting organic production, hindering the transition toward sustainable practices. We recommend proper control mechanisms be introduced in CAP Strategic Plans from each member state to ensure the EU is set on a sustainable production and consumption path. These include proportional assignment of funds to each CAP objective, quantitative targets to set goals and evidence-based interventions, and relevant indicators to facilitate effective monitoring of environmental performance. Both the CAP and the EGD should maintain ambitious environmental commitments in the face of crisis to avoid further degradation of the natural resources on which production systems stand.  相似文献   
108.
The international development community is off-track from meeting targets for alleviating global malnutrition. Meanwhile, there is growing consensus across scientific disciplines that fish plays a crucial role in food and nutrition security. However, this ‘fish as food’ perspective has yet to translate into policy and development funding priorities. We argue that the traditional framing of fish as a natural resource emphasizes economic development and biodiversity conservation objectives, whereas situating fish within a food systems perspective can lead to innovative policies and investments that promote nutrition-sensitive and socially equitable capture fisheries and aquaculture. This paper highlights four pillars of research needs and policy directions toward this end. Ultimately, recognizing and working to enhance the role of fish in alleviating hunger and malnutrition can provide an additional long-term development incentive, beyond revenue generation and biodiversity conservation, for governments, international development organizations, and society more broadly to invest in the sustainability of capture fisheries and aquaculture.Electronic supplementary materialThe online version of this article (10.1007/s13280-020-01451-4) contains supplementary material, which is available to authorized users.  相似文献   
109.
《Ambio》2021,50(12):2286
Exploitation of natural forests forms expanding frontiers. Simultaneously, protected area frontiers aim at maintaining functional habitat networks. To assess net effects of these frontiers, we examined 16 case study areas on five continents. We (1) mapped protected area instruments, (2) assessed their effectiveness, (3) mapped policy implementation tools, and (4) effects on protected areas originating from their surroundings. Results are given as follows: (1) conservation instruments covered 3–77%, (2) effectiveness of habitat networks depended on representativeness, habitat quality, functional connectivity, resource extraction in protected areas, time for landscape restoration, “paper parks”, “fortress conservation”, and data access, (3) regulatory policy instruments dominated over economic and informational, (4) negative matrix effects dominated over positive ones (protective forests, buffer zones, inaccessibility), which were restricted to former USSR and Costa Rica. Despite evidence-based knowledge about conservation targets, the importance of spatial segregation of conservation and use, and traditional knowledge, the trajectories for biodiversity conservation were generally negative.Supplementary InformationThe online version contains supplementary material available at 10.1007/s13280-021-01628-5.  相似文献   
110.
西部大开发政策效应评价   总被引:1,自引:0,他引:1  
经过15年的西部大开发,西部各个省份的综合发展水平怎样?西部大开发是否显著缩小西部与东部地区在综合发展水平和经济增长的差异?哪些政策起到了关键作用?是本文将要探讨的问题。研究方法主要是通过模型与数据的实证研究方法对西部大开发的政策效应进行评价。内容包括:一是通过构建包含了社会、经济、科教与文化、对外开放和资源与环境五大类25个分项指标的综合发展水平评价体系,使用从1997到2013年31个省市的指标数据,并计算出综合评价值来考察西部大开发政策对西部地区各个省份整体发展的影响。从评价值排名上来看发现只有重庆、陕西、四川和内蒙古综合发展水平排名提升明显,而新疆、宁夏和青海发展差距还在拉大,其他省份排名变化不大。从分类指标来看,西部地区整体上社会发展和资源环境与生态提升较为明显,说明中央对于公共服务的转移支付和"退耕还林还草"等保护环境与生态的政策起到了一定的成效。二是选取了交通基础设施建设、中央转移支付和税收优惠这三个主要政策作为计量模型的政策变量,分别考察西部大开发整体和分项政策对于综合发展水平和经济增长率的影响。通过系统GMM方法估计整体西部大开发整体政策效应,以2000年前后对比,政策实施对GDP增长率的提升并不显著,综合发展水平也没有收敛。而以2008年为时间节点,综合发展水平和经济增长速度都得到了显著提升。通过DID估计分项政策,结果表明基础设施投入和转移支付能够有效提升综合发展水平和经济增长速度,税收优惠提升相对较弱。本文建议:在交通基础设施投入方面继续对西部地区予以倾斜,特别是建设西部地区通往东中部地区的交通大通道;培育和完善西部地区的市场经济体系,政府较少干预企业投资决策;加强对于西部落后地区、偏远地区的公共产品投入,加强扶贫工作。  相似文献   
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