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101.
Since its introduction into Danish planning in 1989, Environmental Impact Assessment (EIA) has been widely discussed. At the centre of the debate the question has been whether EIA has actually offered anything new and there has been a great deal of scepticism about the efficacy of the instrument. Although, in principle EIA offers a holistic and proactive methodology, it does not seem to lead to a more holistic and proactive regulation which covers more ground than traditional planning and environmental regulation. In an evaluation of Danish experiences, this study has looked more closely at the effects of EIA. Three types of effects on projects have been examined: changes occurring prior to the formal application; changes during the EIA process; and the mitigation measures that are demanded of projects. The general conclusion is that EIA does generate a significant number of changes to projects. In approximately half of the cases studied, modifications are made prior to the formal application. During the formal EIA process, modifications were made in more than 90% of the cases. However, most of these could be considered as minor. EIA is characterized by being based upon a broad concept of the environment. It was found that a progressive narrowing of the concept of environment takes place during the course of the EIA process.  相似文献   
102.
The number of environmental impact assessment (EIA) screenings in Denmark has increased dramatically since 2000. This is a consequence of increased pig production as well as the concentration of production on larger farms. In the same period, EIA rules have developed primarily due to an increased focus on the protection of groundwater and Natura 2000 sites. In particular, the implementation of Natura 2000 in Danish legislation has increased the demands on many farms. In its rulings on appealed cases, the Nature Protection Board of Appeal has strengthened its demands, and this is mirrored in screening practices. In this paper, the demands formulated in the guidelines of local authorities were analysed in order to investigate how the protection of groundwater, coastal waters, lakes and Natura 2000 sites develops through EIA screening. It is concluded that the level of protection has improved, and that the main cause for this is not EIA regulations as such, but the positive role which the implementation of the Natura 2000 objectives has played in this development. However, it was also found that the formulation of demands varies greatly between the counties, thus often resulting in ambiguity and leaving room for quite different practices in different counties.  相似文献   
103.
在自然林火不再发生的同时,人们为了促进针叶树木的生长清除了落叶树种,并人为地将丰饶的森林变成了农地,由此,欧洲北部原有的针叶林景观发生了很大变化,一些地区的落叶林成分大大减少.然而,在乡村中落叶树种和落叶林得以保存下来,在一些弃耕的农田中也通过自然更新产生了新的落叶林木.我们在研究中做出以下假设,不同地区落叶林目前的分布格局与乡村中农业区和非农业区的分布相关,这种分布的形成又与当地的自然条件和以土地利用变化的形式表现的近期经济发展密切相关.我们的研究对象包括了瑞典北方针叶林和半北方针叶林区域中的6个地点--北博滕(Norrbotten)、翁厄曼兰(Angermanland)、耶姆特兰(Jamtland)、达拉纳(Dalarna)、Bergslagen和斯莫兰(Smaland),分析了乡村内农业区和非农业区中落叶林的空间分布.在每个地区,选择了6个以乡村为中心的5×5km样带.研究结果表明,在不同地区乡村中的不同景观区域,落叶林的分布和组成存在着明显差异.从单个乡村来看,翁厄曼兰中DEC(即落叶林成分)所占的比例平均最高(17%),而耶姆特兰则最低(2%).然而,农业区内和非农业区内DEC的数量却存在着规律性的地区差异,DEC在南方农业区内(斯莫兰)所占的比例最高,北方通常很低.对比之下,非农业区内DEC的数量在北方最高.相对较多的DEC出现在农业大量减少的地区的森林边缘地带(翁厄曼兰、达拉纳、Bergslagen).由于乡村在与落叶林有关的生物多样性中有着重要作用,因此本项研究的结果表明了对整个景观中的落叶林进行综合管理的必要性.通过本项研究,我们还可以看到卫星遥感数据可用于分析景观尺度上落叶树木和林分的空间分布.为了进行更为深入的研究,我们需要改进的专题分辨率以区分落叶林具相关生物特性意义的林分质量.  相似文献   
104.
According to the United Nations Framework Convention on Climate Change (UNFCCC) and Kyoto Protocol under it, industrial countries have to estimate their greenhouse gas emissions annually, and assess the uncertainties in these estimates. In Finland, agricultural methane (CH4) and nitrous oxide (N2O) emissions represent 7% of anthropogenic greenhouse gas emissions, and globally the share is much higher. Agriculture is one of the most uncertain emission categories (representing over 20% of greenhouse gas inventory uncertainty in Finland), due to both high natural variability of the emission sources and poor knowledge of the emission-generating processes. In this paper, we present an uncertainty estimate of agricultural CH4 and N2O emissions from Finland in 2002. Uncertainties were estimated based on measurement data, literature and expert judgement, and total uncertainty in agriculture was calculated using Monte Carlo simulation. According to the calculations, agricultural CH4 and N2O emissions from Finland were 3.7 to 7.8 Tg carbon dioxide (CO2) equivalents, 5.4 Tg being the mean value.Estimates of CH4 emissions are more reliable than those of N2O. N2O from agricultural soils was the most uncertain emission category, and the uncertainty was not reduced by using available national measurement data of N2O fluxes. Sensitivity study revealed that the uncertainty in total agricultural inventory could be 7% points lower, if more accurate emission estimation methods were used, including 1) improved data collection in area estimates of organic soils, 2) climate-specific methods for N2O from agricultural soils as already presented in literature, and 3) more detailed CH4 estimation methods for enteric fermentation which can be achieved by investigating national circumstances and digestible systems of animals in more detail.  相似文献   
105.
在解决复杂的土地管理问题时,对短缺或者有争执的资源进行地理评估有助于不同利益相关者之间沟通认识和增进理解.本文中,我们说明如何使用遥感和GIS收集和汇总瑞典北部驯鹿放牧者和其他土地使用者(林业、采矿业、旅游业等等)的土地使用活动及使用模式的信息.该项目主要基于最终的土地使用者,即驯鹿放牧者们所做的工作,体现了面向土地使用者的新的努力.发展驯鹿业的土地利用规划的基础有以下几个方面:收集并数字化传统的驯鹿栖息地生态学和景观信息将这些信息与来自野外调查及基于人造卫星观测的植被分类结果整合;绘制其他土地使用者的活动情况图.最终的土地利用规划提供的信息有利于驯鹿放牧者与其他利益相关者之间的磋商,并有助于驯鹿管理实施.该项目可作为一种大众参与和计划编制的模式,从而使本土信息和先进的遥感技术融入一个交互式的过程中.  相似文献   
106.
在景观水平的管理中,为了保护具有代表性和连接成片的生境网络,以达到维持生物多样性的目的,就必须在不同规模上将保护、经营和生境恢复等几项工作有机结合.我们认为将自然和社会科学融为一体的两维缺陷分析方法是实施生物多样性政策的有效工具.这个工具把与生物相关的"水平"生态学问题与"垂直"的制度体制和其它社会问题有机结合考虑.以森林生物多样性为例,本文将演示如何将与生物多样性保护有关的生态学和制度等方面的问题综合考虑,从而促进整个区域发展的环境可持续性.尤其,我们用区域性缺陷分析方法,即先确定对"绿色基础设施"起功能性连接作用的重点森林类型和生境模型,以此作为工具进行"水平"缺陷分析.就"垂直"范围而论,通过鉴别政策实施中的体制性障碍我们指出社会科学如何用于在实际景观范围内评估生物多样性政策实施是否成功.研究表明,多学科间的合作方法能应用于其它各类环境,包括其它陆生生物和水生生态系统,在这些生态系统中,重要栖息地的连接性、对栖息地丧失的非线性响应,以及社会和经济问题在同一景观内交织在一起.  相似文献   
107.
Plasma PBDE and thyroxine levels in rats exposed to Bromkal or BDE-47   总被引:2,自引:0,他引:2  
In experimental models, polybrominated diphenyl ethers (PBDEs), a group of brominated flame retardants, have caused effects in a number of biological end-points, including neurobehavioural effects, disturbances in thyroid and steroid hormone homeostasis, and other steroid-related effects. Almost exclusively, only external dose metrics (dose per body weight basis) have been studied in connection to the observed effects. In this study we report on new analyses of plasma PBDE levels in surplus samples from earlier studies on thyroid hormones (TH) in exposed rodents. Female, 7-week old Sprague-Dawley rats were given either Bromkal 70-5 DE (Study I; 18 or 36 mg/kg bw/day) or BDE-47 (Study II; 1, 6 or 18 mg/kg bw/day) daily by gavage for two weeks. At an external dose of 18 mg/kg bw/day significant TH effects (decreased plasma free thyroxin levels) were observed in both studies, corresponding to an internal (plasma) dose of 463 microg sumPBDE/g lipid (Study I) or 421 microg BDE-47/g lipid (Study II). If we compare the contribution of different BDE congeners to the total BDE level in rat plasma after Bromkal exposure (Study II), and in the Bromkal mixture itself, the most important congener in the Bromkal mixture were also found in plasma. However, the relative concentration of BDE-99 was lower, and that of BDE-153 was higher, than that of the mixture, indicating selectivity in uptake, metabolism and/or excretion of the individual BDE congeners. Explicitly, the possible in vivo conversion of BDE-99 to BDE-47, and of BDE-154 to BDE-153 could not be excluded. The internal dose in the present rat study could be compared to reported human serum doses of PBDE. Human serum/blood levels have a wide range, from 3 to 6 ng sumPBDE/g lipid in background samples from Europe, about 10 times higher in US sample, and up to 100 times higher (300-600 ng/g lipid) in upper-end levels in collected samples from USA. As a consequence, the margin between effects levels in the rat and exposure levels in man varies widely, with a quotient roughly from 1000 to 100,000. Generally, it could be expected that this margin is lower than if external dose metrics would be used. An even lower margin could be expected as recent studies have shown effects in offspring at lower doses than those giving effects in our studies. Lastly, it should be noted that humans are already exposed to a mixture of chemicals in daily life, a fact that complicates this kind of comparison.  相似文献   
108.
Fragrances such as OTNE (marketed as Iso-E-Super®) and bactericides such as triclosan (marketed as Igrasan) are present in waste water and thus finally sorbed to sewage sludge. With that sludge they can reach agricultural fields where they potentially can undergo photodegradation processes. In this study the photodegradation of OTNE and triclosan on dried loamy sand was measured under artificial sunlight conditions in laboratory experiments. These compounds were artificially added with concentrations of 1 μg g−1 on pre-rinsed dried loamy sand. The decrease in concentration with light irradiation was measured for 32 d in comparison to soil samples without light irradiation. The estimated light source intensity was 27 W m−2. Within the experiment, the apparent half-life was 7 and 17 d for OTNE and triclosan respectively. The decrease did not simply follow first-order kinetics. The apparent rate constant decreased in the latter stage of reaction, suggesting that part of the chemicals were inaccessible for degradation. Two models, i.e., a diffusion-limited model, and a light penetration-limited model, were used in comparison to the measured data to explain the observed degradation limitations in the latter stages of the experiments. Comparing the hereby obtained model parameters with estimated physico-chemical parameters for the soil and the two chemical compounds, the light penetration-limited model, in which the degradation in the soil surface layer is assumed to be limited due to the shading effect of light in the upper thin soil layer, showed to be the most realistic in describing the photodegradation.  相似文献   
109.
Riparian forests (RF) growing along streams, rivers and lakes comprise more than 2% of the forest area in the Nordic countries (considering a 10 m wide zone from the water body). They have special ecological functions in the landscape. They receive water and nutrients from the upslope areas, are important habitats for biodiversity, have large soil carbon stores, but may emit more greenhouse gases (GHG) than the uplands. In this article, we present a review of the environmental services related to water protection, terrestrial biodiversity, carbon storage and greenhouse gas dynamics provided by RF in the Nordic countries. We discuss the benefits and trade-offs when leaving the RF as a buffer against the impacts from upland forest management, in particular the impacts of clear cutting. Forest buffers are effective in protecting water quality and aquatic life, and have positive effects on terrestrial biodiversity, particularly when broader than 40 m, whereas the effect on the greenhouse gas exchange is unclear.  相似文献   
110.
Recent studies indicate that secondary ozonides of cyclic alkenes are formed in atmospheric reactions and may be relatively stable. The secondary ozonides (SOZs) of cyclohexene (1), 1-methylcyclohexene (2), 4-isopropyl-1-methylcyclohexene (3) and 4-isopropenyl-1-methylcyclohexene (limonene) (4) have been characterized by rapid gas chromatography electron ionization (EI), negative and positive chemical ionization (CI: ammonia, isobutane and methane) and collision-induced dissociation (CID) mass spectrometry. Both EI and positive CI spectra were found unsuitable for reproducible analysis. However, negative CI showed stable (M−H) ions with minor fragmentation. CID of the (M−H) ions resulted in simple and reproducible fragmentation patterns for all four SOZs with loss of m/z 18, 44 and 60, tentatively assigned as H2O, CO2 and C2H4O2 or CO3, respectively. Thus, negative CI-MS–MS in combination with rapid gas chromatography is the preferred method for identification of secondary ozonides of cyclohexenes.  相似文献   
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