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31.
Why the Conservation of Forest Genetic Resources Has Not Worked   总被引:3,自引:0,他引:3  
Abstract:  Genetic diversity is indispensable for long-term forest sustainability and is therefore mentioned in numerous binding and nonbinding political covenants calling for action. Nevertheless, there are significant obstacles to the conservation of forest genetic resources. We discuss hindrances to genetic conservation, mainly in Europe. We identified impediments by reviewing the literature and on the basis of the experiences of the authors in this field and their participation in related political processes. The impediments include (1) difficulties in assessing and monitoring genetic erosion and human impacts (e.g., by the lack of markers showing adaptive variation and the lack of record keeping on the use and transfer of forest-tree germplasm), (2) complexities of European national structures that make the development of a common strategy toward forest genetic conservation problematic, (3) lack of effective forest governance in many parts of the world, (4) the general unattractiveness of genes as flagships in raising public awareness, (5) lack of integration of genetic aspects into biodiversity conservation, and (6) the fact that scientists and politicians are often at cross-purposes. To overcome these impediments, forest geneticists and their peers in species conservation have to participate more actively in decision making. In doing so, they must be prepared to face challenges on 2 fronts: participating in political processes and the provision of significant research findings to ensure that decisions with respect to forest genetic diversity are politically implementable and effectively address targets.  相似文献   
32.
Biogeochemical models are often used for making projections of future carbon dynamics under scenarios of global change. The aim of this study was to assess the accuracy of the process-based biogeochemical model Biome-BGC for application in central European forests from the lowlands to upper treeline as a pre-requisite for environmental impact assessments. We analyzed model behavior along an altitudinal gradient across the alpine treeline, which provided insights on the sensitivity of simulated average carbon pools to changes in environmental factors. A second set of tests included medium-term (30 years) simulations of carbon fluxes, and a third set of tests focused on daily carbon and water fluxes. Model results were compared to aboveground biomass measurements, leaf area index recordings as well as net ecosystem exchange (NEE) and actual evapotranspiration (AET) measurements. The simulated medium-term forest growth agreed well with measured data. Also daily NEE fluxes were simulated adequately in most cases. Problems were detected when simulating ecosystems close to the upper timberline (overestimation of measured growth and pool sizes), and when simulating daily AET fluxes (overestimation of measured fluxes). The results showed that future applications of Biome-BGC could benefit much from an improvement of model algorithms (e.g., the Q10 model for respiration) as well as from a detailed analysis of the ecological significance of crucial parameters (e.g., the canopy water interception coefficient).  相似文献   
33.
Introduction: The European Union (EU) has developed different strategies to internalize the costs of excessive motor traffic in the road freight transport sector. One of these is a relaxation of restrictions on the size and load capacity of trucks that circulate between member States and a proposal has been made for Longer and Heavier Vehicles (LHVs) to be allowed to circulate across borders. LHVs are the so-called “megatrucks” (i.e., trucks with a length of 25 meters and a weight of 60 tonnes). Megatrucks have allowed to circulate for decades in some European countries such as Norway, Finland, and Sweden, world leaders in traffic accident prevention, although the impact that cross-border traffic would have on road safety is still unknown. Methods: This article provides an econometric analysis of the potential impact on road safety of allowing the circulation of “megatrucks” throughout the EU. Results: The findings show that countries that currently allow megatrucks to circulate present lower traffic accident and fatality levels, on average. Conclusions: The circulation of this type of vehicle is only advisable in countries where there is a certain degree of maturity and demonstrated achievements in the field of road safety. Practical applications: European countries that have allowed megatruck circulation obtaining better road safety outcomes in terms of accidents, although the accident lethality rate seems to be higher. Consequently, introducing megatruck circulation requires a prior proper preparation and examination.  相似文献   
34.
The annual averages (1986–1997) of pH are analysed for the most important European Monitoring and Evaluation Programme stations in Europe. The first objective is to discover the different temporal patterns and trends for the pH. To do this, a cluster analysis is developed. The trends are analysed by linear regression for the annual averages. In general, the pH shows an increasing trend significant at 0.05 level and the annual change ranging from +0.01 to +0.05 pH‐units per year for the different clusters obtained. The second objective is to examine the spatial variability of pH in precipitation through the use of principal component analysis. Six statistically significant modes of variability are obtained for the pH which represent the 84.5% of the total variance.  相似文献   
35.
欧洲的恶臭污染法规及测试技术进展   总被引:1,自引:0,他引:1  
欧洲城市中人口密度的增加导致了严重的恶臭污染,几百年来,各种有关恶臭污染的法规相继出台。在过去的30年中,恶臭测试方法有所发展,人们不再轻信环境健康工作者的主观判断,而是将恶臭测试推向定量化的轨道。根据恶臭排放测试,扩散模式以及恶臭标准(以定量恶臭性质的影响研究为基础,确定恶臭污染的可忍受程度),荷兰率先推动了恶臭量化管理趋势。恶臭标准根据各行业的恶臭污染的具体程度制定。嗅觉计测试臭气浓度是一项可靠的技术,目前已经写入欧洲标准(EN13725:2003),将嗅觉计测试法和日本的三点式比较臭袋法进行比较,发现结果具有显著的一致性。嗅辨员的严格筛选也是促成其一致性的关键因素。  相似文献   
36.
欧洲酸雨控制历程及效果综合评述   总被引:4,自引:0,他引:4  
在分析大量文献资料的基础上,综合评述了欧洲酸雨发展和控制的主要历程. 20世纪70年代以来,欧洲酸雨控制主要经历了EMEP建立与达成共识,CLRTAP公约形成与实施平均减排方针,基于临界负荷与生态敏感性制定减排策略,以及多污染物协同控制与追求多重环境效应等4个发展阶段,并取得了显著的控制效果. 1980—2007年,欧洲硫排放减少了84%,NOx排放减少了37%;大气中ρ(SO2)从10.32 μg/m3降至1.26 μg/m3,ρ(NO2)从10.38 μg/m3降至7.15 μg/m3;欧洲降水酸度呈不断下降的趋势. 最后,基于欧洲酸雨控制先进经验的分析,结合实际情况提出了未来我国酸雨控制建议.   相似文献   
37.
Rodin J 《Ambio》2011,40(2):221-230
Between 1985 and 1995, fertility in Eastern Europe declined from 2.2 children per woman to merely 1.5 on region-average. Previous research has emphasized mainly the economic turmoil during transition or the influx of new ideas regarding fertility and family relations. This article suggests that applying a risk management perspective on fertility patterns may put additional light on the reasons behind the fertility decline in post-communist Europe. The complexity of modern social systems has made people increasingly dependent on the state for risk evaluation and risk management. The article formulates the hypothesis that transition itself disrupted the mental models that helped people to navigate among the risks associated to having and raising children. Left to their own devices, women in Eastern Europe became more inclined to postpone childbirth or discard this option altogether.  相似文献   
38.
We investigate the possibility to replace the – so-called – Tier 1 IPCC approach to estimate soil N2O emissions with stratified emissions factors that take into account both N-input and the spatial variability of the environmental conditions within the countries of the European Union, using the DNDC-Europe model. Spatial variability in model simulations is high and corresponds to the variability reported in literature for field data. Our results indicate that (a) much of the observed variability in N2O fluxes reflects the response of soils to external conditions, (b) it is likely that national inventories tend to overestimate the uncertainties in their estimated direct N2O emissions from arable soils; (c) on average over Europe, the fertilizer-induced emissions (FIE) coincide with the IPCC factors, but they display large spatial variations. Therefore, at scales of individual countries or smaller, a stratified approach considering fertilizer type, soil characteristics and climatic parameters is preferable.  相似文献   
39.
欧盟是汽车行驶记录仪应用历史最久和安装车辆最多的地区。欧盟应用的成功经验掀起了周边国家及世界范围内各国争相引入汽车行驶记录仪实施道路交通安全监管的热潮。在广泛、深入调查欧盟汽车行驶记录仪应用情况的基础上,本文从基本概念、产品种类及技术发展、推广应用历程进行了简述,旨在加深人们对汽车行驶记录仪基本概念和应用理念的认识和理解,推动我国汽车行驶记录仪的进一步推广应用及管理体系的建立。  相似文献   
40.
Accurate and complete information on the emissions of persistent organic pollutants (POPs) are essential for interpreting historical, current and future contamination levels in remote areas. However, this information is also crucial for decision makers aiming at further reduction of the environmental loading of these substances on a regional scale. In this study, we identify and discuss specific POP emission inventory features that are deemed essential to understand, predict and control the behaviour of such substances on a European scale. It is shown that the scientific value of official emission data is limited (e.g. for deriving source–receptor relationships on a European scale), as there is insufficient information on spatial, temporal and compound coverage. Likewise, we argue that non-official emission data (i.e. research-driven emission inventories), which are based on aggregated statistics, may be of limited value for the identification of further emission control strategies. It is thus argued that future emission inventories should be developed in a format that is suitable to serve both policy- and research-oriented applications. Further improvement of official emission data with respect to research-driven features seems to be the most sensible way to proceed. Finally, the empirical basis of current emission inventories remains weak, and further research on emission identification and characterisation seem needed (a) to gain confidence in predicted source–receptor relationship as well as (b) for the development of sound control strategies.  相似文献   
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