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901.
This study examines the importance of climate variability when simulating forest succession using a process-based model of stand development. The FORSKA-2V forest gap model, originally developed for forcing with monthly mean climate data, was modified to accept daily weather data. The model's performance was compared using different temporal resolutions of forcing along a bioclimatic transect crossing the boreal region of central Canada, including the aspen-parkland and forest-tundra ecotones. Forcing the model with daily weather data improved the simulation of key attributes of present-day forest along the transect, particularly at the ecotones, compared to forcing with monthly data or long term averages. The results support the hypothesis that climatic variability at daily time-scales is an important determinant of present-day boreal forest composition and productivity. To simulate boreal forest response to climatic change it will be necessary to create climatic scenarios that include plausible projections of future daily scale variability.  相似文献   
902.
通过对环境监理的理论基础和法律依据的分析,提出完善环境监理运行机制,实施三位一体、公从参与、联合执法检查等措施  相似文献   
903.
The Paris Agreement reached during the COP21 in December 2015 represents a timid step towards burden sharing in emission mitigation involving all countries. However, given the heterogeneity of countries and their relative differences in vulnerability to climate change damage and in mitigation costs, compensating schemes are required to reach an effective agreement. This paper investigates the role of the Green Climate Fund (GCF) as a potential compensating measure for both adaptation and mitigation actions under a global climate regime. A dynamic climate-economy computable general equilibrium model (GDynEP) is developed by including both a monetary valuation of climate change damage costs and two alternative methods to determine the allocation of GCF resources among receiving countries and between adaptation and mitigation contributions. Results show that, despite the high costs associated with the implementation of mitigation actions, most developing countries would face even higher costs in case of inaction. Furthermore, the preference of a country for an allocation method is strongly influenced by its characteristics and needs. Consequently, a main policy conclusion is to design country-specific sharing rules for GCF in order to maximize country participation in a global agreement.  相似文献   
904.
Previous analyses of the debate on the assisted colonization of species (AC) omit a critical assessment of the rhetorical dimension of the AC debate. To address this gap, we ask: what kinds of arguments are deployed as mean of persuasion and what are the implications of the rhetorical dimension of the AC debate for decision-making on AC? Our methods consist of textual network analysis, which allowed us to generate maps of the arguments in the debate on AC and analyze these maps using standard network analytical measures. The argument maps of the AC debate emphasize different and multi-faceted value judgments. Some of these are couched in technical terms and thus are implicitly evaluative: what is an appropriate level of risk for focal species and recipient communities, how much knowledge/ignorance is sufficient to warrant action or inaction, and what species or ecosystem services are most valuable and should be prioritized in conservation science and management? Other types of arguments, however, are more explicitly evaluative: socio-economic calculations, defending or criticizing conventional principles of conservation policy, and ethical norms and values. While some of the technical aspects of the debate may be resolved by more research, the controversy over AC is unlikely to be resolved by science alone, because the issue is thoroughly enmeshed in rhetoric about who should have control over AC governance.  相似文献   
905.
赣北珍稀濒危植物分布状况的报告   总被引:1,自引:0,他引:1  
对赣北稀有珍贵植物进行了调查,并对这些植物的自然分布、用途作了介绍,提出今后开展保护稀有濒危植物的建设性意见。  相似文献   
906.
Within a collaborative project between Slovenian Environment Agency (ARSO) and Research Center Jfilich (FZJ), nitrogen reduction levels necessary to reach groundwater quality targets in Slovenia were assessed. For this purpose the hydrological model GROWA- DENUZ was coupled with agricultural N balances and applied consistently to the whole territory of Slovenia in a spatial resolution of 100 x 100 m. GROWA was used to determine the water balance in Slovenia for the hydrologic period 1971-2000. Simultaneously, the displaceable N load in soft was assessed from agricultural Slovenian N surpluses for 2011 and the atmospheric N deposition. Subsequently, the DENUZ model was used to assess the nitrate degradation in soil and, in combination with the percolation water rates from the GROWA model, to determine nitrate concentration in the leachate. The areas showing predicted nitrate concentrations in the leachate above the EU groundwater quality standard of 50 mg NO3/L have been identified as priority areas for implementing nitrogen reduction measures. For these "hot spot" areas DENUZ was used in a backward mode to quantify the maximal permissible nitrogen surplus levels in agriculture to guarantee a nitrate concentration in percolation water below 50 mg NO3/L. Model results indicate that additional N reduction measures should be implemented in priority areas rather than area-covering. Research work will directly support the implementation of the European Union Water Framework Directive in Slovenia, e.g., by using the maximal permissible nitrogen surplus levels as a framework for the derivation of regionally adapted and hence effective nitrogen reduction measures.  相似文献   
907.
选用模糊综合评价法,对溧阳市1985~2011年环境空气质量进行了综合评价,选用SO2、NO2、TSP/PM10作为评价因素,通过计算各评价因素权重分配系数和隶属度,分析了长期空气环境质量变化趋势。结果表明:TSP/PM 10为1985年以来溧阳市首要环境空气质量制约因素,20世纪80年代中期全市空气质量主要隶属于一级标准,20世纪80年代后期主要隶属于二级标准,20世纪90年代初期主要隶属于三级标准,20世纪90年代中后期至今主要隶属于二级标准,近几年受TSP/PM1 0因素影响,在三级标准的隶属度有上升趋势;自20世纪90年代中期始,NO 2超越SO2成为继PM 10之后制约空气质量的第2大因素;经济发展对环境空气质量的规模效应较为显著,技术减排效应逐步显现。  相似文献   
908.
监测分析云龙湖底栖动物种类变化、密度变化,底质组成与变化及生物多样性指数的变化来研究云龙湖水质的变化趋势。研究表明:近5年,云龙湖东湖水质有所改善,西湖富营养化有加重趋势。  相似文献   
909.
露天矿区开发活动主要是在景观层次上进行,其直接导致土地利用/覆被变化(LandUse/Cover Change,LUCC)。本文以黑岱沟大型露天煤矿1987年、1990年、2000年及2010年4期遥感影像的土地利用数据为基础,基于GIS空间分析功能,以破碎度、分离度和优势度景观格局指数和景观类型脆弱度为指标,分析景观格局现状。研究显示:开发初期,耕地和草地虽有所减少,但所占面积保持在80%以上;生态恢复开始后,土地类型向林地和草地转移的面积逐渐增多。景观水平上分析显示,景观上破碎化程度加大,煤矿建设用地斑块面积逐年增大。从景观指数看,耕地、草地、未利用地的破碎度、分离度指数变化呈上升或不稳定状态,建设用地的破碎度和分离度指数有所减小;优势景观类型有所改变,建设用地对于区域景观的控制作用逐渐加强。  相似文献   
910.
气候变化问题日益凸显。应对和适应气候变化刻不容缓。然而,短期内无法有效减缓气候变化产生的不利影响。因此,有必要针对不同领域制定相应的适应措施来提高人们对气候变化的适应能力。北京作为人口众多的大城市及我国的缺水城市之一,气候变化无疑将加剧水资源的供需矛盾。本文针对北京市水资源现状及气候变化对北京市水资源领域已经形成的影响,从自然、工程、政策制度三个角度探讨了北京市水资源领域适应气候变化可采取的对策及保障措施。  相似文献   
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