我国城市生态承载力研究进展

从生态承载力角度研究区域资源-生态-环境问题,是当今生态学、地理学和经济学等学科研究的热点与前沿领域之一。依据现有研究成果,阐述了承载力的概念和什么是城市生态承载力,并对生态承载力的研究方法、研究趋势及其研究存在的问题和方法途径及提高城市生态承载力的对策建议进行了简述。     

浅论环境监测为环境管理服务

结合工作实践,初步论述环境监测在环境管理中的地位、作用及其如何为环境管理服务。     

液/液界面电化学及在环境监测分析中的应用

介绍了液/液界面电化学四种基本结构和主要实验方法,综述了液/液界面电化学分析方法在环境监测分析中的应用。作为一种新方法测定离子载体及能与其形成络合物的金属离子组分的浓度,它具有简便、快捷、经济实用等特点。     

地表水环境监测的质量保证与质量控制

从人员素质、监测分析方法的选定、布点采样方案和措施、实验室内质量控制、数据处理和报告审核等环节分析了目前影响地表水环境监测质量的几大因素,并从环境监测过程的实际出发提出质量保证和质量控制的方法和建议。     

Incentives to improve farm management: EMS, supply-chains and civil society

This paper focuses on impediments to environmentally sound management practices and how these might be overcome, with an emphasis on the role of environmental management systems, supply chains and civil society. It argues that: Farmers are under increased pressure to cut costs and improve production but with little opportunity to increase prices. Commonly short-term economic interest has damaging environmental implications. Current government policy, in Australia and in many other jurisdictions, relies heavily on voluntary arrangements, education and information, as the main policy instruments through which to persuade farmers to adopt better environmental farm management - e.g. the recent push to encourage the use of voluntary environmental management systems. However, there is good evidence to suggest that these can only make a valuable contribution when combined with a range of other policy instruments, including positive and negative incentives, intervention by third parties and in some cases, an underpinning of regulation. Arguably, what is needed is a strategy that builds on the strengths of voluntary environmental management arrangements while compensating for their weaknesses by combining them with other, complementary policy instruments. If so, we must engage with a range of questions that have not so far figured substantially in the policy debate. Although the principal focus has been on the role of government in bringing about on-farm change in management practices, supply chain pressure (at least in respect of agricultural chemicals and practices which threaten food safety) and civil society action are also potentially powerful mechanisms for bringing about change. Government can and should play a role in harnessing such forces in the interests of improved environmental on-farm practices.     

Efficiency analysis for organic agricultural producers: the role of soil-improving inputs

Greater emphasis is being placed on indicators of agri-environmental efficiency of organic production systems. Linking environmental measures with profitability measures based on net income is the only way to develop such indicators. A stochastic production frontier model that explicitly incorporates farm decisions about acquiring and managing organic soil-improving inputs is used to measure efficiency. The results confirm that on-farm self-sufficiency in soil-improving inputs is positively related to farm-level efficiency.     

PCDD/Fs in ambient air collected in Zagreb, Croatia

Levels of PCDD/Fs were measured at four different sites in Zagreb, capital of Croatia. Also one sample was taken during spontaneously initiated open fire on a landfill and one sample where garden waste of unknown content was burnt. Over period 1997–2000, 28 samples were collected and levels ranged between 9 and 306 fg I-TEQ m⁻³, except in the sample collected during landfill fire. Air PCDD/F levels in Zagreb at four sites were different and the highest levels were observed in industrial area. Seasonal variation of levels is also evident with higher levels in winter than in summer. Our results show that PCDD/F levels in ambient air collected in Zagreb are at lower end of the published data range. In general, homologue profiles were quite similar for all locations, the concentration of PCDD homologues increased while the concentration of PCDF homologues decreased with increasing degree of chlorination. PCDD/F levels in the landfill fire sample was 13 200 fg I-TEQ m⁻³ which are much higher than levels in garden waste burning sample or in sample collected at industrial site. During landfill fire, the concentration of 2,3,7,8-TCDF becomes even higher than the concentration of OCDF and is equal to the concentration of 1,2,3,4,6,7,8-HpCDF.     

Mitigation of CO2 Emissions from the EU-15 Building Stock. Beyond the EU Directive on the Energy Performance of Buildings (9 pp)

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Goal Scope and Background. The European Directive on Energy Performance of Buildings which came into force 16 December 2002 will be implemented in the legislation of Member States by 4 January 2006. In addition to the aim of improving the overall energy efficiency of new buildings, large existing buildings will become a target for improvement, as soon as they undergo significant renovation. The building sector is responsible for about 40% of Europe's total end energy consumption and hence this Directive is an important step for the European Union in order that it should reach the level of saving required by the Kyoto Agreement. In this the EU is committed to reduce CO2 emissions relative to the base year of 1990 by 8 per cent, by 2010. But what will be the impact of the new Directive, how large could be the impacts of extending the obligation for energy efficiency retrofitting towards smaller buildings? Can improvement of the insulation offset or reduce the growing energy consumption from the increasing installation of cooling installations? EURIMA, the European Insulation Manufacturers Association and EuroACE, the European Alliance of Companies for Energy Efficiency in Buildings, asked Ecofys to address these questions.

Methods

The effect of the EPB Directive on the emissions associated with the heating energy consumption of the total EU 15 building stock has been examined in a model calculation, using the Built Environment Analysis Model (BEAM), which was developed by Ecofys to investigate energy saving measures in the building stock. The great complexity of the EU-15 building stock had to be simplified by examining five standard buildings with eight insulation standards, which are assigned to building age and renovation status. Furthermore, three climatic regions (cold, moderate, warm) were distinguished for the calculation of the heating energy demand. This gave a basic 210 building types for which the heating energy demand and CO2 emissions from heating were calculated according to the principles of the European Norm EN 832.

Results and Discussion

The model calculations demonstrates that the main contributor to the total heating related CO2 emissions of 725 Mt/a from the EU building stock in 2002 is the residential sector (77%) while the remaining 23% originates from non-residential buildings. In the residential sector, single-family houses represent the largest group responsible for 60% of the total CO2 emissions equivalent to 435 Mt/a.

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- The technical potential: If all retrofit measures in the scope of the Directive were realised immediately for the complete residential and non-residential building stock the overall CO2 emission savings would add up to 82 Mt/a. An additional saving potential compared to the Directive of 69 Mt/a would be created if the scope of the Directive was extended to cover retrofit measures in multi-family dwellings (200-1000m2) and non-residential buildings smaller than 1000m2 used floor space. In addition including the large group of single-family dwellings would lead to a potential for additional CO2 emission reductions compared to the Directive of 316 Mt/a.

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- Temporal mobilization of the potential: Calculations based on the building stock as it develops over time with average retrofit rates demonstrated that regulations introduced following the EPB Directive result in a CO2 emissions decrease of 34 Mt/a by the year 2010 compared to the business as usual scenario. Extending the scope of the EPB Directive to all residential buildings (including single and multi-family dwellings), the CO2 emission savings potential over the 'business as usual' scenario could be doubled to 69 Mt/a in the year 2010. This creates an additional saving potential compared to the Directive of 36 Mt/a.

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- Cooling demand: The analysis demonstrated that in warm climatic zones the cooling demand can be reduced drastically by a combination of lowering the internal heat loads and by improved insulation. With the reduction of the heat loads to a moderate level the cooling demand, e.g. of a terraced house located in Madrid, can be reduced by an additional 85% if the insulation level is improved appropriately.

Conclusions

This study demonstrates that the European Directive on Energy Performance of Buildings will have a significant impact on the CO2 emissions of the European building stock. The main saving potential lies in insulation of the existing building stock. Beyond this, CO2 emissions could, however, be greatly reduced if the scope of the Directive were to be extended to include retrofit of smaller buildings.

Recommendation and Perspective

The reductions should be seen in relation to the remaining gap of 190 Mt CO2 eq. per annum between the current emission levels of EU-15 and the target under the Kyoto-Protocol for the year 2010. The energy and industrial sector will probably contribute only a fraction of this reduction via the newly established EU emissions trading scheme and connected projects under the flexible mechanism. In addition, the traffic sector is likely to continue its growth path leading to a widening of the gap. Thus, there is likely to be considerable pressure on the EU building sector to contribute to the EU climate targets beyond what will be achieved by means of the current EPB Directive. Legislators on the EU and national level are therefore advised to take accelerated actions to tap the very significant emission reduction potentials available in the EU building stock.     

Prioritizing Conservation Effort through the Use of Biological Soil Crusts as Ecosystem Function Indicators in an Arid Region

Abstract: Conservation prioritization usually focuses on conservation of rare species or biodiversity, rather than ecological processes. This is partially due to a lack of informative indicators of ecosystem function. Biological soil crusts (BSCs) trap and retain soil and water resources in arid ecosystems and function as major carbon and nitrogen fixers; thus, they may be informative indicators of ecosystem function. We created spatial models of multiple indicators of the diversity and function of BSCs (species richness, evenness, functional diversity, functional redundancy, number of rare species, number of habitat specialists, nitrogen and carbon fixation indices, soil stabilization, and surface roughening) for the 800,000‐ha Grand Staircase‐Escalante National Monument (Utah, U.S.A.). We then combined the indicators into a single BSC function map and a single BSC biodiversity map (2 alternative types of conservation value) with an unweighted averaging procedure and a weighted procedure derived from validations performance. We also modeled potential degradation with data from a rangeland assessment survey. To determine which areas on the landscape were the highest conservation priorities, we overlaid the function‐ and diversity‐based conservation‐value layers on the potential degradation layer. Different methods for ascribing conservation‐value and conservation‐priority layers all yielded strikingly similar results (r= 0.89–0.99), which suggests that in this case biodiversity and function can be conserved simultaneously. We believe BSCs can be used as indicators of ecosystem function in concert with other indicators (such as plant‐community properties) and that such information can be used to prioritize conservation effort in drylands.     

Poverty,environment and economic growth: exploring the links among three complex issues with specific focus on the Pakistan’s case

Eradicating poverty, reducing environmental degradation and achieving sustainable economic growth are some of the major macroeconomic goals of Pakistan. There are, however, serious interlinkages among these issues. The present paper investigates these linkages and the existing evidence for Pakistan and other countries. The aim of the paper is to examine and test some hypotheses and answer some questions regarding poverty-environment-nexus in Pakistan. The paper uses secondary data and information to probe into these linkages. The paper finds that poverty leads to environmental degradation is a common belief but it is not clearly supported by evidence. What is more strongly supported by evidence is the fact that environmental degradation hurts more the poor. There is a need of studies that deal with the social and environmental impacts of specific factors, and a need of a better understanding of institutional dynamics. More understanding on how levels and changes in poverty relate to changes in environmental quality is needed. There is a need to understand how the levels and rates of change vary with poverty. There is a need to know how and where the changes are taking place. More research is needed on the effects of changes in the population and the dynamics of institutional development. It has been showed that low income groups are the most affected when environmental degradation occur, but not enough information available in Pakistan on the mechanisms. There is a need of empirical studies regarding effect on poor relative to non-poor. More understanding on how poor people depend on, interact with and use their environment in rural and urban areas is needed. Ideally, in Pakistan, we would need to relate data gathered in an area with socio-economic data from the same area, answering this way to questions such as, to what extent are different income groups affected by resource degradation? And, by pollution? Finally, Pakistan should apply open minded and innovative policies in order to take advantage of the many existing opportunities. Some suggestions are eco-labeling schemes, organic practices, fair trade and so forth. Very little research has been conducted in developing countries, especially in Pakistan on the issues involving poverty, environment and development. The present study is an attempt in this regard. The results of the study are expected to assume pivotal importance for policy makers, academics and other researchers. It may help policy makers how to design policy to ensure poverty alleviation vis-à-vis environmental conservation. It may also help academicians to understand the complex poverty-environment-growth nexus. It will also open new avenues for further research in this area.