生态社区综合评价指标体系的初步探讨

生态社区的出现和发展一直广受关注，建立生态社区综合评价指标体系对于生态社区的实践和发展具有重要的意义。本文通过对社区可持续发展理论，生态平衡理论以及生态社区本身系统特点的探讨，尝试建立一个综合评价指标体系，同时对评价指标体系应体现的功能，以及评价指标体系构建的原则做了初步探讨。     

Barriers Beyond the Partners: Bureaucratic and Political Constraints to Implementing Joint Forest Management in Tamil Nadu,India

Whereas past research has treated co-management of common pool resources as if villagers and project implementing authorities were the only relevant actors, numerous external factors beyond the control of these two partners create barriers to successful co-management. This paper draws on discussions with Forest Department officials to examine the influence of these forces on the outcomes of Joint Forest Management (JFM) in Tamil Nadu, India. An empirical inquiry into the operational aspects of JFM indicates the important roles of political parties, powerful people, and other state institutions and functionaries as well as the flow of foreign funding. Further, the strong demand by local people for socio-economic development interventions as opposed to improvement of degraded forests belittles the role of the Forest Department relative to other departments. Numerous other conditioning factors and relationships are explored. The authors call for reforms in public governance to allow better participation of all the actors involved for this participatory management approach to succeed and sustain.     

Perceptions toward stewardship among residents living near U.S. Department of Energy Nuclear Facilities

Although stewardship has been widely defined and used in environmental management and planning, there is a dearth of studies that describe how the lay public perceives this concept. A national sample of residents in 14 states who live near DOE nuclear facilities were interviewed to delineate public understanding and awareness of the stewardship program of the U.S. Department of Energy (DOE). This study discusses the findings of the survey and discusses how institutional trust influences public participation and resident’s choices of potential stewards. Almost 40% of the respondents could not define stewardship; those who did, believed that ‘responsibility,’ ‘management,’ and ‘accountability’ are key elements of stewardship. In addition, about a third of the respondents identified Federal groups and the DOE as potential stewards. Readers should send their comments on this paper to: BhaskarNath@aol.com within 3 months of publication of this issue     

Effects of ocean temperature on the southern range limits of two understory kelps, <Emphasis Type="Italic">Pterygophora californica</Emphasis> and <Emphasis Type="Italic">Eisenia arborea</Emphasis>, at multiple life-stages

Environmental factors have long been shown to influence species distributions, with range limits often resulting from environmental stressors exceeding organism tolerances. However, these abiotic factors may differentially affect species with multiple life-history stages. Between September 2004 and January 2006, the roles of temperature and nutrient availability in explaining the southern distributions of two understory kelps, Pterygophora californica and Eisenia arborea (Phaeophyceae, Laminariales), were investigated along the coast of California, USA and the Baja California Peninsula, Mexico, by limiting either: (a) tissue nitrogen uptake and storage by adult sporophytes during periods of elevated temperature, and/or (b) production of embryonic sporophytes by microscopic gametophytes. Results suggest that while adult sporophytes of both species are tolerant of high temperatures and low nutrients, reproduction by their microscopic stages is not. Specifically, while E. arborea produced embryonic sporophytes at both 12 and 18°C, temperatures commonly observed throughout the southern portion of its range, P. californica produced sporophytes at 12 but not at 18°C. As a result, it appears that the southern distribution of P. californica, which ends in northern Baja California, Mexico, may be limited by temperature acting on its microscopic stages. In contrast, the ability of E. arborea’s microscopic and adult stages to tolerate elevated temperatures allows it to persist in the warmer southern waters of Baja California, as well as to the north along the California coast where both species co-occur.     

GCM-based analysis of water availability along the Tone River and Tokyo Metropolitan Area under climatic changes

Tone River supplies most of the water requirements of the Tokyo Metropolitan Area (TMA). Lowering of Tone flow and yearly fluctuation, however, is causing water shortage along TMA nowadays. This study investigated the future water availability scenarios under climatic changes. A state-of-the-art approach to utilize the output of several GCM has been demonstrated to investigate the future water availability scenarios for TMA from the Tone River. An integrated modeling approach for water balance considering several hydrological risk indices was adopted to quantify the future changes in this case. It is observed that the future summer precipitation along the Tone basin is going to be increased considerably, while an almost constant or decreasing trend is observed for winter season. Natural flow availability for winter or spring seasons thus can be crucial under future scenarios. After reservoir routing, the hydrological risk indices estimated, however, were not found to be changed significantly due to the presence of a robust reservoir system at the upstream.     

SUSTAINABILITY AT THE LOCAL LEVEL: MANAGEMENT TOOLS AND MUNICIPAL TAX INCENTIVE MODEL

The implementation of sustainable development may seem a simple concept when written on paper. However to carry-out long term actions put forward by the Agenda 21 (AG21) at the local level represents one of the main challenges as municipal governments in general do not have the capacity to effectively implement the process. Regional environmental assessment (REA) has shown to be effective in supporting decision-making not only to correct environmental problems due to past unsustainable social-economic developments but also help local governments to implement sustainable actions. However this requires long-term investments of AG21 plans and projects. The allocation of regular and consistent financial resources is one of the main ingredients for the sustainable development process. But traditional plans and projects financed by national and/or international funds may not be sustainable in the long-term because they become dependent on external funding. Research demonstrate that innovative economic instruments such as ecotaxes represent a feasible alternative to sponsor local sustainability because taxes are collected permanently by the government and could be invested in continuous actions. Ecotaxes experiences have provided important reference to structure a municipal incentive model (MIM) to sponsor AG21’s environmental plans and projects on a long-term (permanent) basis. However sustainable development cannot be solely through economic investments. A comprehensive municipal environmental management scheme (MEMS) has been established to support the incentive model. The scheme seeks not only to improve local institutional framework but also incentive continuous participation of local stakeholders at all levels of society. Participatory events and the provision of incentives (educational and financial) are key to motivate society to protect the environment and support actively the sustainable development process as emphasised in the RIO-92 Conference.     

铅锌矿区玉米中重金属污染特征及健康风险评价

以西南某铅锌矿区为研究区域,测定了92份玉米样品中Pb、Zn、Cd、Cr和Ni的含量,开展了矿区玉米籽粒中重金属污染特征及健康风险研究.应用单因子污染指数和内梅罗综合污染指数分析了重金属在玉米中的污染状况,采用健康风险评价模型评价了重金属对人体健康造成的风险,同时利用主成分分析法解析了重金属的主要来源.结果表明,玉米籽粒中Pb、Zn、Cd、Cr和Ni的平均含量分别为0.30、23.75、0.21、1.33和1.15 mg ·kg^-1;除重金属Zn外,其他4种重金属均超过我国食品卫生标准限值,研究区玉米籽粒中Pb、Cd、Cr和Ni的综合污染指数范围介于4.32~9.07之间,均属于重度污染,Zn的综合污染指数小于1;重金属通过玉米籽粒摄入引起的复合重金属污染对成人和儿童均存在健康风险,且对儿童造成的健康风险高于成人.玉米籽粒中5种重金属可以由2个主成分来反映,第一主成分主要支配Pb、Cd、Cr和Ni的来源,第二主成分支配Zn的来源.玉米籽粒重金属含量与土壤重金属含量之间没有明显相关性.     

污泥生物炭去除水中重金属的研究进展

重金属带来的环境风险日益严峻,利用污泥生物炭去除水中重金属污染方面的研究得到了广泛关注。结合当前国内外研究现状,归纳了不同条件下制备的污泥生物炭对水中重金属,如Cd、Pb、Cr、As等的吸附机理,污泥生物炭对大多数重金属的吸附满足物理吸附和化学吸附的多重作用,可通过增加生物炭表面有效基团及有效吸附位点提升吸附性能。同时,总结了影响吸附效率的各种因素,探究了污泥生物炭的再生问题,并对今后污泥生物炭去除水中重金属的研究方向做出了展望。     

Effects of SO2 and H2O on low-temperature NO conversion over F-V2O5-WO3/TiO2 catalysts

F-V_2 O_5-WO3/Ti02 catalysts were prepared by the impregnation method.As the content of F ions increased from 0.00 to 0.35 wt.%,the NO conversion of F-V_2 O_5-WO_3/TiO_2 catalysts initially increased and then decreased.The 0.2 F-V_2 O_5-WO_3/TiO_2 catalyst(0.2 wt.% F ion)exhibited the best denitration(De-NOx) performance,with more than 95% NO conversion in the temperature range 160-360℃,and 99.0% N2 selectivity between 110 and 280℃.The addition of an appropriate amount of F ions eroded the surface morphology of the catalyst and reduced its grain size,thus enhancing the NO conversion at low temperature as well as the sulfur and water resistance of the V_2 O_5-WO3/Ti02 catalyst.After selective catalytic reduction(SCR) reaction in a gas flow containing SO_2 and H_2 O,the number of NH3 adsorption sites,active component content,specific surface area and pore volume decreased to different degrees.Ammonium sulfate species deposited on the catalyst surface,which blocked part of the active sites and reduced the NO conversion performance of the catalyst.On-line thermal regeneration could not completely recover the catalyst activity,although it prolonged the cumulative life of the catalyst.In addition,a mechanism for the effects of S02 and H_2 O on catalyst NO conversion was proposed.