基于生态供给-消耗平衡关系的中尼廊道地区生态承载力研究

中尼廊道地区作为南亚通道建设的关键环节,具有生态环境脆弱且对生态资源依赖性强的基本特征,中尼廊道建设占用生态空间,将增加生态系统对农牧业生产活动的承载压力;因此,开展中尼廊道生态承载力研究对青藏高原生态保护和南亚通道建设具有重要的实践价值和指导意义。本文基于生态供给与消耗平衡关系,通过计算农牧业生产对生态系统净初级生产力的消耗,评估中尼廊道地区的生态承载力,结果表明：（1）中尼廊道地区生态承载力处于富富有余状态,2015年有7个县域生态承载力处于临界超载或平衡有余状态;整体上生态系统尚有较大的生态空间来支撑中尼廊道建设,但建设可能給局部县域带来超载风险。（2）中尼廊道地区生态系统供给量处于稳定波动状态,畜牧业生态消耗在生态消耗中占主导地位（占比超80%）;得益于2005年起实施的草畜平衡政策,中尼廊道地区及其24个县域生态消耗量呈下降趋势,农牧业生产活动对生态系统造成的压力降低,生态承载状态向优发展;但地处粮食主产区、口岸区、城市化辐射区的7个县域,在本地及周边地区日益增长的对农牧业产品的生活需求驱动下生态消耗量处于增加态势。（3）若以实现生物多样性公约所倡导的50%生态资源得到保护为生态保护目标,目前中尼廊道农牧业生产模式产生的生态消耗将超出其可利用供给,区域可持续发展需要关注如何通过中尼廊道建设带动当地产业结构调整以缓解农牧业生产对生态系统的压力。     

供应链上“牛鞭效应”的成因及其有效控制方法分析

许多实证研究与企业调查发现,＂牛鞭效应＂现象广泛存在于供应链结构中.本文首先建立了供应链的经济生态系统模型,并利用该模型充分论证了两点：（1）＂牛鞭效应＂是由供应链自身结构产生的;（2）供应链类似于食物链,它不是契约链,维护供应关系健康持续发展的有效措施是,降低供求双方的依赖程度,而不是通过激励的途径促进供应端企业的供应.这两个结论有别于通常供应链研究的结果,所以本文的结论有益于供应链的理论研究与实践应用.     

大豆-根瘤菌共生体系光合与固氮关系研究

水培大豆和田间生长的大豆,接种根瘤菌 Rhizobium B16-11C 后植株全氮含量、叶片叶绿素含量和净光合速率及种子产量都明显增加。比较 Clark 大豆的结瘤品系和不结瘤品系获类似结果。摘除根瘤后3天内叶片净光合速率无明显变化。大豆植株遮阴、去叶或切掉地上部导致根瘤活性明显下降。但去豆荚不能提高根瘤固氮的比活性。根瘤活性的日变化不能用根瘤蔗糖、淀粉含量或周围温度的变化来解释,其控制因子尚待深入研究。     

医用供应装置的风险分析及应对策略

医用供应装置的医疗事故时有发生。从气体、电气和机械结构等方面,深入分析和评估医用供应装置的风险,提出加强医用供应装置安全性和避免事故发生的应对措施,并介绍ISO国际标准关于医用供应装置的完整标准体系。     

Studies on the Relationship Between Photosynthesis and Nitrogen Fixation in the Symbiotic System of Soybean and Nodule Bacteria( Rhizobium)

The relationship between photosynthesis of soybean and nitrogen fixation of the nodules by symbiotic Rhizobium was studied. The contents of total nitrogen and chlorophyll, the net photosynthetic rate and seed yield of soybean were much higher in either hydroponically cultivated or field-grown plants inoculated with Rhizobium B16–11C (or Clark nodulating strain) than in control without inoculation (or Clark non-nodulating strain). These results show that the symbiotic nitrogen fixation has a beneficial effect on photosynthesis. However, the effect was indirect and slow so that there was no change in the net photosynthetic rate of the soybean leaves until three clays after removing nodules from the soybean roots. On the other hand, decreasing the photosynthate supply to nodule by shade, defoliation or shoot removal of the soybean, the nodule activity declined significantly. It seems that the supply of photosynthate to root nodule is a limiting factor for symbiotic nitrogen fixation. However, the diurnal variation of the nodule activity could not be explained by change neither in the contents of sucrose and starch of the root nodules nor in the ambient temperature. The factor controlling the diurnal variation deserves further study.     

Environmental influences on the replenishment of lizardfish (family Synodontidae) in Caribbean Panama

Lizardfish (family Synodontidae) are little studied despite their potentially important predatory role in epibenthic coral reef communities. The present study documented the temporal and spatial larval supply patterns of five Caribbean lizardfish species together with environmental variables (solar radiation, rainfall, water temperature, onshore-offshore winds, alongshore winds and wind-induced turbulence) to examine: (1) whether species within the same family respond differently to their developmental environment and (2) if larval supply in year-round warm waters is influenced by climatic changes. To address these questions, late-stage larvae of Synodus foetens, Synodus intermedius, Synodus poeyi, Saurida suspicio and Saurida brasiliensis were collected in replicate light traps in three different reef habitats (back-reef, lagoon and exposed) in the San Blas Archipelago, Panama, over 18 consecutive lunar months. Although replenishment of lizardfish occurred year-round, the temporal and spatial supply patterns were species-specific: S. foetens, S. intermedius and S. poeyi were most abundant during the dry season while S. suspicio and S. brasiliensis were most prevalent during the wet season. When seasons were analysed separately, water temperature explained 39 and 26% of the variance in light trap catches of S. foetens and S. intermedius, respectively, in the dry season while wind-induced turbulence accounted for 25% of the variability in S. suspicio and S. brasiliensis catches during the wet season. These findings stress the importance of analysing larval supply in conjunction with environmental data at a high taxonomic resolution to better understand the mechanisms that drive replenishment in reef systems at low latitudes.     

The contribution of PAS 2050 to the evolution of international greenhouse gas emission standards

Background, aim, and scope  The assessment of greenhouse gas (GHG) emissions arising from products (goods and services) is emerging as a high profile application of life cycle assessment (LCA), with an increasing desire from retailers and other supply chain organizations to better understand, and in some cases communicate, the carbon footprint of products. Publicly Available Specification 2050:2008, Specification for the assessment of the life cycle greenhouse gas emissions of goods and services, addresses the single-impact category of global warming to provide a standardized and simplified implementation of process LCA methods for assessing GHG emissions from products. This paper briefly reviews the development process followed for PAS 2050, before examining the treatment of GHG-specific contribution of PAS 2050 to product carbon footprinting. Materials and methods  PAS 2050 was jointly sponsored by the Carbon Trust and the UK Department for Environment, Food and Rural Affairs and was published by the British Standards Institution on 29 October 2008. An independent steering group oversaw the development of the specification, including the establishment of an expert workgroup program, comprehensive international consultation, and expert input on the requirements of the specification. Results  The development process for PAS 2050 resulted in a specification that includes specific requirements that limit the interpretation of the underlying LCA approach to product carbon footprinting. These requirements, including goal setting and life cycle inventory assessment, aspects of system boundary identification and temporal aspects of GHG emissions, clarify the approach to be taken by organizations implementing product carbon footprinting, and simplify the application of LCA procedures in relation to product carbon footprinting. Discussion  Assessment of the emissions arising from the life cycle of products has a clear international component, and delivering consistent results across the supply chain requires the application of consistent methods. There is an emerging recognition that further standardization of methods for product carbon footprinting is needed, and the specific requirements resulting from the PAS 2050 development process make a valuable contribution across a range of GHG assessment issues. Conclusions  The widespread interest in PAS 2050 from individuals and organizations, together with the development of similar guidance by other organizations, confirmed that there is a need for clarification, certainty, and requirements in the field of product carbon footprint analysis. The use of PAS 2050 to refine, clarify, and simplify existing LCA methods and standards has resulted in specific approaches to key GHG assessment issues being developed; it is important that future standards development work considers the impact of these approaches and their further refinement. Recommendations and perspectives  It is the consumption of goods and services by individuals around the world that drives global GHG emission, and PAS 2050 is a first attempt to provide integrated, consistent approaches that directly address the role of consumption at the product level in contributing to GHG emissions. Climate science and GHG assessment techniques are both evolving areas and it will be necessary to review the approach taken by PAS 2050 in the future: a formal review process for PAS 2050 will commence towards the end of 2009 and practitioners are encouraged to participate in this review process.

Mismatches between supply and demand in wildlife tourism: Insights for assessing cultural ecosystem services

Assessing cultural ecosystem services provided by biodiversity requires a combination of ecological and social approaches. In this study, we investigated the capacity of large African mammal species to provide the cultural ecosystem service of wildlife tourism by using a supply and demand framework. First, we tested the relationship between supply and demand for large mammal species in wildlife tourism. Second, we tested whether the trophic level and body size of mammals influenced the mismatch between supply and demand, and whether the patterns of mismatches were consistent among four protected areas (PAs) in three Southern African countries. To quantify supply of species, we counted large mammals along 196 five km road transects within the four PAs; to estimate demand, we gathered 651 face-to-face questionnaires of wildlife tourists and distinguished between their expectation and hope to see specific species. Results show that a higher supply of large mammal species increased the expectation to see a species (linear regression slope β = 0.28, p < 0.01), whereas supply did not affect the hopes to see a specific species (β = −0.04, p = 0.63). Analyses of mismatches revealed that predator species were more demanded in relation to their supply than ungulates. Finally, we found that the demands of wildlife tourists for mammal species in relation to their supply were consistent across the four PAs. Supply-demand analyses reveal that species’ traits, in particular trophic level, shape the hopes of wildlife tourists to see specific mammal species. We propose that the quantification of supply-demand mismatches can be used to identify charismatic species and relevant species’ traits, and can be applied for wildlife tourism assessments within as well as across regions. Supply-demand analyses provide a useful framework and deliver indicators for better assessing cultural ecosystem services involving wildlife and nature-based tourism, and can be used for conservation management.     

重点生态功能区农户的生计风险多维感知及影响因素——以甘南黄河水源补给区为例

重点生态功能区承担着保护与修复生态环境、提供生态产品的重要任务,农户作为该区最重要的生态保护主体,面临着多重风险的冲击,其对生计风险的多维感知不仅会影响其生产行为决策,更关系到重点生态功能区主体功能的发挥,因此,急需准确地了解农户的生计风险多维感知及影响因素,为制定有效的生计风险防范体系提供借鉴。以甘南黄河水源补给区为例,基于多维度生计风险感知测量框架,利用入户调查数据,分析了农户的生计风险感知,并采用经济计量模型分析了影响农户生计风险感知的关键因素。结果表明:①甘南黄河水源补给区农户面临的主要生计风险为家庭发展需求风险、健康风险、社会风险,且重点保护区农户面临环境风险、家庭发展需求风险、政策风险的比例均显著高于恢复治理区和经济示范区农户。②农户对家庭发展需求风险的熟悉性、自愿性、持续性感知均最高,对健康风险的恐慌性、严重性及可能性感知均最高,对社会风险的可控性感知最高。其中,重点保护区农户对政策、市场及健康风险的可控性感知均高于其他区域。③人力资本对可能性感知、严重性感知、恐慌性感知、熟悉性感知产生了显著影响;物质资本对自愿性感知产生了显著影响。最后,提出了农户防范生计风险的对策建议...