生态系统服务权衡最新研究进展

生态系统服务权衡研究对协调生态环境保护和社会经济发展至关重要。为推动生态系统服务管理和提升人类福祉,本文以Web of Science核心合集(WOS)和中国科学引文数据库(CSCD)为数据源,运用文献计量分析法,系统梳理和总结生态系统服务权衡研究的学科知识基础、科学领域结构和热点变化等发展现状以及最新研究进展。研究表明:1)不同研究层面上,生态系统服务间的权衡关系受外部风险和人类需求、参数选取和服务提供者及区域差异性和不均衡性的影响。2)研究方法主要有基于关系识别和具体表征的权衡分析、权衡模拟和预测的模型量化分析和生态系统服务权衡管理优化的多准则分析3类。3)生态系统服务权衡关键驱动因子为城市化、生态工程和气候变化。基于此,我们认为把握生态系统服务权衡不同研究层面的关联特征、创新和优化生态系统服务权衡研究方法、准确甄别生态系统服务权衡关键驱动因子以及充分整合多维生态系统服务权衡资源搭建数据共享平台是未来研究的重点。     

Aquaponics and sustainability: The comparison of two different aquaponic techniques using the Life Cycle Assessment (LCA)

Aquaponics is generally regarded as a sustainable practice, but its environmental burdens were not yet deeply investigated. In this study, Life Cycle Assessment (LCA) was used to assess the environmental impacts of two hypothetical coupled aquaponics systems (CAPS): Raft System (RAFT) and Media-Filled Beds System (MFBS). Rainbow trout (Oncorhynchus mykiss) and lettuce (Lactuca sativa) were considered as cultivated species in both systems. The Simapro^© software V.8.0 was used for calculation. The comparison between the two virtual systems indicated the floating technique as the less impacting one. Even though energy consumption appears to be higher in the floating system, LCA results were markedly influenced by the extensive use of inert materials in MFSB. In both systems, contribution analyses underlined that the main environmental impacts are related to infrastructures, electricity and fish feed. The LCA analyses carried out in this study highlights that the choice of less impacting materials, and the optimization of management practices, should be taken as priorities in order to reduce environmental impacts of this activity.     

华南农业大学农事训练课程的理论与实践——以养蚕与缫丝课为例

以养蚕与缫丝课程模块为例,对其课程内容安排、教学特点、考核方法进行分析,并对其所面临的问题展开探讨,旨在为进一步提高相关实践教学效果提供借鉴。     

Hydrodynamic method for estimating production carrying capacity of coastal finfish cage aquaculture in Southeast Asia

This paper presents the development of a simple and generally applicable hydrodynamic method for the estimation of production carrying capacity (PCC) of coastal finfish cage aquaculture. Dimensional analysis was used to find significant and general interdependencies between the hydrodynamics at fish farm locations and particulate wastes deposited on the seafloor by fish farms. Modeled ratios of deposition to emission of particulate wastes underneath fish farms were found to be primarily a function of the flow Reynolds numbers at the farming locations and the non-dimensional settling velocity of emitted wastes. In the non-dimensional model, farming conditions include daily feed rate, proportion of unconsumed feed, and carbon content in feed and fish feces. The relationship can be used to estimate the PCC of floating net cages imposing a threshold value for deposition. Results of in-situ assessments of the benthic impacts of several fish farms in an aquaculture site in the northwest of Bali, Indonesia were used to validate and demonstrate the effectiveness of the method. Predicted results were able to clearly identify fish farms operating beyond ecologically sustainable carrying capacity. The proposed method has broad applicability and could help make decisions regarding the estimation of production potential of individual farms in pristine areas, for providing first estimates in sites that have scarce data, and for assessment, expansion, and optimization of the currently operating aquaculture sites in Southeast Asia, China and potentially other data-poor island nations. As the method relies on dynamic models, it enables straightforward assessments over the entire aquaculture region.     

浅析日本的森林公益机能经济价值评价

简要分析了日本全国水平的森林公益机能经济价值评价的历史和现状 ,并讨论了将来的发展趋势。日本人对森林公益机能的认识较早 ,频繁的自然灾害和林业经济的不景气是森林公益机能经济价值评价的起因和动机。从 1972年开始的全国森林公益机能的价值评价 ,当时用代替法 (RCM )评价出的金额约为 12 8兆日元 ;1987年单独评价东京圈内的森林价值的结果 ,每公顷森林测算出的价值为 5 0 0万日元 ,如按 5 %的还原率计算 ,其资本还原价高达每公顷 1亿日元。 2 0世纪 80年代还出现了用支付意愿法 (WTP)评价环境财产的事例。至 2 0 0 0年同样用 1972年使用过的代替法 (RCM )重新评价全国森林的结果 ,核算出约 75兆日元的最新数字。但至今为止评价过程中存在问题尚多 ,评价手法上也有局限性 ,其成果仅能为部分林业政策的制定和环境工程的评价起有限的参考作用。指出国际上森林公益机能价值评价今后的动向 ,提出了进一步开展评价理论和方法研究的必要性和重要性 ,并对中国林业可持续发展的启示提出了一些见解     

森林资源资产评估程序和基本方法

论述了森林资源资产评估程序,简要介绍了基本方法。     

Do “stakeholders” represent citizen interests? An empirical inquiry into assessments of policy aims in the National Forest Programme for Germany

Participatory National Forest Programmes (NFPs) intend to democratise forest sector policy, but they may suffer from a fundamental democratic legitimisation deficit since the stakeholders involved are neither democratically authorised nor accountable to the population. In order to scrutinise the empirical relevance of this problem in the case of the German NFP, it is analysed how the German population on the one hand and the NFP participants on the other hand assess central forest policy aims of the NFP, and how far both assessments coincide. Two surveys based on identical questionnaires are used as the data base. The respondents assessed the importance of the respective aims as well as at their implementation. Results show that the population considers the majority of the NFP aims to be generally relevant, but assesses the majority of the aims significantly differently from the stakeholders. The formal legitimisation deficit of the German NFP therefore also matters in terms of content. Discussing the NFP among the elected representatives and in the public seems indispensable.Moreover, the differences in the assessment of some policy aims are significantly dependent on how people judge the image of forest enterprises between the opposing poles of profit orientation and nature protection. Public acceptance of those aims could be furthered more appropriately by adjusting the partly incorrect image of forestry rather than by providing more information about the particular aims and their background.     

农业资源与环境专业农产品质量与安全教学改革

针对农产品质量与安全的课程特点及教学中存在的问题,结合自己的教学实践,从完善教学内容、改善教学方法及改革考核方式等方面提出改革建议,以激发学生学习兴趣,改善教学效果和提高教学质量。