我国农业生态系统营养循环链的断裂与重建

完整的营养循环是农业生态系统健康、可持续发展的重要保障。我国传统农业属于环境友好型生态农业。农业生态系统的营养循环结构完整，持续健康、繁荣。但是，随着工业化、城市化、市场经济的发展以及农业耕作方式的转变，农业生态系统营养循环的结构遭到严重破坏，导致一系列资源、环境、经济与社会问题。通过秸秆还田以及城市生活废弃物（排泄物、厨房垃圾等）向农业生态系统的返还，重建农业生态系统完整的营养循环，是我国农业生态系统持续健康发展的必由之路。     

基于土地利用的北京市农业生态服务价值评估研究

近年来,随着经济社会加速发展与新农村建设的不断深入,在北京这样的大都市中农业的生产功能逐渐被弱化,农业的生态功能越来越凸显重要作用,估算农业的生态服务价值逐渐成为学术界研究的热点。目前国内主要是参照谢高地提出的中国陆地生态系统单位面积服务功能价值表,即用全国生态系统的平均服务价值来估算不同区域的农业生态服务价值,这与北京的社会发展水平、城市定位及都市型现代农业的功能定位是不符合的,因此是不太恰当的。文章以北京农业生态服务价值评估为研究目标,在全国生态系统服务价值评估体系的基础上,对北京市300多位具有相关专业背景的学者进行问卷调查,对中国生态系统单位面积生态服务价值当量表进行有依据的修改,制定出更适合北京区域的不同土地利用类型生态系统服务评估单价体系,并以此表为依据测算了2013年北京农业生态服务价值的理论值与现实值。研究发现北京的农业生态服务价值十分巨大,文章提供了一种更符合北京生态系统状况与经济发展水平的农业生态服务价值评估方法,可以用于已知土地利用面积的农业生态服务价值估算,能够在较短时间内获得较为精确的结果。     

A participatory assessment of agro-ecosystem sustainability in Abesard,Iran

Participatory approaches have emerged in developing countries as an integrated and holistic system approach for assessing the agro-ecosystem sustainability. The aim is to integrate and apply knowledge about natural and social aspects of agro-ecosystems, taking into account their long-term, uncertain and non-linear relationships. The purpose of the study described in this paper was to assess the sustainability of the agro-ecosystem of Abesard in Tehran Province. A participatory landscape/lifescape appraisal (PLLA) method was used within an agro-ecological framework to assess the farmers’ sense of agricultural sustainability based on different categories of sustainability (better-off, average and poor). Results indicated that a majority of farmers think of sustainability solely as an economic issue, followed by sustainability being a combination of ecological and social concerns. Regarding the indicators of sustainability, results revealed that for farmers in the poor group, resilience and stability were critical criteria, whereas for better-off farmers, stability, reliability and resilience were generally important. However, the average group of the farmers was placed between the two groups. Overall, it was concluded that the economic status of households has an influence on the sustainability of their agro-ecosystems and that improvement of their economic situation promotes agricultural sustainability. It could also be concluded that PLLA has the potential to integrate socio-economic (lifescape) and environmental (landscape) dimensions for analysing the sustainability of agro-ecosystems.     

Barter markets for the conservation of agro-ecosystem multi-functionality: the case of the chalayplasa in the Peruvian Andes

The economic liberalization process has exerted acute pressures on Local Food Systems in the Andes, driving their insertion into the cash economy in the context of globalization. Simultaneously, networks of barter markets have emerged in the Andean highlands. An assessment of the role of these markets in conserving the multi-functionality of local agro-ecosystems was conducted in the Lares Valley (Cusco, Peru). We showed that barter markets are endogenous, integrated, non-monetary economic responses that allow for the conservation of agro-ecosystem multi-functionality through the recuperation of control over local production modes. Their function is to buffer cash economy imperfections while satisfying local food needs. The combination of monetary and non-monetary trading is a redefinition of the economic system within the ecological and social limits of the agro-ecosystem. A participatory action research approach enabled the collecting and unravelling of the incommensurability of values associated with the role of barter markets.     

基于能值理论的湖南省农业生态系统绿色GDP核算研究

应用能值分析方法,以湖南省2011年农业生态系统能值投入和产出数据为依据,在计算系统所消耗的不可更新环境资源、不可更新工业辅助能的能值-货币价值基础上,对系统的能值绿色GDP进行了核算。结果表明：经过调整后研究年度湖南省农业生态系统的能值绿色GDP为1953.48亿元,占传统GDP（2768.03亿元）的比重为70.6%。说明该生态系统的经济增长模式仍然是以高能耗,高污染为代价的粗放型增长模式,转变农业发展方式迫在眉睫。     

四川省宁南县农业资源特点及发展前景

宁南县具有丰富的农业资源和良好的农业生产条件。水土保持成果尊定了农业的发展的基础，目前全县共有３种农业生态系统模式，传统家业铧种植业，养殖业模式和山地小庄园模式，建议保护水土资源，增加投入，增加农产品市场竞争力，发展生态农业，实现农业可持续发展。     

区域农业生态系统研究进展

区域农业生态系统在提供人类生活和生产资料的同时,还能维持区域自然环境的平衡。因此,正确认识和把握区域农业生态系统运行规律对于促进我国农业的可持续发展具有非常重要的意义。文章系统阐述了区域农业生态系统研究的主要进展,着重从区域农业生态系统研究的概念、性质、原理及研究方法及研究趋向展开论述。最后简要评述了研究领域的拓展及趋向,认为加强区域农业生态系统的理论、影响因子、作用机制以及定量化研究结果的理论指导性和实践应用性为今后的研究趋向。