关键词： Agriculture   climate change adaptation  

摘要： Climate change is occurring. Deviations from historic temperatures and precipitation plus increased frequency of extreme events are modifying agriculture systems globally. Adapting agricultural management practices offers a way to lessen the effects or exploit opportunities. Herein many aspects of the adaptation issue are discussed, including needs, strategies, observed actions, benefits, economic analysis approaches, role of public/private actors, limits, and project evaluation. We comment on the benefits and shortcomings of analytical methods and suggested economic efforts. Economists need to play a role in such diverse matters as projecting adaptation needs, designing adaptation incentives, and evaluating projects to ensure efficiency and effectiveness.

关键词： Aerial imagery   Forest limit   Krkonose   Land use   Norway spruce   Picea abies   Recruitment   Timberline  

摘要： Questions: What was the main trigger of treeline ecotone advance - rising temperature or agricultural land abandonment? Were the triggering factors of tree expansion homogeneous or did they differ between upper and lower parts of the treeline ecotone? Location: Sudetes Mts., Central Europe (50 degrees N, 15-17 degrees E). Methods: Data were gathered from the treeline ecotone formed by Picea abies at elevations ranging from 1250 to 1490 m. The study area experienced a 1 degrees C temperature increase over the last 100 yr and termination of cattle grazing and grass mowing in the first half of the 20th century. At 38 plots situated at lower ('timberline') and middle or upper ('treeline' and 'outpost treeline') parts of the treeline ecotone, the age structure of all seed origin P. abies was determined. Changes in tree cover and number of trees over the last 60-70 yr were assessed from aerial imagery. The history of agricultural land use for each plot was compiled. Finally, changes in tree establishment were modelled using climatic variables and land-use intensity. Results: We found that tree establishment at treeline had occurred with a 30-40-yr lag after the main establishment peak at timberline. Whereas all treeline plots showed gradual increases in tree cover, timberline tree cover first increased, with some plots then undergoing thinning. Enhanced tree establishment was dependent mainly upon agricultural land abandonment. The effect of land-use changes was more important in the lower than in the upper part of the treeline ecotone. Increasing summer temperatures had a negative influence on seedling establishment in the last few decades. Conclusions: Treeline ecotone densification was attributable to agricultural land abandonment across the entire treeline ecotone with the most important effect at timberline. More recently, seedling establishment has been limited by the effects of drought and/or absence of suitable microsites. We documented that one or two establishme

关键词： 气候变化   脆弱性   治理模式   自主治理  

摘要： 农业是受气候变化影响的脆弱生产系统。研究农业对气候变化的适应与治理问题,解析农业脆弱性的生成机制、探索降低脆弱性的制度化途径、提升应对气候变化风险的能力是气候变化领域的重要议题。气候变化对农业的影响问题涉及多学科交叉问题,是自然科学与社会科学相互交织的系统。对农业气候脆弱性治理的研究经过了从单一自然科学领域的直观评价到自然科学和社会科学领域融合互补研究的过程。农业脆弱性的治理除了政府实施直接激励政策或约束机制外,转变政府主导的治理模式、调动农村微观主体和社区组织资源的模式成为必然的选择。

关键词： 农业   气候变化   适应   措施   国际谈判   进展  

摘要： 针对气候变暖采取稳健的适应措施已成为国际社会共识。该文综合了当前适应气候变化的国际谈判进展及已有的农业适应气候变化措施,指出适应资金严重不足,技术研发、应用与转让难以实施,以及适应气候变化行动实施能力的不足严重制约着适应气候变化行动的有效实施;关于农业适应气候变化的技术措施仍缺乏系统的理论研究与应用示范。在此基础上,提出了未来中国农业适应气候变化需要重点开展的研究任务,即农业气象灾变过程的新特点及其风险管理,农业适应气候变化的大数据决策管理系统研发及适应气候变化的农业气候区划与减灾保产技术研究,以切实推进农业适应气候变化,为确保国家粮食安全与农业可持续发展提供支撑。

关键词： 气候变化   影响   应对措施   展望  

摘要： 目前,气候变化已成为限制农业可持续发展的重要因素之一。该文以汉中市为例,综合分析了气候变化对汉中盆地农业生态系统的影响,提出了相关的应对措施,展望了今后应对气候变化的主要研究方向和工作重点,旨在为应对今后农业生产环境的变化提供科学依据和政策指导。

关键词： Agriculture   Drought   Extreme climatic events   Global circulation model   Heat wave   Plant stress   Dairy   Grazing   Livestock  

摘要： Little is known about the impacts of increased frequencies of extreme climatic events (ECEs) on agricultural landscapes, though such events may be much more detrimental than those of gradual climate change alone. Here we develop an approach for examining the sensitivity of agricultural systems to climatic variability and ECEs on pasture-based dairy farms. Using a combination of spreadsheet formulae, biophysical and economic tools, we compared two approaches for generating future climate scenarios: a 'Gradual' approach, wherein climate projections of changes in monthly average temperature and rainfall were applied without altering the pattern of ECEs, and a 'Variable' approach, where monthly change projections were combined with more heatwaves, longer droughts and more extreme rainfall events to generate future scenarios with increased variability. The sensitivity of each approach was compared by modelling whole-farm system impacts on pasture and milk production, feed intake and profit under 'Low' and 'High' climate change projections based on the Representative Concentration Pathways with the highest greenhouse emissions in 2080 (RCP8.5) at three sites in southern Australia. 'Low' change projections had average warming of 1.6-2.0 degrees C and rainfall 10-18% higher than the historical climate, while the 'High' change scenario had 2.5-3.2 degrees C of warming and 15-30% reductions in rainfall. Both future climate scenarios applied the same average monthly change in rainfall and temperature relative to historical climates, but the relative frequency of events falling in the tails of the historical climate distribution was increased in the Variable approach. When used to simulate impacts on whole farm systems, the Variable approach translated into lower annual pasture growth and utilisation, and greater variation within and across years. Exposure to more frequent ECEs led to greater reliance on purchased feeds and lower long-term profitability, particularly in the Hig

关键词： Global Warming   agricultural productivity   Intergovernmental panel on climate change   General circulation models   general turbulence   climate change   Intergovernmental Panel on Climate Change (IPCC)   Climate   Ecological Impacts of Climate Change   agricultural output  

摘要： This paper evaluates the impact of climate change on agricultural productivity. Cross-sectional variation in climate among Brazilian municipalities is used to estimate an equation in which geographical attributes determine agricultural productivity. The Intergovernmental Panel on Climate Change (IPCC) predictions based on atmosphere-ocean, coupled with general circulation models (for 2030-2049), are used to simulate the impacts of climate change. Our estimates suggest that global warming under the current technological standards is expected to decrease the agricultural output per hectare in Brazil by 18 per cent, with the effects onmunicipalities ranging from -40 to +15 per cent. Warming of the climate system is unequivocal, as is now evident from observations of increases in global average air and ocean temperatures, widespread melting of snow and ice and rising global average sea level. (IPCC, 2007b)

关键词： 气候变化   农业生产   预警机制  

摘要： 随着全球变暖的加剧,气候波动对农业生产的作用愈加突出,现就国内外学者近几十年来有关气候变化与农业生产关系的研究成果进行了归纳总结。结果表明:当前的研究主要聚焦于气候变化对大田作物产量、品质、种植面积及农业投入成本方面,对林果业的研究涉及较少;国内现有的研究方法以试验模拟和定量分析为主,此类研究方法基本偏向于单学科研究,对各学科交叉耦合分析不足,有待进一步深入研究;预警机制的滞后性阻碍了农户应对气候变化能力的有效性,今后需在落实应对气候变化行动的同时,加强农业气象预警机制建设,以提高农户的适应性。

关键词： 气候变化   农业生产   影响  

摘要： 近年来,由于全球气候变暖趋势越来越显著,无形中加大了对农业生产以及粮食产量的影响程度。众所周知,农业生产在国民经济体系中作为最基础性的物质生产部门,其发展程度直接关乎国计民生。本文通过分析气候变化特点,探讨其对农业生产的综合性影响,根据我国国情和具体区域情况,制定出了切实可行的策略,提高农业生产应对气候变化的适应能力。