关键词： conservation   global climate change   organic carbon   US agriculture  

摘要： Increase in the use of conservation practices by agriculture in the United States will enhance soil organic carbon and potentially increase carbon sequestration. This, in turn, will decrease the net emission of carbon dioxide. A number of studies exist that calibrate the contribution of various individual, site-specific conservation practices on changes in soil organic carbon. There is a general absence, however, of a comprehensive effort to measure objectively the contribution of these practices including conservation tillage, the Conservation Reserve Program, and conservation buffer strips to an change in soil organic carbon. This paper fills that void. After recounting the evolution of the use of the various conservation practices, it is estimated that organic carbon in the soil in 1998 in the United States attributable to these practices was about 12.2 million metric tons. By 2008, there will be an increase of about 25%. Given that there is a significant potential for conservation practices, which could lead to an increase in carbon sequestration, there are a number of policy options that can be pursued. These include education and technical assistance, financial assistance, research and development, land retirement, and regulation and taxes.

关键词： Soil organic-matter   Conventional-tillage   Filter strips   United-states   Carbon   Rotation   Productivity   Hapludult   Programs   Nitrogen   United States   Carbon Sequestration   soil organic carbon   agriculture   climate change   filter strips   carbon dioxide emission   hapludults   soil organic matter   productivity   conventional tillage  

摘要： The use of conservation practices by agriculture in the United States will enhance soil organic carbon and potentially increase carbon sequestration. This, in turn, will decrease the net emission of carbon dioxide. A number of studies exist that calibrate the contribution of various individual, site-specific conservation practices on changes in soil organic carbon. There is a general absence, however. of a comprehensive effort to measure objectively the contribution of these practices including conservation tillage, the Conservation Reserve Program, and conservation buffer strips to an change in soil organic carbon. This paper fills that void. After recounting the evolution of the use of the various conservation practices, it is estimated that organic carbon in the soil in 1998 in the United States attributable to these practices was about 12.2 million Mt. By 2008, there will be an increase of about 25%. Given that there is a significant potential for conservation practices to lead to an increase in carbon sequestration, there are a number of policy options that can be pursued. These include education and technical assistance, financial assistance, research and development, land retirement, and regulation and taxes. (C) 2000 Published by Elsevier Science Ltd.

关键词： climate change   mountain agriculture   tourism   participatory integrated assessment   focus groups  

摘要： Winter tourism and mountain agriculture are the most important economic sectors in a major part of the Swiss Alps. Both are highly sensitive to changing climatic conditions. In the framework of the CLEAR project, results from climate impact research in the field of tourism and agricultural production were used to investigate the perception of climatic change by stakeholders and to assess possible adaptations. We used a participatory integrated assessment (PIA) to involve the knowledge, values and experiences of the various social actors in tourism and agriculture (e.g., skiers, tourism managers, farmers) in the research process. Whereas climate change may have various severe direct impacts on the tourism industry, depending on the region, agricultural production may generally benefit from changed climatic conditions. But because of the dependence of farmers on “off-farm” income, the loss due to declining winter tourism in specific areas may cause more important indirect effects. However, the two sectors may adapt actively by choosing from a variety of strategies, and the loss of income from the tourism industry may support the re-evaluation of the various functions agriculture plays in mountain regions, beyond the production of food. The study demonstrates the suitability of the PIA approach to elucidate the interactions between different stakeholders and their perception of the climate change phenomena. A similar participatory approach could be a useful tool to transfer research results and expert knowledge to the political process addressing adaptations to climate change.

关键词： 气候变化   农业生态环境   农作物   生长   气温   降水   太阳辐射  

摘要： 本文研究分析了"#年来晋城市的气候变化趋势，探讨了气候变化对农作物生长发育和对农业生态环境的影响，提出了相应对策。

关键词： Global warming   Drought  

关键词： 气候变化   农业生产   影响   对策  

摘要： 对聊城市 42年来的气候资料进行分析 ,找出主要农业气候学因子的变化规律和特征 ,论证了气候变化对聊城市农业生产的影响。

关键词： Kiwifruit cv hayward. Carbon-dioxide.  

摘要： The determination of `critical thresholds' is an essential task for informed policy decisions on establishing greenhouse gas emission targets. This paper presents a framework for determining critical thresholds for New Zealand agriculture, focusing on three agricultural crops - kiwifruit, grain maize, and Paspalum dilatatum - as exemplars for the fruit production, arable cropping and dairy production industries in New Zealand. The approach is based on the application of a country-scale, integrated assessment model, called CLIMPACTS. The CLIMPACTS system contains a climate change scenario generator, climate and land data, and sectoral impact models. Importantly, CLIMPACTS allows time-dependent assessments of climate change and its effects, which facilitates the identification and examination of thresholds, which largely relate to spatial changes, over time, in regions of economic importance for these crops. However, whether such thresholds are `critical' for New Zealand cannot currently be addressed by the CLIMPACTS model. The determination of `criticality' requires a fully integrated assessment in which the social, economic, and environmental costs and risks associated with these thresholds are comprehensively evaluated.

关键词： 气候变化   农业生产   开发利用   奉贤地区  

摘要： 根据奉贤 1959～ 1999年的降水、气温、日照资料 ,对奉贤 4 0多年的气候变化特征进行分析。结果表明 :4 0多年来奉贤地区年平均气温呈上升趋势 ,特别是进入 2 0世纪 90年代以来增温尤为显著 ,冬季变暖趋势 (为 +0 .4 8℃ /10年 )明显大于春、秋两季 ,夏季气温呈略下降趋势 ;年降水量呈上升趋势 (+6 5.7mm/10年 ) ,月际降水变化幅度加大。夏季降水量增多尤为明显(+91.7mm/10年 ) ,春季、冬季降水量呈波动状态 ,秋季降水量呈下降趋势 (- 38.1mm/10年 ) ;年日照时数依次分为上升期 (6 0年代中后期以前 ) ,下降期 (6 0年代末～ 80年代初 )和在平均值(194 4 .3h)上下振动期 (80年代中期以后 )三个阶段。此外 。

关键词： 气候变化   农业气候资源   作物生产  

摘要： 通过对福建东西南北几个代表点 1 981～ 1 990年、 1 991～ 1 999年、 1 981～ 1 999年光温水气候资源特征值与 1 951～ 1 980年平均值的对比分析 ,结果表明 :80年代以后各季平均气温除闽北变化不明显外 ,其它三地区秋冬变暖明显 ,春冷夏热 ,各地平均年平均气温升高 0 .4℃。 1 2～ 1 5℃、 1 0～ 2 3℃ ( 2 0℃ )活动积温闽南增加 ,闽北减少 ;各地各时段日照时数平均减少 1 0 %～ 1 5% ;各地春雨季降水量增加、梅雨季降水量减少 ,年、生长季降水量闽南略增 ,闽北减少 ;闽北、闽东“三寒”发生次数均有不同程度的增加。并简要地讨论了气候变化对我省水稻、冬种、果树等作物生产的影响 。

关键词： 明代   华南地区   农业经济   气候环境   生态环境  

摘要： 在明代２７６年间，华南气候经过多次振动发 生了由暖到寒的转变。这一转变对当时华南地区的农业产生 过较大的影响：一方面，由于气候振动，气象灾害时常发生，伤 害了劳动力资源，破坏了耕地和其它农业设施，扰乱了农业生 产的秩序。另一方面，由于气候由暖转寒，影响了农作物的组 合，使粮食作物和经济作物的地理分布有了改变。此外，气候 转寒以后，砍伐森林、破坏植被、滥杀动物的情况不断发生，也 在一定的程度上破坏了农业的生态环境。从某种意义上说，气 候变化是制约明代华南农业发展的一个重要因素。