摘要： Because crops have narrow climate thresholds for developmental success, an increasing occurrence of extreme climate events will affect farmers who depend on rainfed agriculture. Increasing patterns of agricultural intensification may lead to still greater vulnerability for farmers because more intensively managed systems may be less resilient to the impacts of climate extremes. Because of farmer vulnerability, the different responses of management intensities to climate extremes should be explored so that sustainable management strategies can be developed to protect farmers from increased climate variability. This thesis explores the potential of agroforestry systems to protect coffee agriculture from climate variability in Chiapas, Mexico. A set of experiments were conducted from July 2004 to November 2005 in the Soconusco region of Chiapas in a high (60-80%), medium (30-65%), and low (10-30%) shade coffee system, where shade is an indicator of management intensity. These sites were chosen to explore the qualitative differences among management systems as they relate to climate. Microclimate variables and soil moisture were measured in these systems to examine the effect of shade cover on microhabitat modification. Evapotranspiration rates were measured to examine water loss as a function of shade cover. Additionally, flower and fruit development were assessed to examine the effects of microclimate and soil moisture on coffee production. Microclimate measurements showed that fluctuations in ambient microclimate decreased significantly as shade cover increased, with similar patterns in soil moisture measurements. Coffee plant evapotranspiration rates were reduced at shade levels ≥30%, with significant effects of light and vapor pressure deficit. Shade cover also affected flowering and fruit set. Flower development was significantly enhanced in sites with ≥30% shade cover, where greater soil moisture measurements were found. Fruit development was also greatly control

关键词： climate change   farmers   species   vulnerability   adaptation   policy  

摘要： The term vulnerability has been used in a variety of contexts, including climate change impact assessment. In this paper those issues relevant to climate change impacts on agriculture and species are discussed. Outputs from models are used to assess the vulnerability of fanners and species to climate and socio-economic change by estimating their sensitivity and capacity to adapt to external factors as a means of identifying what causes the differences in their vulnerability. The results showed that the vulnerability of both farmers and species is dependent on the scenario under consideration. In agriculture, it is the socio-economic scenarios that particularly lead to different patterns of intensification, extensification and abandonment. For species, vulnerability is more related to the climate change scenarios. In both cases, the adaptation options and potential were associated with the different socio-economic futures and policy intervention. The conceptual linking of the two sectors shows that impacts in the agriculture sector and consequent adaptation could have a significant effect on the adaptation potential of species. This demonstrates the importance of cross-sectoral assessments of vulnerability and highlights the importance of sectoral integration in policy development and implementation. (c) 2005 Elsevier Ltd. All rights reserved.

关键词： Climate change  

摘要： Canadian researchers and policy makers dealing with climate change adaptation in the agriculture field frequently point to an apparent lack of interest from producers when the topic is raised. This attitude may be the result of several conditions, including the fact that adaptation, as a term, is poorly understood and rarely recognised and that adaptation strategies are not separable in practice from existing business risk management. Producers' attitudes play a significant role in instituting successful policy and programmes for climate change risk management and need to be acknowledged when conducting applied research into the topic. Many factors influence producers' attitudes and perceptions, among them are news media reports. This paper documents and assesses news media coverage of climate change adaptation issues relevant to the agri-food sector in Canada and shows there are similarities between media portrayal and producers' perceptions of the topic of climate change adaptation. Copyright © 2006 Inderscience Enterprises Ltd.

关键词： 战国末   西汉   气候变化   关中   农业  

摘要： 在中国历史上，关中地区作为黄河流域的一部分，是建都最多的地域。这不仅与关中的地理位置有关，更为重要的是与统治阶级赖以生存的物质基础——农业的发展水平有关。战国末到西汉中期，关中农业在原有的基础上得到了更进一步的发展；但到西汉中期以后，关中农业没有向前发展反而出现倒退了。导致关中农业在这一历史时期出现由盛而衰的局面的原因是多方面的。如政府的人为行为等。但其最根本的原因是当时气候条件发生了变化，进而影响到农业生产。众所周知，中国农业属于是典型的气候型农业，靠天吃饭是中国农业的主要特征。尤其在生产力相对比较落后的古代社会，农业的兴衰成败更是依赖于“天”，即气候。因此，本文主要论述了战国末到西汉时期关中农业出现由盛而衰的局面，并对造成这一局面的根本原因进行了分析，指出当时关中农业对气候的依赖，从而为我们今后的农业发展提供科学的借鉴。论文主要包括以下几部分： 第一部分为绪论。主要概述了古代关中的自然地理环境和秦统一以前关中农业的发展概况，指出了关中农业发展的优势和不足与靠天吃饭农业局面的形成；同时，对秦、西汉时期气候状况和当时农业的发展情况的研究现状分别作了回顾，指出了我的主要观点。 第二部分论述战国末到西汉时期关中农业由盛而衰的变化过程。战国末到西汉中期是关中农业的大发展阶段。其主要表现在当时粮食产量的增加和人口的增长。但到西汉中期以后，关中农业发展出现衰退局面，粮食产量降低，不仅不能满足人们的需要、导致人口的大量减少，而且威胁到统治阶级统治地位的巩固，最终使西汉王朝灭亡。 第三部分论述了战国末到西汉时期关中农业出现由盛转衰这一局面的根本原因。战国末到西汉时期，关中农业出现由盛而衰这一局面的原因是多方面的。如政府对农业的重视程度、人力投入的多寡、技术投入的多少等等。但这只是影响农业发展的一个因素，而不是最根本的原因，其根本原因就是当时气候条件对农业的影响。战国末到西汉中期，气候比较温暖湿润，关中地区大量种植竹、橘柑等亚热带植物。良好的气候条件，为“靠天吃饭”的气候型农业的发展提供了赖以生存气候环境，促进了关中农业的大发展。但到西汉中期以后，气候有所变化，逐渐由温暖向寒冷干旱过渡。这不仅表现在当时冬小麦播种时间较以往提前，而且还表现在统治阶级为改善气候状况对农业的影响，使农业适应气候条件的变化，不仅在关中大规模兴修水利，而且采用了较之以往更先进的耕作技术，如代田法

关键词： 气候变化   农业   影响   进展  

摘要： 本文着重介绍了近几年气候变化对农业影响的最新研究进展,其中包括气象因子对农业生态环境的影响、二氧化碳浓度增加、气候变化对农作物光合作用、生长发育、产量、品质、种类、地理分布、种植制度、农业灾害以及农业成本等领域最新研究进展,最后指出了存在的问题以及研究展望。

关键词： .Precipitation   Ricardian   Measuring the Impact   net revenue   Sugarcane production  

摘要： This study employed a Ricardian model that captures farmers' adaptation to analyze the impact of climate change on South African Sugarcane production under irrigation and dryland conditions. The study utilized time series data for the period 1977 to 1998 pooled over 11 districts. Results showed that climate change has significant nonlinear impacts on net revenue per hectare of sugarcane in South Africa with higher sensitivity to future increases in temperature than precipitation. Irrigation did not prove to provide an effective option for mitigating climate change damages on sugarcane production in South Africa. The study suggests that adaptation strategies should focus special attention on technologies and management regimes that will enhance sugarcane tolerance to warmer temperatures during winter and especially the harvesting phases.

关键词： Climate change   Agriculture   Crops   Precipitation (Meteorology)  

摘要： This paper measures climate change impacts on Sri Lankan agriculture using the Ricardian method. The model examines the net revenue per hectare of the four most important crops in the country The limited range of temperature variation allows only a simple test of temperature impacts, but the greater range of precipitation across the country distinguishes more complex precipitation effects. We then examine the impacts of the climate predictions of five AOGCM models and two simple uniform change scenarios for Sri Lanka. The impacts of rainfall increases are predicted to be beneficial to the country as a whole in all five AOGCM scenarios, but temperature increases are predicted to be harmful. Nationally, the impacts vary from -11 billion rupees (-20 per cent) to +39 billion rupees (+72 per cent) depending on the climate scenarios. With warming, the already dry regions (the Northern and Eastern provinces), are expected to lose large portions of their current agriculture, but the cooler regions (the central highlands), are predicted to remain the same or increase their output. The paper reconfirms that climate change damages could be large in tropical developing countries, but highly dependent on the actual climate scenario.

关键词： 未来气候变化   农业生产   抗逆性   优良品种   水分  

摘要： 1985年世界气象组织、国际科联和联合国环境计划署等共同主持召开的大会上所发表的公告指出,由于人类大量消费化石燃料(煤炭、石油、天然气等),导致排放到大气中的二氧化碳、甲烷、氧化氮和微量气体迅速增加,从而引起显著的温室效应.

关键词： 大兴安岭地区   气候变化   农业生产   影响  

摘要： 利用统计学方法对近30年来大兴安岭地区的气候变化特点进行了研究,在全球气候变暖的大背景下,从温度、降水、蒸发、冻土等气象要素分析得出:该地区气候有明显的变暖趋势,但存在区域差异,同时分析了气候变化对农业生产所产生的影响,为合理利用大兴安岭地区气候资源提供了依据。

关键词： 互助县   气候变化   农业生态   生态环境   自然环境   气温   降水量   时空分布   气候灾害  

摘要： 本文利用30a韵气象资料对影响互助县生态环境主要气候因子的基本特征及其变化进行分析,并探讨自然灾害及人类经济活动对生态环境的影响,为生态环境的保护和建设提供参考依据。