关键词： Watershed modeling   Agricultural watershed   Climate change   SWAT   Water yield   Evapotranspiration  

摘要： Quantifying the hydrological response to an increased atmospheric CO2 concentration and climate change is critical for the proper management of water resources within agricultural systems. This study modeled the hydrological responses to variations of atmospheric CO2 (550 and 970 ppm), temperature (+1.1 and +6.4 degrees C), and precipitation (0%, +/-10%, and +/-20%) based on Intergovernmental Panel on Climate Change projections. The Soil and Water Assessment Tool (SWAT) was used to model the hydrology and impact of climate change in the highly agricultural San Joaquin watershed in California. This watershed has an area of 14,983 km(2) with a Mediterranean climate, resulting in a strong dependence on irrigation. Model calibration (1992-1997) and validation (1998-2005) resulted in Nash-Sutcliffe coefficients of 0.95 and 0.94, respectively, for monthly stream flow. The results of this study suggest that atmospheric CO2, temperature and precipitation change have significant effects on water yield, evapotranspiration, irrigation water use, and stream flow. Increasing CO2 concentration to 970 ppm and temperature by 6.4 degrees C caused watershed-wide average evapotranspiration, averaged over 50 simulated years, to decrease by 37.5%, resulting in increases of water yield by 36.5%, and stream flow by 23.5% compared to the present-day climate. Increasing temperature caused a temporal shift in plant growth patterns and redistributed evapotranspiration and irrigation water demand earlier in the year. This caused an increase in stream flow during the summer months due to decreased irrigation demand. Water yield, however, decreased with an increase in temperature. Increase of precipitation by +/-10% and +/-20% generally changed water yield and stream flow proportionally, and had negligible effects on predicted evapotranspiration and irrigation water use. Overall, the results indicate that the San Joaquin watershed hydrology is very sensitive to potential future climate changes.

关键词： 气候变化   农业生产   影响   措施  

摘要： 概述气候变化对农业生产的影响，并提出了相应的对策。

关键词： 气候变化   粮食安全   极端天气事件   粮食供需   粮食单产   暴雨洪涝   低温阴雨   种植制度   防御工作   粮食生  

摘要： 气候变化对我国农业已经造成了影响,并将继续影响我国农业生产,为我国农业发展带来巨大的挑战。

关键词： Bleaching   capacity building   climate   coral reefs   global warming   robustness  

摘要： The coral reef ecosystem forms part of a 'seascape' that includes land-based ecosystems such as mangroves and forests, and ideally should form a complete system for conservation and management. Aquaculture, including artisanal fishing for fish and invertebrates, shrimp farming, and seaweed farming, is a major part of the farming and gleaning practices of many tropical communities, particularly on small islands, and depends upon the integrity of the reefs. Climate change is making major impacts on these communities, not least through global warming and high CO2 concentrations. Corals grow within very narrow limits of temperature, provide livelihoods for millions of people in tropical areas, and are under serious threat from a variety of environmental and climate extremes. Corals survive and grow through a symbiotic relationship with photosynthetic algae: zooxanthellae. Such systems apply highly co-operative regulation to minimize the fluctuation of metabolite concentration profiles in the face of transient perturbations. This review will discuss research on how climate influences reef ecosystems, and how science can lead to conservation actions, with benefits for the human populations reliant on the reefs for their survival.

关键词： climate change   agriculture   forestry   CO2   growing season   crop yield   frost damage   phenology   flowering   crop cycle   temperature   sowing date   grapevine   maize   wheat   water demand   irrigation   drought   carbon cycle   fire danger  

摘要： This article reviews major impacts of climate change on agriculture and forestry.

关键词： Climate change   Economic impacts   Agriculture   Africa   AEZ  

摘要： This paper examines the distribution of climate change impacts across the sixteen Agro-Ecological Zones (AEZs) of Africa. We combine net revenue from livestock and crops and regress total net revenue on a set of climate, soil, and socio-economic variables with and without country fixed effects. Although African crop net revenue is very sensitive to climate change, combined livestock and crop net revenue is more climate resilient. With the hot and dry CCC climate scenario, average damage estimates reach 27% by 2100, but with the mild and wet PCM scenario, African farmers will benefit. The analysis of AEZs implies that the effects of climate change will be quite different across Africa. For example, currently productive areas such as dry/moist savannah are more vulnerable to climate change while currently less productive agricultural zones such as humid forest or sub-humid AEZs become more productive in the future.

关键词： China   Crop productivity   EPIC model   Impacts   Global warming  

摘要： Increasing atmospheric greenhouse gas concentrations are expected to induce significant climate change over the next century and beyond, but the impacts on society remain highly uncertain. This work examines potential climate change impacts on the productivity of five major crops in eastern China: canola, corn, potato, rice, and winter wheat. In addition to determining domain-wide trends, the objective is to identify vulnerable and emergent regions under future climate conditions, defined as having a greater than 10% decrease and increase in productivity, respectively. Data from the ICTP RegCM3 regional climate model for baseline (1961-1990) and future (2071-2100) periods under A2 scenario conditions are used as input for the EPIC agro-ecosystem simulation model in the domain [30 degrees N, 108 degrees E] to [42 degrees N, 123 degrees E]. Simulations are performed with and without the enhanced CO2-fertilization effect. Results indicate that aggregate potential productivity (i.e. if the crop is grown everywhere) increases 6.5% for rice, 8.3% for canola, 18.6% for corn, 22.9% for potato, and 24.9% for winter wheat, although with significant spatial variability for each crop. However, without the enhanced CO2-fertilization effect, potential productivity declines in all cases ranging from 2.5 to 12%. Interannual yield variability remains constant or declines in all cases except rice. Climate variables are found to be more significant drivers of simulated yield changes than changes in soil properties, except in the case of potato production in the northwest where the effects of wind erosion are more significant. Overall, in the future period corn and winter wheat benefit significantly in the North China Plain, rice remains dominant in the southeast and emerges in the northeast, potato and corn yields become viable in the northwest, and potato yields suffer in the southwest with no other crop emerging as a clear beneficiary from among those simulated in this study. (C) 20

关键词： 气候变化   农业气象灾害   分析  

摘要： 通过对1956～2005年朔州市气象局气温、降水等资料的统计分析,结果表明:朔州气候趋向变暖,其中20世纪90年代后期气温显著上升,冬季增温的贡献最大;降水呈减少的趋势;分析还表明由于气候的变化,导致极端天气气候事件趋多趋强,农业气象灾害发生频次增多,使农作物受灾、成灾面积均有不断增加的趋势,并由此给农业生产带来更大的损失。

关键词： 行为经济学   农业决策   气候变化   适应   时滞   中国东北  

摘要： 利用调查问卷和入户访谈的方法,以中国东北地区11个调查点为研究区,对554户农户进行调查研究,从行为经济学的视角出发,把农业实践者的粮食种植行为作为一种农业经济行为,分析20世纪80年代气候变暖以来,农业实践者在农业种植决策中的行为过程及其与传统经济学理性行为之间的差异。结果显示,在不确定条件下,农业决策行为符合行为经济学的一般规律,在认知偏差和思维定式等因素的影响下,会系统地偏离传统经济学理论,产生非理性行为,从而导致适应与变化之间存在时滞现象:①受启发式认知偏向的影响,农业实践者在作物种类选择、种植计划制定和粮食出售时间确定等方面均表现为非理性的特点;②受中国具体国情和农业生产固有特点的影响,出于"保障生活能够继续"的考虑,农业实践者判断"获得"和"损失"的参照点通常很低,对作物品种选择的行为更倾向于保守。

关键词： 生态环境   气候变化   利弊影响  

摘要： 小浪底水库蓄水后,库区降水量明显增加,平均增幅16.9%;库区和周边的温度均呈增高趋势;夏、秋季日照和蒸发量显著减少,轻雾日数明显增多,相对湿度呈略增大趋势。生态环境得到明显改善,有利于小麦稳产高产,有利于夏玉米丰产丰收,有利于林果业及冬凌草产业的发展,有利于大面积种植薄皮核桃,有利于烟叶生长。虽然也存在一些弊端,但总体上利远大于弊。