关键词： 作物水分亏缺指数   站次比   干旱强度  

摘要： 基于中国西北地区1961-2010年149个气象站点逐日气象资料及春小麦、春玉米和夏玉米生育期资料,采用作物水分亏缺指数(CWDI)为作物干旱指标,明确了研究区域内3种作物干旱的空间分布特征和时间演变规律。研究结果表明:(1)3种作物生长季内及各生育阶段,干旱发生频繁,尤以特旱和重旱发生范围广、频率高,轻旱和中旱多发生在研究区域东部,甘肃南部和陕西南部等个别地区干旱发生频率相对较小。(2)春小麦生长季内干旱发生站次比为79.1%,春玉米生长季内干旱发生站次比为84.5%,夏玉米干旱发生站次比为77.4%;夏玉米生长季内站次比波动较小,春小麦和春玉米波动较大。总体而言,研究时段内春小麦生长期干旱发生站次比呈减小趋势,降幅为每10a减少0.55个百分点,春玉米和夏玉米干旱站次比呈增加趋势,增幅分别为每10a增加0.24个百分点和0.20个百分点。(3)研究区域东部春小麦和春玉米各生育阶段干旱强度呈增加趋势,西部呈下降趋势;夏玉米干旱强度在陕西北部、宁夏和河西走廊呈增加趋势,其它地区多为降低趋势。

关键词： Soil moisture   Soil waterlogging   Field drainage   land capability   Land suitability   Adaptation strategies  

摘要： Waterlogged soils can act as a major constraint on agriculture by imposing limits on the use of machinery and stocking levels. Inappropriate use of waterlogged soils can cause serious damage to soil and water resources. Limitations are particularly pronounced in locations with wetter climates and on soils which have inherent drainage problems. Constraints may also vary temporally due to climate variability and climate change. These issues are investigated through the strategic use of a risk assessment framework that combines climatic and soil factors to map changes in soil wetness risk at country level. Wetness risk is evaluated in terms of soil wetness classes and the constraints it imposes on arable and improved grassland using an empirical land capability scheme. A case study in Scotland analyses spatio-temporal variations of wetness risk and associated land-use constraints for 1961-1980 and 1991-2010 periods and using a future 2050s projection based upon the HadRM3/HadCM3 climate model ensemble. Results suggest increased risk levels in recent decades for south-west and central Scotland which are both important areas for livestock agriculture. However, wetness risk in these high risk areas is tentatively projected to reduce under average 2050s conditions based upon a central estimate from the model ensemble. Wetness risk has been adjusted based upon the assumed presence and performance of subsurface field,drainage systems but this remains a significant uncertainty due to limited data availability. As artificial drainage represents the major alternative adaptation strategy compared to change of land use, the case study highlights a need to further evaluate its efficacy and long-term viability for those areas identified at high risk. (C) 2016 Published by Elsevier B.V.

关键词： Climate change   Bio-economic farm model   Mathematical programming   Biogeochemical grassland model   Grass shadow prices  

摘要： Forage and more widely grassland systems are difficult to analyze in economic terms because a large proportion of what is produced is not marketed. Economic misestimation of these farm products may dramatically alter projected climate change impacts. This study estimates the economic value of grass and assesses the impact of climatic variations on grassland-livestock systems by taking various environmental and climatic factors into account. Accordingly, grass yield responses to nitrogen inputs (N-yield functions) have been simulated using the grassland biogeochemical PaSim model and then fed into the economic farm-type supply AROPAj model. We developed a computational method to estimate shadow prices of grass production, allowing us to better estimate the effects of climatic variability on grassland and crop systems. This approach has been used on a European scale under two Intergovernmental Panel on Climate Change climate scenarios (AR4 A2 and B1). Results show a significant change in land use over time. Accordingly, due to decreases in feed expenses, farmers may increase livestock, thereby increasing overall greenhouse gas emissions for all scenarios considered. As part of autonomous adaptation by farming systems, N-yield functions extending to pastures and fodders allow us to improve the model and to refine results when marketed and non-marketed crops are considered in a balanced way.

关键词： Greenhouse gas   Best agricultural management practices   C-offset   Land use and land use change  

摘要： The worldwide historical carbon (C) losses due to Land Use and Land-Use Change between 1870 and 2014 are estimated at 148 Pg C (1 Pg = 1 billion ton). South America is chosen for this study because its soils contain 10.3% (160 Pg C to 1-mdepth) of the soil organic carbon stock of the world soils, it is home to 5.7% (0.419 billion people) of the world population, and accounts for 8.6% of the world food (491 million tons) and 21.0% of meat production (355 million tons of cattle and buffalo). The annual C emissions from fossil fuel combustion and cement production in South America represent only 2.5% (0.25 Pg C) of the total global emissions (9.8 Pg C). However, South America contributes 31.3% (0.34 Pg C) of global annual greenhouse gas emissions (1.1 Pg C) through Land Use and Land Use Change. The potential of South America as a terrestrial C sink for mitigating climate change with adoption of Low-Carbon Agriculture (LCA) strategies based on scenario analysis method is 8.24 Pg C between 2016 and 2050. The annual C offset for 2016 to 2020, 2021 to 2035, and 2036 to 2050 is estimated at 0.08, 0.25, and 0.28 Pg C, respectively, equivalent to offsetting 7.5, 22.2 and 25.2% of the global annual greenhouse gas emissions by Land Use and Land Use Change for each period. Emission offset for LCA activities is estimated at 31.0% by restoration of degraded pasturelands, 25.6% by integrated crop-livestock-forestry-systems, 24.3% by no-till cropping systems, 12.8% by planted commercial forest and forestation, 4.2% by biological N fixation and 2.0% by recycling the industrial organic wastes. The ecosystem carbon payback time for historical C losses from South America through LCA strategies may be 56 to 188 years, and the adoption of LCA can also increase food andmeat production by 615 Mton or 17.6 Mton year(-1) and 56 Mton or 1.6 Mton year(-1), respectively, between 2016 and 2050. (C) 2016 Elsevier Ltd. All rights reserved.

关键词： Climate change adaptation   Scenarios   Regional planning   Canada   Agriculture   Integrated assessment   Uncertainty  

摘要： The amount of information required to adapt to climate change is vast: downscaled climate projections, information on environmental impact, sectoral performance, external drivers, regional strategies, policies and practices. It can be argued that most of this information is accessible at the community/regional level, and thus, the important challenges to adaptation are not information gaps, but constraints created by fragmented planning decisions and a sector-by-sector basis for financial and human resource allocations. To strategically address this through adaptation planning, we developed and tested a place-based decision-making framework that creates an integrated platform for considering regional and global sectoral drivers in Eastern Ontario, Canada. Using available socioeconomic and biophysical information from regional authorities, alternative future scenarios were used to describe the range of socioeconomic futures and their vulnerabilities to climate change. We found that: (1) integration of diverse sets of available data (rather than narrowly focused sectoral assessments) helped identify shared common objectives (maximizing the long-term environmental, economic, social well-being within the region), (2) a high degree of congruence existed as the key drivers of change, irrespective of sector, (3) exploring the future scenarios highlighted shared regional priorities and helped identify adaptation priorities requiring more integrated regional planning.

关键词： Agricultural sector   Basic census area   Climate change   Indicator tool   Vulnerability  

摘要： To propose specific adaptation strategies in the agricultural sector based on vulnerability to climate variability and climate change at the local level, we built a vulnerability index using an indicator tool at a fine spatial scale. This index was applied as a case study in the municipality of Guasave, Sinaloa, Mexico, at the basic census area (BCA) level. We used a total of 37 variables organized into three groups with equal weighting: exposure (13), sensitivity (13), and adaptive capacity (11). From the 20 rural BCAs located in the study area, eight were categorized as having very low vulnerability;five had low vulnerability;two had medium vulnerability because of the lack of basic services (sewers, water, and electricity) and a high rural population density;three had high vulnerability due to a high frequency of days with temperatures below 5 A degrees C and the lack of basic services;and two had very high vulnerability, characterized by a high percentage of production units (PUs) with losses due to climate factors, a high rural population density, and a high frequency of days with temperatures below 5 A degrees C. Approximately 50 % of the municipal rural population lives in BCAs vulnerable to climate change. This methodology allowed us to identify the most susceptible agricultural areas at the local level and the variables that require more attention so that we can propose adaptation strategies and minimize vulnerability due to climate change.

关键词： 气候变化   农业气象灾害   病虫害  

摘要： 农业生产对气候的依赖强度非常高,为了确保各个地区的高产与丰收,研究气候变化,以及气候对气象灾害与病虫害的影响十分关键。通过对相关文献的参考,同时对相关数据的总结分析,发现当气候开始全球变暖之后,基本所有的农业气象灾害都加重,而且发生的频率也有很大幅度提高,极端气候出现的频次也开始增多,为农业生产造成了很大的危害。下面就对这些方面进行分析,希望给有关人士一些借鉴。

摘要： Industrial agriculture, constructed and maintained through the human-nature divide, causes enormous environmental and social destruction. Because of its contributions to climate change, there is a dire need to understand and encourage the ability of alternative systems of more sustainable food production to adapt to changing conditions. By viewing agriculture as a social-ecological system (SES), I used a place-based resilience approach to study the adaptive capacity of non-industrial, individual growers in Arizona’s Verde Valley. Using a political ecology lens, in-depth interviews, and grounded theory, I developed an understanding of the characteristics and processes that influence climate change adaptation that emerge from the specific historical, cultural, and environmental conditions of this SES. Through coding and analysis, I found that opportunities and barriers for adaptation were deeply dependent on the processes and contexts of the agricultural system. Key elements of the growers’ adaptive capacities to climate change are climate change awareness and belief, alternative agricultural practices and ideologies, and larger structural barriers. Therefore, to create climate change-resilient agricultural systems, we must not only target individual beliefs and ideologies but also the systemic conditions they are embedded within.

关键词： Nordic agriculture   climate vulnerability   geographic visualization   interactive map  

摘要： Nordic agriculture must adapt to climate change to reduce vulnerability and exploit potential opportunities. Integrated assessments can identify and quantify vulnerability in order to recognize these adaptation needs. This study presents a geographic visualization approach to support the interactive assessment of agricultural vulnerability to climate change. We have identified requirements for increased transparency and reflexivity in vulnerability assessments, arguing that these can be met by geographic visualization. A conceptual framework to support the integration of geographic visualization for vulnerability assessments has been designed and applied for the development of AgroExplore, an interactive tool for assessing agricultural vulnerability to climate change in Sweden. To open up the black box of composite vulnerability indices, AgroExplore enables the user to select, weight, and classify relevant indicators into sub-indices of exposure, sensitivity, and adaptive capacity. This enables the exploration of underlying indicators and factors determining vulnerability in Nordic agriculture.