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1.
Climate change can bring positive and negative effects on Chinese agriculture, but negative impacts tend to dominate. The annual mean surface temperature has risen about 0.5–0.8 °C. The precipitation trends have not been identified during the past 100 years in China, although the frequency and intensity of extreme weather/climate events have increased, especially of drought. Water scarcity, more frequent and serious outbreaks of insects and diseases, and soil degradation caused by climate change have impacted agro-environmental conditions. However, temperature rise prolonged the crop growth seasons and cold damages have reduced in Northeast China. The projection of climate change indicates that the surface temperature will continue to increase with about 3.9 to 6.0 °C and precipitation is expected to increase by 9 to 11 % at the end of 21st century in China. Climate warming will provide more heat and as a consequence, the boundary of the triple-cropping system (TCS) will extend northwards by as much as 200 to 300 km, from the Yangtze River Valley to the Yellow River Basin, and the current double-cropping system (DCS) will move to the central part of China, into the current single cropping system (SCS) area which will decrease in SCS surface area of 23.1 % by 2050. Climate warming will also affect the optimum location for the cultivation of China’s main crop varieties. If no measures are taken to adapt to climate changes, compared with the potential yield in 1961–1990, yields of irrigated wheat, corn and rice are projected to decrease by 2.2–6.7 %, 0.4 %–11.9 % and 4.3–12.4 % respectively in the 2050s. Climate warming will enhance potential evaporation and reduce the availability of soil moisture, thus causing a greater need for agricultural irrigation, intensifying the conflict between water supply and demand, especially in arid and semi-arid areas of China. With adequate irrigation, the extent of the reduction in yield of China’s corn and wheat can be improved by 5 % to 15 %, and rice by 5 % or so than the potential yield in 1961–1990. Adaptive measures can reduce the agricultural loss under climate change. If effective measures are taken in a timely way, then climate change in the next 30–50 years will not have a significant influence on China’s food security. 相似文献
2.
气候变暖对中国不同地区农业的影响 总被引：50，自引：2，他引：48
摘要：利用国家统计局《中国农村统计年鉴》1984-2003年的数据和同期年平均温度的观测数据,分析了我国不同地区20年间温度变化、农业生产资料投入以及播种面积变化对粮食总产的影响。结果表明,以温度升高为主要特征的气候变化对东北地区农作物增产有明显促进作用,对华北、西北和西南地区的农作物增产有一定抑制作用,对华东和中南地区的农作物粮食产量的影响则不明显。农业投入的增加对各地区的农作物增产在早期作用均显著,后期则增长缓慢。而各地区播种面积的变化对其总产量影响不太明显,但华东和中南地区农业播种面积的持续下降对粮食总产量有较大的抑制作用。 相似文献
3.
基于1981—2010年东北地区55个农业气象观测站发育期数据、16个气象站逐日气象资料,采用趋势变率、秩相关分析、主成分分析和结构方程模型等方法,分析了近30年东北春玉米关键发育期的变化特征,探讨了春玉米发育期对不同时间尺度气象因子的响应规律。结果表明:1981—2010年春玉米关键发育期 (播种期、抽雄期、成熟期) 均有延后趋势,大部分地区春玉米生长前期 (播种期—抽雄期) 日数减少,生长后期 (抽雄期—成熟期) 日数增加,全生育期日数增加。在绝大多数年份,春玉米播种期在温度适播期之后,成熟期在初霜日之前。近30年对东北春玉米生育期日数影响最大的气象要素为温度,主成分分析结果显示,年际尺度的升温、温度生长期的延长和作物生长期的高温对生育期日数影响显著;结构方程模型指出,作物生长期的最高温度和最低温度对生育期日数影响有间接效应,主导气象要素能够解释生育期日数变异的44%。全球变暖背景下,东北春玉米发育期变化是作物响应气候变化和农业生产适应气候变化的共同结果。 相似文献
4.
Agricultural climatic resources （such as light,temperature,and water） are environmental factors that affect crop productivity.Predicting the effects of climate change on agricultural climatic resource utilization can provide a theoretical basis for adapting agricultural practices and distributions of agricultural production.This study investigates these effects under the IPCC （Intergovernmental Panel on Climate Change） scenario A1B using daily data from the high-resolution RegCM3 （0.25° ×0.25°） during 1951-2100.Model outputs are adjusted using corrections derived from daily observational data taken at 101 meteorological stations in Northeast China between 1971 and 2000.Agricultural climatic suitability theory is used to assess demand for agricultural climatic resources in Northeast China during the cultivation of spring maize.Three indices,i.e.,an average resource suitability index （Isr）,an average efficacy suitability index （Ise）,and an average resource utilization index （K）,are defined to quantitatively evaluate the effects of climate change on climatic resource utilization between 1951 and 2100.These indices change significantly in both temporal and spatial dimensions in Northeast China under global warming.All three indices are projected to decrease in Liaoning Province from 1951 to 2100,with particularly sharp declines in Isr,Ise,and K after 2030,2021,and 2011,respectively.In Jilin and Heilongjiang provinces,Isr is projected to increase slightly after 2011,while Ise increases slightly and K decreases slightly after 2030.The spatial maxima of all three indices are projected to shift northeastward.Overall,warming of the climate in Northeast China is expected to negatively impact spring maize production,especially in Liaoning Province.Spring maize cultivation will likely need to shift northward and expand eastward to make efficient use of future agricultural climatic resources. 相似文献
5.
The effects of past climate change on the northern limits of maize planting in Northeast China 总被引：8，自引：0，他引：8
Northeast China (NEC) is one of the major agricultural production areas in China and also an obvious region of climate warming. We were motivated to investigate the impacts of climate warming on the northern limits of maize planting. Additionally, we wanted to assess how spatial shifts in the cropping system impact the maize yields in NEC. To understand these impacts, we used the daily average air temperature data in 72 weather stations and regional experiment yield data from Jilin Province. Averaged across NEC, the annual air temperature increased by 0.38 °C per decade. The annual accumulated temperature above 10 °C (AAT10) followed a similar trend, increased 66 °C d per decade from 1961 to 2007, which caused a northward expansion of the northern limits of maize. The warming enabled early-maturing maize hybrids to be sown in the northern areas of Heilongjiang Province where it was not suitable for growing maize before the warming. In the southern areas of Heilongjiang Province and the eastern areas of Jilin Province, the early-maturing maize hybrids could be replaced by the middle-maturing hybrids with a longer growing season. The maize in the northern areas of Liaoning Province was expected to change from middle-maturing to late-maturing hybrids. Changing the hybrids led to increase the maize yield. When the early-maturing hybrids were replaced by middle-maturing hybrids in Jilin Province, the maize yields would increase by 9.8 %. Similarly, maize yields would increase by 7.1 % when the middle-maturing hybrids were replaced by late-maturing hybrids. 相似文献
6.
Future cereal production in China: The interaction of climate change,water availability and socio-economic scenarios 总被引：4，自引：0，他引：4
Xiong Wei Conway Declan Lin Erda Xu Yinlong Ju Hui Jiang Jinhe Holman Ian Li Yan 《Global Environmental Change》2009,19(1):34-44
Food production in China is a fundamental component of the national economy and driver of agricultural policy. Sustaining and increasing output to meet growing demand faces significant challenges including climate change, increasing population, agricultural land loss and competing demands for water. Recent warming in China is projected to accelerate by climate models with associated changes in precipitation and frequency of extreme events. How changes in cereal production and water availability due to climate change will interact with other socio-economic pressures is poorly understood. By linking crop and water simulation models and two scenarios of climate (derived from the Regional Climate Model PRECIS) and socio-economic change (downscaled from IPCC SRES A2 and B2) we demonstrate that by the 2040s the absolute effects of climate change are relatively modest. The interactive effects of other drivers are negative, leading to decreases in total production of ?18% (A2) and ?9% (B2). Outcomes are highly dependent on climate scenario, socio-economic development pathway and the effects of CO2 fertilization on crop yields which may almost totally offset the decreases in production. We find that water availability plays a significant limiting role on future cereal production, due to the combined effects of higher crop water requirements (due to climate change) and increasing demand for non-agricultural use of water (due to socio-economic development). Without adaptation, per capita cereal production falls in all cases, by up to 40% of the current baseline.By simulating the effects of three adaptation scenarios we show that for these future scenarios China is able to maintain per capita cereal production, given reasonable assumptions about policies on land and water management and progress in agricultural technology. Our results are optimistic because PRECIS simulates much wetter conditions than a multi-model average, the CO2 crop yield response function is highly uncertain and the effects of extreme events on crop growth and water availability are likely to be underestimated. 相似文献
7.
气候变化的影响与适应已经成为农业生产面临的现实而紧迫的问题。1956-2005年东北地区增温1.5℃,幅度明显高于全国平均水平,给作物生产带来复杂的影响。东北是重要的国家商品粮生产基地,对国家粮食安全起着重要作用。探讨区域层面上适应气候变化的能力建设更具有针对性和现实性。文章分析了近50 a来东北地区气候变化的主要表现及其对农业生产的影响;针对气候变化过程中人类活动对土地利用和温室气体的影响,提出了东北地区适应和减缓气候变化的策略和措施,强调在农业生态、水资源利用、环境保护等多方面综合开展工作,积极采取行动,最终达到维护气候环境、充分利用气候资源的目的,为东北粮食生产安全、农业可持续发展做出贡献。 相似文献
8.
This is the second part of the authors’ analysis on the output of 24 coupled climate models from the Twentieth-Century Climate in Coupled Models (20C3M) experiment and 1% per year CO 2 increase experiment (to doubling) (1pctto2x) of phase 3 of the Coupled Model Inter-comparison Project (CMIP3). The study focuses on the potential changes of July–August temperature extremes over China. The pattern correlation coefficients of the simulated temperature with the observations are 0.6–0.9, which are higher than the results for precipitation. However, most models have cold bias compared to observation, with a larger cold bias over western China (>5°C) than over eastern China (<2°C). The multi-model ensemble (MME) exhibits a significant increase of temperature under the 1pctto2x scenario. The amplitude of the MME warming shows a northwest–southeast decreasing gradient. The warming spread among the models (～1°C– 2°C) is less than MME warming (～2°C–4°C), indicating a relatively robust temperature change under CO 2 doubling. Further analysis of Geophysical Fluid Dynamics Laboratory coupled climate model version 2.1 (GFDL-CM2.1) simulations suggests that the warming pattern may be related to heat transport by summer monsoons. The contrast of cloud effects also has contributions. The different vertical structures of warming over northwestern China and southeastern China may be attributed to the different natures of vertical circulations. The deep, moist convection over southeastern China is an effective mechanism for "transporting" the warming upward, leading to more upper-level warming. In northwestern China, the warming is more surface-orientated, possibly due to the shallow, dry convection. 相似文献
9.
We used daily maximum temperature data (1986–2100) from the COSMO-CLM (COnsortium for Small-scale MOdeling in CLimate Mode) regional climate model and the population statistics for China in 2010 to determine the frequency, intensity, coverage, and population exposure of extreme maximum temperature events (EMTEs) with the intensity–area–duration method. Between 1986 and 2005 (reference period), the frequency, intensity, and coverage of EMTEs are 1330–1680 times yr–1, 31.4–33.3°C, and 1.76–3.88 million km2, respectively. The center of the most severe EMTEs is located in central China and 179.5–392.8 million people are exposed to EMTEs annually. Relative to 1986–2005, the frequency, intensity, and coverage of EMTEs increase by 1.13–6.84, 0.32–1.50, and 15.98%–30.68%, respectively, under 1.5°C warming; under 2.0°C warming, the increases are 1.73–12.48, 0.64–2.76, and 31.96%–50.00%, respectively. It is possible that both the intensity and coverage of future EMTEs could exceed the most severe EMTEs currently observed. Two new centers of EMTEs are projected to develop under 1.5°C warming, one in North China and the other in Southwest China. Under 2.0°C warming, a fourth EMTE center is projected to develop in Northwest China. Under 1.5 and 2.0°C warming, population exposure is projected to increase by 23.2%–39.2% and 26.6%–48%, respectively. From a regional perspective, population exposure is expected to increase most rapidly in Southwest China. A greater proportion of the population in North, Northeast, and Northwest China will be exposed to EMTEs under 2.0°C warming. The results show that a warming world will lead to increases in the intensity, frequency, and coverage of EMTEs. Warming of 2.0°C will lead to both more severe EMTEs and the exposure of more people to EMTEs. Given the probability of the increased occurrence of more severe EMTEs than in the past, it is vitally important to China that the global temperature increase is limited within 1.5°C. 相似文献
10.
Impacts of climate change on crop evapotranspiration with ensemble GCM projections in the North China Plain 总被引：2，自引：1，他引：1
As one of the key grain-producing regions in China, the agricultural system in the North China Plain (NCP) is vulnerable to climate change due to its limited water resources and strong dependence on irrigation for crop production. Exploring the impacts of climate change on crop evapotranspiration (ET) is of importance for water management and agricultural sustainability. The VIP (Vegetation Interface Processes) process-based ecosystem model and WRF (Weather Research and Forecasting) modeling system are applied to quantify ET responses of a wheat-maize cropping system to climate change. The ensemble projections of six General Circulation Models (GCMs) under the B2 and A2 scenarios in the 2050s over the NCP are used to account for the uncertainty of the projections. The thermal time requirements (TTR) of crops are assumed to remain constant under air warming conditions. It is found that in this case the length of the crop growth period will be shortened, which will result in the reduction of crop water consumption and possible crop productivity loss. Spatially, the changes of ET during the growth periods (ETg) for wheat range from ?7 to 0 % with the average being ?1.5?±?1.2 % under the B2 scenario, and from ?8 to 2 % with the average being ?2.7?±?1.3 % under the A2 scenario/consistently, changes of ETg for maize are from ?10 to 8 %, with the average being ?0.4?±?4.9 %, under the B2 scenario and from ?8 to 8 %, with the average being ?1.2?±?4.1 %, under the A2 scenario. Numerical analysis is also done on the condition that the length of the crop growth periods remains stable under the warming condition via breeding new crop varieties. In this case, TTR will be higher and the crop water requirements will increase, with the enhancement of the productivity. It is suggested that the options for adaptation to climate change include no action and accepting crop loss associated with the reduction in ETg, or breeding new cultivars that would maintain or increase crop productivity and result in an increase in ETg. In the latter case, attention should be paid to developing improved water conservation techniques to help compensate for the increased ETg. 相似文献
11.
作物系数是计算作物蒸散量的关键参数。利用2006—2008年和2011年辽宁锦州玉米农田生态系统的涡度相关、气象、作物发育期及叶面积指数观测数据,分析不受水分胁迫条件下玉米逐日作物系数特征及其与叶面积指数的关系。研究表明:作物系数与玉米农田实际蒸散均呈单峰型变化,约在7月末至8月初达到最大值 (玉米开花吐丝期)。在此基础上,建立了不受水分胁迫条件下玉米逐日作物系数与叶面积指数关系 (达到0.01显著性水平), 同时,采用积温表示的标准化生育期方法模拟相对叶面积指数,并建立了逐日作物系数与相对叶面积指数关系 (达到0.01显著性水平),解决了无叶面积观测地区玉米逐日实际蒸散量的计算。研究结果可为玉米农田用水管理以及灌溉措施的制定提供参考。 相似文献
12.
气候变化对中国农业生产影响研究展望 总被引：32，自引：0，他引：32
综述了气候变化背景下中国农业气候资源、农业气象灾害(干旱、洪涝、高温热浪、低温灾害)和农业病虫害的变化趋势与规律,从农业生产潜力变化、作物种植制度变化和作物品质变化等方面阐明了气候变化对中国农业生产的影响事实,分析了气候变化对中国农业生产的可能影响和中国农业生产适应气候变化的对策措施。在此基础上,针对气候变化背景下中国气候资源的时空分布特点及农业生产出现的新情况、新问题,指出了当前中国关于气候变化对农业影响研究存在的不足,提出了未来气候变化对中国农业生产影响研究需要重视的方面,为确保气候变化背景下中国的农业生产安全及粮食安全提供决策支持。 相似文献
13.
为探求未来气候变化对我国东北玉米品种布局的影响,基于玉米生产潜力和气候资源利用率,结合区域气候模式输出的2011—2099年RCP_4.5,RCP_8.5两种气候背景气象资料和1961—2010年我国东北地区91个气象站的观测数据,分析了未来气候变化情况下,东北玉米品种布局、生产潜力、气候资源利用率的时空变化。结果表明:未来东北地区玉米可种植边界北移东扩,南部为晚熟品种,新扩展区域以早熟品种为主,不能种植区域减少。未来玉米生产潜力为南高北低,增加速率均高于历史情景,水分适宜度最低,而历史情景下温度是胁迫玉米生产的关键因子。未来东北玉米对气候资源利用率整体下降,其中RCP8.5情景利用率最低。 相似文献
14.
Qingfeng Meng Peng Hou David B. Lobell Hongfei Wang Zhenling Cui Fusuo Zhang Xinping Chen 《Climatic change》2014,122(1-2):341-349
Latitudes above 45°N have been characterized by rates of warming faster than the global average since 1980. However, the effects of this warming on crop production at these latitudes are still unclear. Using 30-years of weather and crop management data in Heilongjiang area of China (43.4° to 53.4°N), combined with the Hybrid-Maize model, we show that that maize yields would have stagnated in most areas and decreased in the southern part of Heilongjiang if varieties were assumed fixed since 1980. However, we show that through farmers’ adaptation, warming has benefitted maize production for much of this region. Specifically, farmers gradually chose longer maturing varieties, resulting in a net 7–17 % yield increase per decade. Meanwhile, farmers also rapidly expanded maize area (from 1.88 million ha in 1980 to 4.01 million ha in 2009) and the northward limit of maize area shifted by more than 290 km from ~50.8°N to ~53.4°N. Overall, benefits from warming represented 35 % of the overall yield gains in the region over this period. The results indicate substantial ongoing adaptations and benefits at north high-latitudes, although they still represent a small fraction of global maize area. The sustainability of crop area expansion in these regions remains unclear and deserves further study. 相似文献
15.
Projections of climate impacts on crop yields simulated for different General Circulation Model (GCM) scenarios are used, in a recursively dynamic general equilibrium framework, to account for potential economy-wide impacts of climate change in Egypt. Comparing these impact projections to those obtained under a reference, business-as-usual, scenario assuming some moderate changes in the political, economic or technological spheres, indicates that global warming has potentially negative effects. The analysis is based on a global assessment of potential climate change-induced variations in world commodity production and trade. The Egyptian agricultural sector, and the non-agricultural sector to a lesser extent, are projected to be increasingly less self-sufficient. Specific potential adverse impacts are identified. The simulation results show that high-cost adaptation measures involving major changes in the agricultural system and practices may mitigate these adverse impacts. Stimulating economic development of the rural areas and creating appropriate conditions for effective diffusion and development of technologies — particularly for the agricultural sector — would seem a desirable strategy. Perhaps, more importantly, the simulation results show that the assumption of exogenously determined technological progress may be inappropriate, in which case the potential adverse impacts of a future warming of the global climate are likely to be fewer than is indicated in this study — if prevailing constraints on productivity growth in the major food and feed grains are ‘released’ by endogenous advances in technology. 相似文献
16.
Based on daily 500-hPa geopotential height from ERA-Interim reanalysis data, this study analyzed the day-to-day circulation variance in cold season (October–March) by composite and correlation analysis. Two same-length time periods were compared, namely, the hiatus period (1999–2013) and the rapid warming period (1984–1998). Spectral analysis revealed that over the mid–high latitudes of the Northern Hemisphere, the most outstanding peak in the daily 500-hPa geopotential height variance was of quasi-biweekly timescale (about 10–20 days), accounting for about 32% of the total variance. During the warming hiatus, quasibiweekly disturbance (QBD) changed remarkably in Northeast Asia. On average, within the domain 42°–50 °N, 128°–142 °E, the QBD variance changed from 1860 m2 in the rapid warming period to 2475 m2 in the hiatus period, increasing by about 33% and statistically significant at the 95% confidence level. Lead–lag analysis showed that the QBD signal could be traced back by about 14 days, with an origin around the Ural Mountains. Then, the signal developed and propogated southeastward, with its location about 10 days prior to its peak in West Siberia, and about 6 days prior to its peak in the Sayan Mountains, and finally moving to Northeast Asia. By comparing the propagation process between the two periods, we found that the propagation paths were basically the same, but there were evident differences in the intensity of the signals. The intensification of QBD may have been related to the increased energy conversion from mean flow to QBD transients. The frequency of low-temperature extremes in negative QBD phases was much higher than under normal conditions or in positive phases. Associated with the enhanced QBD, the probability of extreme low temperature increased from 19% during the rapid warming period to 27% during the warming hiatus. 相似文献
17.
与IPCC第五次评估报告相比,第六次评估报告（AR6）有关农业的评估对象由作物生产系统延伸到粮食供应链系统,气候变化对作物生产不利影响的证据在加强。气候变化改变了作物适宜种植区,使中高纬度及温带地区作物种植界限向高纬度、高海拔地区推移。人为引起的气候变暖阻碍了作物产量的增长,地表O3浓度增加使作物产量降低,CH4排放加剧了这种不利影响。气候变化加剧作物病虫草害,极端气候事件高发加剧了粮食不安全,推升了国际粮食价格。适应措施有助于减缓气候变化不利影响,基于自然的适应方案在增强作物生产系统气候恢复力和保障粮食安全方面具有较高潜力。从保障国家粮食安全和重大战略需求出发,AR6报告对我国农业应对气候变化相关工作的启示如下：需要高度重视气候变化背景下作物种植适宜区转变与种植带北移的重要战略价值,合理规划农业生产布局;加强农业气象灾害和病虫害防治体系和能力建设,保障粮食生产稳定性;关注气候变化对国际作物生产和谷物贸易的影响,统筹国内、国际市场粮食资源,保障粮食安全;推进农业温室气体减排与作物生产高效协同,为实现国家减排目标做出贡献。 相似文献
18.
农业洪涝灾害是国内外灾害研究的重要分支领域。该文采用分类归纳总结已有研究成果并与观测事实相佐证的方法,从农业洪涝相关概念出发,系统阐述了中国农业洪涝灾害的研究进展,评述了气候变暖对中国农业洪涝灾害的影响。基于影响作物及发生时段,中国农业洪涝灾害可分为影响越冬作物的春涝、影响夏播夏收和夏季作物生长的夏涝及影响秋播秋收作物的秋涝。农业洪涝灾害的形成及强度,是天气气候、作物抗涝性、地形地貌、土壤结构及人类活动等多种因素综合作用的结果;气候变暖背景下,中国农业洪涝成灾率呈南方增强北部减缓的趋势,总体呈上升趋势;一方面与极端降水事件的变化有直接关系,另一方面受作物气候适宜性变化等的间接影响。农业洪涝灾害的致灾机理包括物理性破坏、生理性损伤及生态性危害。其影响包括对农业生产环境、作物生态生理和生长发育的影响及诱发病虫害等。气候变化背景下的农业洪涝综合性指标、基于灾变过程的综合风险评估及气候变暖对不同作物洪涝灾害的影响事实将是未来重点研究方向。 相似文献
19.
热害、洪涝、干旱和冷害是影响我国双季稻安全生产的主要气象灾害。气候变化背景下,双季稻遭受的极端气候事件增加,应对气象灾害的任务更加紧迫。我国双季稻主要气象灾害的时空分布特征不同:热害、洪涝和干旱发生频率整体呈增加趋势,西部南部较高;冷害弱减轻,北高南低,不同生育期存在差异。文中对双季稻生产的影响、监测预警技术（站点监测、遥感监测、指标预警、数理统计和动态机理模型）以及防御气象灾害的减灾保产技术进行了阐述。针对当前气候资源的时空分布特点以及关于双季稻气象灾害研究存在的不足,提出了双季稻气象灾害在未来研究中需要重点关注的科学问题,即双季稻气象灾变过程及其动态监测指标体系、气候变暖背景下双季稻气象灾害遥感监测技术及其气象灾损动态评估技术、星-地耦合的双季稻气象灾变过程数值模式研发、双季稻种植制度对气候变化的适应性及其抗灾减灾新技术与示范研究,为双季稻有效防御气象灾害和稳产高产提供依据和技术支撑。 相似文献
20.
Temporal and geographical variation in the onset of climatological spring in Northeast China 总被引：1，自引：0，他引：1
Haifeng Zheng Neil B. McLaughlin Xingyuan He Xingyang Yu Zhibin Ren Dan Zhang 《Theoretical and Applied Climatology》2013,114(3-4):605-613
Indications of earlier onset of spring have been observed in behavior of diverse animal and plant species in the Northern Hemisphere in response to recent climate warming. Knowledge of changes in the spring onset is a critical requirement for understanding ecosystem adaption to climate change, especially for agricultural regions. In this study, we present a climatological approach for detecting the temporal and spatial variability in onset of spring with particular emphasis on how they vary along geographical parameters. Yearly dates for spring onset were computed for 71 climate stations in Northeast China based on daily surface air temperature records. These analyses were conducted for the two study periods (1960–2004 and 1979–2004). We also examined the boundary shifts of spring onset for three selected dates between the periods of 1960–1978 and 1979–2004. The results showed that advancement of spring onset was more pronounced for the period of 1979–2004 than for the period of 1960–2004 (4.0 vs. 2.2 days/decade). For the 22 stations where the spring advancement was statistically significant in the two periods, the mean rate of advancement was ?0.6 days/decade during the period of 1960 to 1978. The trends of advancement of spring onset decreased with both increasing latitude and altitude up to 300 m above sea level, and these geographical effects were clearer during 1979–2004. Analysis of boundary shifts of three specific dates revealed that the spring onset has moved to higher latitudes for each date with an average shift of about 1° of latitude (about 110 km). Our results suggest that attempts to address how ecosystems will adapt to spring advancement associated with climate warming should consider the differences in response rates and geographical effects across the study area. 相似文献