Climate has been changing in the last fifty years in China and will continue to change regardless any efforts for mitigation. Agriculture is a climate-dependent activity and highly sensitive to climate changes and cli...Climate has been changing in the last fifty years in China and will continue to change regardless any efforts for mitigation. Agriculture is a climate-dependent activity and highly sensitive to climate changes and climate variability. Understanding the interactions between climate change and agricultural production is essential for society stable development of China. The first mission is to fully understand how to predict future climate and link it with agriculture production system. In this paper, recent studies both domestic and international are reviewed in order to provide an overall image of the progress in climate change researches. The methods for climate change scenarios construction are introduced. The pivotal techniques linking crop model and climate models are systematically assessed and climate change impacts on Chinese crops yield among model results are summarized. The study found that simulated productions of grain crop inherit uncertainty from using different climate models, emission scenarios and the crops simulation models. Moreover, studies have different spatial resolutions, and methods for general circulation model （GCM） downscaling which increase the uncertainty for regional impacts assessment. However, the magnitude of change in crop production due to climate change （at 700 ppm CO2 eq correct） appears within ±10% for China in these assessments. In most literatures, the three cereal crop yields showed decline under climate change scenarios and only wheat in some region showed increase. Finally, the paper points out several gaps in current researches which need more studies to shorten the distance for objective recognizing the impacts of climate change on crops. The uncertainty for crop yield projection is associated with climate change scenarios, CO2 fertilization effects and adaptation options. Therefore, more studies on the fields such as free air CO2 enrichment experiment and practical adaptations implemented need to be carried out.展开更多
Temperature is one of the most prominent environmental factors that determine plant growth,development, and yield.Cool and moist conditions are most favorable for wheat.Wheat is likely to be highly vulnerable to furth...Temperature is one of the most prominent environmental factors that determine plant growth,development, and yield.Cool and moist conditions are most favorable for wheat.Wheat is likely to be highly vulnerable to further warming because currently the temperature is already close to or above optimum.In this study,the impacts of warming and extreme high temperature stress on wheat yield over China were investigated by using the general large area model（GLAM） for annual crops.The results showed that each 1℃rise in daily mean temperature would reduce the average wheat yield in China by about 4.6%-5.7% mainly due to the shorter growth duration,except for a small increase in yield at some grid cells.When the maximum temperature exceeded 30.5℃,the simulated grain-set fraction declined from 1 at 30.5℃to close to 0 at about 36℃.When the total grain-set was lower than the critical fractional grain-set（0.575-0.6）, harvest index and potential grain yield were reduced.In order to reduce the negative impacts of warming, it is crucial to take serious actions to adapt to the climate change,for example,by shifting sowing date, adjusting crop distribution and structure,breeding heat-resistant varieties,and improving the monitoring, forecasting,and early warning of extreme climate events.展开更多
基金funded by the National 973 Program of China (2012CB955904)the National Natural Science Foundation of China (31171452)the Sustainable Agriculture Innovation Network initiated and funded by Defra UK and Minstry of Agriculture of China (H5105000)
文摘Climate has been changing in the last fifty years in China and will continue to change regardless any efforts for mitigation. Agriculture is a climate-dependent activity and highly sensitive to climate changes and climate variability. Understanding the interactions between climate change and agricultural production is essential for society stable development of China. The first mission is to fully understand how to predict future climate and link it with agriculture production system. In this paper, recent studies both domestic and international are reviewed in order to provide an overall image of the progress in climate change researches. The methods for climate change scenarios construction are introduced. The pivotal techniques linking crop model and climate models are systematically assessed and climate change impacts on Chinese crops yield among model results are summarized. The study found that simulated productions of grain crop inherit uncertainty from using different climate models, emission scenarios and the crops simulation models. Moreover, studies have different spatial resolutions, and methods for general circulation model （GCM） downscaling which increase the uncertainty for regional impacts assessment. However, the magnitude of change in crop production due to climate change （at 700 ppm CO2 eq correct） appears within ±10% for China in these assessments. In most literatures, the three cereal crop yields showed decline under climate change scenarios and only wheat in some region showed increase. Finally, the paper points out several gaps in current researches which need more studies to shorten the distance for objective recognizing the impacts of climate change on crops. The uncertainty for crop yield projection is associated with climate change scenarios, CO2 fertilization effects and adaptation options. Therefore, more studies on the fields such as free air CO2 enrichment experiment and practical adaptations implemented need to be carried out.
基金Supported by Dorothy Hodgson Postgraduate-NERC-Hutchinson Whampoa Ph.D.Scholarship and Key Projects in the National Science & Technology Pillar Program in the 11th Five-Year Plan Period:Demonstration of Adaptation to Climate Cnange in Vulnerable Region of China(2007BAC03A06)
文摘Temperature is one of the most prominent environmental factors that determine plant growth,development, and yield.Cool and moist conditions are most favorable for wheat.Wheat is likely to be highly vulnerable to further warming because currently the temperature is already close to or above optimum.In this study,the impacts of warming and extreme high temperature stress on wheat yield over China were investigated by using the general large area model（GLAM） for annual crops.The results showed that each 1℃rise in daily mean temperature would reduce the average wheat yield in China by about 4.6%-5.7% mainly due to the shorter growth duration,except for a small increase in yield at some grid cells.When the maximum temperature exceeded 30.5℃,the simulated grain-set fraction declined from 1 at 30.5℃to close to 0 at about 36℃.When the total grain-set was lower than the critical fractional grain-set（0.575-0.6）, harvest index and potential grain yield were reduced.In order to reduce the negative impacts of warming, it is crucial to take serious actions to adapt to the climate change,for example,by shifting sowing date, adjusting crop distribution and structure,breeding heat-resistant varieties,and improving the monitoring, forecasting,and early warning of extreme climate events.
