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Under the 1.5 °C and 2.0 °C warming scenarios, few studies have explored the different influences of CO2, temperature, and precipitation on wheat yield in China. Hence, we analyzed the different influences of above factors on wheat yield after analyzing the wheat yield change. Results show that (1) the wheat yield of China would increase under the two warming scenarios. The spring wheat yield of the Northeast Spring Wheat Region (DB_S) and the Northwest Spring Wheat Region (XB_S) would increase more than that in the other two spring wheat-planting subregions. The winter wheat yield of the Southwest Winter Wheat Region (XN_W) and Middle and Lower Yangtze Winter Wheat Region (CJ_W) would increase more significantly compared with that in the other three winter wheat-planting subregions. (2) CO2 fertilization was identified as the main factor leading to a wheat yield increase, with an estimated increase of 12–18% under the 1.5 °C warming scenario and 18–21% under the 2.0 °C warming scenario. (3) Without considering CO2 fertilization, compared with precipitation, temperature dominated the spatial patterns of the wheat yield responses to climate change. Temperature influence on wheat yield was mainly reflected in the amplitudes of yield increase, while precipitation mainly affected the proportion of yield-increasing area. For wheat-planting regions with less precipitation, such as the North Spring Wheat Region (BB_S) and the Huang-Huai Winter Wheat Region (HH_W), the wheat yield increase caused by precipitation was usually more pronounced. Our findings would help inform policy decisions related to wheat production in China to better cope with future climate warming. [ABSTRACT FROM AUTHOR]

Analysis of Vegetation Dynamic Change in Five Countries of Central Asia Based on Google Earth EngineNIAN Yanyun, DU Ruohua College of Earth and Environmental Sciences, Lanzhou University, Lanzhou 730000, China Abstract:The changes of vegetation in Central Asia and its response to climate change are particularly important for understanding the contribution of climate change in the ecologically sensitive and fragile regions in the five countries of Central Asia, includingTurkmenistan, Uzbekistan, Tajikistan, Kyrgyzstan, Kazakhstan. This paper obtained the temporal and spatial variation characteristics of NDVI in the five countries of Central Asia from 1987 to 2017; and then explored the response of vegetation changes to climate change based on the remote sensing images and data processing capability provided by the GEE platform, and used the annual maximization synthesis method to process the Landsat surface reflectance data combined the simple linear regression. The results showed that: the vegetation activity in Central Asia was generally enhanced between 1987 and 2017, especially vegetation enhancement was more significant in mountain-based Kyrgyzstan, while the trend of vegetation degradation in Turkmenistan was obvious; The vegetation improvement areas in Central Asian had been concentrated in the central desert region of Turkmenistan and Uzbekistan, the central of Tajikistan, most of Kyrgyzstan and the central and northern parts of Kazakhstan in the past 30 years; vegetation degradation areas were concentrated in the Amu Darya Basin in the southern Aral Sea, and densely populated areas in Uzbekistan, Tajikistan and Kyrgyzstan, and arid areas in northwestern Kazakhstan; vegetation changes in Central Asia were closely related to climate change and human activities. Vegetation changes in Turkmenistan and Uzbekistan were mainly affected by climate improvement and human activities such as water resources utilization, agricultural planting structure, and carrying capacity. The impact of human activities on vegetation had gradually changed from a strong negative impact to a positive effect; Tajikistan and Kyrgyzstan were mainly affected by the positive climate, while human activities had a negative impact on vegetation growth; vegetation changes in Kazakhstan were mainly dominated by climate, and increasing temperature had an inhibitory effect on grassland vegetation growth. [ABSTRACT FROM AUTHOR]