| Based on the meteorological observation data from 1961 to 2014 and the growth period data in the main growing areas of spring maize, summer maize, winter wheat,single-season rice, double-cropping early rice and late rice from 1980 to 2014, the characteristics and the overall trend of climatic variation in our country were analyzed, and the photosynthetic potential productivity, the photosynthetic thermal potential productivity and the climatic potential productivity dynamic were simulated with statistical model of the crop growth. Besides, the impacts of different climate resources on climatic potential productivity were made clear, and The variabilities of distribution patterns of planting suitability and its effect on yield in crop growing areas in 1961-1980 (period ?) and 1981-2014 (period ? )were studied. The aim was to supply theoretical basis for reduce the possible negative impacts of climate change and optimize the distribution of grain crops. Main conclusions are as follows:(1)In 1961-2014, sunshine hours showed a gradually decreasing tend from time and higher in the northwest than the southeast from space; It increased in most regions except the northwest and southwest regions. The annual temperature, the accumulated temperature of 0? and 10 ? all showed a rising tendency and higher in the southeast than the northwest from space. The increase of the annual temperature in the north was more than the south. Inter-annual fluctuation of precipitation was large, which has been rising since the 21st century, increasing from the northwest to the southeast from space and increasing more obviously in the southeast than other regions. Reference crop evapotranspiration present a fluctuating trend of decrease-increase from time,and it in the northeast and southwest regions was low;It showed a decreasing trend in most areas. The climate in China and in the main growing areas of double cropping rice showed an overall tendency of warm and wet, whereas the climate in the main growing areas of spring maize, summer maize,winter wheat and the single-season rice became warm and dry.(2)The photosynthetic potential productivity in the main planting areas of six crop was from high to low: spring maize(24439kg·hm-2), single-season rice(23928kg·hm-2),summer maize(19247kg·hm-2 ), winter wheat(19089kg·hm-2), double-cropping late rice(18144kg·hm-2),double-cropping early rice( 15491 kg·hm-2); They all showed decreasing tends from time and was similar to the variation characteristics of sunshine hours. The photosynthetic thermal potential productivity in the main planting areas of six crop was from high to low: spring maize(18918kg·hm-2 ),single-season rice(16668kg·hm-2), summer maize (16150kg·hm-2), double-cropping late rice( 157039kg·hm-2), double- cropping early rice( 123 78kg · hm-2), winter wheat(8240kg·hm-2); It in the main growing areas of spring maize, single-season rice and double-cropping early rice were decreased first and then increased, summer maize and double-cropping late rice were decreased continuously, whereas winter wheat was increased; It in the main growing areas of double-cropping early rice and late rice were high in the south and low in the north,whereas other crops were high in the east and low in the west.The climatic potential productivity in the main planting areas of six crop was from high to low: spring maize(12343kg·hm-2), single-season rice(l 1524 kg·hm-2),summer maize (11474kg·hm-2), double-cropping late rice( 10055kg·hm-2),double-cropping early rice (9459kg·hm-2),winter wheat(4913kg·hm-2); Inter-annual fluctuation of the climatic potential productivity was large, generally present a fluctuating trend of increase from time, except for summer maize; It was geographically high in the east and low in the west, and high in the south and low in the north;Under the influence of water resources, its the region difference of variation trend in crop planting areas was apparent.(3)The climatic potential productivity of spring maize, summer maize and double- cropping late rice had the highest correlation with precipitation; The climatic potential productivity of winter wheat had the highest correlation with the annual temperature; The climatic potential productivity of single-season rice and double-cropping early rice had the highest correlation with the accumulated temperature of 10?. The reduction of radiation had negative effects on climatic potential productivity of six crops. However, the increase of thermal resources and precipitation and the reduction of reference crop evapotranspiration had positive effects on climatic potential productivity of six crops. the comprehensive effects of climate resources were conducive to the improvement of climatic potential productivity, except for summer maize, and Climate change went against the production of summer maize.(4) For the climatic potential productivity of spring maize, the very suitable and suitable zones were located in Bohai Rim and the Mid-area of the Southwest; For summer maize, the very suitable and suitable zones were located in the eastern coastal area; For winter wheat, the very suitable and suitable zones were located in the southern part of the Huanghuaihai region, central and southern Shaanxi, border areas between Guizhou and Yunnan; For single-season rice, the very suitable and suitable zones were located in the southeast coastal area and the southeast of the Southwest; For double-cropping early rice, the very suitable and suitable zones were located in the southwest of Zhejiang and most parts of Guangdong and Guangxi; For double-cropping late rice, the very suitable and suitable zones were located in the southwest of Zhejiang and Fujian, most parts of Guangdong and Guangxi, Hainan and parts of Yunnan. Compared with the period I, during period II, the yield of spring maize, winter wheat, single-season rice, double- cropping early rice and late rice obtained stably increased by 5.1%, 6.7%, 9.9%, 3.7%, 3.1%, respectively; The yield of summer maize obtained stably decreased by 2.3%. |
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