Study On Adaptation Of The Growth Environment Of Major Grain Crops To Climate Change In China

Climate change has mixed impacts on many ecological systems and brought unpredicted risks to human livelihood, it is particularly important to respond and adapt to climate change. The agriculture is fully dependent on the factors of climate resource and consequences of climate change of adverse impacts,agriculture production is fragility and vulnerability under the climate change. So it is necessary to adapt to climate change for agricultural producton and food security. The major grain crops, such as wheat, maize and paddy, are very important to the stable of agricultural production and the security of human livelihood.In order to adapt to climate change for agricultural production successfully, we should ensure appropriate spatial distribution of the three major grain crops in the climate change.Based on the daily observation data of 824 meteorological stations during 1951 to 2012 released by national meteorological information center, this paper evaluated the change trends of agricultural climate resource, such as the heat, moisture and winter conditions for crop growth. Secondly, we determined the climate influence of wheat, maize and paddy by the demand difference to the light, hot and water. We analyzed the temporal and spatial variation of the agricultural hydrothermal conditions by the ordinary kringer method. Then the maps of spatial disrtribution of the climate factors, elevation and soil was put to the Max Ent model for the environment variables, and the agricultural stations of wheat, maize and paddy was taken to the Max Ent model for the species variables. The distributions of the suitable cultivation zone of spring and winter wheat, spring and summer maize, single and double paddy were simulated by the Max Ent model from 1951 to 2012. The characteristics of change of the suitable cultivation zone of spring and winter wheat, spring and summer maize, single and double paddy were detected by the spatial analysis model. Thirdly, the distributions of the suitable cultivation zone of wheat, maize and paddy were obtained by the means of space superposition of spring and winter wheat, spring and summer maize,single and double paddy, respectively. The spatio-temporal changes of the suitable cultivation zone of wheat, maize and paddy in the agricultural region were analyzed. With the suitable cultivation zone of crops was influenced by the altitude, this study also analyze the spatio-temporal changes of the suitablecultivation zone of wheat, maize and paddy in the three gradient terrains. Fouthly, the suitable cultivation zone of major grain crops was got through the space superposition of the spatial distribution of wheat,maize and paddy. Then this paper evaluated the adaptation ability of the planting environment of crop to climate change for the study on adaptation of the growth environment of major grain crops. This paper gets the following conclusions:The changes of agricultural climate resources in direction and trend had the regional differences between 1951 and 2012. The distribution area of lower value of sunshine hours expanded, and the distribution area of higher value of sunshine hours narrowed. The change trend of sunshine hours was falling in the past 62 years. The annual mean temperature, accumulated temperatures of the daily men temperature≥0 ℃, meam temperature in the coldest month and extreme lowest temperature increased significantly for most of China, whose contours moved northward in the past 62 years. The mean temperature in the hottest month can be identified into the falling region and rising region. The middle and lower reaches of the Yellow River and the Yangtze River belong to the region in a remarkable reduction.And the other region of China belongs to the rising region. For the frost-free period, over large parts of China(80%), it was extended by both a later first frost date and an earlier last frost date. Furthermore, the magnitude of the changes in the three indices(the first frost date, last frost date and frost-free period) were higher in the north and east regions, but lower in the south and west. The contour of the eastern of 400 mm rainfall moved toward to the northeast a litter. The annual precipitation had a decreasing trend in the north region and an increasing trend in the south region. But the number of precipitation days in the south region reduction.The adapt ability of growth environment of wheat and maize to climate change increased and decreased in the north and south agricultural regions, respectively. However, the adapt ability of growth environment of paddy to climate change decreased and increased in the north and south agricultural regions betweem 1951 and 2012, respectively. What’s more, the suitable grade of plant zone of wheat was raise in the agricultural regions of Inner Mongolia and Great Wall Corridor, Huang-Huai-Hai, Loess Plateau. In the agricultural regions of Southwest, Mid-and-Lower Reachers of the Yangtze River, South China and Gansu-Xinjiang, the suitable grade of plant zone of wheat falled. For the suitable grade of plant zone of maize, it was rise in the agricultural regions of Northeast, nner Mongolia and Great Wall Corridor, LoessPlateau and Huang-Huai-Hai, but it was reduction in the agricultural regions of Southwest, Mid-and-Lower Reachers of the Yangtze River and South China.From 1951 to 2012, the adapt ability of growth environment of wheat, maize and paddy to climate change has a temporal and sptatial differentiation in the nine agricultural regions and three gradient terrains. In other words, under the background of climate change, the suitable grade of growth zone of wheat rised in the first step, and it decreased in the second and third step. The suitable grade of growth zone of maize has the region differences in the first step, some area rised, and other area decreased. The suitable grade of growth zone of maize increased in the second step. On the paddy, the suitable grade of plant zone increased and decreased in the first and second step, respectively. Therefor, the adapt ability of growth environment of wheat, maize and paddy to climate change in the first step was increased, more directional and fall, respectively. The adapt ability of planting environment of wheat, maize and paddy to climate change in the second step was followed by decline, rise and rise.From 1983 to 2012, the majority of adapt abilities of growth environment of grain crops(including wheat, maize and paddy) to climate change are mostly fluctuation with ten years. In other words,the adapt abilities of growth environment of wheat were fluctuation in the nine agricultural regions. The adapt abilities of growth environment of paddy were fluctuation exclude the agricultural region of South China. The adapt ability of growth environment of maize increased in the agricultural region of Northeast,and it was falling in the agricultural region of Inner Mongolia and Great Wall Corridor and Huang-Huai-Hai, and it was fluctuation in other agricultural regions. In the first step, for wheat and maize,the adapt abilities of growth environment were fluctuation. In the second step, the adapt abilities of planting environment of wheat and paddy to climate change were fluctuation with ten years between 1983 and 2012.The unsuitable zone of paddy growth expanded in the first step, and the unsuitable zone of maize growth also expanded in the second step. Therefor, the adapt ability of growth environment of paddy in the first step and the adapt ability of growth environment of maize in the second step all declined during 1983 to2012.The adapt abilities of growth environment of major grain crops to climate change have the spatio-temporal variation in the agricultural region and province between 1951 and 2012. In the agricultural region, the adapt abilities of growth environment of major grain crops to climate change were falling in theagricultural region of Northeast, Huang-Huai-Hai and Mid-and-Lower Reachers of the Yangtze River, and the change trend were adversed in the rest of agricultural regions. In the province, the suitable grade of growth zone of major grain crops in some provinces declined, which were Heilongjiang, Shandong, Jiangxi,Hunan, Guangdong and Guangxi provinces. According, the suitable grade of growth zone of main grain crops in some provinces increased, which were Jilin, Liaoning, Inner Mongolia and Xinjiang Uygur Autonomous Region, Henan, Hubei, Anhui and Jiangsu province. Therefor, the adapt ability of growth environment of major grain crops to climate change rised in the north provinces and falled in the south provinces mostly, respectively.The main contribution of this paper is to found nearly 60 years, mainly temperature contours of China are northward migration, the frost-free period extended gradually, but the key contours of precipitation was stable. Secondly, this paper simulated the suitable zone of crop growth and analyzed the changes in the perspective of geographical science. Thirdly, this study intergrated the ecology model and the spatial analysis methods of geography. It is could enrich the research methods on the science of agricultural adaptation to climate change.