利用最大熵法(MaxEnt)模拟中国冬小麦分布区的年代际动态变化

从冬小麦地理分布的生理机制、生长特性和熟制出发,基于气候因子对冬小麦种植区分布的贡献,从区域尺度和年尺度收集了影响冬小麦种植分布的气候因子,并利用最大熵方法(MaxEnt)模拟和筛选了影响冬小麦分布的最佳气候因子组合即春化温度(0～7℃)持续的天数、最冷月平均温度、潜在蒸散量和年降水量,构建了冬小麦种植分布-气候关系模型,分析了1961-2010年中国冬小麦种植区及高适宜区的变化.结果表明,冬小麦可种植区的最冷月平均温度范围为-12～15℃,冬小麦的存在概率随着0～7℃持续天数的增加而增加,年降水量过低将严重影响冬小麦种植区分布的存在概率,年降水量低于200mm的地区不存在冬小麦分布.研究结果还表明,1961-2010年中国冬小麦种植区呈北移西扩趋势,高适宜区发生北移,从而增加了中国北方高寒地区的冬小麦可种植面积,同时有效提高了中国北方地区的气候资源利用率,可增加冬小麦产量.研究结果可为准确预测现在和未来气候条件下中国冬小麦的分布情况,科学合理地应对气候变化提供依据.

Inter-decadal Variability of Winter Wheat Planting Zone in China during 1961 to 2010 Simulated by Maximum Entropy(MaxEnt)

The authors analyzed the climatic indices affecting winter wheat planting zone in China in this paper based on winter wheat growth characteristics, physiological mechanism of winter wheat and multiple crops system at regional and annual scale. After this, the main climate indices controlling winter wheat planting zone were identified by the maximum entropy （MaxEnt） method： duration in days of 0℃ to 7℃, the lowest monthly average temperature, potential evapotranspiration, and annual precipitation. At last, the Chinese winter wheat distribution - climate relationship was established and the changes of winter wheat planting zone and its high suitable area were given from 1961 to 2010. The results indicated that the threshold of the lowest monthly average temperature which determines the winter wheat planting zone was - 12℃ to 15℃, the existence probability of winter wheat increases as the increases of the duration days of 0℃ to 7℃, and the existence probability of winter wheat was affected strongly by annual precipitation and the area with below 200mm of precipitation was none-existence of winter wheat. The winter wheat planting zone in China shifted northward and westward from 1961 to 2010, and high climate suitable zone also shifted northward. Finally, the shifts may raise the utilization efficiency of climate resources, increase crop yield. By the results of study, the distribution of winter wheat could be predicted exactly from past to future, and it is helpful for improving layout of winter wheat planting zone in China and coping with the negative effects resulted from climate change.