近30年中国农作物种植结构时空变化分析

Spatio-temporal changes in Chinese crop patterns over the past three decades

综合运用时序变化趋势、空间集聚分析等方法,从种植结构类型和种植比例变化趋势分析了1980年以来中国县域种植结构的时空特征。结果表明:1近30年来中国前10位的种植结构类型有16种,2002年后多元种植结构逐步替代单一型种植结构。粮食作物占优的单一种植结构类型呈逐年递减趋势,其中1980年全国82.7%的县级农业种植结构是水稻、小麦、玉米及其组合种植类型,2002年后的果蔬类型增加改变了种植结构格局。2全国种植县中有47%的水稻、61%的小麦和29.6%的玉米的种植比例显著减少,其他作物呈现增加趋势。粮食作物由以水稻为主的格局调整为水稻、小麦和玉米共存格局,其中玉米种植面积比例在空间上变化最为显著,在中国形成北东—西南向的"玉米减少带"。种植结构调整热点的城市地区,城市化对种植结构变化影响显著,水果和蔬菜类种植比例在城市化地区快速增加。3种植结构变化趋势在1300个县形成空间集聚效应,水稻的高高聚集占全国县数的2.86%、小麦占5.64%、玉米占6.11%、大豆为4.53%、麻类为1.62%、棉花占7.77%、蔬菜占8.24%、薯类占12%、水果占10%、糖料占1.41%、油料占9.35%,主要分布于中国东北、新疆和沿海的城市化地区。

The study aims to investigate the spatio-temporal changes in crop patterns in China since 1980. In doing so, the analysis methods of time-series trend and spatial cluster were used to cover the major eleven crops at county scale. The results indicate that（1） There are 16 kinds of crop combinations ranking in the China＇s top 10 during the past 30 years. Yet since 2002, the simplified cropping structure has been gradually replaced by the multiple cropping structure,which suggests an increase in the diversity index of crop patterns. In 1980, about 82.7% of China＇s counties have a similar crop pattern which is composed of rice, wheat, corn and their combinations, however, this pattern largely changed after 2002 due to the increase in the planting area of fruit and vegetables.（2） In the same period, rice planting area of 47% of the counties, wheat planting area of 61% of the counties of and corn area of 29.6% of the counties experience a significant decrease, while other crops show an increasing trend. As a result, ricedominated cereal crops in China are slightly adjusted to the coexistence of rice, wheat and maize crops. In particular, maize area proportion shows a significant change, which forms a socalled ＂corn decreased belt＂spanning from northeast to southwest of China. Urbanization had an important impact on crop patterns as fruit and vegetable planting areas rapidly grow so as to meet the increasing demands in urbanized areas.（3） Crop patterns also show an obvious spatial cluster effect in China＇s 1300 counties. The proportion of high cluster accounts for 2.86%,5.64%, 6.11%, 4.53%, 1.62%, 7.77%, 8.24%, 12%, 10%, 1.41% and 9.35% of China＇s counties for rice, wheat, maize, soybean, fibers, cotton, vegetables, potatoes, fruits, sugars and oils,respectively. These crops are distributed in Northeast China, Xinjiang, Northern Shaanxi Plateau, Yunnan- Guizhou Plateau and the metropolis areas. This finding of this study can support the decision making in agricultural restructuring and adaptation to climate change.