中国耕地空间格局变化对粮食生产的影响

The Impact of Cropland Spatial Pattern Change on Grain Production in China

耕地是粮食生产的基础,近几十年来中国耕地空间格局变化显著,对粮食生产造成一定影响。本研究以1990年、2000年、2010年土地覆被数据为基础,探究耕地空间格局变化,并基于县级农业统计数据和土壤有机质数据得到空间分辨率为1 km的耕地单产数据集,以此作为耕地粮食生产力的代表值。结果表明:1990—2010年,东北、西北地区耕地开垦剧烈,黄淮海平原耕地面积下降;研究期内新增耕地的主要来源是草地(46.9%),减少的耕地前10年主要转为林地(36.6%),后10年转为建设用地(53.0%);耕地的空间格局变化造成平均粮食生产力下降2.0%,在此期间建设用地多占用优质耕地,而新开垦的耕地粮食生产力普遍较低。

Cropland is the basis of grain production.In recent decades,the spatial pattern of cropland in China has changed significantly,which has caused some impact on grain production.Based on land cover data of 1990,2000,and 2010,this study explored changes in the spatial pattern of cropland,and constructed a database with a spatial resolution of 1 km based on county-level agricultural statistics and soil organic matter data,which is the representative of crop productivity.The results show that:during the period from 1990 to 2010,drastic reclamation happened in Northeast and Northwest China while the cropland acreage decreased in Huang-Huai-Hai Plain;the main source of new cropland during the study period was grassland(46.9%),and the lost cropland was mainly converted to forest land(36.6%)in the first ten years and then to construction land(53.0%)in the following ten years;the changes in the spatial pattern of cropland have caused a decrease of 2.0%in the average crop productivity,and during this period,the construction land mostly occupied high-quality cropland,while the newly reclaimed cropland had lower crop productivity.