中国粮食生产时空变化及其耕地利用效应

基于粮食产量计量模型，运用LMDI方法，分解中国粮食生产时空变化的耕地利用四因素（规模、结构、强度、程度），结果表明：1978-2012 年，耕地利用变化对粮食生产的累积效果表现为强度效应最大，结构效应和程度效应其次，规模效应最小。其间，造成粮食增量的强度效应逐步减弱，程度效应由负转正并渐强；造成粮食减量的结构效应逐步加大，规模效应后期显著放大。1996-2008 年，粮食生产出现从东南沿海地区向北部和西部内陆地区的空间转移，主要是因为沿海地区城镇密集，耕地利用结构变化与规模变化对粮食的减量效应更为明显，甚至有复种下调出现程度负效应，而耕地利用强度变化对粮食的增量效应相对较小，内陆农区耕地利用效应则呈相反趋向。由此论文最后探讨国家粮食可持续增产的耕地利用策略。

Effects of Cultivated Land Use on Temporal-Spatial Variation of Grain Production in China

There are four factors which denote four types of cultivated land use by drawing on grain production calculating model: grain yield per hectare (intensity effect), cultivated land area (scale effect), planting structure (structure effect) and multiple-cropping index (degree effect). Changes of grain production in China were thus studied by quantifying the contributions from changes in cultivated land use using LMDI method. The results showed: During 1978-2012, there was more aggregated intensity effect than degree effect on the total grain increment, while there was more structure effect than scale effect on the grain reduction. Intensity effect, the largest contributor for China's grain production all the time, decreased step by step, whereas degree effect, whittling down the production in the early phase, then turned to an indispensable promoting factor for its steadily uplift. Structure effect in weakening grain output increased over time, and scale effect expanded markedly from 1998 to 2012 because of the dramatic decline in cultivated area. Spatially, grain production in eastern coastal China was evidently shrinking when the northern and western inland experienced a compensating increase during 1996-2008. The higher positive intensity effect and degree effect were observed in the northern and western peripheral region, while the highly urbanized coastal region had the higher negative scale effect and structure effect, even in some cases with negative degree effect, thus enlarging the regional disparity of China's grain production. From the decomposition findings, the paper concluded with some suggestions for cultivated land use to enhance China's grain security.