中国农地利用结构变化的碳效应及时空演进趋势研究

Study on Carbon Effects and Spatial-Temporal Evolution Trend based on the Changes of Agricultural Land Use in China

研究目的:分析了中国农地利用的碳效应特征和趋势。研究方法:测算各省农地利用碳排放的基础上,采用Kernel密度估计法。研究结果:(1)Kernel密度估计显示,中国农地利用净碳排放的地区差距有所缩小但幅度较小,净碳排放全国均有增长趋势,尤其是中部。(2)2000—2015年林地碳汇量增长了10.58%,草地碳汇则呈现微弱的逐年递减趋势。(3)2001—2015年生态退耕所产生的碳汇年均递减率为19.22%,因建设占用所引发的碳排量年均递增率为2.96%。(4)同2008年相比,中、西部地区生态退耕碳汇效应呈现"先升后降"的趋势,而东部地区出现下降趋势;中、西部建设占用碳排放效应逐渐赶超东部地区。研究结论:中国不同地区农地利用方式不同,碳效应也存在差距,推进农地的优化配置,发展低碳农业。

The purpose of the paper is to analyze the carbon effects and the evolution trend of agricultural land use in China. Based on measuring the carbon emissions of agricultural land use in 31 provinces, the kernel density estimation method is used to analyze carbon effects and spatial-temporal characteristics of structural changes in agricultural land use in China. The results show that 1）The kernel density estimation demonstrates that the regional disparities of net carbon emissions of agricultural land use in China became smaller. The net carbon emissions increased in the eastern, central and western China, especially in the central China. 2）In 2000-2015 forest carbon sinks grew 10.58%, while the grass showed a weak carbon sink decreasing trend. 3）The ecological restoration led to an average annual 19.22% carbon decrease, and the average annual increase of carbon emissions caused by the construction occupation was 2.96%. 4）Compared with the year of 2008, the carbon sink effect of ecological restoration increased first and then decreased in the central and western China, but it showed a downward trend in the eastern China. The carbon emissions caused by the construction occupying agricultural land in the central and western China gradually exceeded that in the eastern China. In conclusion, there are different ways of land use in different regions of rural China, and there is a gap in carbon effect. The government should promote the optimal allocation of agricultural land and develop low carbon agriculture.