湖北省农地利用方式变化的碳效应特征与空间差异

Study on carbon effects and spatial differences based on changes of agricultural land use in Hubei Province

农地利用方式变化是引起碳排放的一个重要因素,优化农地利用结构成为推动农业绿色发展的重要手段。本文运用LMDI分解法和聚类分析,分析湖北省农地利用方式变化的碳效应特征与空间差异,进一步基于Kernel密度估计法研究其时空动态演进趋势。研究发现:(1)1993—2015年湖北省农地利用碳排放年均递增2.77%,总体呈现四阶段变化特征。其中,农业经济发展因素累积引发276.33%的碳增量,结构、效率、农业劳动力因素则分别累计实现8.05%、79.14%、89.14%的碳减排。(2)对碳排放总量和强度进行聚类分析表明,武汉等7个区域属于"低-低"型,荆州、黄冈属于"高-低"型,宜昌、襄阳属于"高-高"型,随州、仙桃属于"低-高"型。(3)2005—2015年林地和草地碳汇量均呈现一定幅度的递减态势,因生态退耕产生的碳汇波动比较大,因建设占用产生的碳排放虽有波动但大体呈现"先升后降"的趋势。(4)运用Kernel密度估计湖北省农地利用净碳排放演进特征发现,总体上湖北省各地市州的农地利用净碳排放的差距呈现缩减态势。分区域来看,鄂东地区各地市州农地利用净碳排放差距有微弱的扩大后又出现明显的缩小,但净碳排放整体上无明显变化;鄂中地区各地市州差距扩大,净碳排放整体有减少态势;鄂西地区各地市州差距有所扩大但不明显,净碳排放整体有增长态势。基于研究结论,提出加强农地碳库建设,建设以绿色为导向的农地补偿制度等推进湖北省农地利用低碳化和可持续化的对策建议。

The changes of agricultural land use is an important factor to cause carbon emission,and optimizing structure of agricultural land use has become an important means to promote the green development of agriculture.Using LMDI and cluster analysis,this paper analyzed the carbon effects and spatial differences of land use change in Hubei Province.Based on the Kernel density estimation method,the spatiotemporal dynamic evolution trend of net carbon emission from agricultural land use in Hubei Province was systematically investigated.The results showed:①From 1993 to 2015,agricultural land carbon emission in Hubei was increasing at an average rate of 2.77%annually,showing four stages of changes in general.The development of agricultural economy led to 276.33%of carbon increment.Structure factor reduced 8.05%carbon emission,efficiency factor reduced 79.14%carbon emission and labor factor reduced 89.14%carbon emission.②The cluster analysis of the total and intensity of carbon emission showed that,Wuhan and other 7 regions belonged to‘low-low’type,Jingzhou and Huanggang belonged to‘high-low’type,Yichang and Xiangyang belonged to the‘high-high’type,Suizhou and Xiantao belonged to‘low-high’type.③The carbon sequestration of forest land and grass presented certain amplitude decreasing trend from 2005 to 2015.The carbon sink produced by ecological restoration fluctuated greatly.The carbon emission of construction occupation on arable land showed the trend of‘rise first and then decrease’.④Using the Kernel density estimation to estimate the evolution characteristics of net carbon emission from agricultural land use in Hubei,it is found that the regional gap of net carbon emission from agricultural land use was decreasing in every city of Hubei in general.From regional perspective,the regional gap of net carbon emission from agricultural land use in eastern Hubei had been slightly enlarged and then significantly reduced,but net carbon emission in eastern Hubei as a whole had not changed significantly.The regional gap of net carbon emission from farmland use in central Hubei had been widened,and net carbon emission in central Hubei as a whole had declined.The regional gap of net carbon emission from agricultural land use in western Hubei had been widened but not obvious,and net carbon emission in western Hubei as a whole had increased.Based on the research conclusions,the paper puts forward some countermeasures and suggestions to promote the low carbonization and sustainability of agricultural land use in Hubei Province,such as strengthening the construction of agricultural land carbon pool and building a green oriented agricultural land compensation system.