中国森林碳汇的区域差异及动态演进分析

基于1988—2013年全国森林资源清查数据,采用改进的森林蓄积量法估算了中国大陆31个省(市、区)的森林碳汇量,并以单位面积森林碳汇量为指标,借助Dagum基尼系数和Markov链方法系统分析了中国森林碳汇的区域差异及其动态演进趋势。结果表明:1)中国森林碳汇在省域间存在较大差距,由南方林区向西南、东北林区递增变化;2)Dagum基尼系数及其分解结果显示,中国森林碳汇的地区差异呈波动下降趋势。从四大林区来看,南方、北方和东北地区内差距与全国一致,基本呈下降趋势。而西南地区内差距呈现先上升后下降趋势。地区间差距是造成中国森林碳汇区域差异的首要原因,并且地区间净差距和超变密度差距对全国总体差异的贡献率呈此消彼长的"∞"型变化。3)Markov链分析发现,不同水平的森林碳汇地区间跨区流动的可能性较低。但从动态演进来看,中国森林碳汇呈上升态势,预期较低水平的省份将逐步减少,整体会向着高水平趋势发展。

Regional differences and dynamic evolution of forest carbon sink in China

Based on the data of forest resources inventory during 1988-2013 in China, the forest carbon sink of 31 provinces is estimated by using an improved forest inventory method. The regional difference and dynamic evolution of forest carbon sink in China are systematically analyzed by means of Dagum Gini coefficient and Markov chain method. The results indicated that:1) There is a large gap in the forest carbon sink in each province. It presents the increasing trend of the south region to the southwest and the northeast region;2) Dagum Gini coefficient and its decomposition results show that the regional difference in forest carbon sink in China show a downward trend. Among four major forest regions, the gaps in the south, the north and the northeast are in line with the whole country, and the trend is basically declining. However the gap in the southwest region is first increased and then decreased. The regional gap is the leading cause of differences in China''s forest carbon sink. Moreover, the differences between the net and the over-variable density in the region are an x-shaped contribution to the overall difference in the country;3) According to Markov chain analysis, different levels of forest carbon transfer are less likely to flow across regions. But from the prospective of dynamic evolution, China''s forest carbon sink are on the rise, and lower-level provinces are expected to decline gradually. In addition, the overall trend will move towards higher levels.