江苏省森林植被碳储量分布结构及变化特征

2010年以来，江苏省森林资源呈现出面积下降但蓄积增长的分化走势，森林类型和区域分布发生结构性变化，对全省森林植被碳储量产生较大影响。基于全国第8次（2010年）、第9次（2015年）2期森林资源清查资料，利用生物量转换因子连续函数法对5 a间全省森林植被碳储量、碳密度、地理空间分布格局及动态变化的特征和原因进行了研究。结果表明:1）2015年江苏省森林/林木碳储量分别为3 638.10×10⁴t、4 594.59×10⁴t，相比2010年增长8.94%、11.53%，森林碳密度23.15 t/hm²，增加14.22%。2）2015年全省乔木林碳储量3 321.73×10⁴t，同比增长9.97%，树种（组）碳储量比重标准差下降4.38，其中杨树比重降低17.45 %，树种碳储量更平衡；碳储量林龄分布由2010年时集中于中龄林（53.86%）大幅调整为23∶33∶44（幼∶中∶近成过），结构更为合理。3）2015年全省森林碳储量在地理板块间分布比重为苏北57.26%、苏南32.61%、苏中10.13%，前两者分别降低10.5%、增长10.65%，区域分布结构趋于均衡，不同类型在市域间表现较大差异性。经分析，全省各森林类型间、树种间、林龄间、区域间的碳储量、碳密度结构趋向合理，增长的可持续性得到强化，在不同地区间造林绿化、采伐消耗、森林抚育等针对性措施驱动下，全省碳库潜力巨大，未来增长空间与速度可观。同时，在四旁树和散生木碳储量估算方法、不同树种（组）宜地生物量转换因子甄选、江淮地区灌木经济林和竹林单位面积碳储量因子选取等方面做了讨论，以期为更高精度下基于清查数据估算华东平原省份森林植被碳储量提供借鉴。

Characteristics of Carbon Storage Distribution Structure and Dynamic Change of Forest Vegetation in Jiangsu Province

Since 2010,the forest resources in Jiangsu Province have shown differentiation trend:decrease in forest area and increase in accumulation growth.Structural changes occurred in forest types and regional distribution,which exerted great impact on forest carbon storage in the whole province.Based on the ninth (2015) and eighth (2010) national forest resource inventory data,the characteristics and driving forces of the changes in carbon reserves,carbon density,spatial distribution patterns and forest vegetation were studied by using the continuous function method of biomass conversion factor.The results showed that :1) the forest carbon storage and the carbon storage of trees in Jiangsu Province in 2015 was 3 638.10×10⁴ t and 4 594.59×10⁴ t,increased by 8.94% and 11.53%,respectively,compared to 2010,and the forest carbon density in 2015 was 23.15 t/hm²,increased by 14.22%.2) The forest carbon storage of arbor tree species was 3 321.73×10⁴ t,increased by 9.97%.The standard deviation weight of the carbon storage of the dominant tree species/group decreased by 4.38,of which the poplar tree species accounted for 17.45%,and the carbon storage of the tree species were more balanced.The proportion of forest age distribution of the carbon storage among young/middle aged/premature,mature and over mature stands were 23∶33∶44 in 2015,more reasonable in structure than 2010,in which the middle aged forest stands accounted for 53.86%.3) By 2015,the geographical distribution of forest carbon reserves in the province was 57.26% in northern Jiangsu,32.61% in southern and 10.13% in central part of Jiangsu.The proportion of the northern Jiangsu increased by 10.5% and that of the southern Jiangsu decreased by 10.65%.The structure tended to be optimal,and the forest types varied in different districts or areas.It was concluded that the structure of carbon storage and density among forest types,tree species,forest ages and regions tended to be reasonable,and the sustainability of growth was strengthened in Jiangsu Province,driven by afforestation,cutting consumption and forest tending among different regions.There would be a huge potential carbon pool,its growth space would be large and its growth speed would be considerably great in the future.Additionally,this paper made a useful discussion on the method of estimating the reserves of the “four-side trees” and scattered wood carbon reserves,the selection of the suitable biomass conversion factor of different tree species,the selection of the shrub economic forest and the selection of the carbon reserves in the unit area of the bamboo forest in region of the Changjiang River and the Huaihe River,in order to estimate the carbon storage of the forest vegetation in the East China Plain based on the higher precision.