为了促进城市森林固碳增汇,提升城市森林生态系统功能和价值,基于武汉市环城林带2008年和2018年的两期森林资源二类调查数据,采用生物量连续转化因子法和含碳系数法,对环城林带的森林碳储量和碳密度进行了估算,对比分析了10 a间的动态变化。结果 表明:(1)10 a间环城林带森林碳储量和碳密度增幅明显,分别由64 692.413 3 t和27.389 7 t/hm2增长到119 789.961 3 t和47.243 4 t/hm2。到2018年,环城林带森林碳储量理论价值约为987.85万元;(2)到2018年,森林碳储量最多的区域为江夏区段,但各区段之间的碳储量差异在缩小。森林碳密度最大的区段已由东西湖区段转变为蔡甸区段;(3)森林碳储量呈现出向少数几个群落类型聚集的趋势,到2018年樟树林已成为环城林带碳储量最多的群落类型;(4)近、成熟林的碳储量和碳密度增幅明显,但是幼龄林依然是环城林带森林碳储量的绝对主体。综上,武汉市环城林带森林碳储量具有较大的增汇潜能,但需要及时开展森林精准抚育,以确保增汇潜能的有效释放并促进碳储量结构平衡。
In order to promote the carbon sequestration of urban forest and enhance the function and value of urban forest ecosystem, based on the second-class survey data of forest resources in the city-encircling forest belt of Wuhan in 2008 and 2018, the biomass continuous expansion factor method and carbon coefficient method were adopted to estimate the forest carbon storage and carbon density of the city-encircling forest belt, and its changes in decade were compared. The results showed that:(1)the carbon storage and carbon density had increased significantly in the past 10 years; the carbon storage and carbon density in the city-encircling forest belt had increased from 64 692.413 3 t and 27.389 7 t/hm2 to 119 789.961 3 t and 47.243 4 t/hm2, respectively; by 2018, the theoretical value of forest carbon storage in the city-encircling forest belt was about 9.878 5 million yuan;(2)by 2018, the section with the largest forest carbon storage was the Jiangxia District, but the carbon storage difference between the sections was narrowing; the section with the highest carbon density had changed from the Dongxi Lake District to the Caidian District;(3)the forest carbon storage showed a trend of gathering to a few community types; by 2018, camphor forest had become the community type with the largest carbon storage in the city-encircling forest belt;(4)the carbon storage and carbon density of near-mature and mature forests increased significantly, but young forests were still most of the carbon storage in city-encircling forest belt. The forest carbon storage in the city-encircling forest belt had great potential for increasing carbon storage, but accurate forest tending should be carried out in time to ensure the effective release of carbon storage potential and promote the structural balance of carbon storage.
