重庆市乔木林碳储量动态分析及潜力预测

Carbon Storage and Dynamic Changes of Arbor Forests in Chongqing City

对碳储量和碳密度进行定量估算和动态分析,可为生态建设和森林合理经营提供参考,为碳汇特征提供科学依据。利用重庆市第六次(2002年)、第七次(2007年)、第八次(2012年)、第九次(2017年)森林资源连续清查数据,采用连续生物量扩展因子法,估算了4次森林资源连续清查周期内乔木林碳储量和碳密度,并进行动态分析;利用分起源主要优势树种的单位面积蓄积-林龄Logistic生长方程,预测2022年重庆市乔木林碳储量和碳密度。结果表明:(1)2002~2017年,重庆市乔木林碳储量由4086.02×10~4t增至10923.65万t,碳密度由2002年的26.67t/hm^2增长至44.84t/hm^2;(2)天然林的碳储存能力远大于人工林;(3)阔叶林、针阔混交林近几年对碳储量的贡献逐步增大,但以马尾松为主的针叶林仍然是全市碳储量的主要贡献者;(4)重庆市乔木林结构逐步改善,结构更加合理,碳密度随着林龄增加而升高,碳储量增长潜力大;(5)到2022年,重庆市乔木林总碳储量和平均碳密度分别达到15561.74万t和52.79t/hm^2,与2017年相比增加了42.5%和17.7%。全市乔木林面积占森林面积的69.3%,增加单位面积蓄积、进一步实施天然林保护、提高人工林生产力、制定合理的乔木林采伐强度和更新造林方式,有助于提高碳储存能力。

Quantitative estimation and dynamic analysis of carbon storage and carbon density can provide reference for ecological construction and rational forest management and scientific basis for carbon sink characteristics. Based on the data from the 6 th(2002), 7 th(2007), 8 th(2012)and 9 th(2017)consecutive forest inventory data of Chong qing City, using the method of continuous biomass expansion factor, the carbon storage and carbon density of arbor forests were estimated for four consecutive forest resource inventories, and the dynamic analysis was carried out. Based on the logistic growth equation of unit area accumulation of dominant tree species of different originsforest age, the carbon storage and carbon density of arbor forest in Chongqing City in 2022 were predicted. The results showed as follows:(1)From 2002 to 2017, the carbon storage of arbor forest in Chongqing City increased from 40.8602 million to 109.2365 million ton, and the carbon density increased from 26.67 t/hm^2 in 2002 to 44.84 t/hm^2 in 2007;(2)The carbon storage capacity of natural forests is much higher than that of artificial forests;(3)The contribution of broad-leaved forest and mixed coniferous and broadleaved forest to carbon storage has gradually increased in recent years, but coniferous forest dominated by masson pine is still the main contributor to carbon storage in the city;(4)The structure of arbor forest in Chongqing City is gradually improved and more reasonable. The carbon density increases with the age of the forest and the potential for carbon storage growth is great;(5)By 2022,the total carbon reserves and average carbon density of arbor forest in Chongqing City will reach 155.6174 million ton and 52.79 t/hm^2 respectively, with an increase of 42.5% and17.7% compared with 2017. The area of arbor forest in the whole city accounts for 69.3% of the forest area. Increasing the accumulation per unit area, further implementing natural forest protection, improving the productivity of plantation forests, formulating reasonable cutting intensity and reforestation methods, would help improve the carbon storage capacity.