摘要
The National Forest Inventory(NFI)is an important resource for estimating the national carbon balance(These data were unpublished data,and we could only obtain the data before 2008 through data search by now).Based on the data from sample plots,the literature,and NFI,as well as the relationships between volume,biomass,annual litterfall and soil respiration of different forest types,the net ecosystem production(NEP),changes in forest biomass carbon storage(△Cbiomass)and non-respiratory losses(NR)of China’s forests during 1999-2008 were estimated,and the forest soil carbon sequestration(△Csoil)was assessed according to the carbon balance principle of the forest ecosystem(△Csoil=NEP-NR-△Cbiomass).The results showed that the total NEP,△Cbiomass,NR and△Csoil values for China’s forests were 157.530,48.704,31.033 and 77.793 Tg C yr^(-1) respectively,and average NEP,△Cbiomass,NR,and△Csoil values were 101.247,31.303,19.945 and 49.999 g C m^(-2) yr^(-1) respectively.There were large spatial differences in forest soil carbon sequestration in different parts of China.The forest soil in Jiangxi,Hunan,Zhejiang,Fujian,Anhui,Shanxi,Shaanxi,Guangxi and Liaoning served as carbon sources and the carbon released was about 25.507 Tg C yr^(-1).The other 22 provinces served as carbon sinks and the average carbon sequestration by forest soil came to 103.300 Tg C yr^(-1).This research established a method for evaluating soil carbon sequestration by China’s forests based on the NFI,which is a useful supplement to current statistical data-based studies on the forest ecosystem carbon cycle,and can promote comparable studies on forest soil carbon sequestration with consistent research methods at the regional scale.
基于样地资料、文献资料和森林资源清查资料,以及不同森林类型蓄积、生物量、年凋落量和土壤呼吸之间的函数关系,估算1999-2008年间中国森林生态系统的NEP(净生态系统生产力)、△Cbiomass(现存森林植被碳储量增量)和NR(非呼吸代谢消耗光合产物),再根据森林生态系统碳平衡方程,初步估算中国森林土壤碳汇(△Csoil=NEP-△Cbiomass-NR)。研究结果表明:中国森林生态系统总的NEP、△Cbiomass、NR和△Csoil分别为157.530、48.704、31.033和77.793 Tg C yr^(-1),单位面积NEP、△Cbiomass、NR和△Csoil分别为101.247、31.303、19.945和49.999 g C mm^(-2) yr^(-1)。中国森林土壤碳汇存在较大的空间差异,江西、湖南、浙江、福建、安徽、山西、陕西、广西和辽宁9省(区)森林土壤为碳源,释放的碳约为25.507 Tg C yr^(-1)。其他22个省(区)森林土壤为碳汇,吸收的碳约为103.300 Tg C yr^(-1)。本研究建立了基于森林资源清查资料的中国森林土壤碳汇评价方法,是对现有的基于统计资料进行森林生态系统碳循环研究的有益补充,将推动具有可比性的、按照一致性的研究方法开展的区域尺度森林土壤固碳功能研究。
基金
The Fundamental Research Funds of Chinese Academy of Forestry (CAFYBB2020SY015)。
