Variation characteristics of soil organic carbon and its fractions in the permafrost region after forest fire disturbance
Soil organic carbon(SOC)in permafrost regions of the Northern Hemisphere is an important part of the global carbon pool and plays an important role in the global carbon balance process.With global climate change,forest fires occur frequently in mid-high latitudes permafrost regions,which induces rapid degradation of permafrost,leading to a large loss of SOC,and forming a positive feedback effect on climate warming.Therefore,it is of great significance to study the changes of SOC and carbon fraction in permafrost regions with varied fire severities for the management of SOC pool.In this paper,the burned area in 2009 in the permafrost area of Alongshan Town,Da Xing'anling Mountains was selected as the research object in 2023.The SOC con-tent,density and fraction were analyzed at depths of 0～1 m at different fire severity sites by the adjacent sample plot comparison method.The results showed that:(1)In the unburned plots,with increasing soil depth,SOC content and density,free particulate organic carbon(fPOC),occluded particulate organic carbon(oPOC)and particulate organic carbon(POC)contents decreased.Compared with 0～10 cm,the SOC content,SOC densi-ty,fPOC,oPOC and POC contents at depth of 90～100 cm decreased by 84.75％,2.78％,99.82％,91.86％and 98.97％,respectively;the content of mineral-associated organic carbon(MAOC)increased by 830.93％.(2)Compared with the unburned plots,the SOC content and density at the lightly burned plots decreased by 9.78％and 9.30％at the depth of 0～1 m,respectively.The contents of fPOC,oPOC,POC and MAOC in-creased by 5.03％,39.95％,11.19％and 15.98％,respectively.The SOC content,SOC density,fPOC,POC and MAOC contents at the severely burned plots decreased by 65.11％,68.48％,72.53％,54.29％and 81.81％,respectively.The content of oPOC increased by 30.84％.(3)The effects of fire severity,soil depth and their interaction on SOC content,density and its fractions contents were extremely significant.In conclu-sion,forest fire has a significant impact on SOC and its fractions,resulting in a large loss of SOC and its frac-tions,changing the distribution pattern of SOC pool,and reducing the quality and stability of soil carbon pool.The results of this study can provide basic data support for the post-fire soil carbon dynamics in the permafrost region of the Da Xing'anling Mountains.
permafrostDa Xing'anling Mountainsforest fire disturbancefire severitysoil organic carboncarbon fraction
万方数据
维普
