Effects of Litter Addition and Removal on Soil Microbial Necromass Carbon in a Natural Forest of Castanopsis carlesii
[Objective]To investigate the effects of changes in litter inputs on soil microbial necromass carbon,and provide scientific evidence for a comprehensive understanding of the interactions between plants,soil,and microorganisms on long-term carbon sequestration in forests.[Method]The study focused on a subtropical natural forest of Castanopsis carlesii,a randomized block group experimental design was employed,with three treatments including litter removal,litter addition,and control.Soil physicochemical properties,amino sugar contents,and microbial necromass carbon contents were measured.Pearson correlation analysis and partial least squares path modeling(PLS-PM)were utilized to explore the influencing factors of microbial necromass carbon contents.[Result]After litter removal,the contents of total amino sugars,glucosamine,galactosamine,and mannoseamine in the soil decreased by 14.7%,33.4%,9.3%,and 16.1%,respectively;and the galactosamine decreased by 21.7%after litter addition.The fungal necromass carbon and total microbial necromass carbon contents in the soil decreased by 16.2%and 16.1%,respectively,while bacterial necromass carbon content showed no significant change after litter removal;the total microbial necromass carbon content decreased significantly by 9.2%after litter addition,but the contribution of microbial necromass carbon to soil organic carbon under the two treatments was not significantly different.Path analysis showed that microbial biomass carbon content,soil water content,and microbial biomass were key factors driving the accumulation of soil microbial necromass carbon content under changes in litter input.[Conclusion]Altering the input of litter significantly regulates the accumulation of soil microbial necromass carbon,with a particularly pronounced impact on fungal necromass carbon and a relatively minor effect on bacterial necromass carbon contents.This highlights the significance of litter in the accumulation of microbial necromass carbon contents,and maintaining an appropriate level of surface litter facilitates the stability of soil carbon pools.
万方数据
维普
