间伐补阔对华西雨屏区杉木人工林土壤团聚体稳定性及有机碳的影响OA

[Objective]Thinning and replanting of broadleaf trees play a significant role in enhancing soil fertility and improving soil structure in degraded plantations.However,the responses of soil aggregate sta-bility and aggregate organic carbon to such management remain unclear.[Method]This study focused on a Cunninghamia lanceolata plantation.Four treatments were established:thinning and replanting of Schima superba(CS),thinning and replanting of Liquidambar formosana(CL),thinning and replanting of Schima superba and Liquidambar formosana(CLS),and thinning without replanting(NP).The unthin-ning treatment(NT)was used as the control.The study systematically analyzed the effects of thinning and replanting of broadleaf trees on soil aggregate stability and aggregate organic carbon content.[Result]Com-pared with NT treatment,thinning and replanting of broadleaf trees generally reduced the content of soil aggregates>5 mm,mean weight diameter(MWD),and geometric mean diameter(GMD).The content of aggregates>5 mm,MWD,and GMD under CLS treatment were generally higher than those under CL and CS treatments.Thinning and replanting of broadleaf trees exerted slight effects on organic carbon con-tent and contribution rate of aggregates with different size fractions.However,the organic carbon content of aggregates<0.25 mm in CS and CL treatments was generally higher than that of other size fractions.In all treatments,the contribution rate of the>5 mm aggregate fraction was significantly higher than that of other size fractions.[Conclusion]Thinning and replanting of broadleaf trees generally reduced soil ag-gregate stability without significantly altering aggregate organic carbon content.Among the treatments,the CLS treatment exhibited the highest soil aggregate stability after thinning.