林业科学研究2025，Vol.38Issue(5)：49-58,10.DOI:10.12403/j.1001-1498.20240494
麻栎纯林及其混交林对土壤有机碳含量和稳定性的影响研究
Effects of Pure and Mixed Forests of Quercus acutissima on Soil Organic Carbon Content and Stability
摘要
Abstract
[Objective]This study aims to assess the impact of different tree species compositions on soil organic carbon(SOC)content and its stability,providing insights for enhancing soil carbon sequestration in North Subtropical forests.[Method]Based on the Q.acutissima pure forest and Q.acutissima-P.masso-niana mixed forest with the same age and similar stand conditions in Nanjing Lishui Forest Farm,the or-ganic carbon and its components,microbial residue carbon,fine root and litter characteristics,and en-zyme activities in the soil layers of 0～20 cm and 20～40 cm in the two forests were measured.The SOC stability was evaluated,and a structural equation model(SEM)was used to identify key factors influencing SOC content and stability.[Results](1)The SOC,mineral bound organic carbon(MAOC),coarse particu-late organic carbon(cPOC),and fine particulate organic carbon(fPOC)ranged from 21.90 to 42.30 g·kg-1,13.34 to 27.05 g·kg-1,6.75 to 14.24 g·kg-1,and 1.72 to 3.84 g·kg-1,respectively.The SOC content of mixed forests was significantly higher than that of pure forests(p<0.05),and there was an obvious"epimer-ization effect".(2)The contributions of MAOC,cPOC and fPOC to SOC ranged from 53.70%to 65.69%,26.12%to 37.18%and 5.55%to 10.00%,respectively,and the contributions of MAOC to SOC were higher in mixed forests than in pure forests,with significant differences in the 0～20 cm soil layer(p<0.05).(3)Soil microbial residual carbon(MNC)content ranged from 3.11 to 7.61 g·kg-1 and contributed 11.70%to 19.88%to SOC.The MNC content of the 20～40 cm soil layer of the mixed forest was significantly higher than that of the pure forest(p<0.05).(4)Structural equation models showed that both POC and MAOC had highly significant positive effects(p<0.001)on SOC content,POC was strongly influenced by basic soil physicochemical properties,and MAOC was strongly influenced by enzyme activity.Soil physicochemical properties,fine root and litter characteristics had highly significant positive effects(p<0.001)on MNC and enzymatic activity,which in turn influenced the MAOC/SOC ratio.[Conclusion]Compared to the pure Quercus acutissima forest,the mixed Quercus acutissima-Pinus massoniana forest exhibited higher en-zymatic activity,fine root biomass,and a lower fine root C:N ratio,which enhanced SOC input and pro-moted soil carbon metabolism and transformation.This led to higher SOC and MAOC contents,as well as an increased proportion of MAOC in total SOC,resulting in greater SOC content and stability in the mixed forest.关键词
树种组成/有机碳含量/稳定性/微生物残体碳/影响因素Key words
species composition/organic carbon content/stability/microbial necromass carbon/influencing factor分类
农业科技引用本文复制引用
孟董悦,刘大源,关庆伟,张琳婧,张宇恬,史珑燕..麻栎纯林及其混交林对土壤有机碳含量和稳定性的影响研究[J].林业科学研究,2025,38(5):49-58,10.基金项目
江苏省林业科技创新与推广项目(LYKJ[2022]04) （LYKJ[2022]04）
