生态学报2025，Vol.45Issue(6)：2698-2709,12.DOI:10.20103/j.stxb.202405081034
不同外源碳输入对两种杉木林土壤有机碳分解激发效应的影响
Effects of different exogenous carbon inputs on the soil organic carbon decomposition and priming effect in two Chinese fir forests
摘要
Abstract
Soil organic carbon decomposition is one of the key processes in soil carbon cycling,and regulated by input of exogenous carbon through influencing microbial community composition and enzyme activity,which is defined as priming effect.However,how the quality and input method of exogenous carbon influences priming effect in forest soils with different fertility remains unclear.In this study,two soils with different properties(poor and fertile)from Chinese fir forests were collected as rearch subjects,and 13 C-labeled Chinese fir litter and glucose solution were added.The Chinese fir litter was added to the soils using two methods:placing intact litter on soil surface(IL)and uniformly mixing litter powder into soil(CL).The amount of CO2 released from the soil and its 13 C isotopic value were measured during 120-day incubation,and soil nutrient content and microbial community structure were also measured.The results showed that:(1)the input of intact litter resulted in a negative priming effect,while glucose addition induced the positive priming effect.They had significant impact on the cumulative primed carbon and the intensity of the effect is signally regulated by soil nutrients.As the same time,the cumulative primed carbon by intact litter addition and glucose addition were-1.22 mg C/g SOC and 4.80 mg C/g SOC in poor soil,respectively,and were-1.73 mg C/g SOC and 1.56 mg C/g SOC in fertile soil.(2)Compared to placing intact litter on soil surface,mixing litter powder into the soil caused positive priming effect(2.21 mg C/g SOC)in poor soil,but negative priming effect(-1.72 mg C/g SOC)in fertile soil.(3)Compared with the control treatment,exogenous carbon input significantly increased soil carbon-acquiring enzyme(36.1%),nitrogen-acquiring enzyme(88.6%)and phosphorus-acquiring enzyme(21.4%)in both Chinese fir forests.(4)Soil bacterial biomass significantly differed between two addition methods of litter in both soils(P＜0.01),with biomass being 27.0%greater under litter powder addition than intact litter addition in poor soil and 19.2%greater in fertile soil.(5)Cumulative primed carbon was positively correlated with soil enzyme activity related to nitrogen cycling,and negatively correlated with soil bacteria biomass.In summary,the quality and addition method of exogenous organic carbon affects the priming,which is regulated by soil property,especially microbial community composition and enzyme activity.These results provide theoretical support for managing soil organic carbon in subtropical Chinese fir forests.关键词
杉木林/土壤有机碳分解/激发效应/土壤性质/微生物群落组成Key words
Chinese fir forest/soil organic carbon decomposition/priming effect/soil property/microbial community composition引用本文复制引用
陶玉兰,刘新颖,赵学超,王清奎..不同外源碳输入对两种杉木林土壤有机碳分解激发效应的影响[J].生态学报,2025,45(6):2698-2709,12.基金项目
国家自然科学基金(32171752) （32171752）
