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

作　　者：陶玉兰 刘新颖 赵学超 王清奎 TAO Yulan;LIU Xinying;ZHAO Xuechao;WANG Qingkui(Anhui Provincical Key Laboratory of Forest Resources and Silviculture,Hefei 230036,China;School of Forestry and Landscape Architecture,Anhui Agricultural University,Hefei 230036,China)

机构地区：[1]安徽农业大学,林木资源培育安徽省重点实验室,合肥230036 [2]安徽农业大学林学与园林学院,合肥230036

出　　处：《生态学报》2025年第6期2698-2709,共12页Acta Ecologica Sinica

基　　金：国家自然科学基金(32171752)。

摘　　要：有机碳分解是陆地生态系统土壤碳循环的重要过程,外源碳输入可以通过调控微生物的群落结构与活性来影响土壤有机碳的分解,即激发效应。然而,外源碳的质量及添加方式对土壤激发效应的影响及其对土壤性质的响应尚不清楚。为此,采集了低高两种养分含量的杉木人工土壤作为研究对象,向其输入^(13)C标记的杉木凋落叶和葡萄糖。杉木凋落叶的添加分为两种方式:完整叶片覆于土表(IL)和叶片粉碎后均匀加入土中(CL)。通过室内培养120 d,测定土壤释放CO_(2)的量及其^(13)C值,并分析土壤养分和微生物群落结构。结果表明:(1)添加完整杉木叶产生负激发效应,而添加葡萄糖则相反。它们产生的土壤累积激发碳差异显著且效应强度受到土壤养分的显著调控,在低养分土壤中分别为-1.22 mg C/g SOC和4.80 mg C/g SOC,在高养分土壤的为-1.73 mg C/g SOC和1.56 mg C/g SOC。(2)与IL相比,CL处理下土壤累积激发碳为正激发(2.21 mg C/g SOC),而在高养分土壤中呈负激发(-1.72 mg C/g SOC)。(3)与CK相比,外源碳输入后土壤碳氮磷三类酶活性在两林地中均显著增加。(4)在两种土壤中,土壤细菌含量在IL与CL处理之间均差异显著(P<0.01),其中在低养分土壤中CL处理下土壤细菌含量比IL处理高27.0%,而在高养分土壤中仅增加了19.2%。(5)土壤累积激发碳与土壤氮酶活性呈正相关,与细菌呈负相关。综上可知,外源碳的质量及添加方式影响了土壤有机碳的分解过程且受到土壤性质的调控,尤其是土壤微生物群落组成和酶活性,该研究成果为亚热带杉木林土壤有机碳的管理提供了理论支撑。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 CO_(2)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 additi

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 

分 类 号：S15[农业科学—土壤学]