森林土壤不同粒径颗粒的碳矿化研究  

Experimental Study on Carbon Mineralization of Different Sizes Particle in Forest Soils

作　　者：马红亮[1,2] 陈灿灿 尹云锋[1,2] 高人[1,2] MA Hongliang;CHEN Chanchan;YIN Yunfeng;GAO Ren(Key Laboratory for Humid Subtropical Eco-geographical Processes of the Ministry of Education,Fujian Normal University,Fuzhou 350007,China;School of Geographical Sciences,Fujian Normal University,Fuzhou 350007,China;Anyang Vocational and Technical College,Anyang,Henan 455099,China)

机构地区：[1]福建师范大学湿润亚热带生态地理过程教育部重点实验室,福州350007 [2]福建师范大学地理科学学院,福州350007 [3]安阳职业技术学院,河南安阳455099

出　　处：《土壤学报》2024年第5期1247-1259,共13页Acta Pedologica Sinica

基　　金：国家自然科学基金项目(31770659);福建省公益类科研院所专项(2020R1002005)资助。

摘　　要：土壤是由不同粒径颗粒组成的,各粒径颗粒的性质差异大、在土壤中的空间位置不同。为了研究它们各自碳的变化差异,评估这些颗粒在土壤有机碳稳定和周转中的作用。选择亚热带阔叶林土壤,采用物理分组的方法,获得不同粒径土壤颗粒(>2000、2000~250、250~53、<53、53~20、20~2、<2μm),与全土等质量开展矿化试验,研究碳矿化量差异、主要碳形态变化及其相互关系,反向探究不同粒径颗粒在全土壤中的作用。结果表明,不同粒径颗粒按照质量比例作为权重计算的CO_(2)累积排放量、全碳、C/N、芳香性指数、游离氧化铁含量占全土的95.0%~101.8%。<2μm和20~2μm土壤颗粒CO_(2)累积排放量显著高于其他颗粒和全土。全土及各颗粒土壤CO_(2)累积排放量与比表面积、总孔隙体积、全碳、土壤可溶性有机碳(DOC,Dissolved organic carbon)、土壤微生物生物量碳(Soil microbial biomass carbon,MBC)、易氧化有机碳、游离氧化铁呈正相关性,而与C/N呈负相关性。通过对不同粒径颗粒16个指标降维分析,综合特征指数显示<2μm和20~2μm颗粒最高,即它们的综合作用最大。因此,全土壤的碳变化可追溯到土壤不同粒径颗粒碳的不同变化及关系,且土壤小粒径的团聚或被大粒径颗粒包闭可能是降低全土碳矿化的机理之一,有利于维持全土壤碳的稳定或增加保存。【Objective】Soil is composed of different size particles,and the properties of each particle and their spatial position in the soil are different.However,prior studies focused on a small range of different aggregates or particle sizes.Thus,this study aimed to investigate different carbon changes in each particle with a wide range and evaluate the role of the turnover and stability of soil carbon for each particle in bulk soil.【Method】After collecting soil samples from subtropical broad-leaved forest,the soil particles(>2000,2000-250,250-53,<53,53-20,20-2,<2μm)were obtained by physical fractionation.Moreover,the mineralization experiment was carried out with the same soil weight for each particle and bulk soil to study the difference in mineralization amount,carbon change trend and their relationship.Furthermore,after the dimension reduction of seventeen variables,a composite characteristic index was considered for each soil particle by principal component analysis.【Result】Although all soil particles were provided as the same amount for incubation to study their different carbon mineralization,their proportion in bulk soil was used to simulate their summation and compare them with bulk soil.The calculated sum values in cumulative CO_(2) emissions,total carbon,C/N,aromatic index,and free oxide iron content for all soil particles according to the proportion of each particle in bulk soil are 95.0%-101.8%of the bulk soil.In addition,it was 132.6%and 116.7%for the calculated sum values of the proportion of specific surface area and total pore volume in bulk soil.It was also observed that the cumulative CO_(2) emissions of<2μm and 20-2μm particles were significantly higher than those of other particles and bulk soil.The correlation analysis showed that the cumulative CO_(2) emissions of bulk soil or particles were positively correlated with specific surface area,total pore volume,total carbon,DOC,MBC,readily oxidized carbon,and free iron oxide,but negatively correlated with C/N.Moreover,this correlation an

关 键 词：亚热带森林土壤 物理分组 碳稳定 碳矿化 CO_(2)排放 

分 类 号：S714.2[农业科学—林学]