子午岭林区不同林分土壤DOM光谱特征及驱动因子分析  

Spectral Characteristics and Driving Factors Analysis of Soil Dissolved Organic Matter in Different Forest Types in Ziwuling Forest District

作　　者：孟永霞 李鹏[1,2] 肖列[1,2] 张超雅 杨殊桐[1,2] 刘家亮 MENG Yong-xia;LI Peng;XIAO Lie;ZHANG Chao-ya;YANG Shu-tong;LIU Jia-liang(Hydrological and Water Resources System,School of Water Resources and Hydropower,Xi'an University of Technology,Xi'an 710048,China;State Key Laboratory of Eco-Hydraulics in Northwest Arid Region of China,Xi'an University of Technology,Xi'an 710048,China)

机构地区：[1]西安理工大学水利水电学院水文水资源系,陕西西安710048 [2]西安理工大学西北旱区生态水利国家重点实验室,陕西西安710048

出　　处：《光谱学与光谱分析》2025年第3期768-773,共6页Spectroscopy and Spectral Analysis

基　　金：陕西省2023年重点研发计划项目(2023-ZDLSF-65),国家自然科学基金项目(U2243201)资助。

摘　　要：溶解性有机质(DOM)是反映土壤碳循环及养分循环的重要参数。描述不同林分类型和土壤深度的DOM成分及组成对理解森林碳循环过程尤为重要。采用三维荧光激发发射矩阵(EEM)和平行因子分析(PARAFAC)相结合的方法,分析子午岭林区油松林(YS)和麻栎林(ML)在不同土壤深0~20、20~60及60~100 cm下DOM的变化规律及其影响因素。结果表明,ML林地溶解有机碳(DOC)平均含量较高,YS林地较低,随着土壤深度的变化有显著变化。采用PARAFAC鉴定出4种荧光组分,其中C1和C2为类腐殖酸荧光组分,主要集中在0~20 cm,而C3和C4为类蛋白质荧光组分,随土壤深度的增加占比增大。荧光参数指标表明,0~20 cm的DOM来源主要以陆源输入为主,而60~100 cm主要以微生物活动等引起的自生源为主。通过相关性分析,发现2种林分DOC与4种土壤酶活性均有显著的相关性,YS土壤中DOC与TN呈显著正相关(p<0.05),而在ML土壤中,DOC与TP呈极显著正相关(p<0.01)。偏最小二乘法结构方程模型(PLS-PM)结果表明,理化性质和土壤酶既可以独立主导DOM,又可以共同作用影响DOM。此结果有助于了解子午岭林区油松和麻栎林地土壤DOM的变化规律,为森林生态系统碳循环提供一定的理论依据。Dissolved organic matter(DOM)is an important parameter reflecting forest soil s carbon and nutrient cycles.Therefore,describing the composition and structure of DOM from different forest types and soil depths is particularly important for understanding the forest carbon cycling process.This study used a combined method of three-dimensional fluorescence excitation-emission matrix(EEM)and parallel factor analysis(PARAFAC)to analyze the variation characteristics of DOM in Pinus tabuliformis forest(YS)and Quercus acuteserrata forest(ML)at 0~20,20~60,and 60~100 cm.The average content of dissolved organic carbon(DOC)was higher in ML forest land,while it was lower in YS forest land and varied significantly with changes in soil depth.Four fluorescent components were identified using PARAFAC,among which C1 and C2 are humic and fulvic acid components,belonging to the humic-like fluorescence component.They are mainly concentrated in the 0~20 cm and gradually decrease with increasing soil depth.C3 and C4 are tryptophan and tyrosine-like components,respectively,belonging to the protein-like fluorescence component,and their proportion increases with increasing soil depth.Fluorescence parameter indices of soil profiles indicated that the dominant source of DOM in the 0~20 cm depth was primarily from terrestrial inputs,while in the 60~100 cm depth,it was mainly derived from autochthonous sources caused by microbial activities.Correlation analysis showed significant correlations between two forest stands DOC and four soil enzymes.Additionally,in the YS soil,DOC was significantly positively correlated with TN(p<0.05),whereas in the ML soil,DOC was highly significantly positively correlated with TP(p<0.01).The results of the Partial Least Squares Path Modeling(PLS-PM)indicated that both physicochemical properties and soil enzymes could independently dominate DOM and interact to influence DOM.These results contribute to understanding the dynamic characteristics of soil DOM in the soil profile of Pinus tabuliformis and Quercus acutes

关 键 词：子午岭林区 溶解性有机质 土壤剖面 平行因子 

分 类 号：S155.48[农业科学—土壤学]