摘要
以46年生杉木(Cunninghamia lanceolata)及锥栗(Castanea henryi)人工林为对象,研究其表层土壤(0-5cm,5-10cm)可溶性有机质(DOM)数量和光谱学特征,比较2树种差异对土壤可溶性有机质的影响。结果表明,杉木林土壤可溶性有机碳(DOC)及可溶性有机氮(DON)含量均显著高于锥栗林,其芳香化及腐殖化程度亦高于锥栗林,但荧光效率值低于锥栗林。荧光光谱图显示,杉木林土壤DOM在芳香性脂肪族及木质素类复杂结构荧光基团处的吸收大于锥栗林。傅里叶红外光谱中吸收强度最大的谱带来自于形成氢键的-OH的伸缩振动,此外还有碳水化合物中烷氧基C-O及氨基酸C-N的振动等。相关分析结果显示,土壤DOM光谱学特征值与土壤养分含量间存在一定程度的相关性。与锥栗林相比,杉木林土壤DOM含量更高,结构更复杂,更有利于土壤养分的存蓄。
The aim of this study was to identify quantitative and qualitative differences of soil dissolved organic matter（DOM）isolated from Cunninghamia lanceolata（CL）and Castanea henryi（CH）plantations,which were two common economic tree species in Fujian province of China,and to relate their spectroscopic characteristics to soil properties.The structural characteristics of DOM by means of UV absorbance,fluorescence（in emission and synchronous modes）and fourier-transform infrared（FTIR）spectroscopic techniques were examined.The results showed that,dissolved organic carbon（DOC）and dissolved organic nitrogen（DON）content of soil from CL was significantly higher than that of CH in both 0-5cm and 5-10 cm soil layers.Content of soil DOM in two forests decreased 36%~75% from 0-5cm to 5-10 cm.The aromaticity（SUVA）and the humification indices（HIXem,HIXsyn）of soil DOM from CL were significantly higher than those of CH,and they decreased with depth in both forests,while fluorescence efficiency（Feff）showed an opposite trend.The main emission peaks of soil DOM in the synchronous fluorescence spectra arose from aromatic amino acid,aromatic aliphatic and protein-like fluorophores.FTIR spectra of soil DOM from two forests featured-OH from hydrogen bond,C-O from carbohydrate,C-N from amino acid,aromatic C=O,and COO-from carboxylic acid.Correlation analysis showed that,there were relationship between soil properties and spectroscopic characteristics of soil DOM at different levels.It indicated that,soil DOM from CF was nutrient richer and contained more complex and highly condensed compounds in comparison with that of CH,and molecules with more complex structure were more likely to be absorbed onto upper soil surface other than migrating to deeper soil layer due to their poor mobility,the difference of soil DOM between the two forests might be attributed to the litterfall input.
出处
《水土保持学报》
CSCD
北大核心
2014年第5期170-175,共6页
Journal of Soil and Water Conservation
基金
国家自然科学青年基金项目(31100467)
国家自然科学基金重点项目(31130013)
国家自然科学基金面上项目(31270659
31370465)
福建师范大学优秀青年骨干教师培养基金项目(FJSDKY2012008)
关键词
杉木
锥栗
可溶性有机碳
可溶性有机氮
紫外光谱
荧光光谱
红外光谱
Cunninghamia lanceolata
Castanea henryi
dissolved organic carbon
dissolved organic nitrogen
ultraviolet spectrum
fluorescence spectrum
fourier-transform infrared spectrum
