中文摘要：

为了解植被恢复对侵蚀红壤可溶性有机质含量及结构特征的影响,以福建省长汀县河田镇植被恢复后的侵蚀红壤及对照裸地为研究对象,对两试验地0–60 cm深土壤中可溶性有机质的含量及光谱学特征进行了比较研究。结果表明：侵蚀红壤植被恢复后,土壤可溶性有机碳含量显著提高,在土表到60 cm深度的6个10 cm土层中,植被恢复土壤可溶性有机碳含量分别提高为对照裸地相应土层的5.6、4.7、4.6、3.1、2.4及2.2倍。可溶性有机氮含量在两试验地之间的差异在各土层中不一致。植被恢复各土层侵蚀红壤可溶性有机质的芳香化指数显著高于对照裸地,荧光发射光谱腐殖化指数略高于对照裸地,植被恢复后的侵蚀红壤与对照裸地间荧光同步光谱腐殖化指数无明显差异。荧光同步光谱图中,两试验地侵蚀红壤可溶性有机质的吸收主要为类蛋白质及芳香性脂肪族荧光基团的吸收。傅里叶红外光谱结果显示,与对照裸地相比,植被恢复后的侵蚀红壤土壤可溶性有机质中官能团种类更多,且含有更多芳香碳及羧基碳。两试验地土壤可溶性有机质均表现为芳香化及腐殖化程度随土层的加深而降低。相关性分析显示,土壤可溶性有机质的芳香化及腐殖化指数与土壤碳氮总量有极显著正相关关系。总之,侵蚀红壤经植被恢复后,土壤可溶性有机碳含量及可溶性有机质的芳香化指数显著提高,可溶性有机质的腐殖化指数略有增大,可溶性有机质结构更复杂,更不易被分解,因此有利于土壤肥力的恢复。

英文摘要：

Aims Dissolved organic matter（DOM） plays an important role in soil nutrient cycling. The chemical stability,capability of absorption on mineral soil surface and availability to microbes of DOM could be influenced by its composition and chemical structure. The objective of this study was to investigate the effects of vegetation restoration on content and spectroscopic characteristics of DOM in eroded red soil.Methods The study site is located in Changting,Fujian Province,in subtropical China. Soil samples in the depth of 0–60 cm from eroded red soil（ERS） and vegetation restoration（VR） sites were collected in July,2013.Dissolved organic carbon（DOC） and dissolved organic nitrogen（DON） contents were determined and the spectroscopic characteristics of soil DOM were measured by means of ultraviolet（UV） absorbance,fluorescence（in emission and synchronous modes） and fourier-transform infrared（FTIR） spectroscopic techniques.Important findings The content of soil DOC in VR was significantly higher than in ERS. For soil layers from 0to 60 cm at a 10 cm interval,content of DOC in VR was 5.6,4.7,4.6,3.1,2.4 and 2.2 times of that in ERS,respectively. The difference in DON content between VR and ERS varied inconsistently across soil layers. In all soil layers,the Special Ultraviolet-Visible Absorption（SUVA） of DOM from VR was significantly higher than that from ERS; HIXem（Humification Index,emission mode） of DOM from VR was slightly higher than that from ERS; while there was no apparent difference in HIXsyn（Humification Index,synchronous mode） of DOM between the two sites. In the synchronous fluorescence spectra of DOM,the main emission peaks arose from protein-like and aromatic-aliphatic fluorophores. FTIR spectra showed that there were more functional groups in DOM from VR,with higher absorption proportion of aromatic rings and carboxylates. The aromaticity and humification index of soil DOM decreased with increasing soil depth at both sites,which were positively related to total