土壤学报2025，Vol.62Issue(5)：1308-1318,11.DOI:10.11766/trxb202408070322
洪泽湖河湖交汇区不同植被覆盖土壤溶解性有机质光谱特征研究
Spectral Characteristics of Dissolved Organic Matter in Soils with Diverse Vegetation Cover in the River-Lake Confluence Area of Hongze Lake
摘要
Abstract
[Objective]Soil dissolved organic matter(DOM)plays an important role in the biogeochemical processes in wetland ecosystems.This study aimed to uncover the total quantity,components,and source features of DOM in the river-lake confluence area of Hongze Lake.[Method]The spectral characteristics of DOM in soil covered by lake-sedge,reed,poplar,and willow in the river-lake confluence area of Hongze Lake were studied using UV-visible absorption spectroscopy and the three-dimensional fluorescence spectroscopy method.[Result]The results showed that the DOM content of soil covered by different vegetation was in the order of reed wetlands,lake-sedge wetlands,poplar forests,and willow forests.Additionally,soil within 40 cm of reed wetlands contained a dissolved organic carbon level of 193.2 mg·kg-1.The soil DOM values of A250/A365,SUVA254,SUVA260,and SR ranged from 3.7 to 4.5,1.3 to 1.8,0.86 to 1.8,and 3.6 to 4.9,respectively.Moreover,the molecular weight,aromaticity,and hydrophobicity of lake-sedge wetlands soil were significantly higher than those of other soils.As revealed,DOM's molecular weight,aromaticity,and hydrophobicity decreased in the 20-40 cm soil layer as opposed to the 0～20 cm soil layer.As shown by EEM-PARAFAC,four fluorescence components,terrestrial humic acid-like,marine humic acid-like,fulvic acid-like,and protein-like,have been recognized.Humic acid-like substances were found in all soil layers,with 55.1%to 70.1%being the majority,but the 20-40 cm soil layer saw a rise in protein-like substances,especially in reed wetlands soil.The FI,BIX,and HIX indices of DOM varied depending on the vegetation,with a range of 1.3 to 1.5,0.47 to 0.72,and 1.7 to 7.4,respectively.The soil DOM properties were greatly influenced by the coverage of different vegetation.Also,terrestrial humic acid-like substances were the dominant soil DOM in the river-lake confluence area of Hongze Lake,with a lesser level of self-obtained and a higher degree of humification.[Conclusion]In summary,the research results revealed the differences in total DOM content and spectral characteristics of soils with different vegetation cover in the river-lake confluence area of Hongze Lake.It further provides a scientific basis for understanding DOM environmental behavior in the river-lake confluence area,thus,strengthening carbon sequestration efficiency in key areas and enhancing habitat protection.关键词
土壤/溶解性有机质/光谱特征/植被覆盖/河湖交汇区/洪泽湖Key words
Soil/Dissolved organic matter/Spectral characteristic/Vegetation coverage/River-lake confluence area/Hongze Lake分类
林学引用本文复制引用
程虎,吴玉东,郭俨辉,闵炬,陆海鹰,韩建刚,张龙江,纪荣婷..洪泽湖河湖交汇区不同植被覆盖土壤溶解性有机质光谱特征研究[J].土壤学报,2025,62(5):1308-1318,11.基金项目
中央级公益性科研院所基本科研业务费专项(GYZX240103)和国家自然科学基金项目(42477376)共同资助 Supported by the Basic Special Business Fund for Research and Development for the Central Level Scientific Research Institutes,Nanjing Institute of Environmental Sciences,Ministry of Ecology and Environment(No.GYZX240103),and the National Natural Science Foundation of China(No.42477376) （GYZX240103）
