Liang Zi-Yan, Li Xiao-Ming, Wang Tao, Duan Bao-Li, Lei Yan-Bao
Institute of Mountain Hazards and Environment, Chinese Academy of Sciences and Ministry of Water Resources, Chengdu 610041, China; University of Chinese Academy of Sciences, Beijing 100049, China.
Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
Ying Yong Sheng Tai Xue Bao. 2022 Apr;33(4):1074-1082. doi: 10.13287/j.1001-9332.202204.032.
Dissolved organic matter (DOM), the most active type of soil organic matter, plays a key role in soil biogeochemical cycling. Therefore, exploring the source, composition, environmental response, and accumulation mechanism of DOM during vegetation succession has great significance for predicting soil carbon cycling. In this study, DOM was extracted from topsoil and subsoil at plots after 12, 30, 40, 50, 80, and 120 years of primary succession along the Hailuogou Glacier retreat area. The concentrations and spectral characteristics of DOM were analyzed via a combination of elemental analysis, ultraviolet-visible spectroscopy, and three-dimensional fluorescence excitation-emission matrix spectroscopy. The results showed that concentrations of soil dissolved organic carbon and dissolved organic nitrogen of both topsoil and subsoil increased significantly during vegetation succession. Along the chronosequence, the protein-like components and optical indices were significantly enhanced, humic-like components and the optical indices decreased, the aromaticity degree of DOM increased first and then decreased. Soil pH and NH-N content explained 62.2% of the total variation of surface soil DOM components, while soil moisture and pH explained 64.3% of that of subsurface soil DOM, indicating that environmental conditions were key factors affecting the concentrations and composition of soil DOM in the Hailuogou Glacier retreat area.
溶解有机 matter (DOM) 是土壤有机质中最活跃的类型，在土壤生物地球化学循环中起关键作用。因此，探究植被演替过程中DOM的来源、组成、环境响应及积累机制，对预测土壤碳循环具有重要意义。本研究在海螺沟冰川退缩区沿初级演替12、30、40、50、80和120年的样地中，从表层土壤和亚表层土壤中提取DOM。通过元素分析、紫外可见光谱和三维荧光激发 - 发射矩阵光谱相结合的方法，分析了DOM的浓度和光谱特征。结果表明，在植被演替过程中，表层土壤和亚表层土壤的溶解有机碳和溶解有机氮浓度均显著增加。沿时间序列，类蛋白组分和光学指数显著增强，类腐殖质组分和光学指数降低，DOM的芳香度先增加后降低。土壤pH值和NH-N含量解释了表层土壤DOM组分总变异的62.2%，而土壤湿度和pH值解释了亚表层土壤DOM总变异的64.3%，表明环境条件是影响海螺沟冰川退缩区土壤DOM浓度和组成的关键因素。
