摘要
溶解有机质(DOM)作为土壤中最活跃的有机组分,在土壤生物地球化学过程中起着关键作用,探讨植被演替过程中DOM的来源、组成、环境响应与累积规律,对预测土壤碳循环过程具有重要意义。本研究从海螺沟冰川退缩区植被原生演替序列选取演替年龄分别为12、30、40、50、80、120年的样地采集表层和亚表层土壤样本,测定DOM浓度并进行紫外-可见光光谱和三维荧光光谱分析,研究原生演替过程中DOM含量和组成的变化特征及其影响因素。结果表明:土壤DOM浓度随演替年龄的增加而显著增加。土壤DOM中类蛋白组分、荧光指数和生物指数随演替时间的增加而减小,类腐殖质组分和腐殖化程度随演替过程不断增加,土壤DOM芳香化程度先增加后减小。pH值、铵态氮含量解释了62.2%的表层土壤DOM组分变异,土壤含水率和pH值解释了64.3%的亚表层土壤DOM组分变异,说明环境因素是影响海螺沟冰川退缩区原生演替过程中土壤DOM数量和组成的重要因子。
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.
作者
梁紫嫣
李晓明
王涛
段宝利
类延宝
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)
出处
《应用生态学报》
CAS
CSCD
北大核心
2022年第4期1074-1082,共9页
Chinese Journal of Applied Ecology
基金
国家自然科学基金项目(31971632)
四川省科技厅项目(2020YFH0215,2021ZHYZ0002,2021YFH0008)资助。
关键词
土壤溶解性有机质
原生演替
三维荧光光谱
紫外-可见光光谱
冰川退缩
soil dissolved organic matter
primary succession
three-dimensional fluorescence excitation emission matrix spectra
ultraviolet-visible absorption spectra
glacial retreat
