不同退化程度高寒草甸土壤可溶性有机质含量及光谱特征  

Content and Spectral Characteristics of Soil Dissolved Organic Matter in Alpine Meadows with Different Degradation Degrees

作　　者：钱虹宇 陈子彦 冯小轩 周南丁 罗原骏 蒲玉琳 胡玉福 QIAN Hong-yu;CHEN Zi-yan;FENG Xiao-xuan;ZHOU Nan-ding;LUO Yuan-jun;PU Yu-lin;HU Yu-fu(College of Resources,Sichuan Agricultural University,Chengdu,Sichuan Province 611130,China;College of Grassland Agriculture,Northwest A&F University,Yangling,Shaanxi Province 712100,China)

机构地区：[1]四川农业大学资源学院,四川成都611130 [2]西北农林科技大学草业与草原学院,陕西杨陵712100

出　　处：《草地学报》2024年第12期3715-3721,共7页Acta Agrestia Sinica

基　　金：四川省科学技术厅应用基础研究项目(2021YJ0341);四川省科学技术厅重点研发项目(2022YFS0469)资助。

摘　　要：探讨土壤可溶性有机质(Dissolved organic matter,DOM)对高寒草甸退化的响应,可为退化高寒草地系统生态恢复和碳汇功能提升提供基础数据与理论依据。本试验采用空间代替时间法和光谱技术,研究不同退化程度(未退化、轻度退化、中度退化和重度退化)高寒草甸土壤DOM含量及结构及化学组成的变化。结果表明:未退化草甸土壤DOM含量及占比分别为486.72 mg·kg^(-1)和0.14%,退化草甸土壤DOM含量和占比分别较未退化草甸显著降低55.25%~69.68%,33.79%~49.66%;结构特征:草甸退化提高了土壤DOM的芳香化程度,而分子量与腐殖化程度先增加后降低,在中度退化草甸最大;化学组成:草甸退化导致土壤DOM中的醇酚类与芳香类吸收峰相对强度减少,而多糖类、炔烃类吸收峰相对强度增多。综上,高寒草甸退化会导致土壤DOM的结构简单化、稳定性降低,增加了土壤DOM损失,影响了土壤碳库的稳定,增大了土壤质量下降的风险。Study on the response of soil dissolved organic matter(DOM)to alpine meadow degradation is helpful to provide basic data and theoretical basis for ecological restoration and carbon sink function improvement of degraded alpine meadow system.The soil DOM content,structural characteristics and chemical composition in alpine meadows with different degradation degrees(non-degraded meadow,lightly degraded meadow,moderately degraded meadow,heavily degraded meadow)were studied by using space instead of time sampling method and spectrum technology.The results showed that the content and distribution ratio of DOM in the soil of non-degraded meadow were 486.72 mg·kg^(-1)and 0.14%,respectively.The content and distribution ratio of DOM in three degraded meadows were significantly lower than those of non-degraded meadow by 55.25%-69.68%and 33.79%-49.66%,respectively.In terms of structural characteristics,meadow degradation leads to a gradual increase in the aromatization degree of soil DOM,while the molecular weight and degree of humification increase first and then decreased,and reached the maximum in moderately degraded meadow.In terms of chemical composition,meadow degradation leads to a gradual decrease in the relative intensity of the absorption peaks of alcohols,phenols and aromatics,while the relative intensity of absorption peaks of polysaccharides and alkynes gradually increased.In summary,the degradation of alpine meadow will lead to the simplification of soil DOM structure and the reduction of stability,increase the loss of soil DOM,affect the stability of soil carbon pool,and increase the risk of soil quality decline.

关 键 词：若尔盖高原 草甸退化 高寒土壤 可溶性有机碳 

分 类 号：S151[农业科学—土壤学]