三江源地区高寒草地土壤功能的水平分异特征及其沿发生层的垂直变化  

Horizontal Variation Characteristics of Alpine Grassland Soil Function and Vertical Changes Along Soil Genetic Horizons in the Three-River Headwaters Region

作　　者：李柏键 申聪聪 刘四义 吴华勇 王继琛 赵冬辉 葛源[1,2] LI Bo-jian;SHEN Cong-cong;LIU Si-yi;WU Hua-yong;WANG Ji-chen;ZHAO Dong-hui;GE Yuan(State Key Laboratory of Urban and Regional Ecology,Research Center for Eco-Environmental Sciences,Chinese Academy of Sciences,Beijing 100085,China;University of Chinese Academy of Sciences,Beijing 100049,China;State Key Laboratory of Soil and Sustainable Agriculture,Institute of Soil Science,Chinese Academy of Sciences,Nanjing 210008,China)

机构地区：[1]中国科学院生态环境研究中心城市与区域生态国家重点实验室,北京100085 [2]中国科学院大学,北京100049 [3]中国科学院南京土壤研究所土壤与农业可持续发展国家重点实验室,南京210008

出　　处：《环境科学》2023年第3期1562-1571,共10页Environmental Science

基　　金：第二次青藏高原综合科学考察项目(2019QZKK0306,2019QZKK0308)。

摘　　要：三江源地区是研究土壤生态系统功能响应气候变化的热点区域.为了研究三江源地区高寒草地土壤剖面功能特征和驱动机制沿发生层的差异,分析了高寒草地土壤剖面不同发生层的土壤功能指标(包括呼吸、氮转化速率和酶活等)以及与环境因子之间的相关关系.结果表明,土壤功能特征在高寒草甸和高寒草原之间不存在显著差异,表层土相比于深层土具有更高的呼吸、氮转化速率和酶活.土壤理化性质中全氮含量是不同发生层土壤功能特征的关键驱动因子,分别解释了土壤功能特征18.3%、21.4%和27.5%的水平分异.气候和植被因子主要在表层土中通过改变土壤理化性质间接影响土壤功能,但是大气氮沉降在深层土中对土壤功能仍存在影响.结果显示,三江源地区高寒草地土壤表现出显著的氮受限特征,为全球气候变化背景下土壤功能多样性的维持和对气候变化的响应提供了新的见解.The Three-River Headwaters region is a hotspot for studying the response of soil function to climate change.To study the horizontal variation characteristics of alpine grassland soil function and vertical changes along soil genetic horizons,soil functional indicators(including respiration,nitrogen conversion rate,and enzymatic activity)of different genetic horizons in alpine grassland soil profiles and their correlations with environmental factors were analyzed.The results showed that there were no significant differences in soil functional characteristics between alpine meadows and steppes,and topsoil had higher respiration rates,nitrogen conversion rates,and enzymatic activities than those of subsoil.Total nitrogen was a key driver of soil functional characteristics in different genetic horizons,explaining 18.3%,21.4%,and 27.5%of the horizontal variation in functional characteristics,respectively.Climate and vegetation factors mainly affected soil function indirectly by changing soil physicochemical properties in topsoil,but atmospheric nitrogen deposition still affected soil function in subsoil.These results indicate the significant nitrogen limitation of alpine grassland soil in the Three-River Headwaters region,and the findings provide a new insight into the maintenance of soil functional diversity and the response to climate change in the context of global climate change.

关 键 词：三江源地区 土壤剖面 发生层 土壤功能 环境因子 

分 类 号：X14[环境科学与工程—环境科学]