青藏高原表土磁化率空间分布特征及影响因素  

Spatial Distribution Characteristics and Influencing Factors of Magnetic Susceptibility of Topsoil on the Qinghai-Tibet Plateau

作　　者：陈雅敏 宋效东[1] 刘峰[1] 叶明亮 张楚 张甘霖[1,2,3] CHEN Yamin;SONG Xiaodong;LIU Feng;YE Mingliang;ZHANG Chu;ZHANG Ganlin(State Key Laboratory of Soil and Sustainable Agriculture,Institute of Soil Science,Chinese Academy of Sciences,Nanjing 210008,China;University of Chinese Academy of Sciences,Beijing 100049,China;Key Laboratory of Watershed Geographic Sciences,Nanjing Institute of Geography and Limnology,Chinese Academy of Sciences,Nanjing 210008,China)

机构地区：[1]土壤与农业可持续发展国家重点实验室(中国科学院南京土壤研究所),南京210008 [2]中国科学院大学,北京100049 [3]中国科学院南京地理与湖泊研究所流域地理科学重点实验室,南京210008

出　　处：《土壤学报》2024年第2期361-371,共11页Acta Pedologica Sinica

基　　金：第二次青藏高原综合科学考察研究(2019QZKK0306-02);国家自然科学基金项目(42130715);中国科学院青年创新促进会项目(2021310)共同资助。

摘　　要：土壤磁化率是古环境重建的常用代用指标,对表土磁化率与现代环境的关系研究有助于理解磁化率产生差异的原因。当前,区域尺度上土壤磁化率变化成因认识尚不清楚,限制了磁化率作为古环境重建重要代用指标的精准应用。本研究系统调查了青藏高原的254个样点表层(发生层A层)土样,测定土壤磁化率和其他土壤属性,结合母质、气候、地形和植被等数据,阐明青藏高原地区土壤磁化率空间变化特征及其主要影响因素。结果表明:(1)不同母质类型之间,表层土壤磁化率(χ_(lf))无显著差异,百分频率磁化率(χ_(fd)%)差异显著,表现为黄土和砂页岩风化物>冰碛物和结晶盐风化物,其他母质类型之间无显著差异;不同土地利用之间,表层土壤χ_(lf)无显著差异,χ_(fd)%差异显著:森林和旱地>草地>荒地。(2)各因子对土壤磁化率影响表现为植被>理化性质>地形>母质。(3)空间分布上,χ_(lf)与χ_(fd)%均呈现由东南向西北降低的趋势。此外,χ_(lf)和χ_(fd)%的空间分布规律与青藏高原植被分区相吻合。因此,磁化率能更好地指示植被空间分布。【Objective】Soil magnetic susceptibility is a commonly used proxy index for paleoenvironment reconstruction.The study on the relationship between topsoil magnetic susceptibility and the modern environment is helpful to understand the reasons for the difference in magnetic susceptibility.Researchers around the world had conducted numerous studies on the correlation between soil magnetic susceptibility of sediments and modern soils in different regions and environmental factors.However,previous studies mainly focused on the correlation between soil magnetic susceptibility and climate.This correlation between soil magnetic susceptibility and climate was inconsistently recognized by different researchers because climate is only one of the influencing factors for the variation of soil magnetization rate.The main controlling factors of soil development and soil magnetic susceptibility may vary from region to region,and the magnetic susceptibility reflects the combined effect of multiple environmental factors.At present,the lack of understanding of the causes of soil magnetic susceptibility changes at the regional scale limits the accurate application of magnetic susceptibility as an important proxy index for paleoenvironmental reconstruction.Thus,we hypothesized that(1)the spatial distribution patterns of soil magnetic susceptibility in different regions can respond to environmental variables besides climate and(2)the Normalized Difference Vegetation Index(NDVI),which is the result of the combined effect of climate,topography and soil,can better respond to magnetization rates.【Method】The Qinghai-Tibet Plateau is the youngest natural geographic unit in the world with closely integrated horizontal and vertical zonation,influencing regional and global energy and water cycles.It is one of the areas where global changes have had the most significant impact on the land surface because it had undergone six major geological tectonic events and has a variety of parent rock types.The natural environment of the Qinghai-Tib

关 键 词：青藏高原 表土 磁化率 气候 

分 类 号：S152[农业科学—土壤学]