青藏高原中部土壤有机质含量对不同深度土壤温湿度的影响研究  

Impact of Soil Organic Matter Content on Soil Moisture and Temperature at Different Depths in the Central Qinghai-Xizang Plateau

作　　者：符晴 阳坤 郑东海[3] 陈莹莹 FU Qing;YANG Kun;ZGENG Donghai;CHEN Yingying(College of Atmospheric Sciences,Lanzhou University,Lanzhou 730000,Gansu,China;Department of Earth System Science,Tsinghua University,Beijing 100084,China;National Qinghai-Xizang Plateau Data Center,Institute of Qinghai-Xizang Plateau Research,Chinese Academy of Sciences,Beijing 100101,China)

机构地区：[1]兰州大学大气科学学院,甘肃兰州730000 [2]清华大学地球系统科学系,北京100084 [3]中国科学院青藏高原研究所-国家青藏高原科学数据中心,北京100101

出　　处：《高原气象》2022年第5期1097-1108,共12页Plateau Meteorology

基　　金：国家重点研发计划项目(2017YFA0603703);国家自然科学基金项目(41975125,41871273)。

摘　　要：青藏高原中东部地区土壤有机质含量较高,会改变土壤水热性质,从而影响土壤水热传输,但青藏高原土壤有机质含量如何影响温湿度廓线及其空间异质性仍缺乏系统性研究.本文利用那曲相似气候条件下的32个站点的土壤温湿度和有机碳含量观测资料,系统分析了不同土壤有机质含量对暖季不同深度(5,10,20和40 cm)土壤温湿度廓线特征及其空间差异的影响.研究发现,土壤有机质含量是影响5 cm、10 cm土壤水分和5 cm土壤温度空间分布的关键因子.土壤有机质含量显著影响从地表到20 cm深度的土壤水分的廓线特征及变化:有机质含量越高,持水能力越强,导致从地表到20 cm深度土壤水分含量整体偏高.此外,土壤温度的廓线特征及变化也深受土壤有机质含量的影响:有机质含量越高,热惯量越低,土壤温度的日变化振幅越小,且热量向深层传输的相位滞后越明显.Soil organic matter content is relatively high in the central and eastern Qinghai-Xizang Plateau,which may change the soil hydrothermal properties and thus affect the transport of soil water and heat.However,there is still a lack of systematic quantification on how soil organic matter content affects soil moisture and temperature profiles as well as their spatial heterogeneity on the Qinghai-Xizang Plateau.In this study,this effect is quantified using the in situ soil moisture and temperature data as well as soil organic carbon contents collected at 32 stations under similar climatic conditions in Naqu.The soil temperature and moisture dynamics in different depths(5,10,20 and 40 cm)with different organic matter contents and their spatial heterogeneity during the warm season were systematically analyzed.It is found that the soil organic matter content is a key factor determining the spatial distribution of soil moisture at 5 cm and 10 cm depth and temperature at 5 cm depth.The soil organic matter content also significantly affects the profile characteristics and dynamics of soil moisture from the surface to20 cm depth.A higher organic matter content tends to produce a greater water holding capacity,resulting in higher soil moisture contents from the surface to 20 cm depth.In addition,the profile characteristics and variations of soil temperature are largely influenced by the soil organic matter content as well.The higher organic matter content leads to lower thermal inertia,smaller amplitudes of diurnal soil temperature variation,and thus longer time lag of heat transfer to the deeper layers.The findings of this study will provide an important reference for improving the soil moisture and temperature simulations of land surface models in alpine meadows.

关 键 词：青藏高原 土壤有机质 土壤水分 土壤温度 

分 类 号：P461[天文地球—大气科学及气象学]