有机质对青藏高原多年冻土活动层土壤持水性能的影响  

Impact of Soil Organic Matter on Water Hold Capacity in Permafrost Active Layer in the Tibetan Plateau

作　　者：孙岩[1] 王一博[1,2] 孙哲[1] 刘国华[1] 高泽永[2] 

机构地区：[1]兰州大学资源环境学院,甘肃兰州730000 [2]中国科学院西北生态环境资源研究院冻土工程国家重点实验室,甘肃兰州730000

出　　处：《中国沙漠》2017年第2期288-295,共8页Journal of Desert Research

基　　金：冻土工程国家重点实验室开放基金项目(SKLFSE201501);国家自然科学基金项目(41271092)

摘　　要：土壤水分特征曲线描述土壤基质势ψ和含水量θ之间的函数关系,表征土壤的持水性能,是研究土壤水分入渗、蒸发、土壤侵蚀及溶质运移的关键。高寒气候特征使有机质在青藏高原地区大量积累,为确定多年冻土活动层土壤持水性能的影响因素,尤其是有机质的影响,在长江源北麓河地区采样分析。结果表明:相比于土壤粒度分布,容重和有机质是影响土壤持水性能的主要因素,其中高基质势下(0^-30kPa)以容重影响为主,低基质势下(-100^-1 500kPa)以有机质影响为主;有机质通过改变土壤结构和增强土壤的吸附性而影响土壤持水性能,同时影响程度取决于有机质的多少,土壤持水性与有机质含量呈正相关关系。本次研究有助于认识高寒地区土壤水文特征,对展开土壤水文过程的研究提供理论基础。Soil water characteristic curve as a characterization of water holding capacity and the description of the function relationship between matric potential ψ and water content θ is the key to study the soil water infiltration, evaporation, soil erosion and solute transport. Affected by alpine climate characteristics, organ- ic matter was extensively accumulated on the Tibetan Plateau. In order to determine the factors influencing soil water retention of active layer in permafrost regions, especially the influences of organic matter, sam- ples was collected and analyzed from the Beiluhe Basin of the Tibetan Plateau. The results indicated that compare with soil particle-size distribution, bulk density and organic matter were the major factors that in- fluenced the water holding capacity. High matric potential （0 to --30 kPa） was given priority to with bulk density while low matric potential （- 100 to --1 500 kPa）was given priority to with organic matter; organic matter can affect soil water retention by altering soil structural and enhancing soil sorption, meanwhile, the influence extent depended on organic matter content with a positive correlation. This study were useful for understanding soil hydrological characteristics and provided theoretical basic for hydrological process in al- pine region.

关 键 词：青藏高原 土壤水分特征曲线 土壤转换函数 有机质 

分 类 号：S152.7[农业科学—土壤学]