黄土高原草地土壤有机碳分布及其影响因素  

DISTRIBUTION OF SOIL ORGANIC CARBON IN GRASSLAND ON LOESS PLATEAU AND ITS INFLUENCING FACTORS

作　　者：刘伟[1,2] 程积民[1] 高阳[3] 程杰[3] 梁万鹏[3] 

机构地区：[1]中国科学院水利部水土保持研究所,陕西杨凌712100 [2]中国科学院研究生院,北京100049 [3]西北农林科技大学动物科技学院,陕西杨凌712100

出　　处：《土壤学报》2012年第1期68-76,共9页Acta Pedologica Sinica

基　　金：中国科学院战略性先导科技专项--应对气候变化的碳收支认证及相关问题(XDA05050202);中国科学院重要方向项目(KZCX2-YW-441;KZCX2-YW-149);黄土高原土壤侵蚀与旱地农业国家重点实验室基金项目(10502-Z8);国家重点基础研究发展计划973项目(2007CB106803)资助

摘　　要：以黄土高原水平方向的4种主要草地类型为研究对象,分析了不同草地类型土壤有机碳(SOC)的分布特征及其影响因素。结果表明:土壤有机碳含量随土壤深度的增加而降低,其中0～20 cm土壤有机碳含量与20～40、40～60、60～80、80～100 cm有机碳含量差异显著。4种草地类型土壤有机碳含量分布规律:0～40 cm为高山草甸草原>典型草原>森林草原>荒漠草原,40～100 cm为高山草甸草原>森林草原>典型草原>荒漠草原;4种草地类型中各土层土壤有机碳含量最高的是高寒草甸,其空间变异最大,最小的是荒漠草原,其变异最小。黄土高原上高寒草甸草原、森林草原、典型草原土壤有机碳均集中分布在浅表层0～40 cm,分别占0～100 cm的71%、50%、46%,而荒漠草原各层分布较均匀;黄土高原土壤有机碳含量与海拔高度呈显著正相关(p<0.01);0～40 cm土壤有机碳含量与土壤含水量呈显著正相关(p<0.01);与全氮有极显著的正相关性,相关系数达0.984 3;与年均温呈极显著负相关(p<0.01),几种草地类型100 cm深土壤有机碳含量与年降水量无明显相关。Distribution of soil organic carbon （SOC） and its affecting factors in four different types of natural grasslands （forest steppe, typical grassland, alpine meadow steppe and desert steppe） in the Loess Plateau were analyzed. Results show that content of soil organic carbon decreases with soil depth, and is significantly higher in 0~20 cm than in 20~40 cm, 40~60 cm, 60~80 cm and 80~100 cm. In the 0~40 cm soil layer, the distribution of organic carbon content in the four types of grasslands tends to be in the order of Alpine meadow steppe 〉 typical grassland 〉 forest steppe 〉 desert steppe; while in the 40~100 cm soil layer, in the order of Alpine meadow steppe 〉 forest steppe 〉 typical grassland 〉 desert steppe. In the Alpine meadow steppe, forest steppe and typical steppe of the Loess Plateau, soil organic carbon is concentrated in the surface layer （0~40 cm）, accounting for 71%, 50% and 46% of the total in the profile （0~100 cm）, while the distribution is more uniform in the desert steppe; Soil organic carbon content is positively related （p〈0.01） to altitude; in the 0~40 cm soil layer, to soil water content （p〈0.01）; and to total nitrogen （r=0.984 3）;but negatively related to annual mean temperature （p〈0.01）. Moreover, it has no obvious relationship with annual precipitation in the 100 cm soil layer in all the four types of grasslands.

关 键 词：黄土高原 草地 土壤 有机碳 分布特征 影响因素 

分 类 号：S812.2[农业科学—草业科学] S153.6[农业科学—畜牧学]