微地形对高寒草地土壤有机碳及氮含量的影响  

Effects of Micro-topography on Soil Organic Carbon and Nitrogen Content in Alpine Grassland

作　　者：杨鹏[1] 赵锦梅[1] 雷隆举 徐长林[2] 王正安 YANG Peng;ZHAO Jinmei;LEI Longju;XU Changlin;WANG Zhengan(Forestry of College, Gansu Agriculture University, Lanzhou, Gansu 730070, China;College of Pratacultural Science, Gansu Agriculture University, Lanzhou, Gansu 730070, China;College of Resources and Environment, Gansu Agriculture University, Lanzhou , Gansu 730070, China)

机构地区：[1]甘肃农业大学林学院,甘肃兰州730070 [2]甘肃农业大学草业学院,甘肃兰州730070 [3]甘肃农业大学资源与环境学院,甘肃兰州730070

出　　处：《水土保持通报》2018年第3期94-98,共5页Bulletin of Soil and Water Conservation

基　　金：国家自然科学基金项目"东祁连山区高寒灌丛土壤水文效应研究"(41661060);甘肃省自然科学研究资助项目"高寒草地土壤大孔隙特征及优先流过程研究"(1606RJZA005)

摘　　要：[目的]系统分析高寒草地不同微地形条件下土壤有机碳及氮含量的变化规律,为高寒地区合理利用草地提供理论参考。[方法]在天祝高寒草地区选取7类不同微地形作为研究对象,测定其表层(0—30cm)土壤有机碳及氮含量。[结果]随着土层深度的增加,位于坡底平地,土壤全氮和铵态氮含量呈减小的趋势,位于阴坡不同坡位,土壤全氮含量呈"V"型变化,土壤铵态氮呈减小的趋势,位于阳坡不同坡位,土壤全氮含量呈减小的趋势,土壤铵态氮含量呈先增大后减小的趋势;所有微地形中,随着土层深度的增加,土壤有机碳含量呈减小的趋势;随着土层深度的增加,坡底平地,中坡阳面和中坡阴面微地形中,土壤水解氮含量呈减小的趋势,下坡阳面和下坡阴面微地形中,土壤水解氮含量呈先减小后增大的趋势,上坡阳面和上坡阴面微地形中,土壤水解氮含量呈先增大后减小的趋势。土壤表层全氮、水解氮、有机碳的含量的变化为:下坡位>上坡位>中坡位,而铵态氮的含量呈现先减小后增大的趋势。[结论]地形的微变化明显影响土壤氮有机碳和素的含量。[Objective]The study analyzed the variation of soil organic carbon（SOC）and nitrogen（N）content under different micro-topography in alpine grassland area in order to provide a theoretical basis for the reasonable use of grassland in alpine grassland.[Methods]This study selected 7 different kinds of microtopography in alpine grassland of Tianzhu to measure SOC and N in the land surface（0—30 cm）.[Results]With the increase of soil depths,the content of total N and NH4-N decreased at the flat area of valley bottom.The content of soil total N showed a＂V＂trend and NH4-N decreased in different position of northfacing slopes.In different position of south-facing slopes,the content of soil total N decreased,but soil content of NH4-N showed an increase trend initially and decreased later.With the increase of soil depths,the content of SOC decreased in all micro-topography,while the content of soil hydrolyzable nitrogen decreased in terrace,middle and south-facing slope,middle and north-facing slope micro-topography.The content of hydrolyzable N decreased initially and then increased in bottom and south-facing slope and bottom andnorth-facing slope micro-topography,while increased initially and then decreased in top and south-facing slope and top and north-facing slope.[Conclusion]The variation of total N,hydrolyzable N and SOC content at different topographic positions was ranked as：bottom slope〉top slope 〉middle slope.The content of NH4-N decreased initially and then increased.In conclusion,the variation in micro-topography impacts the content of SOC and N dramatically.

关 键 词：微地形 有机碳 氮素 高寒草地 

分 类 号：S812.2[农业科学—草业科学]