甘肃臭草入侵对亚高山草地土壤碳氮库的影响  

Effect of Melica przewalskyi invasion on soil carbon and nitrogen pools of subalpine grassland

作　　者：曹静娟[1] 尚占环[2,3] 郭瑞英[4] 崔光欣[2] 

机构地区：[1]甘肃农业大学草业学院,甘肃兰州730070 [2]兰州大学青藏高原生态系统管理国际中心草地农业科技学院,甘肃兰州730020 [3]中国科学院青藏高原研究所,北京100085 [4]兰州大学干旱与草地生态教育部重点实验室,甘肃兰州730000

出　　处：《草原与草坪》2010年第5期11-14,19,共5页Grassland and Turf

基　　金：世界银行/全球环境基金(052456CHA-GS-Y-4);国家自然科学基金(30730069)资助

摘　　要：甘肃臭草（Melica przewalskyi）型退化草地是祁连山北坡常见的一种毒杂草草地退化类型。以臭草型退化草地和其周边未遭受臭草入侵的未退化草地为研究对象,分析了臭草入侵对草地植被群落结构和草地土壤碳、氮库的影响。结果表明,臭草入侵导致草地植被群落结构特征发生明显变化,甘肃臭草代替针茅成为草地群落优势物种。土壤含水量、容重、pH、电导率等土壤指标在两样地间也存在差异。臭草入侵并形成杂草群落后,增加了草地土壤有机碳、全氮的含量,但与未退化草地相比,无显著性差异（P〉0.05）,臭草型退化草地土壤有机碳、氮储量（0~30 cm）显著高于未退化草地（P〈0.05）。说明甘肃臭草的侵入只改变了亚高山草地的植被群落结构,没有导致草地固碳、固氮能力的降低。In the northern slopes of Qilian Mountains,Melica przewalskyi was a common miscellaneous species invading into the degraded grassland.The grassland with Melica przewalskyi invasion and the adjacent un-degraded grassland were selected to test the effect of M.przewalskyi invasion on vegetation community,soil organic carbon and nitrogen pools.The results showed that the structure of vegetation community changed markedly after the invasion of M.przewalskyi,which became the dominant species instead of Stipa capillata.The basic soil properties were different between the two sample types,such as soil moisture,soil bulk density,pH and soil conductivity.When M.przewalskyi community formed,soil organic carbon（SOC）and total nitrogen（TN）concentrations increased,but with no significant difference（P0.05）comparing with the un-degraded grassland.SOC and TN stocks（0 to 30 cm）in soil of M.przewalskyi invaded grassland were significantly higher than that of un-degraded grassland（P0.05）.It indicated that M.przewalskyi invasion only changed the structure of vegetation community,whereas the capacity of carbon and nitrogen sequestration did not decrease.

关 键 词：祁连山北坡 亚高山草地 臭草 杂草入侵 碳库 氮库 

分 类 号：S143.1[农业科学—肥料学]