矮嵩草草甸氮素利用率对养分添加与冬季增雪的短期响应  

Short-term effects of nutrient additions and snow increase in winter on nitrogen utilization rate of Kobresia humilis meadow

作　　者：魏晴[1,2] 周华坤[1] 姚步青[1] 王文颖[2] 刘泽华[2] 赵新全[1] 

机构地区：[1]中国科学院西北高原生物研究所,西宁810000 [2]青海师范大学,西宁810008

出　　处：《生态学杂志》2015年第2期491-496,共6页Chinese Journal of Ecology

基　　金：国家自然科学基金项目(31172247;31201836和31472135);青海省自然科学基金项目(2013-Z-916);中国科学院战略性先导科技专项(XDA05070202);国家科技支撑项目(2011BAC09B06-02和2014BAC05B03);青海省重点实验室发展专项(2013-Z-Y07;2014-Z-Y01)资助

摘　　要：研究设4个实验处理[冬季增雪(W)、施N肥、施P肥和对照],通过15N稳定性同位素标记研究短期内增施氮磷肥及水分对青藏高原矮嵩草(Kobresia humilis)草甸氮素利用率的影响。结果表明:群体水平上,植物地上部分15N绝对浓度最高;土壤中氮素残留量较高,说明短期内氮素未被充分吸收利用,且活体植物氮素的吸收利用大于凋落物;氮素利用率为P处理>N处理>W处理>CK。说明养分与水分是限定矮嵩草草甸的氮素利用率的因子,其中养分是最关键因子。The effects of nutrient and water additions on nitrogen utilization rate of alpine plantswere investigated using the SN labeling technique in a Kobresia humilis meadow over a short termperiod. Four treatments were set up as follows： increased snow in winter （W） , N fertilization（N）, P fertilization （P）, and control （CK）. About one month after the labeling, the SN abso-lute abundance of below-ground of plants was the highest. More added N was recovered in thesoil. This indicates that N was not fully used by plants in the short term, and less N was trans-ferred into litter. The N utilization rates for plants under different treatments were in order of Ptreatments 〉 N treatments 〉 W treatments 〉 CK. This reflects that nutrient and moisture modify Nutilization rate of alpine plants in K. humilis meadows, and the nutrient is more important.

关 键 词：15N标记 冬季增雪 施N肥 施P肥 矮嵩草草甸 

分 类 号：S812[农业科学—草业科学]