生态学报2017，Vol.37Issue(3)：778-787,10.DOI:10.5846/stxb201508141706
氮素添加和功能群去除对糙隐子草和大针茅根系特征的影响
The response of Cleistogenes squarrosa and Stipa grandis root characteristics to nitrogen adding gradient and removal of function groups
摘要
Abstract
Overgrazing has severely degraded the grassland of Northern China causing serious loss of soil nitrogen (N).Along with the degraded steppe,Cleistogenes squarrosa will replace Stipa grandis,which was the original dominant species,to become the dominant plant in the community.In order to understand this transition,a study was made to examine the effect of N and selected functional plant groups on the rooting characterisitics of S.grandis and C.squarrosa.Two experiments were conducted in degraded grassland communities that were dominated by C.squarrosa.on the Xilingol steppe.on a degraded community.In Experiment 1 involved N addition along an increasing gradient (0,10.5,17.5,28g N/m2)while in Experiment 2,two of three functional groups (high-energy,middle-energy and low-energy functional groups) were removed (1,0,0;0,2,0;and 0,0,3) and adding N fertilizer(0,17.5 g N/m2) in a factorial arrangement.After two years,the root length,diameter,area,and volume of S.grandis and C.squarrosa were measured using a Delta-T SCAN analyzer.Root response to N fertilizer as well as to the removal of functional groups,with two N levels,were analyzed.Under pressure from competition by other functional groups,the root length,area,and volume of S.grandis significantly increased under high N fertilizer (28 gN/m2) while root diameter and volume of C.squarrosa with 17.5 gN/m2 were significantly higher than the other three N application rates.In Experiment 2,we did not detect a response in S.grandis to nitrogen addition (17.5 gN/m2) while removing functional groups but the root diameter of C.squarrosa increased significantly.In general removal of plant functional groups affects the root length and area of S.grandis and the root length,diameter and area of C.squarrosa.While the interaction between nitrogen addition and removal of plant functional groups affects the root diameter and volume of C.squarrosa,and it did not affect S.grandis.关键词
大针茅/糙隐子草/氮素/根系/功能群Key words
Stipa grandis/Cleistogenes squarrosa/nitrogen/root/functional group引用本文复制引用
秦洁,鲍雅静,李政海,张靖,孟根其其格,李梦娇..氮素添加和功能群去除对糙隐子草和大针茅根系特征的影响[J].生态学报,2017,37(3):778-787,10.基金项目
中央高校基本科研业务费专项资金资助项目(DC201502070303) （DC201502070303）
国家自然科学基金金资助项目(30771528) （30771528）
国家火炬计划项目金资助项目(2012GH531899) （2012GH531899）
