少花蒺藜草入侵对沙质草地氮库的影响  

Effects of invasive Cenchrus spinifex on nitrogen pools in sandy grassland

作　　者：张婷[1] 付卫东[1] 张瑞海[1] 宋振[1] 柏超[1] 黄成成[1] 张国良[1] 

机构地区：[1]中国农业科学院农业环境与可持续发展研究所,北京100081

出　　处：《应用生态学报》2017年第5期1522-1532,共11页Chinese Journal of Applied Ecology

基　　金：国家重点研发计划项目(2016YFSF03)资助~~

摘　　要：以我国北方大面积发生的入侵植物少花蒺藜草为对象,研究了其对科尔沁沙质草地土壤氮库和地上植物氮库的影响,并在室内条件下,以自然生境中少花蒺藜草伴生牧草披碱草和扁穗冰草为对照,利用^(15)N同位素技术分析了少花蒺藜草的生物固氮能力.结果表明:与对照裸地和本地植物鹅观草样地相比,少花蒺藜草入侵地土壤总氮库分别显著增加47.5%和20.8%,土壤铵态氮库分别显著降低25.6%和25.2%.与鹅观草相比,少花蒺藜草地上部分植物氮库显著降低18.7%.少花蒺藜草的^(15)N原子丰度、^(15)N原子百分超、^(15)N原子加权百分超均显著低于披碱草和扁穗冰草.少花蒺藜草和披碱草的氮肥利用率分别为48.5%和47.0%,差异不显著.与披碱草相比,少花蒺藜草生物固氮率为60.2%Ndfa.少花蒺藜草对氮素高效利用的特征,揭示了其适应沙质草地生态系统并蔓延的一种生态适应机制.： Cenchrus spinifex is an invasive study, we focused on analysis of the effects Horqin sandy grassland. In addition, a pot study the biological nitrogen fixation ability plant found in large areas of northern China. In this of C. spinifex on soil nitrogen and plant nitrogen pools in experiment with 15N tracing techniques was designed to of C. spinifex, compared with two native grasses, Ely- mus dahuricus and Agropyron cristatum. The total soil nitrogen pool in C. spinifex invaded-area in- creased significantly by 47.5% and 20.8%, and the soil ammonium nitrogen pool decreased signifi- cantly by 25.6% and 25.2%, compared with those in bare and native plant Roegneria kamoji areas, respectively. The plant shoot nitrogen pool decreased significantly by 18.7% in C. spinifex compared with native plant R. kamoji. Atom% 15N, atom% 15N excess and atom% 15N weighting excess of C. spinifex were all significantly lower than those of E. dahuricus and A. cristatum. The nitrogen use efficiencies of C. spinifex and E. dahuricus were 48.5% and 47.0%, respectively, and no significant difference was observed. Ndfa of C. spinifex accounted for 60.2%, when growing together with E. dahuricus. These results suggested that the characteristics on the high efficient use for nitrogen of this invasive weed might an ecological adaptation mechanism, leading to successful colonization and spread in Horqin Steppe.

关 键 词：少花蒺藜草 土壤氮库 植物氮库 生物固氮 

分 类 号：S451[农业科学—植物保护]