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生态学杂志 ›› 2004, Vol. ›› Issue (6): 25-28.

• 研究报告 • 上一篇    下一篇

土壤-牧草氮素供需状况变化对高寒草甸植被演替与草地退化的影响

曹广民, 吴琴, 李东, 胡启武, 李月梅, 王溪   

  1. 中国科学院西北高原生物研究所, 西宁, 810001
  • 收稿日期:2003-12-10 修回日期:2004-03-10 出版日期:2004-12-10
  • 通讯作者: 曹广民,男,1963年生,副研究员,主要从事高寒草地生态系统物质循环的研究.
  • 基金资助:
    中国科学院知识创新工程重大资助项目(KZCX1-SW-01和(KSCX2-1-07)

Effects of nitrogen supply and demand status of soil and herbage system on vegetation succession and grassland degradation in alpine meadow

CAO Guangmin, WU Qin, LI Dong, HU Qiwu, LI Yuemei, WANG Xi   

  1. Northwest Plateau Institute of Biology, Chinese Academy of Sciences, Xi'ning 810001, China
  • Received:2003-12-10 Revised:2004-03-10 Online:2004-12-10

摘要: 在中国科学院海北高寒草甸生态系统定位站,选取处于不同退化阶段的具有典型代表意义的草甸草场为研究对象,通过对其土壤氮素矿化补给能力、牧草对氮素的需求量的研究,探讨土壤牧草氮素供需状况变化对高寒草甸植被演替与草地退化的影响。结果表明,在牧草生长季5~8月,高寒草甸土壤的氮素矿化补给量为15.86g·m-2,而随着高寒草甸退化程度的加重,植物群落中优势种群由禾草演替为禾草+苔草+嵩草、嵩草至杂类草,其牧草生长需要的总氮量分别为22.86、24.87、37.3、14.96g·m-2,只有在杂类草草甸阶段,其牧草生长对氮素的需求才与其土壤氮素供求相适配,可见养分是高寒草甸植被演替与草场退化的重要驱动因子之一。

Abstract: Four typical pastures which represented different degradation stage of alpine meadow were selected at Haibei station of alpine meadow ecosystem.Thus,the studies on soil nitrogen supply ability due to its mineralization and herbages' demand for nitrogen were conducted.Consequently,effects of nitrogen supply and demand status of soil and herbage system on vegetation succession and grassland degradation in alpine meadow was discussed.The results showed that during the herbages growing period from May to August,through nitrogen mineralization,soil supplied 15.86 g穖-2.However,with the aggravation of grassland degradation,the dominate population in the communities was succeessed fromGramineae to Gramineae and Cyperaceae,and then to Kobresia,and forb.During the process of succession,the herbages' total demands for nitrogen were 22.86,24.87,37.3 and 14.96g穖-2,respectively.Only at the stage of soil nitrogen supply can meet the demands of herbage's growth.Therefore,nutrient is one of the most important driving factors that lead to vegetation succession and pasture degradation in alpine meadow region.

Key words: Eringonidium graminicola Sundevall, Adonia variegata Goeze, Nabis sinoferus Hsiao, Predation function, Helicoverpa armigera Hubner

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