生物多样性 ›› 2012, Vol. 20 ›› Issue (1): 3-11.DOI: 10.3724/SP.J.1003.2012.09077

• 研究报告 • 上一篇    下一篇

不同氮素水平下入侵种豚草与本地种黄花蒿、蒙古蒿的竞争关系

王晋萍1,2, 董丽佳1,2, 桑卫国1,*()   

  1. 1 中国科学院植物研究所植被与环境变化国家重点实验室, 北京 100093
    2 中国科学院研究生院, 北京 100049
  • 收稿日期:2011-05-09 接受日期:2011-10-21 出版日期:2012-01-20 发布日期:2012-02-14
  • 通讯作者: 桑卫国
  • 作者简介:*E-mail: swg@ibcas.ac.cn
  • 基金资助:
    中国科学院知识创新工程项目(KSCX-YW-Z-1022);国家重点基础发展规划项目(973 Program 2009CB119200)

Effects of different nitrogen regimes on competition betweenAmbrosia artemisiifolia, an invasive species, and two native species, Artemisia annua and Artemisia mongolica

Jinping Wang1,2, Lijia Dong1,2, Weiguo Sang1,*()   

  1. 1 State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing 100093
    2 Graduate University of the Chinese Academy of Sciences, Beijing 100049
  • Received:2011-05-09 Accepted:2011-10-21 Online:2012-01-20 Published:2012-02-14
  • Contact: Weiguo Sang

摘要:

已有研究表明, 土壤氮素增加可提高外来植物的入侵性, 降低本地植物的竞争力。为揭示全球氮沉降对入侵种与本地种之间竞争关系的影响, 我们于2010年5-8月在中国科学院北京森林生态系统定位研究站温室内, 采用取代系列实验方法(standard replacement experiment), 研究了3个氮素水平下入侵种豚草(Ambrosia artemisiifolia)与本地种黄花蒿(Artemisia annua)、蒙古蒿(Artemisia mongolica)的生长特征及种内、种间竞争关系的变化。实验采用双因素-随机区组设计, 设置了低氮、中氮和高氮3个氮素水平, 每一氮素水平分别设置豚草和黄花蒿、豚草和蒙古蒿组成的竞争实验, 生长90 d后测量株高和生物量。结果表明: 单栽情况下, 随氮素水平的增加3个物种的株高均增加, 而生物量均无显著变化; 混栽情况下, 3个物种株高和生物量随氮素水平的增加变化各异, 豚草呈极显著增加趋势, 而黄花蒿无明显变化, 蒙古蒿则先增加后减少。豚草的快速生长使其在竞争中处于优势地位, 对本地种黄花蒿和蒙古蒿产生明显的竞争效应。但不同氮素水平下, 豚草对本地种的竞争力不同: 低氮素水平下, 豚草<两个本地种; 中氮素水平下, 黄花蒿<豚草<蒙古蒿; 高氮素水平下, 豚草>两个本地种。氮素添加显著提高了豚草的种间竞争力, 改变了豚草与本地种之间的竞争关系, 使竞争有利于入侵种。据此推测, 在全球变化的背景下, 氮沉降的增加将会促进外来种豚草的入侵, 增加本地群落的可入侵性。

关键词: 豚草, 黄花蒿, 蒙古蒿, 种间竞争, 生物入侵, 氮素水平

Abstract

Evidence suggests that increased nitrogen levels heighten exotic species’ invasiveness and reduce the competitive potential of native species. To reveal the impact of nitrogen deposition on competition between invasive and native species, we compared the growth ofAmbrosia artemisiifolia, an invasive species, and two native species, Artemisia annua and Artemisia mongolica under three nitrogen regimes through replacement series experiments in a greenhouse at the Chinese Academy of Science’s Beijing Forest Station. Our results showed that heights of the three species significantly increased, but total biomass did not respond to the enhancement of nitrogen levels in monoculture plantings. When planted in mixtures, however, the heights and total biomass of some species responded to increasing nitrogen levels;Ambrosia artemisiifolia significantly increased, Artemisia annua exhibited no difference, and Artemisia mongolica first increased and then decreased with the increase of nitrogen levels. The growth response of Ambrosia artemisiifolia led to a competitive advantage over two native species. The dynamics of this competition differed at different nitrogen levels: Ambrosia artemisiifolia was a weaker competitor than native species at low level of nitrogen availability, but was a stronger competitor under high nitrogen level. Moreover, the competitive effects of Ambrosia artemisiifolia on Artemisia annua were stronger than on Artemisia mongolica. Nitrogen addition significantly enhanced the competitive ability of Ambrosia artemisiifolia and altered the competition relationship between these species, tipping the scales in favor of the Ambrosia artemisiifolia. Our study indicated that nitrogen deposition associated with global change may facilitate the invasion of Ambrosia artemisiifolia, and may enhance the vulnerability of native communities to invasion.

Key words: Ambrosia artemisiifolia, Artemisia annua, Artemisia mongolica, interspecific competition, invasion, nitrogen regimes