外来入侵植物对生物多样性影响及本地植

物的响应

摘要: 越来越多的证据表明, 入侵植物能通过杂交和基因渐渗等对本地种造成遗传侵蚀, 甚至产生新的“基因型”来影响本地种的遗传多样性; 通过生境片断化, 改变本地种种群内和种群间的基因交流, 造成近亲繁殖和遗传漂变, 间接影响本地种的遗传多样性。另一方面, 本地种能对入侵植物做出适应性进化响应, 以减小或消除入侵植物的危害。本地种在与入侵植物的互作过程中产生了一系列的适应进化、物种形成以及灭绝事件, 且这些事件不仅局限于地上生态系统, 土壤生物多样性同样受到影响, 甚至也能发生进化响应。为更全面地了解外来植物入侵的生态后果和本地生物的适应潜力, 本文综述了外来植物入侵对本地(地上和地下)生物(遗传)多样性的影响以及本地生物的进化响应, 讨论了外来植物入侵导致的遗传和进化变化与其入侵性的关系, 并提出了一些值得研究的课题, 如土著种与外来种的协同进化、植物―土壤反馈调节途径和全球变化其他组分与生物入侵的关系等。

关键词: 生物入侵, 生物多样性, 生态系统

Impacts of alien plant invasions on biodiversity and responses of

native species

Abstract: The impacts of invasive alien species on the genetic diversity and evolutionary

responses of native species are poorly understood. Accumulating evidence shows that invasive plant species can lead to genetic erosion of natives directly through hybridization and gene

infiltration, or even affect genetic diversity of natives through creation of new “genotypes”. Exotic species can also alter genetic diversity of natives indirectly through habitat fragmentation and modification, processes which influence gene flow within and among populations and result in inbreeding and genetic drift. On the other hand, some studies show that native species can respond evolutionarily to invasive plants, thereby reducing or eliminating invasive impacts. While interacting with invasive species, native species in both above- and below-ground ecosystems exhibit a series of evolutionary events such as adaptation, speciation or extinction. To more

comprehensively evaluate the ecological impacts of biological invasions and the adaptive potential of natives, here we review the impacts of invasive plants on biological (genetic) diversity of native species, and the evolutionary responses of natives. We also discuss relationships between the genetic and evolutionary responses of natives and the success of invasive plants, and propose topics for further research.

Key words: biological invasions, biodiversity, ecosystem

21世纪全球变化趋势加剧的新形势下, 全球贸易、旅游和交通的迅速发展, 为外来种的远距离迁移与入侵、传播与扩散创造了条件, 外来生物入侵的危险也日益增加。外来入侵物种通过改变入侵地的自然生态系统、降低物种多样性而对当地社会、经济甚至人类的健康产生严重危害(D’Antonio & Kark, 2002; Dennis, 2004)。然而,人们对外来生物入侵的生态危害, 尤其是入侵对土著物种遗传多样