Invasive alien clonal plants are competitively superior over co-occurring native clonal plants
Invasive alien clonal plants are competitively superior over co-occurring native clonal plants
复制标题
入侵的外来克隆植物比共存的本地克隆植物具有竞争优势
DOI：
10.1016/j.ppees.2019.125484
复制
发表时间：
2019-10-01
影响因子：
3.6
通讯作者：
van Kleunen, Mark
中科院分区：
文献类型：
--
作者：
Wang, Yong-Jian;Chen, Duo;van Kleunen, Mark
外来植物入侵是全球变化的重要组成部分，并可能严重威胁当地植物区系和全球生物多样性。入侵植物的一个引人注目的模式是，世界上许多最糟糕的入侵植物都是无性系物种。然而，目前尚不清楚入侵克隆植物是否普遍优于本地克隆植物，以及这种模式是否会受到环境条件的影响。为了验证氮的有效性和对天敌的抑制是否会改变外来入侵植物和本地克隆植物之间的竞争结果，我们选择了中国5对外来入侵植物和共生的本地克隆植物。我们在单种栽培（即种内竞争）和两种混合栽培（即种间竞争）中种植它们，有或没有添加N，有或没有抑制敌人（使用杀虫剂和杀菌剂）。总体而言，入侵的外来无性系植物生物量显著高于本土无性系植物，并且利用了更多的氮素。入侵克隆植物在种间竞争中比种内竞争生长得更好，而本土克隆植物则相反。然而，这种竞争起源相互作用在添加氮后比未添加氮时弱。在没有天敌抑制的情况下，本地无性系植物在种间竞争中比外来入侵植物遭受更大的叶片伤害，但只有在没有N添加的情况下。然而，敌人的抑制对外来入侵植物和本地无性系植物的生长有相似的益处。研究结果表明，在强限氮条件下，中国入侵克隆植物的竞争优势已明显高于本土植物，且在添加氮后，这种竞争优势进一步增强。这意味着许多栖息地的持续富营养化可能进一步刺激克隆植物的入侵。
Alien plant invasions are a major component of global change, and can severely threaten local floras and global biodiversity. A striking pattern of invasive floras is that many of the world's worst invasive plants are clonal species. However, it is still unclear whether invasive clonal plant species are in general competitively superior over native clonal plant species and whether this pattern can be affected by environmental conditions. To test whether nitrogen (N) availability and suppression of enemies can alter the competitive outcome between invasive alien and resident native clonal plants, we selected five pairs of invasive alien and co-occurring native clonal plant species in China. We grew them both in monocultures (i.e. with intraspecific competition) and in two-species mixtures (i.e. with interspecific competition) with or without N addition, and with or without suppression of enemies (using insecticide and fungicide application). Overall, invasive alien clonal plants produced significantly more biomass than native clonal plants, and took more advantage of N addition. Invasive clonal plants tended to grow better with interspecific than with intraspecific competition, whereas the reverse was true for native clonal plants. This species-origin-by-competition interaction, however, was weaker with than without N addition. Without enemy suppression, native clonal plants experienced more leaf damage than invasive aliens when they grew in interspecific competition with each other, but only in the absence of N addition. Nevertheless, enemy suppression benefited growth of invasive alien and native clonal plants to similar degrees. Our results show that already under strongly N-limited conditions, invasive clonal plants in China are competitively superior over natives, and that this competitive superiority of invasive clonal plants becomes even stronger after N addition. This implies that the ongoing eutrophication of many habitats is likely to further stimulate invasions by clonal plants.