College of Life Sciences, Shaanxi Normal University, 710119, Xi'an, P.R. China.
Sci Rep. 2018 Feb 16;8(1):3136. doi: 10.1038/s41598-018-21546-z.
Elevated nitrogen associated with global change is believed to promote the invasion of many vigorous exotic plants. However, it is unclear how a weak exotic plant will respond to elevated nitrogen in the future. In this study, the competitive outcome of a weak invasive plant (Galinsoga quadriradiata) and two non-invasive plants was detected. The plants were subjected to 3 types of culture (mixed, monoculture or one-plant), 2 levels of nitrogen (ambient or elevated at a rate of 2 g m yr) and 2 levels of light (65% shade or full sunlight). The results showed that elevated nitrogen significantly promoted the growth of both the weak invader and the non-invasive plants in one-plant pots; however, growth promotion was not observed for the non-invasive species in the mixed culture pots. The presence of G. quadriradiata significantly inhibited the growth of the non-invasive plants, and a decreased negative species interaction was detected as a result of elevated nitrogen. Our results suggest that competitive interactions between G. quadriradiata and the non-invasive plants were altered by elevated nitrogen. It provides exceptional evidence that an initially weak invasive plant can become an aggressive invader through elevated nitrogen deposition.
与全球变化相关的氮素升高被认为会促进许多活力旺盛的外来植物的入侵。然而，目前尚不清楚弱势外来植物将来会如何应对氮素升高。本研究检测了一种弱势入侵植物（三叶鬼针草）和两种非入侵植物的竞争结果。将植物置于 3 种培养方式（混合、单种或单株）、2 种氮水平（环境或以 2 g m yr 的速率升高）和 2 种光照水平（65%遮荫或全日照）下。结果表明，氮素升高显著促进了单株培养盆中弱势入侵植物和非入侵植物的生长；然而，混合培养盆中的非入侵物种并未观察到生长促进。三叶鬼针草的存在显著抑制了非入侵植物的生长，并且由于氮素升高，检测到负物种相互作用的减少。我们的结果表明，氮素升高改变了三叶鬼针草和非入侵植物之间的竞争关系。这提供了一个特殊的证据，表明最初较弱的入侵植物可以通过氮素沉积成为一个具有侵略性的入侵物种。
