我国植物入侵的态势严峻，理解入侵机制进而探索如何降低群落可入侵性，是生态学家的主要任务之一。项目将从土著种对外来种的有利作用及其在植物入侵演替中的影响，分析入侵成功的原因。为此，项目以入侵种加拿大一枝黄花为对象，采用空间格局调查与受控实验的方法，揭示土著植物对该入侵植物的各类有利作用，包括非资源环境胁迫的缓解，资源有效性的提高、啃食的保护、传粉者的吸引以及繁殖体的富集；同时，总结每类作用主要提供者的生物学特征；并且，指明每类作用在加拿大一枝黄花个体生长和适合度、种群繁殖与增长中的主效应和交互效应。项目以有利作用为核心揭示外来植物定植、建群与扩张等入侵过程中的障碍及其克服，从而显著区别于以往强调种间负相互作用的入侵生态学研究；并因此可从弱化土著种对入侵种有利作用的角度，探索提高入侵预警准确性、防控效率的方法，还能够将正相互作用纳入以负相互作用为基础的群落模型中，以促进对植物分布与表现的理解。

China is heavily invaded by an array of exotic plants, so to realize the invasion reasons and consequently control invasive plants effectively is now an urgent task. This study used invasive Solidago Canadensis as the model plant to experimentally examine the positive effects of native plants on these two invaders. We will test the influences of the species and density of native plants on individual fitness, population distributions and growth rates of the invasive plants, the resources availability and non-resource levels, as well as these influences change over time. Our aim to determine the characters of facilitative natives, the effect of facilitation and the influences of environments conditions on the size of this effects, as well as mechanisms of facilitation in invasive successions, and thus to indicate the obstacles and overcoming in establishment and colonization of alien plant. Based on these, the results can contribute to the distribution, abundance and coexistence of plants, and the inclusion of facilitation into the theory, models and paradigms of population and community ecology which can alter many basic predictions.