Despite considerable efforts devoted to investigate the community assembly processes driving plant invasions, few general conclusions have been drawn so far. Three main processes, generally acting as successive filters, are thought to be of prime importance. The invader has to disperse (1st filter) into a suitable environment (2nd filter) and succeed in establishing in recipient communities through competitive interactions (3rd filter) using two strategies: competition avoidance by the use of different resources (resource opportunity), or competitive exclusion of native species. Surprisingly, despite the general consensus on the importance of investigating these three processes and their interplay, they are usually studied independently. Here we aim to analyse these three filters together, by including them all: abiotic environment, dispersal and biotic interactions, into models of invasive species distributions. We first propose a suite of indices (based on species functional dissimilarities) supposed to reflect the two competitive strategies (resource opportunity and competition exclusion). Then, we use a set of generalised linear models to explain the distribution of seven herbaceous invaders in natural communities (using a large vegetation database for the French Alps containing 5,000 community-plots). Finally, we measure the relative importance of competitive interaction indices, identify the type of coexistence mechanism involved and how this varies along environmental gradients. Adding competition indices significantly improved model's performance, but neither resource opportunity nor competitive exclusion were common strategies among the seven species. Overall, we show that combining environmental, dispersal and biotic information to model invasions has excellent potential for improving our understanding of invader success.

中文翻译：

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对比环境、扩散和生物相互作用的影响，解释入侵植物在高山群落中的分布。


尽管付出了大量努力来调查驱动植物入侵的群落组装过程，但迄今为止还没有得出一般性结论。三个主要过程通常充当连续的过滤器，被认为是最重要的。入侵者必须分散（第一个过滤器）到一个合适的环境（第二个过滤器），并通过竞争性互动（第三个过滤器）成功地在接收者社区中建立，使用两种策略：通过使用不同的资源（资源机会）来避免竞争，或者竞争排除本地物种。令人惊讶的是，尽管人们普遍认为研究这三个过程及其相互作用的重要性，但它们通常是独立研究的。在这里，我们的目标是一起分析这三个过滤器，将它们全部包括在内：非生物环境、扩散和生物相互作用，进入入侵物种分布模型。我们首先提出了一套指数（基于物种功能差异），旨在反映两种竞争策略（资源机会和竞争排除）。然后，我们使用一组广义线性模型来解释自然群落中七种草本入侵者的分布（使用包含 5,000 个群落地块的法国阿尔卑斯山大型植被数据库）。最后，我们衡量竞争性相互作用指数的相对重要性，确定所涉及的共存机制的类型以及其如何随环境梯度变化。添加竞争指数显着提高了模型的性能，但资源机会和竞争排除都不是这七个物种的共同策略。 总的来说，我们表明，结合环境、扩散和生物信息来模拟入侵对于提高我们对入侵者成功的理解具有巨大的潜力。