Understanding the mechanisms of biological invasion is fundamental for biodiversity conservation in the Anthropocene. This study focused on a large-scale colonization pattern of exotic seed plants, which include 1094 species characterized by different geographical origins, into the insular flora of Japan. We investigated a nation-wide pattern of species richness and phylogenetic structure (clustering/over-dispersion) of exotic and its recipient native species (4664 species). We tested the invasion hypotheses associated with environmental filtering, biological resistance of recipient assemblages, human disturbance and biogeographical origins of exotics. The exotics originated from the same (Palearctic and Indo-Malay) and adjacent (Nearctic and Oceanic) biogeographical regions were widely distributed across the country under temperate climate condition, whereas tropical exotic plants from remote regions (Afrotropic, Australasian, and Neotropical) colonized mainly the south-western parts of Japan. Exotic species richness and phylogenetic structure, especially those from the same/adjacent regions, were well explained by climatic, edaphic, and topographic factors, supporting the environmental filtering hypothesis. For all the biogeographical origins, exotic richness was positively associated with native richness, opposing the biological resistance hypothesis. Human disturbance was positively associated with exotic richness, while its relationships with the exotics’ phylogenetic structure varied according to their biogeographical origins. These findings indicate that site’s invasibility was determined by the combination of exotic’s biogeographical origins and abiotic/biotic conditions of its recipient native flora. Our results suggest that global warming may accelerate the northward expansion of tropical exotic plants while future land-use changes can promote biological invasion regardless of exotics’ origins.

了解生物入侵的机制是人类世间生物多样性保护的基础。这项研究集中于外来种子植物的大规模定殖模式，其中包括1094种具有不同地理起源特征的物种进入日本的岛上植物区系。我们调查了全国范围内外来物种及其受体本地物种（4664种）的物种丰富度和系统发育结构（聚类/过度分散）的模式。我们测试了与环境过滤，接收者组合的生物抵抗力，人类干扰以及外来生物的生物地理起源有关的入侵假说。在温带气候条件下，起源于同一地区（古印度和马来语）以及相邻地区（近海和大洋洲）的外来植物在全国范围内分布广泛，而来自偏远地区（非洲，澳大利亚和新热带）的热带外来植物主要是定植的。日本的西南部。气候，水文和地形因素很好地解释了外来物种的丰富性和系统发育结构，特别是来自相同/相邻地区的外来物种，其丰富性和系统发育结构支持了环境过滤假说。对于所有的生物地理起源，异国情调的丰富度与本地的丰富度呈正相关，这与生物学抵抗力假设相反。人为干扰与异国情调正相关，而其与外来物种系统发育结构的关系则根据其生物地理起源而变化。这些发现表明，该地点的可入侵性是由外来生物的地理地理来源及其受体天然菌群的非生物/生物条件共同决定的。我们的结果表明，全球变暖可能会加速热带外来植物的向北扩张，而未来的土地利用变化无论外来来源如何，都可能促进生物入侵。