Biological invasions are a defining feature of the Anthropocene, but the factors that determine the spatially uneven distribution of alien plant species are still poorly understood. Here, we present the first global analysis of the effects of biogeographic factors, the physical environment and socio-economy on the richness of naturalized and invasive alien plants. We used generalized linear mixed-effects models and variation partitioning to disentangle the relative importance of individual factors, and, more broadly, of biogeography, physical environment and socio-economy. As measures of the magnitude of permanent anthropogenic additions to the regional species pool and of species with negative environmental impacts, we calculated the relative richness of naturalized (= RRN) and invasive (= RRI) alien plant species numbers adjusted for the number of native species in 838 terrestrial regions. Socio-economic factors (per-capita gross domestic product (GDP), population density, proportion of agricultural land) were more important in explaining RRI (~50 % of the explained variation) than RRN (~40 %). Warm-temperate and (sub)tropical regions have higher RRN than tropical or cooler regions. We found that socio-economic pressures are more relevant for invasive than for naturalized species richness. The expectation that the southern hemisphere is more invaded than the northern hemisphere was confirmed only for RRN on islands, but not for mainland regions nor for RRI. On average, islands have ~6-fold RRN, and >3-fold RRI compared to mainland regions. Eighty-two islands (=26 % of all islands) harbour more naturalized alien than native plants. Our findings challenge the widely held expectation that socio-economic pressures are more relevant for plant naturalization than for invasive plants. To meet international biodiversity targets and halt the detrimental consequences of plant invasions, it is essential to disrupt the connection between socio-economic development and plant invasions by improving pathway management, early detection and rapid response.

中文翻译：

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地球上归化和入侵植物物种相对丰富的驱动因素。

生物入侵是人类世的一个决定性特征，但决定外来植物物种空间不均匀分布的因素仍然知之甚少。在这里，我们首次对生物地理因素、物理环境和社会经济对归化和外来入侵植物丰富度的影响进行了全球分析。我们使用广义线性混合效应模型和变异划分来解开个体因素的相对重要性，更广泛地说，是生物地理学、物理环境和社会经济的相对重要性。作为对区域物种库和具有负面环境影响的物种的永久人为增加量的衡量标准，我们计算了根据 838 个陆地区域的本地物种数量调​​整后的归化 (= RRN) 和入侵 (= RRI) 外来植物物种数量的相对丰富度。社会经济因素（人均国内生产总值（GDP）、人口密度、农业用地比例）在解释 RRI（约 50% 的解释变化）方面比 RRN（约 40%）更重要。暖温带和（亚）热带地区的 RRN 高于热带或较冷地区。我们发现，社会经济压力与入侵物种的相关性比与归化物种丰富度的相关性更高。只有岛屿上的 RRN 证实了南半球比北半球受到更多入侵的预期，而大陆地区和 RRI 均未得到证实。与大陆地区相比，岛屿的平均 RRN 约为 6 倍，RRI > 3 倍。82 个岛屿（占所有岛屿的 26%）比本土植物拥有更多的归化外来植物。我们的研究结果挑战了人们普遍认为的社会经济压力与植物归化比入侵植物更相关的预期。为了实现国际生物多样性目标并制止植物入侵的有害后果，必须通过改善路径管理、早期检测和快速反应来破坏社会经济发展与植物入侵之间的联系。