When colonizing new areas, alien plant species success can depend strongly on local environmental conditions. Microclimatic barriers might be the reason why some alien plant species thrive in urban areas, while others prefer rural environments. We tested the hypothesis that the climate in the native range is a good predictor of the urbanity of alien species in the invaded range. The relationship between climate in the native range and the percentage of artificially sealed surfaces (urbanity) at the occurrences of 24 emerging alien plant species, in European areas with a temperate climate (termed oceanic Europe) was evaluated. We found that alien species growing in more urban environments originated from warmer or drier native ranges than found in oceanic Europe. These results have strong conservation implications as climate-warming will likely lift climatic barriers that currently constrain numerous alien plant species to cities, boosting the role of cities as points of entry for invasive plants.

在新地区定居时，外来植物物种的成功在很大程度上取决于当地的环境条件。小气候的障碍可能是某些外来植物物种在城市地区蓬勃发展而其他物种偏爱乡村环境的原因。我们检验了以下假设：原生范围的气候是入侵范围内外来物种都市性的良好预测。在温带气候的欧洲地区（称为欧洲海洋），评估了原生气候和人工密封表面百分比（城市性）之间的关系，其中出现了24种新兴外来植物。我们发现，与欧洲大洋洲相比，在更多城市环境中生长的外来物种起源于更温暖或更干燥的原生范围。