Data from: The effects of climate warming and disturbance on the colonization potential of ornamental alien plant species

1. A large number of alien plant species have been introduced as ornamental garden plants to Europe, but relatively few have become invasive. Low climatic suitability may be limiting the current invasion potential of many alien ornamental species. However, with ongoing disturbance and climate change, this barrier may be reduced for some species.
2. Here we tested how colonization ability (a prerequisite for invasion) of frequently planted alien ornamentals depends on disturbance and heating, and on their species characteristics. We sowed seeds of 37 non-naturalized alien herbaceous garden-plant species into native grassland plots with and without disturbance, and with and without infrared heating lamps. To assess whether their responses differ from those within the regional wild flora, we also sowed 14 native species and 12 naturalized alien species. During two years, we assessed the likelihoods of germination, first-year survival, second-year survival and flowering of these 63 study species.
3. The heating treatment, which also reduced soil moisture, decreased all measures of colonization success, but more so for sown native species than for the non-naturalized and naturalized alien ones. The disturbance treatment increased colonization success, and because heating decreased productivity of the undisturbed grassland plots, it also increased invasibility of these plots. Average colonization success of non-naturalized aliens was reduced by heating, but some species were not affected or performed even better with heating, particularly those with an annual life span and a high seed mass. Winter hardiness improved colonization ability of non-naturalized aliens, but this advantage was reduced in the heated plots.
4. Synthesis. Disturbance increased and heating decreased the absolute colonization success of most of the 63 species sown. However, heating had stronger adverse effects on the resident grassland and sown native species than either type of sown alien species. Together, these results suggest that some alien plants may have greater colonization success relative to native plants under a warmer climate.

1. 大量外来植物物种作为观赏园艺植物被引入欧洲，但仅有相对较少的物种成为入侵种。较低的气候适宜性可能限制了多数外来观赏植物当前的入侵潜力。然而，随着持续的干扰与气候变化，这一限制屏障可能会在部分物种中被削弱。
2. 本研究探究频繁栽培的外来观赏植物的定殖能力（入侵的必要前提）如何受干扰、增温及其物种性状的影响。我们将37种未归化外来草本园艺植物的种子，播撒至设置了干扰/无干扰、红外加热灯（infrared heating lamps）/无红外加热的原生草原样地中。为评估其响应与区域野生植物区系内物种的差异，我们同时播撒了14种本土物种与12种归化外来物种。在为期两年的监测周期内，我们针对这63种研究物种的萌发率、一年生存活率、二年生存活率以及开花概率进行了评估。
3. 增温处理同时降低了土壤含水量，对所有定殖成功相关指标均产生了抑制作用，且对播撒的本土物种的抑制效果强于未归化与归化外来物种。干扰处理则提升了定殖成功率；由于增温降低了未受干扰草原样地的群落生产力，因此反而提升了这些样地的可入侵性。未归化外来物种的平均定殖成功率因增温而下降，但部分物种并未受影响，甚至在增温条件下表现更佳，尤其是那些具有一年生生活型且种子质量较高的物种。越冬抗寒性提升了未归化外来物种的定殖能力，但这一优势在增温样地中被削弱。
4. 研究总结：对于本次播撒的63个物种而言，干扰提升了绝大多数物种的绝对定殖成功率，而增温则降低了其绝对定殖成功率。然而，增温对本地草原群落与播撒的本土物种的负面影响，强于两类播撒的外来物种类群。综合来看，这些结果表明，在气候变暖的背景下，部分外来植物相较于本土植物可能拥有更高的定殖成功率。