More than 13,000 naturalized alien species of vascular plants have been recorded worldwide, and horticulture is the major pathway of plant invasions. Botanic gardens play a vital role in conserving plant diversity and preventing extinction, but they also cultivate many species with invasion potential.
Examining the role of horticulture in plant invasions, this study rigorously examines the direct and indirect relationships between species traits, horticultural use, native range size and naturalization success. Using a dataset—downloaded from GBIF and other sources—of nearly 4,000 species with defined adaptive strategies, the authors reveal that species grown in botanic or domestic gardens are significantly more likely to become naturalized than those not cultivated.
The study finds that naturalization is linked to particular adaptation strategies among plant species, but that species using these strategies are also more likely to be cultivated. In other words—horticulture is not just a major pathway for invasions, it also tends to select alien species with the highest invasive potential.