From cultivation to invasion - naturalization of garden ornamentals

Study of German parks and gardens shows climatic suitability as main factor behind naturalization and suggests 45 species to become naturalized in the future

GBIF-mediated data resources used : 1,124,139 species occurrences
Burning bush (Euonymus alatus)–one of the 45 species identified in the study. Photo by Sara Rall via iNaturalist–licensed under CC BY-NC 4.0.

Not only having important aesthetic value, private gardens and public parks also provide important ecosystems services in urban areas. Ornamental plants, however, are also the most important pathway for alien plant introductions worldwide.

A study from Germany investigated what factors might lead to a successful local naturalization of garden plants by surveying planted flora in 111 public and private gardens in the small city of Radolfzell in southern Germany. The researchers recorded species, abundance, lifeform and whether the plant was native or not. For alien plants, the authors also assessed the current naturalization status worldwide.

In total, the authors identified 1268 species of which 75 per cent were alien. Using GBIF-mediated occurrences, the authors modelled the distribution of the alien species, not surprisingly finding that local naturalization success was linked to climatic suitability.

By projecting models into future climatic scenarios, they identified 45 species not currently naturalized in Germany but widely naturalized in other parts of the world–and thus likely to become naturalized in the future through increased climatic suitability.

Link to original article

Mayer K, Haeuser E, Dawson W, Essl F, Kreft H, Pergl J, Pyšek P, Weigelt P, Winter M, Lenzner B and van Kleunen M (2017) Naturalization of ornamental plant species in public green spaces and private gardens. Biological Invasions. Springer Nature 19(12): 3613–3627. Available at: