How has common buckthorn affected native plants in North America?

The common buckthorn (Rhamnus cathartica), along with the glossy buckthorn (R. frangula), was introduced to North America from Eurasia and has since become a significant invasive species.12

In the context of ecology and conservation, these plants are classified as serious pests because they aggressively colonize the understories of native forests. By establishing dense populations, common buckthorn outcompetes native vegetation for resources such as light, water, and nutrients, effectively displacing native plant communities and disrupting local ecosystem balance.2