How can invasive plants such as common buckthorn displace native plants?

In the context of ecological disturbance, invasive plants like the common buckthorn (Rhamnus cathartica) displace native species primarily through habitat degradation.

Buckthorn disrupts native ecosystems by creating a wall of dense vegetation that effectively blocks sunlight, preventing native plants from accessing the light necessary for survival. Because it is capable of growing in a wide range of conditions—including both full sun and dense shade—it can successfully invade and take over the understories of native forests.12

By outcompeting native species for essential resources such as light, water, and living space, buckthorn reduces the ability of native plants to thrive. This process of interspecific competition can lead to a decline in local biodiversity, as the invasive species forms dense thickets that offer little support for the native flora and fauna that originally occupied the habitat.134