Nearly a third of the park’s plant species are non-native, and some of these species are extremely invasive and threaten the integrity of our natural communities. You will find invasive plants spreading into the more pristine and less disturbed areas of Acadia’s forests, wetlands, and islands.
Purple loosestrife (Lythrum salicaria) is one species that has been actively managed in park wetlands since 1988 and after 30 years of intensive management, purple loosestrife populations at Acadia National Park are at very low levels.
Acadia’s Invasive Plant Management Team (IPMT) monitors the park’s forests and wetlands for the presence of 25 invasive plant species every year and removes what they can. Other than purple loosestrife, some of the most problematic species at Acadia include shrubs like glossy buckthorn (Rhamnus frangula), Japanese barberry, (Berberis thunbergii), and Morrow’s honeysuckle (Lonicera morrowii); vines like Asiatic bittersweet (Celastrus orbiculatus); and herbaceous plants like Japanese knotweed (Fallopia japonica). See below for a full list of Acadia's target invasvie plant species.