Saturday, January 7, 2017

Invasive Plant Species

Invasive plants are non-native species whose introductions can have negative economic or ecological impacts. Unfortunately, some of these species are becoming common on the Maine landscape. Invasive species often outcompete native plants creating monocultures that can require time and money to mitigate. These same species are often less valuable as wildlife habitat.

Multiflora rose hips

My Trees and the Maine Forest students have been studying invasive plant species this week. We spent the class block searching the T.A. forest and identifying as many invasive species as possible. It was eye opening to see just how many of these once ornamental plants have escaped and begun to grow wild along the Eastern Trail. In all, seven species were identified within sight of the trail in less than a quarter mile.

Japanese knotweed along the Eastern Trail

Areas of recent disturbance are the most common places to find invasive plants. Many of them are early successional species perfectly adapted to grow quickly and outcompete the native plants around them. In their natural home ranges, these same species are much less pervasive. Here in North America, they lack the predators and disease that our native species have to deal with. Several of our common invasive species produce berries that can be valuable winter food for songbirds and small rodents (see the common buckthorn below). Unfortunately, seeds are then spread great distances in bird scat creating new infestations.

Common buckthorn berries

Invasive Plant Species Observed 1/6/17:
  • Muliflora Rose (Rosa multiflora)
  • Shrubby Honeysuckle (Lonicera sp.)
  • Japanese Knotweed (Fallopia japonica)
  • Norway Maple (Acer platanoides)
  • Asiatic Bittersweet (Celastrus obiculatus)
  • Common Buckthorn (Rhamnus cathartica)
  • Japanese Barberry (Berberus thunbergii)