Threats

Invasive Plants

Invasive, non-native plants threaten to forever alter our landscape. At present, roughly one third of the plants (~ 900) species growing wild in Massachusetts were intentionally or accidentally brought to North America, most of them from Europe or Asia. However, of these, only about 20 are extremely aggressive, establishing in natural habitats, where they can alter water regimes, interrupt nutrient cycling, and outcompete native plants. Most of the most successful, and hence most troublesome, non-native plants exhibit the following characteristics:

· Prolific seed producer
· Adaptable to many habitat types
· Generalized pollinator system
· Spread by birds
· Rapid growth

In the Mill River watershed, the most troublesome invasive plants are (ranked in order):

Asiatic bittersweet (Celastrus orbiculatus) Upland areas, in sun especially, but persisting in shade

Japanese knotweed (Reynoutria japonica) Disturbed areas along roads and rivercourses, floodplains

Purple loosestrife (Lythrum salicaria) Marshes, Wet Meadows, Roadside ditches

Multiflora rose (Rosa multiflora) Old fields, wetlands, floodplains

Russian olive (Eleagnus umbellata) Roadside edges, old fields

Japanese barberry (Berberis thunbergii) Old fields, rich woods

Morrow's honeysuckle (Lonicera morrowii) Old fields, rich woods, wetlands

Glossy buckthorn (Rhamnus frangula) Roadsides, floodplains, forest—extremely varied

Phragmites (Phragmites australis) Open wetlands

Burning bush (Euonymus alatus) Rich forests, floodplain edges

Moneywort (Lysimachia nummularia) Floodplain forest

Goutweed (Aegepodium ) Lawns, forest edges

Species to watch for:
Swallowwort (Cynanchum nigrum & C. rossicum) Roadsides, oldfields, forest with partial shade

Focus on Invasives: CUT, CHIP, CUT, CHOP! During Fall 2000, Vic Covaleski organized an the First Annual Invasives Pull at the West Whately Wildlife Management Area. In a single day, half a dozen volunteers cut, chopped and pulled all the Russian Olive and nearly all the Multiflora Rose bushes in a 10-acre field. Although used by wildlife, these non-native plants are aggressive and readily invade natural habitats. To ensure that the plants won't resprout, a licensed pesticide applicator was on hand to paint the cut stumps with the herbicide known as Round-Up. Overall, the day was a great success, with lots of camaraderie and clear accomplishment. "We got a lot done and felt really good about it," says Covaleski. Another invasives round-up is planned for fall 2002. For more information, contact Covaleski at 665-3488.