Plant Invasives
Exotic, Non-native, Alien, Noxious, or Non-Indigenous
Plants that become invasive have unique characteristics that give them the ability to thrive and spread aggressively outside their natural ranges.
Invasive plants can:
- Produce large numbers of seeds each season
- Spread by rhizomes and root fragments
- Tolerate many soil types and weather conditions
- Spread easily and efficiently, usually by wind, water, or animals
- Grow rapidly, allowing them to displace slower growing plants
- Spread rampantly when they are free of the natural checks and balances found in their native range
Non-native plants often spread because the insects, diseases, and foraging animals that naturally keep them in check in their native ranges are absent in their new locations. Invasive plants impact native plant and animal communities by displacing native vegetation and disrupting habitats as they become established and spread over time. Disturbed or abandoned lands provide easy places for invasive plants to become established.
Salem Sound Coastwatch, partnering with local land trusts, park and recreation departments, and conservation commissions, works to tackle the invasive plant problem throughout the Salem Sound watershed. Often groups will call us looking for a service day, and we organize a plant removal project.
Action: Perennial Pepperweed Control
Perennial Pepperweed (Lepidium latifolium) is a flowering plant that is native to Europe and western Asia. It arrived via the tanneries in Peabody, MA (1924) and Norton, CT (1933) on cow hides delivered from the West. Not until the epic 2006 Mother’s Day flood did it begin to spread rapidly in Essex County. In 2007, we found it above the high tide line on beaches and salt marshes in Salem Sound and the Great Marsh. Its spread at such an alarming rate that the MA-NH-ME Pepperweed Control Working Group was formed. As a member, Salem Sound Coastwatch enlists volunteers between June and August to pull this highly invasive plant.
Pepperweed spreads quickly, colonizing upper wetland edges, riparian areas, disturbed land, and roadways because:
- Each plant releases hundreds of tiny seeds
- Plants spread by rhizomes and seeds
- Seeds and roots remain viable in salt water and thus may be dispersed by tidal currents, as well as by animals, humans, or vehicles
- Root fragments are as small as 2.5cm and can re-sprout and grow into a multi-stemmed plant.