Outbreak populations of invasive species in the United
States cover a land and water area approximately the size of California, at
Over 100,000,000 acres !
The annual economic cost (including impact and control
Measures) to the United States is well over $120 billion/year.
Invasive plant species owe their success to one or
More of the following characteristics:
a) they tend to be generalists that tolerate a
Variety of different habitats.
b) they grow rapidly, and often produce abundant
c) they lack natural enemies (competitors, predators,
Parasites) in their new ecosystem.
ONE FOUND IN FOWL MEADOW ON TRIP mile a minute vine
(Melaleuca quinquennervia) – An Australian tree that was first
Introduced into south Florida in the early 20th
Century. It displaces sawgrass marshes in the Everglades and adversely affects
Hydrology by drawing down water.
Cheatgrass (Bromus tectorum) – Accidentally introduced from Europe
In the late 19th
Century, it quickly spread across overgrazed rangelands and has replaced native
Grasses across much of the western U.S.
(Puerariamontana) - is a vine native to Asia that was deliberately introduced to prevent erosion in
Deforested regions of the Deep South. It
Blankets and smothers native trees and shrubs, as well as buildings and farm machinery!
Moth (Lymantriadispar) –
From Europe and Asia, was first introduced to Medford, Massachusetts in 1869 as
Part of an effort to begin
a commercial silk industry. The caterpillars annually defoliate millions
Of acres of trees – outbreak years are especially damaging.
Zebra mussel (Dreissenapolymorpha) –
Native to Russia, it first appeared in 1988 in Lake Erie, believed to be
Introduced by the ballast of ships traversing the Saint Lawrence Seaway. The
Mussels out competenative shellfish foul boat hulls, and clog industrial water
Artemesia (Artemesia vulgaris) – Large
Perennial weed native to Eurasia; it has squarish stems, deeply dissected leaves and
Numerous small flowers on terminal spikes. It tends to form thick stands that
Exclude all other species.
Tall reed with dense seed heads; a native subspecies (P.
Occurs in parts of New England
The Eurasian subspecies (P. A. Australis) is
Problematic because it forms huge monocultures in
Marshes and excludes less common native species.
Rose (Rosa multiflora) - a densely spreading perennial shrub that
Is native to Japan.
It is a generalist that forms dense, impenetrable thickets,
And rapidly outcompetes surrounding vegetation. Fringed stipules and several fruits on one
Inflorescence are distinctive.