Many non-native species introduced into American gardens do not escape to become problems in nature, but those which have no natural enemies or controls and reproduce rapidly here can become noxious invaders.
By crowding out a diverse natural ecosystem, invasives can turn a formerly healthy environment into a barren and otherwise lifeless wastelands which support little or no wildlife. Some invasives (buckthorns) have fruit which is relished by birds, but the nutritional value is minimal, so this junk food will not help sustain them for long migrations for example. The birds spread the seeds, and unwittingly help to destroy their natural food sources. Our native trees, vines, shrubs and plants are crowded out, and fewer species are supported.
Here is a Rogues Gallery of some of the worst local invasives which have been identified on NRTP or nearby property. This list is incomplete; sadly there are many additional plants which should be added to this list.
Purple Loosestrife (not to be confused with native loosestrive)
Japanese Honeysuckle (not to be confused with native honeysuckle)
What can you do to help?
Learn to identify these species and make sure they are not lurking in corners of your yard!
Discourage local nurseries from selling them. (some but not all are illegal to sell in some states)
Volunteer for a work party to help us remove them from trust lands.
Spread the word! Educate your family and neighbors.