A 20-year study of plant life in a fifty mile radius of New York City by the Brooklyn Botanic Garden has found that more than 50 plant species native to the region face extinction under pressure from decreasing undeveloped land and the spread of non-native invasive plants and insects from Europe and Asia.
Non-native plants, like the oriental bittersweet, which is crowding out American bittersweet, and thepurple loosestrife, which is taking over local wetlands, were introduced by gardeners as fast-growing ornamental plants (both are still available from specialty retailers). They spread into the wild, where the plants in the local ecosystem were unable to compete with them.
Non-native insects, like the wooly adelgid threatening eastern hemlocks and the Asian longhorned beetle threatening pretty much all the forests on the east coast, are believed to have been introduced inadvertently in wooden packing material from overseas shipments.
Both the BBG and the Greenbelt Native Plant Center of the city’s Parks Department have programs to try to restore the disappearing species, but Dr. Gerry Moore of the BBG would like to see private citizens get involved. Moore suggests that gardeners actively plant endangered plants, like American bittersweet and the coastal violet, in their own gardens. The disappearance of a single plant, he pointed out, can lead to the disappearance of insects and birds which have evolved to depend on them.