Humans are the major cause of habitat destruction and have been for many centuries. When people came from Europe to colonize North America, they brought with them the plants and animals of their homelands. The plants that were brought purposely from Europe had spent centuries evolving along with the disturbance of humans and of grazing animals. The native North American plants were no match for this when subjected to the same disturbances (Crosby 1986).
One important fact to take home from this trip through the history of plants introduced into Massachusetts is that the species that are considered most invasive right now were in many cases introduced to the region over a century ago. This could mean that the species that are currently being introduced as garden ornamentals could be the next big problem a hundred years from now. Horticulturalists and gardeners alike may want to keep this in mind when deciding whether to plant exotic introduced species or native ones. Maybe we should all be doing our part to preserve what is left of the uniqueness of the New England region.