The following link sets forth a scientific basis for the positive aspects that wolves have in ecosystem restoration. http://www.pinedaleonline.com/wolf/pdf/Wolves-NationalParks.pdf
Wolves have historical ties to most of the United States. Hundreds of years ago wolves roamed throughout most of the north easten United States, until humans decided we would be better off without them. A bounty was sent out for wolves and they were killed by the hundreds. Since then ungulates and other large herbacious species have been allowed to feed freely without many predators, besides hunters. This has caused ecosystems to struggle and vegitation has declining compared to past times. Although coyotes are present in the state of Maine, they do not obtain the same ecological niche that the wolf should hold in maintaining some of the larger ungulate populations. Wolves can positively improve small regions of a larger ecosystem.