It was already a huge product of human activity: the forest there was cut for firewood, great colds killed the rest in the XVIIe century and grazing sheeps kept it treeless. Pine was chosen because it is endemic and one of the few species able to grow on such poor soils, washed out by rain and sea salt.
You have to love all the people on this website giving advice on Europeans and Canadians on forest management, and that they should abandon any economic use of forests, while they see no problem with the rest of their economic choices fuelling global warming.