Forest migration is the movement of large seed plant dominated communities in geographical space over time. The emphasis of forest migration is placed on the movement of the populations that make up the forest community. Though an individual tree is permanently fixed in a location, tree populations may migrate over the landscape through successful dispersal and establishment into new regions and/or a lack of regeneration in a portion of its previous habitat range over the course of generations. Tree migration is controlled by two overlying forces: environmental suppression and dispersal capacity of the population by seed. Though the true rate of forest expansion is difficult to quantify, efforts are being made to evaluate and predict past, current, and future rates and extents of forest mo