Dr. Curt Stager and Martha Foley gaze into the crystal ball to imagine the Adirondack Park in 300 years. The effects of invasive species may be more noticeable than those of global warming. Three of the commonest trees face disease threats — most severely, the beech. Southern hardwoods like hickory and oak will not likely move in, even with an increase in temperature, and native maples may do even better with a longer growing season.