Red spruce and eastern hemlock are already declining in some areas, and these species are projected to be extirpated from the southeast by 2100 as a result of the combined stresses of warming, air pollution, and insects. If temperature continues to increase and precipitation becomes more variable, conditions for pine growth may begin to deteriorate. Even if regional forest productivity remains high for pine species, the center of forest productivity could shift northward into North Carolina and Virginia, causing significant economic and social impacts.