Scientists found that certain species of trees will not rapidly advance uphill as global temperatures rise. In other words, subalpine forests will not follow the climate up the mountain. Using field experiments in the Rocky Mountains, scientists tested how two types of emerging tree seedlings responded to artificial warming and watering at three locations. They found that Engelmann spruce may not move to higher elevations as temperatures rise. Further, the spruce may die off at lower elevations. Its overall range could shrink. The hardy limber pine may advance upward, but likely at the same slow pace as in today’s climate.