Climate change is not entirely the reason behind the population shift of trees
One of the primary predictions of climate change is that plant species will adapt by spreading into zones that have similar attributes. That is, plant species adapted to temperate zones will over time move into newly-temperate zones as the climate changes. Recent studies showing the movement of trees in North America, however, show an additional pattern. The trees are moving westward, not just northward, as the global temperature warms.
Read
America's Trees are Moving West, and No One Knows Why
By Robinson Meyer
May 17, 2017
The Atlantic