Global warming will shift habitat lines causing certain species to die out such as ones that live on mountain tops that won’t be able to increase their altitude. It will also leave some areas more prone to drought making hard for trees to produce their protective sap to keep infestations of bugs out; in addition to making the area more prone to wildfires.
It is believed that the easy access to carbon may in fact cause the plants to grow quicker and healthier if planted in areas with large amounts of water in nutrient rich soil. This will disrupt the distribution of species.
I think this article brings up some good points and uses good sources, it contains a lot of graphs and charts and is worth reading. It talks about other forest disturbances such as storms and bug infestations.