Simply put, a Forester will care for the forest as a whole while an Arborist will care for an individual tree.
Foresters will receive their formal education and training in college. The education and training of an Arborist is less formal than a college degree. The International Society of Arboriculture offers different certification opportunities that are recognized as the gold standard of arborist education and training.
On January 6, I finished my requirements to become an ISA Certified Arborist. Now we can say that the tree farm has an official tree guy! Seriously though, ISA offers many learning opportunities, and I look forward to putting that to use on the farm.