Question
we planted a tulip poplar tree last year from a part time vendor of trees and shrubs. the tree seemed to have been been wrapped in burlap about 3 or 4 feet up its trunk for some time. the bark is lifting and splitting about a foot up. the tree is fast-growing and doing well otherwise.

Answer
If I am reading this correct --the burlap was left on the rootball and extends up the trunk about 3-4 feet. Remove the burlap from the trunk. It is causing the trunk to heat up and the cracks are what is called sun scald. The wrap was put there to prevent sun scald in the winter months but should have been removed in the spring. The burlap will cause a rise in the temperature of the bark causing the cells to expand and crack and allow an insect called a borer to infest the trunk. I would remove the burlap and spray the trunk area with an insecticide for borers called Merit. This will kill any borers present and prevent other borers from attacking for up to 3 months.