Bark Bark Forest Measurement and Modelling. Tools Diameter Bark is the outer sheath of the tree.
Some trees annually shed bark, while others have persistent bark.
The inner bark transports photosynthates from the crown, while the outer bark has a major protective role. The bark protects the bole from insects and damage from physical abrasion. It is also important for fire resistance. The underbark measurement of diameter or sectional area at breast height is more closely related to wood volume than the equivalent measurement over bark. Thus, the determination of bark is important for estimating wood volume that could be extracted from trees or logs.