The spatial representation for a Timber Supply Area or TSA Supply Block: A Timber Supply Area is a designated area established by the Ministry in order to practice sound, integrated, resource management principles to improve the allowable annual cuts. TSAs were originally defined by an established pattern of wood flow from management units to the primary timber-using industries. They are the primary unit for allowable annual cut (AAC) determination. A TSA Supply Block is a designated area within the TSA where the Ministry approves the allowable annual cuts