What is Log bucking?

Bucking is the process of cutting a felled and delimbed tree into logs. Significant value can be lost by sub-optimal bucking because logs destined for plywood, lumber, and pulp each have their own value and specifications for length, diameter, and defects. Cutting from the top down is overbucking and from the bottom up is underbucking.

In British English, the process is called logging-up or crosscutting.