Guidelines for Clipping Branches (USFS)

Trimming and cutting branches
• Be sure to use the proper tool when cutting brush and limbs. If the vegetation is
clearly too thick for loppers, use a pruning saw. Conversely, use loppers for
small brush rather than trying to mow it down
with a pruning saw.
• The thickened section of bark just outside the spot
where a branch joins the tree is called the “bark
collar”. When cutting branches, always cut just to
the outside of this. Make sure it is cut flat and not
pointed in any way as this could injure other
passing users.
• When cutting large branches, make a partial cut underneath before cutting down
from the top. This will ensure that the cut is clean and doesn’t strip away bark
when it falls.
• Place all cut brush as far away as possible from the trail corridor, at least out of sight, with the butt end facing away from the trail.

Complete doc here.