pole saw
long-handled tool with a pruning saw on the end. used to cut branches from a distance.
pollarding
specialty pruning technique in which a tree with a large-maturing form is kept relatively short. Starting on a young tree. internodal cuts are made at a chosen height. resulting in sprouts. Requires regular (usually annual) removal of the sprouts arising from the same cuts. Callus knobs develop at the cut height from repeated pruning.
pore space
air or water-filled spaces between soil particles.