Counting a tree’s annual rings is a reliable way to estimate its age when records are unavailable; this method has been adapted for living trees. An instrument called an increment borer extracts a sma...Counting a tree’s annual rings is a reliable way to estimate its age when records are unavailable; this method has been adapted for living trees. An instrument called an increment borer extracts a small, pencil-sized piece of wood, or core sample, from the trunk of the tree. A mini-auger is drilled by hand from the bark to the center (pith) of the tree, and the resulting core sample extracted from the hole displays the annual rings (or increments of growth) of the tree at that point in the tree.
