Collecting material for "Live Staking", stakes are typically "between 18 and 24 inches in length and at least 3/8th inch in diameter from long, upright branches taken off the parent plant. Lengths and diameters may vary though depending on the species, your collecting goals, and the site conditions..." (Water and Land Resources Division 2001).

Obviously, branches are usually used to do no harm to the "donor tree", but in a case where it has no future, anyway, if it fits this description, can a sapling trunk be used?