A micro-borer was developed to extract increment cores from woody stems too small to accept conventional borers. The carbon steel bit, 3.4 mm in diameter and 40 mm in length, is inserted in a rechargeable, portable drill for use in the field. An extractor is forced through the bit with the aid of a C-clamp to remove the 2.4 mm diameter core. The small diameter cores transmit light well and annual increments are easily discernable. The micro-borer, when coupled with the use of conventional borers and observations of bud scale scars, permits age determinations for entire populations ranging from juveniles to adults.
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