Modeling stem profiles for Pinus densiflora in Korea

A new taper model is presented for Pinus densiflora in Korea. The new variable-exponent model describes well the gradually changing tree form along the stem. The changing exponent of the new model can be used to graphically compare different stem forms among tree groups. And various form indices numerically expressing stem form are derived from the new model. Five form indices: (1) taper rate of the butt section, (2) inflection point, (3) parabolic or paraconic range, (4) minimum exponent, and (5) relative height at the minimum exponent, are useful analytical tools for numerically comparing stem forms and stratifying trees into different form groups.