Comparing stem taper functions and analysis the taper ratio of three poplar clones (Populus x euramericana) in Navarre

F. Rodríguez, C. Molina


The present work analyzes three stem taper functions on three clones of Populus x euramericana (Canadá Blanco, I-214 and MC) in Navarre to elaborate a merchantable volume equation. To minimize the effect of the autocorrelation a continuous autoregressive error structure CAR(2) or CAR(3), depending the clone analyzed, is used. On the other hand, the local form exponent of the three clones is compared by two methods: the analysis of variance of the individual estimation of the local form exponent, and contrasting the maximum likelihood statistic between adjustments. The Canadá clone is the more conical clone of the three clones analyzed. The data come from 143 poplars in even-aged stands with the same frame of plantation (real frame at 4,5 × 4,5 m).


poplar clones; stem form; autocorrelation; volume; taper; Navarre