Modelling the influence of radiata pine log variables on structural lumber production

We run logit models to explain the variability of Pinus radiata structural lumber in 71 second and third unpruned logs. The response variable was proportion with a static modulus elasticity greater or equal than 8000 MPa, pMSG8+, explanatory variables were log volume, branch index, largest branch, internode wood basic density, acoustic velocity. average pMSG8+ volume 44,30 % 36,18 respectively. Ten selected based on meeting statistical assumptions, their goodness fit, significance parameters. best (R2 - adj. > 0,75) included velocity (AV) as variable, which explained 56,25 pMSG8+. Models without AV presented fit ranging from 0,60 0,75 adj.), highest weight followed by branch. It is possible model even when not available; however, this requires density calibrated for growing zone.