Modelling the effects of stem sweep, branch size and wood stiffness of radiata pine on structural timber production

Summary The effects of changing three important biological traits — stem sweep (SWE), branch size (BRS) and modulus of elasticity (MoE) — on the radiata pine production system were examined using data obtained from the Australian radiata pine industry and from scientific experiments. Significant improvements in sawlog grade, structural timber grade recovery and the proportion of higher-grade timber can be obtained by reducing SWE and BRS and by increasing MoE. A 10% reduction in sweep reduced sawlog degrade by 17.1% and increased green timber recovery by about 0.5%. A 10% reduction in BRS decreased the volume of degraded sawlog by 68% and increased structural timber recovery by 0.6–1.6%. An increase of 10% in MoE increased structural timber recovery by 12.3–13.1%. The main advantage of modelling the effects of biological traits using data from industry is greater reliability relative to models based on assumptions. The modelling provides quantitative information that the timber industry can use to increase its productivity and profitability.

[1]  B. Turnbull.  The Empirical Distribution Function with Arbitrarily Grouped, Censored, and Truncated Data , 1976 .

[2]  Oscar García,et al.  SIMPLIFIED METHOD-OF-MOMENTS ESTIMATION FOR THE WEIBULL DISTRIBUTION , 1981 .

[3]  G. L. Bennett,et al.  Simulation of Genetic Changes in Life Cycle Efficiency of Pork Production. I. A Bioeconomic Model , 1983 .

[4]  D. J. Cown,et al.  TIMBER RECOVERY FROM PRUNED PINUS RADIATA BUTT LOGS AT MANGATU: EFFECT OF LOG SWEEP , 1984 .

[5]  A. Anton,et al.  BENDING STRENGTH, STIFFNESS, AND STRESS-GRADE OF STRUCTURAL PINUS RADIATA: EFFECT OF KNOTS AND TIMBER DENSITY , 1984 .

[6]  H. Bier.  BENDING PROPERTIES OF STRUCTURAL TIMBER FROM A 28-YEAR-OLD STAND OF NEW ZEALAND PINUS RADIATA , 1985 .

[7]  N. L. Johnson,et al.  Continuous Univariate Distributions. , 1995 .

[8]  C. L. Todoroki.  LOG ROTATION EFFECT ON CARRIAGE SAWING OF SWEPT LOGS , 1995 .

[9]  Robert Evans,et al.  Sampling Plantation Eucalypts for Wood and Fibre Properties , 1997 .

[10]  Bruce L. Greaves,et al.  Assumptions underlying the use of economic weights: are they valid in breeding for eucalypt kraft pulp? , 1997 .

[11]  J. Hillers,et al.  Developing breeding objectives for beef cattle production 1. A bio-economic simulation model , 1998 .

[12]  J. Gibson,et al.  Effects of production and marketing circumstances on economic values for beef production traits , 1998 .

[13]  J. Gibson,et al.  Economic values for beef production traits from a herd level bioeconomic model , 1998 .

[14]  D. J. Cown,et al.  MODELLING PINUS RADIATA LUMBER CHARACTERISTICS. PART 1: MECHANICAL PROPERTIES OF SMALL CLEARS , 1999 .

[15]  J. Turner,et al.  PREDICTION OF FINAL SWEEP IN PRUNED PINUS RADIATA LOGS FROM JUVENILE SWEEP MEASUREMENTS , 1999 .

[16]  Jugo Ilic,et al.  Acoustic segregation of Pinus radiata logs according to stiffness , 2000 .

[17]  D. McNickle,et al.  Modeling internode length and branch characteristics for Pinus radiata in New Zealand , 2002 .

[18]  D. M. Chong,et al.  PLYRS plantation management system , 2002 .

[19]  G. Downes,et al.  RELATIONSHIP BETWEEN WOOD DENSITY, MICROFIBRIL ANGLE AND STIFFNESS IN THINNED AND FERTILIZED PINUS RADIATA , 2002 .

[20]  P. Xu,et al.  Estimating the influence of knots on the local longitudinal stiffness in radiata pine structural timber , 2002, Wood Science and Technology.

[21]  Ross L. Dickson,et al.  ACOUSTIC SEGREGATION OF PINUS RADIATA LOGS FOR SAWMILLING , 2004 .

[22]  Satish Kumar.  Genetic parameter estimates for wood stiffness, strength, internal checking, and resin bleeding for radiata pine , 2004 .

[23]  M. Powell.  Breeding Radiata Pine to Maximise Profit from Solid Wood Production : Summary Report , 2005 .

[24]  J. Wolf,et al.  Breeding objectives for beef cattle used in different production systems: 1. Model development , 2005 .

[25]  M. Powell,et al.  Developing breeding objectives for radiata pine structural wood production. I. Bioeconomic model and economic weights , 2006 .

[26]  Harry X. Wu,et al.  Developing breeding objectives for radiata pine structural wood production. II. Sensitivity analyses , 2006 .

[27]  Peter Carter,et al.  Sorting Logs and Lumber for Stiffness Using Director HM200 , 2007 .

[28]  J. Ilic,et al.  Inheritance and Genetic Gain in Wood Stiffness in Radiata Pine Assessed Acoustically in Young Standing Trees , 2008 .