Nicholas Davies edited Results.tex  over 7 years ago

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While the study was larger than preceding attempts, the sample number was still small when considering heritability calculations. The lack of data resulted in wide 95\% credible intervals, which require more samples to tighten. The heritability indicates that growth strain can be influenced by breeding, and are in line with the 0.32 reported by \citet{Murphy_2005}, but are significantly higher than the 0.02 value reported by \citet{naranjo2012early}. Density, diameter at age two (growth), volumetric shrinkage, acoustic velocity and stiffness all have significantly large heritability that breeding for values of these traits is achievable, the values are similar to those reported for other eucalypt species \citep{Hung_2014, Hein_2012, Blackburn_2010, Blackburn_2014, Hamilton_2008}.   \begin{table}   \begin{tabular}{ c c c }  Property &Heritability &95\% credible intervals \\  

All stems measured within each family were averaged to give correlations between properties at the family level. All correlations increase in strength when compared to individual stem correlations. A very strong positive relationship is evident between growth-strain and stiffness at the family level. This means that reducing growth-strain will require reducing wood stiffness at the population level. On the positive side, \textit{Eucalyptus} species have such high wood stiffness that a reduction would not have practical implications from a wood processing viewpoint.  \begin{table}   \begin{tabular}{ c c c c c c }  & Density & Volumetric Shrinkage & Acoustic Velocity & Stiffness & Strain \\   Diameter &0.18 [-0.13, 0.48] &-0.54 [-0.73, -0.27] &0.47 [0.19, 0.69] &0.47 [0.19,0.69] & 0.39 [0.09, 0.63]\\   Density & &-0.29 [-0.56, 0.03] &0.20 [-0.11, 0.49] & 0.37 [0.06, 0.62]& 0.32 [0.01, 0.58]\\   Volumetric Shrinkage & & &-0.71 [-0.84, -0.51] &-0.71 [-0.84, -0.51] & -0.65 [-0.81, -0.43]\\   Acoustic Velocity & & & &0.98 [0.97, 1.0] & 0.88 [0.79, 0.94]\\   Stiffness & & & & & 0.89 [0.80, 0.95]\\   \end{tabular}   \caption{Pearson correlation between average family values for measured wood properties. 95\% confidence intervals in brackets.}   \end{table}  \begin{table}   \begin{tabular}{ c c c c c c }  &Density &Volumetric Shrinkage &Acoustic Velocity &Stiffness &Strain &Strain\\  Diameter &-0.17 [-0.46, 0.15] &-0.43 [-0.66, 0.14] &0.27 [-0.04, 0.54] &0.25 [-0.07, 0.52] &0.19 [-0.12, 0.48] 0.48]\\  Density && 0.27 [-0.04, 0.54] &-0.20 [-0.48, 0.11] &0.01 [-0.30, 0.32] &-0.12 [-0.41, 0.20] 0.20]\\  Volumetric Shrinkage &&& -0.59 [-0.76, -0.34] & -0.55 [-0.73, -0.28] &-0.47 [-0.68, -0.17] -0.17]\\  Acoustic Velocity &&&&0.98 [0.95, 0.99] &0.80 [0.65, 0.89] 0.89]\\  Stiffness &&&&& 0.79 [0.64, 0.88] 0.88]\\  \end{tabular}   \caption{Pearson correlation between average family values for measured wood properties. 95\% confidence intervals in brackets.}   \end{table}