## 3 Results
### Wood Color  
The CIE L*a*b* color values differed between the burned and reference spruce sapwood at all tree heights. In pine sapwood, the difference in color between the burned and reference trees was evident in the butt logs but smaller in the middle and top logs. The L*, a*, and b* values are presented in Figure 6, Figure 7, and Figure 8, respectively. \begin{table}
\begin{tabular}{l r r r r r r r r} \hline \hline  & \multicolumn{4}{c}{**Norway Spruce**} & \multicolumn{4}{c}{**Scots Pine**} \\ \hline
**Source** & **F** & **df1** & **df2** & **Sig.** & **F** & **df1** & **df2** & **Sig.** \\ \hline Fire damage class & 5.943 & 2 & 133 & 0.003 & 0.410 & 2 & 150 & 0.665 \\ Height class & 9.215 & 2 & 133 & \textless{}0.001 & 4.974 & 2 & 150 & 0.008 \\ Radial position & 1.400 & 1 & 133 & 0.239 & 93.330 & 1 & 150 & \textless{}0.001 \\ Basic density & 1.563 & 1 & 133 & 0.213 & 8.400 & 1 & 150 & 0.004 \\ Fire damage class * radial position & 5.367 & 2 & 133 & 0.006 & 0.671 & 2 & 150 & 0.513 \\ Radial position * basic density & 0.040 & 1 & 133 & 0.841 & 54.860 & 1 & 150 & \textless{}0.001 \\ \hline
**Random effect** & **Variance** & \multicolumn{4}{c}{**Variance**} \\ \hline Stand & 654.551 & \multicolumn{4}{c}{373.526} \\ Tree & 275.985 & \multicolumn{4}{c}{151.485} \\ Residual & 1070.354 & \multicolumn{4}{c}{525.179} \\ \hline
**Fitting statistics** & \multicolumn{4}{c}{} \\ \hline R\({}^{2}\) & 42.4\% & \multicolumn{4}{c}{79.5\%} \\ Bias & 1.55 (1.6\%) & \multicolumn{4}{c}{0.00} \\  & & \multicolumn{4}{c}{(0.0\%)} \\ RMSE & 42.4 (44.9\%) & \multicolumn{4}{c}{21.6} \\ \hline \multicolumn{4}{l}{* refers to interaction.} \\ \hline \hline \end{tabular}
\end{table} 
Table 16: Fixed effects in the linear mixed model (Equation (10)) for moisture gradient and variation in random effects. \begin{table}
\begin{tabular}{l r r r r r r r} \hline \hline  & \multicolumn{4}{c}{**Norway Spruce**} & \multicolumn{4}{c}{**Scots Pine**} \\ \hline
**Variable** & **Estimate** & \multicolumn{2}{c}{**Std. Error**} & **95\% CI** & **Estimate** & \multicolumn{2}{c}{**Std. Error**} & **95\% CI** \\ \hline  & & **Lower** & **Upper** & & **Lower** & **Upper** \\ \hline Intercept & 134.068 & 51.752 & 31.704 & 236.431 & 17.895 & 31.324 & \textless{}43.998 & 79.788 \\ Fire damage class (ref: no damage) & & & & & & & \\  More damaged side & \textless{}30.077 & 16.500 & \textless{}62.713 & 2.559 & \textless{}18.665 & 29.080 & \textless{}76.124 & 38.793 \\  Less damaged side & \textless{}30.108 & 16.946 & \textless{}63.627 & 3.411 & \textless{}20.975 & 29.098 & \textless{}78.471 & 36.520 \\  Height class (ref: top log) & & & & & & & \\  Butt log & \textless{}29.964 & 7.100 & \textless{}44.007 & \textless{}15.922 & \textless{}14.387 & 5.682 & \textless{}25.614 & \textless{}3.160 \\  Middle log & \textless{}14.362 & 8.178 & \textless{}30.537 & 1.813 & \textless{}2.399 & 5.890 & \textless{}14.037 & 9.239 \\  Radial position (ref: heartwood) & & & & & & & \\  Sapwood & 92.055 & 59.173 & \textless{}24.986 & 209.097 & 292.496 & 28.989 & 235.217 & 349.775 \\  Basic density & \textless{}0.107 & 0.126 & \textless{}0.356 & 0.142 & 0.136 & 0.060 & 0.016 & 0.255 \\  Interaction of fire damage class * radial position (ref: no damage or heartwood) & & & & & & & \\  More damaged side * sapwood & \textless{}44.223 & 13.530 & \textless{}70.985 & \textless{}17.462 & \textless{}9.415 & 9.096 & \textless{}27.387 & 8.557 \\  Less damaged side * sapwood & \textless{}24.310 & 13.809 & \textless{}51.624 & 3.003 & \textless{}0.641 & 9.064 & \textless{}18.550 & 17.268 \\  Interaction of radial position with basic density (ref: heartwood * basic density) & & & & & & & \\  Sapwood * basic density & \textless{}0.032 & 0.157 & \textless{}0.343 & 0.280 & \textless{}0.530 & 0.072 & \textless{}0.672 & \textless{}0.389 \\ \hline \hline \end{tabular}
\end{table} 
Table 17: Fixed coefficients in the linear mixed model (Equation (10)) for moisture content.