Plots on lutites and migmatites were selected for this study in order to compare two plantations of the same age, but located over two different geological materials.

The following figures include the estimated marginal means of the dasymetric variables: total height and normal diameter (corrected in the covariance function, data from the plots before the treatment in 2003 are used as a covariate). A statistical analysis comparing between levels of the factor “treatment” corresponding to each level of the factor “time” and the levels of the repeated means is also included.

Different effects were observed in both types of plots. In the first plot (Fig. 6.4), the statistical analysis revealed significant increases in height and diameter growth as a result of the application of ash and phosphorus, mainly from 2005 onwards. The time-treatment interaction revealed some differences between the treatments, with benefits to both plots. In the second plot (Fig. 6.5) increases in the normal diameter for WA and WAP treatments were significant. The different response of the plantations may be due to the differences in the nutritional state, as indicated by the different site index values (18.7 and 23.1 m in the lutites and migmatites, respectively).

Fig. 6.3 Foliar macronutrients in soils over lutites and migmatites. Control untreated, WA applications of 4.5 Mg wood ash ha-1 for three consecutive years (2003, 2004, 2005), WAP single applications of 4.5 Mg wood ash ha-1 and 0.1 Mg P2O5 ha-1

-j

‘O

Fig. 6.4 Estimated marginal means of Pinus radiata D. Don in plots over lutites. Control untreated, WA application of 4.5 Mg wood ash ha-1 for three consecutive years (2003, 2004, 2005), WAP single applications of 4.5 Mg wood ash ha-1 and 0.1 Mg P2O5 ha-1. In the repeated measures analysis, the sphericity assumption was not valid and therefore values of P-Huynh Feldt were used in univariate tests of their interactions. Ht total height, Dn normal diameter