Table 3. Model coefficients, 95% confidence intervals, significance levels and R2 (representing the percentage of explained variance by fixed and random factors (conditional, R2c) and by fixed factors (marginal, R2m) for the linear mixed effect model that aims to separate irreversible cambial growth (D G+) from changes caused by radial hydraulic and osmotic changes (including radial transfer of osmotica) prior to, and after girdling. For the model prior to girdling, sensor position was not significant; for the model following girdling, the positions below and above were significantly different and there were significant interactions between sensor position and all four variables of Equation 1. Using tree number, sample position and sampling date (random effects) and D x and D b (fixed factors), our model was able to explain a large proportion of variation introduced by radial hydraulic capacitance.