Table 2 Results of the linear mixed-effect model with tree ID as random effect for examining the possible influence of fixed effects (Age, Size, and their interaction) on the response variable (height increment (Δh))
Model | Value | DF | t value | p value |
|---|---|---|---|---|
Equation 3 | ||||
 Intercept | 4.3526 | 2739 | 22.5541 | < 0.0001 |
 Age | − 0.0173 | 2739 | − 1.6349 | 0.1022 |
 dbh ∙ h | − 0.000224 | 88 | − 17.893 | < 0.0001 |
Equation 4 | ||||
 Intercept | 4.9404 | 2738 | 12.4781 | < 0.0001 |
 Age | − 0.0227 | 2738 | − 1.695 | 0.09019 |
 dbh ∙ h | − 0.000495 | 88 | − 6.791 | < 0.0001 |
 Age ∙ (dbh ∙ h) | 0.000003 | 2738 | 1.7000 | 0.0892 |