Table 3. Optimal models for the effects of stand factors and diversity on forest biomass, productivity and their stability (S_B and S_P, respectively) at different plot sizes, obtained through model selection procedure. For the grain sizes from 400 to 1200 m2, we used mixed-effects models and thus the chi-square values were reported for variables retained in the model. While for the 2500 m2 grain size, we used ordinary regression and thus F values were reported (see Methods for details).