Fig. 3From: Selection of mixed-effects parameters in a variable–exponent taper equation for birch trees in northwestern SpainObserved diameters (circles), mean response (dashed line) and calibrated response (solid line) for a tree with diameter at breast height d = 33.3 cm and total height h = 18.6 m. The additional data used for calibration (d i = 26.0 cm at h i = 6 m) is represented by a black dot Back to article page