Fig. 4From: Multi-sensor modelling of a forest productivity index for radiata pine plantationsVariation in mean error for parametric models (filled black circles) and non-parametric models using k-NN with an optimised value of k (open circles) for models that a do not include age and b include age. Note that model precision is not given for use of LiDAR without age (panel a) as these models are not feasibleBack to article page