Fig. 8From: Analysing the effect of stand density and site conditions on structure and growth of oak species using Nelder trials along an environmental gradient: experimental design, evaluation methods, and resultsGraphical illustration of the non-linear smoothers f 1 − f 6 from eq. 5 for α h,v as the dependent variable. Straight line: estimate, dashed lines: 95 % confidence area; v = volume, DCI = Hegyi-indexBack to article page