Comparison between the standing stem volume in mixed and pure stand. Standing volume of (a) Norway spruce, (b) European beech, and (c) total stand in the mixed stand over the reference values for the pure stand. For the mean total stand standing volume (rhombus) 421 m³ ha⁻¹ y⁻¹ where measured while 434 m³ ha⁻¹ y⁻¹ are expected on the basis of the neighbouring pure stands.