Fig. 1

Effect of light availability on the number of vascular plant species (per 400 m²) in the forest understorey. Depicted are the four different ways to quantify light availability: direct measurement (top left); estimated cover of canopy > 5 m (top right); hemisphere simulation based on terrestrial laser scanning data (bottom left); and crown projection area derived from typical crown sizes per species and their position in the plots (bottom right). Dashed lines indicate 95% confidence interval of the regression. Non-significant regressions are indicated by dashed lines (and dotted confidence lines)