Fig. 6.

a Leaf area indices (m²·m⁻²) of sunlit and shaded portions of the leaves of bracken and Setaria in the course of a day with regard to the average leaf–sun geometry of the study area. b Annual average of the diurnal course of irradiance at the ECSF meteorological station (1998–2005; Bendix et al. 2008a), sum of absorbed direct and diffuse PAR by sunlit and shaded leaves of bracken and Setaria plotted on the left ordinate axis and typical solar elevation in degrees on the right ordinate axis