Canopy space filling and tree crown morphology in mixed-species stands compared with monocultures

Left: In canopies of un-thinned or just moderately thinned mixed species stands (95% and 75% line, respectively) the sum of the crown cross section area mostly exceeds pure stands (100% reference line) due to multiple crown overlaps. Right: Mixing species with varying morphological traits can cause a selection effect (a-c) but beyond this may trigger a morphological plasticity which can lead to denser canopy space filling, completer light capture, and productivity gains of mixed versus pure stands (d-f).