Sunflecks in the upper canopy: dynamics of light‐use efficiency in sun and shade leaves of Fagus sylvatica

• DOI: 10.1111/nph.18222
• Publication Date: 2022-05-15T12:38:34Z
• Authors: Maxime Durand; Zsofia R. Stangl; Yann Salmon; Alexandra J. Burgess; Erik H. Murchie; T. Matthew Robson
• Keywords: Shade tolerance; Shade avoidance

Sunflecks are transient patches of direct radiation that provide a substantial proportion the daily irradiance to leaves in lower canopy. In this position, faster photosynthetic induction would allow for higher sunfleck-use efficiency, as is commonly reported literature. Yet, when sunflecks too few and far between, it may be more beneficial shade prioritize efficient photosynthesis under shade. We investigated temporal dynamics induction, recovery shade, stomatal movement during sunfleck, sun Fagus sylvatica from three provenances contrasting origin. found complete full shorter time than leaves, but respond due their much larger amplitude induction. The core-range provenance achieved opening which better efficiency denser canopies canopy positions. Our findings represent paradigm shift future research into light fluctuations canopies, drawing attention ubiquitous importance photosynthesis, not only lower-canopy where prevalent, particularly upper longer common openness.