Bioelectrical synchronization of Picea abies during a solar eclipse.

Regular light-dark cycles greatly affect organisms, and events like eclipses induce distinctive physiological and behavioural shifts. While well documented in animals, plant behaviour during eclipses remains largely unexplored. Here, we monitored multiple spruce trees to assess their individual and collective bioelectrical responses to a solar eclipse. Trees anticipated the eclipse, synchronizing their bioelectrical behaviour hours in advance. Older trees displayed greater anticipatory behaviour with early time-asymmetry and entropy increases. These results reveal a relationship between trees, shaped by individual age and physiology as well as collective history. This highlights the significance of synchrony in plants, offering new insights into coordinated behaviours in nature.