Bioelectrical Synchronisation of Spruce Trees during aSolar 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, synchronising their individual bioelectrical behaviour hours in advance. Older trees displayed greater anticipatory behaviour with early time-asymmetry and entropy increases, characteristic of memory dynamics in open dissipative systems such as trees. These results reveal a complex relationship between individual and collective tree behaviour, shaped by individual age and physiology as well as collective history and memory. This highlights the adaptive significance of synchrony and collective memory in plants, offering new insights on coordinated behaviours in nature. One Sentence SummaryTrees anticipate and respond collectively to a solar eclipse.