Can trees anticipate solar eclipses? Scientists reanalyze the phenomenon

For months, the idea went around the world. A group of researchers claimed to have observed that several European spruce trees began to modify their bioelectric activity up to 14 hours before a partial solar eclipse, also synchronizing their response between individuals of different ages. The conclusion was as surprising as it was ambitious: the trees not only reacted to the eclipse, but seemed to anticipate it. The hypothesis immediately attracted the attention of the media and aroused enormous interest among those who study plant intelligence. However, the story has taken an unexpected turn. A new article published in Trends in Plant Science reviews that research point by point and maintains that the available evidence does not support such a claim. Far from confirming that trees predict eclipses, the authors defend that there are much simpler explanations compatible with what plant biology knows today. The interesting thing is that neither of the two works questions that plants produce complex electrical signals. In fact, this phenomenon is widely documented. What is under discussion is what exactly these signals mean and how far the conclusions drawn from them can go. The debate has become one of the most recent examples of how science advances: one research proposes a novel idea, another tries to put it to the test and both require careful review of the data before accepting extraordinary claims. several specimens of Picea abies, the European red spruce, during the partial solar eclipse on October 25, 2022 in a forest in the Italian Dolomites. To do this, the researchers installed a network of electrodes on both live trees and stumps and continuously recorded the electrical variations of the plant tissues. The authors observed that during the eclipse the electrical activity of the trees decreased, something they considered consistent with the temporary reduction in sunlight. However, the most striking aspect appeared long before the astronomical phenomenon. According to their analysis, the oldest trees began to show electrical changes approximately 14 hours before the eclipse. In addition, they detected synchronized patterns between different specimens, interpreted as a possible collective response of the forest. The researchers even proposed that the veteran trees played a leading role in this coordination by presenting more intense signals than the young individuals. To interpret these results they resorted to advanced mathematical tools, complexity analysis, temporal correlations and even a theoretical framework based on quantum field theory to explain the synchronization observed between the trees. Based on all this, they proposed that the forest could behave as a highly correlated system, where electrical activity reflected collective responses to environmental changes. The conclusions aroused enormous expectation because they seemed to radically expand our understanding of plant behavior. But precisely because of their scope they also provoked intense scrutiny by other specialists. Regular cycles of light and darkness profoundly influence organisms, and events such as eclipses induce characteristic physiological and behavioral changes. The new analysis calls into question virtually all of the conclusions. The subsequently published review article does not discuss the electrical recordings obtained during the experiment. What calls into question is the interpretation that was made of them. The authors recall that anticipatory responses in plants exist and are well documented. Many species can prepare for future situations when they have reliable environmental cues, such as changes in light quality, soil moisture, or certain chemicals emitted by other plants. However, they insist that to speak of authentic anticipation, several conditions must be met: that there is a reliable prior signal, that the event is relevant to survival, and that responding earlier provides a clear adaptive advantage. And that is where, according to the authors, the eclipse studied fails the test. In the place where the analyzed trees grew, the occultation of the Sun was relatively modest. The work estimates that the average reduction in available light was only 10.5% for about two hours. Furthermore, the light intensity continued to be above the level necessary to saturate the photosynthesis of these fir trees, so the eclipse would hardly have posed a significant physiological challenge for them. In other words, if the eclipse barely altered the normal functioning of the forest, it is difficult to explain why evolution would have favored such a sophisticated mechanism to anticipate it. What if the explanation was in time? One of the strongest arguments of the new study appears when the researchers review the meteorological conditions recorded during the hours before the eclipse. eclipse.The night before there was a sharp drop in temperature accompanied by precipitation. But that was not all. The authors also incorporated data from the international lightning detection network and discovered that precisely during that interval of about 14 hours, a significant episode of atmospheric electrical activity was concentrated near the forest. Within a radius of 200 kilometers, 664 electrical discharges were recorded between October 22 and 25, 2022. Of these, 20 occurred less than 45 kilometers from the study site and 18 coincided exactly with the time window prior to the eclipse. The three lightning strikes detected less than 10 kilometers away also occurred during that same period. For the authors, this coincidence offers a much more parsimonious explanation for the increase in bioelectric activity observed in the trees. Atmospheric discharges generate electromagnetic fields capable of affecting living organisms and could have influenced the electrical recordings obtained during the experiment. In addition, they propose that larger trees act as better receptors of these electromagnetic fields, which would explain why older specimens showed more intense signals without the need to assume that they remembered previous eclipses. Older trees showed a more pronounced anticipatory behavior, with an early increase in temporal asymmetry and entropy. The real one message is not about eclipses Regardless of who is right, both works agree on a fundamental aspect: the electrical activity of plants represents an extremely promising field of research. The problem, the critical article highlights, is that we still do not know how to differentiate precisely which part of these signals reflects truly adaptive physiological processes and which simply responds to environmental disturbances or physical phenomena without direct biological meaning. That is why he insists that experiments with many more replications, rigorous controls and comparisons between multiple eclipses, storms and other environmental conditions will be necessary before we can talk about anticipatory behaviors. Paradoxically, the controversy may end up benefiting this discipline. Instead of closing the debate, it has raised new questions about how trees communicate, what information their electrical signals actually contain, and the extent to which a forest functions as a coordinated community. The possibility of trees exchanging information remains an area of ??enormous scientific interest. But, at least for now, the available evidence does not allow us to affirm that they are capable of predicting the arrival of a solar eclipse. What both studies do demonstrate is that we are still very far from understanding all the processes that occur silently inside a forest.