Scientists debunk claim that trees can anticipate a solar eclipse, as suggested by 2025 study

In 2013, Italian computer scientist Alberto Brandolini established a principle that went viral and somewhat characterises communication in these times. He wrote: ‘The amount of energy required to refute nonsense is an order of magnitude greater than that required to produce it.’ Although it would be impossible to prove this asymmetry (let alone quantify it), I was reminded of this law when I read the devastating and well-documented article by Novoplansky and Yizhaq on the claim that eclipses could be predicted by certain plant species, such as spruce trees in an Italian forest.

When, in the spring of last year, Chiolerio and colleagues claimed to have found that trees in a forest in the Dolomites were able to sense that a small partial eclipse was going to occur, by measuring a series of electrical signals that were altered – more so in older trees than in younger ones – the news spread like wildfire, becoming one of those surprising stories that now adorn the media and fill entertainment slots.

It had all the right elements, starting with a kind of collective plant intelligence, a fashionable topic in pop science in recent years, capable of communicating relatively complex states. It played on the appeal that eclipses have for us as surprising phenomena of nature, something that has always allowed speculation to slip in, giving it a certain plausibility. The Moon is undoubtedly a subject that comes and goes in its relationship with the different phases of life and all kinds of events that, even though science debunked them centuries ago, will continue to be relatively beloved. Finally, if everything is given a sufficiently elaborate scientific framework, it seems that research brings us back to reality with a fact of cosmic resonance.

But dismantling it, and that is the work of Novoplanski and Yizhak, requires going further and checking whether this scientific appearance is supported. It takes a lot more effort and, in fact, few people ever bother to do it; that is why it is worth reading this work, which dismantles, one by one, the assumptions on which the initial, almost supernatural, claim is based. There are no mechanisms by which a pine forest can react to small decreases in light that do not occur regularly or interfere with vegetative processes, nor were the measurements of this anticipatory behaviour explained by the eclipse but probably by a cold night a few hours earlier.

It is gratifying to read how, through rationality and expert knowledge, the authors have carried out this exercise, which shows that, although it takes much more energy to debunk a hoax than to create one, science ultimately advances through these steps which, as the title paraphrases, prevent an eclipse of reason.

As a researcher in the field of terrestrial-solar physics, I am greatly surprised that an eclipse is attributed with such a profound impact on trees located under light conditions well above photosynthetic saturation. A partial eclipse of small magnitude, such as the one recorded in the previous study by Chiolerio et al. (2025), generates minor environmental variations compared to those produced by the passage of a dense cloud or a weather front.

The work published by Novoplansky and Yizhaq in the journal Trends in Plant Science fulfils a crucial objective: to dismantle narratives that are appealing but methodologically weak. Research on plant behaviour needs quality control because, as we have seen, it is a field susceptible to excessive interpretations, anthropomorphic analogies, or reckless use of concepts. This article brings order, reminding us that correlation does not imply causation.

From the point of view of scientific communication, it is essential to prevent highly suggestive stories for the general public, such as trees “warning” each other of an eclipse, from obscuring the need for solid evidence. The media attention received by the study of these eclipse-sensitive trees shows that spectacular stories can spread without critical analysis. And this is very dangerous.

Finally, this study invites reflection on the need for reproducible experiments, with strict environmental controls and adequate consideration of alternative explanations such as storms, temperature drops or lightning. The science of eclipses, which historically has been a natural laboratory of extreme precision, cannot afford unfounded speculative interpretations that will ultimately undermine society's interest in science in the medium term.