Scientists aren’t buying claims that trees talk to each other during eclipses

For centuries, humans have wondered if trees are more than passive bystanders in nature. Do they sense? Do they communicate? Some researchers think so, but a new study claiming that spruce trees “talk” to one another during solar eclipses is drawing serious skepticism from scientists.

The bold claim comes from a research team that monitored three spruce trees in the Italian Alps during a 2020 solar eclipse. They recorded synchronized changes in the trees’ bioelectrical signals: Tiny electrical currents that naturally occur in living tissues.

These changes began hours before the eclipse and were especially strong in older trees, the researchers note. According to the study’s co-author Monica Gagliano, this behavior suggests the trees were not just reacting to darkness but actively anticipating it, functioning as a coordinated “collective system” as they talked to each other.

The finding has been gaining some spotlight in headlines, especially when framed as evidence of some forest-wide communication system. The study, published in Royal Society Open Science, even suggests this may be an early sign of tree cognition or memory.

But many plant scientists are not convinced. A plant ecologist named James Cahill says that the sample size is too small, especially for this many variables. Others argue that the claims are far too bold, especially with the limited sample size.

There’s no doubt that this particular study has some glaring issues. For one, the youngest tree wasn’t even in the same area as the older trees, one ecologist pointed out.

And it’s not just the number of trees that’s raising eyebrows. Critics argue that the study fails to include a basic comparison: how these trees behave during ordinary transitions from day to night. Since many plants naturally adjust to changes in light, an eclipse might simply trigger a normal light-response, not a sign of trees “talking” to each other.