A new critique has challenged a 2025 study suggesting spruce trees in Italy's Dolomites synchronized their bioelectrical activity before a partial solar eclipse. Researchers argue the findings stem from pseudoscience rather than plant communication. The original authors defend their preliminary results amid ongoing debate.
In October 2022, scientists attached electrodes to three spruce trees, aged 20 to 70 years, and five stumps in the Costa Bocche forest in Italy's Dolomite mountains. They observed a spike in bioelectrical activity during a partial solar eclipse on October 22, with the activity peaking mid-eclipse and fading afterward. Led by physicist Alessandro Chiolerio of the Italian Institute of Technology and plant ecologist Monica Gagliano of Southern Cross University, the team published their findings in 2025, interpreting the response as trees anticipating the darkening skies. They noted older trees reacted earlier and more intensely, hinting at a form of memory and signal transmission to younger trees.
The study sparked media attention and a documentary but faced immediate skepticism from peers. Critics pointed to the small sample size and numerous uncontrolled variables. Forest ecologist Justine Karst of the University of Alberta drew parallels to the disputed 'wood-wide web' idea, where trees supposedly share resources via fungal networks—a concept her 2023 research found lacking evidence.
A detailed critique, published in February 2026 in Trends in Plant Science, was co-authored by evolutionary ecologist Ariel Novoplansky and Hezi Yizhaq of Ben-Gurion University of the Negev in Israel. Novoplansky dismissed the eclipse's impact, noting it reduced sunlight by just 10.5% for two hours—less than typical cloud cover fluctuations. He proposed alternative explanations like temperature changes or nearby lightning strikes. 'My serious doubts had arisen from the very basic premise regarding the adaptive rationale the entire study hinged upon,' Novoplansky told reporters.
Plant ecologist James Cahill of the University of Alberta in Calgary labeled the work pseudoscience, comparing it to the 'mother tree' claims by Suzanne Simard. 'This field of plant behavior/communication is rampant with poorly designed “studies” that are then twisted into a narrative,' Cahill said. He praised the critique for offering logical alternatives and urged testing multiple hypotheses.
Chiolerio and Gagliano maintain their measurements of temperature, humidity, rainfall, and solar radiation showed no strong links to the electrical transients. They did not monitor electric fields, leaving room for lightning effects. Gagliano emphasized, 'Our paper reports an empirical electrophysiological/synchrony pattern... we discussed candidate cues explicitly as hypotheses rather than demonstrated causes.' Both researchers view their work as an initial field report, with further studies planned through peer-reviewed channels. They reject pseudoscience labels, insisting disagreements be settled via transparent methods and data.
