Do Trees *Really* “Feel” Eclipses? A Deep Dive into New Research and the Ongoing Debate
Last year, a fascinating study claimed that spruce trees in Italy’s Dolomite mountains exhibited synchronized bioelectrical activity in anticipation of a partial solar eclipse. This sparked considerable media attention, even inspiring a documentary. However, the findings were immediately met with skepticism from other researchers, questioning the methodology and validity of the conclusions. Now, a new critique published in the journal Trends in Plant Science is intensifying the debate, challenging the notion that trees can “feel” eclipses and highlighting the importance of rigorous scientific standards in the burgeoning field of plant neurobiology.
The Original Study: An “EKG for Trees” in the Dolomites
The initial research, led by physicist Alessandro Chiolerio from the Italian Institute of Technology and plant ecologist Monica Gagliano of Southern Cross University, involved attaching electrodes to three spruce trees (aged 20-70 years) and five tree stumps in the Costa Bocche forest. This setup essentially created an “EKG for trees,” monitoring their bioelectrical activity.
On October 22, 2022, during a partial solar eclipse, the sensors detected a marked increase in bioelectrical activity. This activity peaked during the eclipse’s maximum obscuration and then subsided. The researchers interpreted this spike as a coordinated response to the darkening conditions, suggesting the trees were somehow anticipating the event. Furthermore, older trees showed a stronger and earlier electrical response than younger trees, leading the team to hypothesize that trees develop response mechanisms – a form of “memory” linked to gravitational effects – and potentially even transmit this knowledge to younger trees via bioelectrical waves.
The Rising Tide of Skepticism: Concerns About Methodology and Interpretation
The publication of the study quickly drew criticism from the plant science community. Concerns centered around the small sample size, the large number of variables, and the potential for alternative explanations for the observed bioelectrical fluctuations. Justine Karst, a forest ecologist at the University of Alberta in Canada, drew parallels to a controversial 2019 study promoting the “wood-wide web” concept – the idea that trees communicate and share resources through mycorrhizal fungi networks. Karst co-authored a 2023 study that found insufficient evidence to support the wood-wide web theory, highlighting the need for robust data before accepting such claims.
The “Pseudoscience” Accusation
Ariel Novoplansky, an evolutionary ecologist at Ben-Gurion University of the Negev in Israel, was particularly vocal in his criticism. He co-authored the recent critique in Trends in Plant Science, arguing that the study’s publication was premature and potentially misleading. Novoplansky believes the observed spikes in bioelectrical activity were more likely caused by temperature shifts or lightning strikes, rather than a response to the eclipse itself.
“The premise that trees would be functionally affected by such a minor ‘passing cloud’ effect – a mere 10.5 percent reduction in sunlight for two hours – seemed highly improbable,” Novoplansky explained to GearTech. He also pointed out that trees regularly experience far greater fluctuations in light levels due to normal cloud cover. He further challenged the idea of trees “remembering” past eclipses, noting that each eclipse follows a unique path, rendering past experiences irrelevant for predicting future events. The gravitational changes associated with a partial eclipse are also minimal, comparable to those caused by a new moon.
Novoplansky views the 2025 paper as “the encroachment of pseudoscience into the heart of biological research.”
The Broader Context: Plant Communication and the Risk of Overselling
The debate surrounding the eclipse study highlights a broader issue within the field of plant behavior and communication. James Cahill, a plant ecologist at the University of Alberta in Calgary, Canada, expressed concern about a trend of poorly designed studies being sensationalized and used to promote specific worldviews. He cited the “Suzanne Simard ‘mother tree’ debacle” as a prime example, referring to the widespread acceptance of the idea that older trees nurture younger trees through underground fungal networks, a claim that has faced increasing scrutiny.
Cahill supports Novoplansky’s critique, stating that the original study should have tested multiple hypotheses rather than focusing solely on the eclipse response. He emphasizes the importance of rigorous scientific methodology and avoiding interpretations driven by preconceived notions.
While acknowledging that plants possess established communication mechanisms – particularly through volatile compounds and root exudates – Cahill stresses that evidence for other forms of communication, such as through mycorrhizal networks, remains inconclusive. “Nothing else…has withstood independent investigation,” he stated.
The Researchers Respond: Acknowledging Limitations and Defending Their Work
Chiolerio and Gagliano stand by their research, emphasizing its preliminary nature. Chiolerio explained to GearTech that they measured various weather-related factors, including temperature, humidity, rainfall, and solar radiation, but found no strong correlation with the observed bioelectrical transients. However, they did not measure environmental electric fields or gravitational changes, acknowledging the possibility that lightning or other factors could have played a role.
Gagliano defended their interpretation of the data, stating that their paper reported an empirical electrophysiological pattern during the eclipse window, including changes occurring *before* maximum occultation. She argued that attributing the activity solely to weather or lightning is a hypothesis, not a proven cause. She emphasized the need for site-specific, time-aligned measurements to establish a causal link between these factors and the observed bioelectrical signals.
“We acknowledged the limited sample size and described the work as an initial field report; follow-up work is ongoing and will be communicated through peer-reviewed channels,” Gagliano added. She dismissed the accusation of pseudoscience, stating that scientific disagreements should be resolved through transparent methods, data, and rigorous testing.
Chiolerio expressed frustration with the public attention surrounding the critique, stating that their primary goal was to share their research findings, not to seek public acclaim.
The Future of Plant Neurobiology: A Call for Rigor and Transparency
The debate surrounding the “eclipse-feeling trees” study serves as a crucial reminder of the importance of scientific rigor and transparency in the rapidly evolving field of plant neurobiology. While the idea of plants possessing complex sensory abilities and communication networks is captivating, it’s essential to avoid overinterpretation and premature conclusions. Future research must focus on:
- Larger sample sizes: To ensure the results are statistically significant and representative.
- Controlled experiments: To isolate variables and determine causal relationships.
- Multiple hypothesis testing: To avoid confirmation bias and consider alternative explanations.
- Independent replication: To verify findings and build confidence in the results.
- Open data and methods: To promote transparency and facilitate collaboration.
The study of plant behavior holds immense potential for advancing our understanding of the natural world. However, it’s crucial to approach this field with a critical eye, prioritizing evidence-based research and avoiding the temptation to sensationalize findings. As Cahill aptly put it, the goal should be to “get the science back on track” and move beyond personal worldviews towards a more objective and accurate understanding of plant life.
DOI: Trends in Plant Science, 2026. 10.1016/j.tplants.2025.12.001
DOI: A. Chiolerio et al., Royal Society Open Science, 2025. 10.1098/rsos.241786