Hours before a solar eclipse, spruce trees 'talk' to each other

Spruce trees retain ancient memories of their environment and communicate with one other in the hours preceding a solar eclipse, a new international study suggests.

"We now see the forest not as a mere collection of individuals, but as an orchestra of phase correlated plants," Alessandro Chiolerio, Italian Institute of Technology and University of the West of England, and the study co-leader, said in a statement.

An interdisciplinary team consisting of researchers from Italy, the United Kingdom, Spain and Australia built custom sensors and placed them across a forest in the Dolomite mountains in Italy. Using the sensors, the team recorded simultaneous bioelectrical responses from the spruce trees.

Before and during the eclipse, electrical activity from individual trees became "significantly" more synchronized, the researchers found. This phenomenon, they say, is evidence the forest is a unified living system.

"By applying advanced analytical methods — including complexity measures and quantum field theory — we have uncovered a deeper, previously unrecognized dynamic synchronization not based on matter exchanges among trees," Chiolerio said.

The older trees in the forest had an early response to the eclipse that was more pronounced, the authors say. This suggests the old trees hold ancient memories they can access. When events are coming up, the old trees "remember" and inform younger trees.

"Basically, we are watching the famous 'wood wide web' in action!" Monica Gagliano, Southern Cross University, Australia, and study co-leader, said in the statement.

Gagliano said the findings about the older trees in particular emphasize the importance of preserving these trees.

"The fact that older trees respond first — potentially guiding the collective response of the forest — speaks volumes about their role as memory banks of past environmental events," Galiano said.

"This discovery underscores the critical importance of protecting older forests, which serve as pillars of ecosystem resilience by preserving and transmitting invaluable ecological knowledge," she added.

The study was published on April 30 in the journal Royal Society Open Science.

A documentary on the research, Il Codice del Bosco (The Forest Code), is set for release in Italy this month. You can check out the official trailer here.