Roxane FELLER ROETHLISBERGER

In the 1990s, Canadian ecologist Suzanne Simard made a groundbreaking discovery that challenged everything we thought we knew about how forests work. While studying managed forests in British Columbia, she noticed something puzzling: when birch trees were removed to promote the growth of valuable Douglas firs, the firs did not flourish as expected, they actually struggled and grew more slowly. Determined to understand why, Simard traced the movement of nutrients using radioactive carbon isotopes. What she found was astonishing. Trees were actively sharing resources through vast underground fungal networks known as mycorrhizae. These delicate, thread-like fungi connect the roots of different trees across the forest floor, forming a complex web that allows the exchange of carbon, water, nutrients, and even chemical signals, sometimes between entirely different species. She discovered that older, larger trees often serve as central "hubs" or "mother trees," supporting younger saplings by redistributing vital resources and helping the entire ecosystem remain resilient. When these key trees are removed, the underground network weakens, and the health of the remaining forest declines. Simard’s research overturned the traditional Darwinian view of forests as battlegrounds of ruthless competition. Instead, she revealed a far more sophisticated reality: forests operate as highly cooperative systems where trees communicate, support one another, and even warn neighboring trees about threats like drought, disease, or insect attacks. What appears to the human eye as a silent, still forest is, in truth, a vibrant, interconnected living network, built not on isolation and rivalry, but on deep connection and mutual aid.