Trees use an underground fungal network to share food and send warning signals to each other.

Dr. Suzanne Simard named this system the Wood Wide Web in 1997. Her research at the University of British Columbia showed that different tree species trade carbon through fungal threads called mycelium. These threads are so small that miles of them can fit in one teaspoon of soil.The fungi attach to tree roots to help the tree absorb water and minerals. In exchange, the tree gives the fungi up to 30% of the sugar it makes from sunlight. This partnership helps both the tree and the fungi survive.When insects attack a tree, the tree sends chemical signals through the network. Nearby trees receive these signals and start making chemicals to protect themselves. A 2013 study at the University of Aberdeen showed that even garden plants like tomatoes use these networks.Scientists have also seen dying trees send their remaining nutrients into the web. This helps the rest of the forest stay healthy. This discovery shows that forests are communities that work together rather than just individual plants competing for space.