How do trees communicate through their root systems?

Trees communicate and share resources primarily through networks of mycorrhizal fungi that connect their roots, often called the "wood wide web." These fungal threads, called hyphae, intertwine with tree roots and can link hundreds of trees together. Through these networks, trees exchange nutrients like carbon, nitrogen, and phosphorus. Older, larger trees sometimes called "mother trees" can send sugars to younger seedlings that lack sufficient sunlight to photosynthesize effectively. Trees also release chemical signals through their roots into the soil, warning neighboring trees of pest attacks or drought stress. Neighboring trees can then respond by producing defensive compounds. Some of this signaling also happens through the air via volatile chemicals, but the fungal root networks remain the most significant pathway for resource sharing.