The detection of neighbors by plants

Whether plants detect and respond to neighboring plants is crucial for a complete understanding of how plants interact with each other. If plants do not detect and respond to neighbors, interactions are determined by the way in which each species alters available resources and the passive responses of nearby plants. If plants do detect and respond to neighbors, interactions are not regulated by resource availability alone. Most reports of plants detecting and responding to neighbors have focused on avoidance, where either roots or shoots grow away from a detected neighbor. However, a recent paper by Gersani and colleagues has demonstrated that soybeans increase root growth in soil shared with conspecific competitors. Their findings shed light on a new ecological role for noncognitive behavior in plants.