Lines of Communication
Plants form communication lines among themselves and their neighbors. This provides a direct early warning system for threats in the neighborhood.
Most land plants are connected indirectly through mycelial fungi. The relationship between the fungi and plant is mutualistic.
Besides nutritional benefits, plants employ the fungi as communication conduits. For plants without runners, mycorrhizae make a fine chat line.
Such communication improves a plant’s fitness. Plants are better able to prepare themselves for attack and more successfully avert damage.
When attacked, plants emit volatile airborne compounds that warn of their situation and solicit help from the natural enemies of their assailant.
Neighboring plants eavesdrop on each other and respond by priming their own defenses. They may do so quite selectively.
The plumbing of poplars is such that leaves do not have a direct connection to their neighbors. But volatiles released by a leaf under attack waft to neighbors, divulging data about the nature of the attacker.
Should an attacker move to graze nearby, the new prey revs its defense faster. The plant itself benefits by its own emissions but so do neighboring plants.
