Acacia Trees Communicate Danger

Most of you know acacia wood from furniture or decorative wood items. It’s even used as a food additive sometimes. But there’s more going on inside acacia trees than you might think at first glance. In 2015, German forester Peter Wohlleben offered a controversial idea: trees can talk. As the vampire tree, there is evidence that trees behave in groups rather than as solitary organisms. They share resources and can help each other. Underground, tree roots communicate with fungi and exchange signals. This may include things like alerts about insect assaults, for example. Chemical signals sent from one tree to another can alert other members of the colony. Nutrients are shared, which is how saplings survive when they are too little to reach the sunshine beneath the canopy of larger trees. But there's a lot more.

If a giraffe starts eating the leaves of an acacia tree, the plant produces ethylene gas. This gas, when it reaches other acacia trees, causes them to start producing tannins in their leaves. Large quantities of tannins will make the giraffe sick. It could even kill it, so the giraffe is forced to stop eating. All because one tree was able to signal other trees. Even more bizarre is that giraffes know this. They graze with the wind, and walk ahead of the gas clouds because they have evolved to be aware that acacia trees do this.