May 3, 2020
This is miscellany, but it's pretty interesting. Evidently plants actually scream when damaged, and the very high frequency sound comes from bubbles they emit when under stress...
Scientists Heard Plants Produce Loud Screams When Damaged! #teamtrees
Dec 20, 2019
The video does not (nor do the researchers) actually play the sound of those screams, though, which would make the discovery much more memorable (even though I prefer not to hear screaming sounds).
If this sounds far-fetched, consider that plants are also known to communicate with each other through electrical and chemical means...
It shows instead that trees of the same species are communal, and will often form alliances with trees of other species. Forest trees have evolved to live in cooperative, interdependent relationships, maintained by communication and a collective intelligence similar to an insect colony. These soaring columns of living wood draw the eye upward to their outspreading crowns, but the real action is taking place underground, just a few inches below our feet.
“Some are calling it the ‘wood-wide web,’” says Wohlleben in German-accented English. “All the trees here, and in every forest that is not too damaged, are connected to each other through underground fungal networks. Trees share water and nutrients through the networks, and also use them to communicate. They send distress signals about drought and disease, for example, or insect attacks, and other trees alter their behavior when they receive these messages.”
Scientists call these mycorrhizal networks.
To communicate through the network, trees send chemical, hormonal and slow-pulsing electrical signals, which scientists are just beginning to decipher.
Trees also communicate through the air, using pheromones and other scent signals. Wohlleben’s favorite example occurs on the hot, dusty savannas of sub-Saharan Africa, where the wide-crowned umbrella thorn acacia is the emblematic tree. When a giraffe starts chewing acacia leaves, the tree notices the injury and emits a distress signal in the form of ethylene gas. Upon detecting this gas, neighboring acacias start pumping tannins into their leaves. In large enough quantities these compounds can sicken or even kill large herbivores.