Nature's Remarkable Defence System
The Sweet Thorn tree (Vachellia karroo) possesses an extraordinary natural defence mechanism against overbrowsing. When subjected to prolonged feeding by herbivores, the tree increases its production of tannins, causing its leaves to become increasingly bitter and less palatable.
Even more remarkably, the tree releases ethylene gas into the surrounding air, effectively warning neighbouring trees to begin producing tannins as well. This sophisticated communication system encourages browsing animals to move on to other areas, reducing pressure on individual trees and helping to ensure the long-term survival and health of the Sweet Thorn population.
