The Deer Forest Blog reported that a recent study found that some trees know when they are being browsed by deer…and they put up a defense mechanism to stop it.
The study looked at beech and maple saplings that comprised the regenerating under-story in a forest, and thus were often browsed by deer. The researchers simulated deer browsing by clipping buds off the saplings and then applying deer saliva to the wounds.
They found that the saliva caused the saplings to increase production of salicylic acid, which signals a tree to produce more tannins. Tannins are bitter and not palatable to deer. The scientists concluded that the production of tannins may deter future browsing by deer on those saplings. Saplings that were clipped off but not treated with deer saliva did not produce tannins or initiate other defense metabolites.
Bottom line: Some species of saplings that are browsed by deer initiate a defense mechanism so that the trees are literally not eaten alive by the animals, thus perpetuating the growth of under-story and the health of a forest.
Fascinating! Isn’t nature grand?