December 22, 2023
“Mast” is defined as “the fruit of forest trees and shrubs” - in other words, nuts, pinecones, and seeds. “Masting” is the synchronized overproduction of that fruit. Every 3-5 years all the oak trees in a region will produce an overabundance of acorns. Pine trees have mast years every 7-10 years and 2023 is clearly one of those years! Masting is beneficial to trees as the intermittent over abundance means there are many more nuts or pinecones than the local squirrel population can possibly eat and therefore many more seeds that eventually become trees.
The overproduction seems to be triggered in part by environmental stress. It takes 2-3 years for a tree to make a pinecone so this year’s bumper crop of pinecones might be a response to the severe drought of 2020. The ability of trees to synchronize their mast years isn’t completely understood. Obviously, all the trees in the drought affected region would be simultaneously stressed so it makes sense that all our pine trees would have an abundance of cones this year. But there isn’t always an apparent environmental stress that can be attributed to the synchronized response. So how do the trees all know when to mast?
Researchers believe trees communicate through the vast mycorrhizal (fungi) network below ground and/or through the exchange of pollen and pheromones above ground. Such communication has been well documented in response to pests. When one tree’s leaves are being attacked by insects, the tree will manufacture bitter compounds that make its leaves less palatable. Once one tree starts manufacturing the compound, other trees in the area start to manufacture it as well, long before they are also inundated with pests.
Our pigs, who love acorns, spend lazy days sleeping under oak trees, waiting for the sound of an acorn hitting the ground. Unfortunately, though, they’ve mostly just been pelted by a plethora of prickly, sticky pinecones. Pigs do not like pinecones. The squirrels, woodpeckers, deer and most of the other inhabitants of our forest are thrilled, but the pigs are not. They look at me suspiciously, as if they are quite sure that somehow, I am to blame. In as much as I have personally contributed to climate change by living a fossil fuel dependent life, I acknowledge that they may have a point and I apologize, and honk sympathetically, as I drive by.