It’s ‘acornucopia’ this year as oak trees overproduce progeny

    (Emma Lee/WHYY)

    (Emma Lee/WHYY)

    If it seems to you like the world is awash in acorns, you’re not nuts.

    This is a “mast year” for several species of oak tree, forestry experts say. That’s when oak trees go a bit bonkers and produce 10 times as many acorns as usual.

    Arborists say the phenomenon happens every few years, but they have few answers about what causes the boom and bust cycles.

    Mast years may be one way oaks outwit their predators and ensure long-term survival, one expert said.

    “During a mast year, oaks produce so many acorns that there are plenty of seedlings, even after the squirrels and chipmunks are done” eating, said Marc Abrams, a professor in Penn State University’s ecosystem science and management department. “This year is just really exceptional.”

    Acorns and squirrels may be synonymous, but acorns feed far more than just tree rodents. Deer, turkeys, mice, birds, rabbits, raccoons, insects and other creatures find acorns appetizing. Mast years allow wildlife to feast until they’re gorged, while still creating enough acorns to seed new trees in a phenomenon called “predator satiation.” Hickory and beech trees also have mast years, Abrams added.

    What’s good for nature, though, isn’t always good for humans.

    Because a single large oak can produce 1,000 acorns during an average autumn, a mast year means it’ll instead drop 10,000 acorns. That makes even walking near an oak tree during a mast year a risky endeavor, with acorns plunging out of the sky like squirrel-lodged missiles and gathering on the ground like marbles to send you sprawling.

    “We sleep with the windows open most nights. The acorns fall and hit the car roofs so often, it wakes us up,” said Chris Illuminati, who has an oak towering outside his Lawrenceville, New Jersey, home. “When they hit the right spot, it sounds almost like a gunshot.”

    Now, what to do with all those acorns?

    You can boil out the tannins, make them into a flour, and eat them like the Native Americans did. Or you can get crafty. You apparently can even use them to defeat dermatitis and diarrhea.

    But it’s probably a bad idea to throw them. That could help you get fired or arrested.


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