Trees use the summer solstice as a starting gun, scientists have discovered.
Keep reading for just $1
$1 trial for two weeks, thereafter $8.50 every two months, cancel any time
Already a subscriber? Sign in
Signed in as . Sign out
Black-Backed Gulls
Meth & HIV in Fiji
Dung beetles
Centro
Rogaining
On the longest day of the year, beech trees across Europe simultaneously start tracking temperature, and use that information to “decide” en masse whether to produce a bumper crop of fruit in the next season.
Pinning down what prompts these mast events is important in New Zealand, because we need to prepare for them: all that extra food in the ecosystem creates a plague of predators like rats, mice and possums, which turn on native birds and lizards once the fruit runs out.
We’ve long known masts are triggered by summer temperatures. But we had no idea the cue was so precise.
The solstice solution is one of those elegant findings that seems obvious in hindsight, says Dave Kelly, an emeritus professor and plant ecologist at the University of Canterbury who contributed to the Nature Plants paper. “I think it’s amazing… The beautiful, astonishing thing about it is, it’s so hard to measure,” he says, pointing out that in the week approaching the solstice, days lengthen by only a minute and a half. “They’re tiny differences. I would look at that and say, ‘No way could a plant measure that that accurately.’ But clearly, somehow, they are.”
Kelly studies snow tussock; that species, he’s found, also uses the solstice as a starting point. Whether our forests of southern beech, which fuel our most problematic masts, do, too, has not yet been checked—but Kelly suspects it is lining up with the others.
Black-Backed Gulls
Meth & HIV in Fiji
Dung beetles
Centro
Rogaining
More by Catherine Woulfe