Friends here just returned from Canada, a marathon road trip from Ontario to the east coast in just five days — through the land of fall colours. It’s mid-October, and the trees are at the height of their glory in eastern Canada, and I have to admit — I miss being there to see it. My friends very thoughtfully brought me home a handful of crimson maple leaves, which I promptly arranged in a quirky display around a tin of maple syrup at the centre of the dining room table.
The landscape here, both natural and human, is gloriously beautiful in many respects, but there really doesn’t seem to be much in the way of fall colour. Yesterday, I noticed to my surprise that the trees along the boulevard on my street are maple trees. Leaves are starting to fall, but they’re not red, or yellow, or orange… the leaves sort of turn brown and fall off, as though they just got tired and gave up. Why is that, I wondered? What’s the difference?
This article in today’s Toronto Star (“The Hues, The Hows, and The Whys”) helps explain the phenomenon, though scientists admit that there hasn’t been much research into the subject. Bavaria’s fall weather — grey skies and relatively mild temperatures — seems to be the culprit.
“ALGONQUIN PARK—First clue. On one side of the road through Algonquin Park the maples glow red. On the other, they’re on fire. The blazing side is the north, which gets more rays from a southward-creeping sun.
Second clue. Algonquin, one of the first spots in the province for the yearly transformation of fall foliage, is an elevated region often hit by the earliest cold snaps.
Third clue. Peel apart any two fallen red maple leaves that are stuck together. If one leaf shows green where it was attached, then the other shielded it from the sun.
The picture is Lake Massawipi in the Eastern Townships (“l’Estrie”) in Quebec, near the place I spent my summers as a child.
The combination of cold and sun merely answers one question — what triggers the chemical reactions that produce the blaze of colour now lighting up much of southern Ontario.
But how and why leaves undergo their spectacular transformation is a mystery proving a lot more difficult to unravel. In particular, science is struggling with the Darwinian question: what is the survival advantage that favoured the evolution of fall colours in some trees?”
“What’s truly astonishing, everyone agrees, is that the answers are still up in the air almost two centuries after naturalists began studying the fall colour transformation.
“Here’s a process that occurs in the most spectacular fashion smack-dab in the greatest concentration of academics in the world, in the northeast of North America. It’s the botanical equal of charismatic fauna like the panda bears. Yet it’s attracted little attention or funding,” says David Lee, speaking from the Harvard University research forest.”