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By Greg Lecker
Unseasonably cool weather and early snow presents us with the dissonance of autumn foliage AND snow!
It’s not uncommon for oaks to retain their leaves for much of the winter,
Autumn oaks bear reddish-brown leaves – underappreciated compared with maples and other trees. And yet, the juxtaposition of mottled green and red hues heightens the perceived saturation of these hues.
Walking around the not entirely frozen Green Heron Pond, I’m happy to have the paths and boardwalk entirely to myself – except for one other solitary walker. We commiserate about our foggy glasses – the result of our pushing up our masks. He walks beyond; and I carry on. The tamarack (larch) trees have not discarded their leaves (needles). In fact, they have only partially transformed from green to yellow-gold.
Tree foliage is not the only natural element that seems to be paused between states. The ponds and especially the somewhat warmer water flowing underneath the boardwalk remain open in the small center of the pools. Green duckweed looks summer fresh even as it is surrounded by freshly fallen snowflakes.
Red-twig dogwood has transformed its stems to its fiery winter red. Even its center leaf vein runs red – like blood.
I’m relieved that there are still a few sugar maples that are holding onto their leaves.
Deciduous trees lose leaves in autumn to conserve moisture. In addition, decreased sunlight produces reduced photosynthesis rates. As temperatures fall, photosynthesis slows, and as days shorten, less light is available to enable photosynthesis. Plants form a partition (abscission layer) between twig and leaf stem. The barrier seals off the flow of nutrients and water; and trapped sugars are used to produce anthocyanin. Leaf attachments weaken, leaves fall.
Walking back to the Oswald Visitor Center, I pass the Maple Sugar House and the Frog Hollow workshop. I wish for success for all the work to be done in these workshops for the maple sugar syrup harvest to come in 2021!
Greg Lecker is a Minnesota Master Naturalist Volunteer.
Thank you so much for this. It’s good to help us appreciate all seasons. Winter is not my favorite, but I am always stunned by the bare trees against the snow or the sky—they are uniquely beautiful.
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