Nature Notes


By Boak Wiesner

I felt as if I had never left. Again, a few flakes drifted down slowly. Again, the falling afternoon temperature was accompanied by a chill wind, more like Jack Frost slicing at my nose, rather than merely nipping.  All in all, a typical day for this winter. Yet, knowing that March is here, transitions were on my mind: transitions of the seasons, transitions occurring in the forest, transitions of one ecosystem to another.  Is this the last really cold snap?

Though this particular winter’s cold will persist for several weeks more still, it is only three weeks until the Vernal Equinox. This is the time of year when the increase in the length of days is changing the most rapidly. Soon, the sap will be running in the maple trees. One way to identify a Sugar Maple tree is by its twigs: they’re the color of milk chocolate.

DSC_0116The forest itself undergoes transitions both natural and not. After floundering through some hip-deep snow from the road down to the pond (and wishing I was a moose all the while, they with their long, flexible legs), I took a break near a large dead Sugar Maple. The trees that grow here natively are attacked by a whole host of various insects and fungi that are, of course, also native. As with all species, some members of a population are more resistant to them. This one could easily have been well over a hundred years old.

DSC_0101Some changes brought about by humans include the inadvertent importation of the fungus that causes Dutch Elm Disease. Infected trees attempt to stymie the effects of the disease by altering their xylem and, by doing so, cause their own demise. The effects of the disease notwithstanding, the bark of elms can be removed in large sheets in the spring when the new annual ring of wood is growing. Elm bark was used for covering the walls of the dwellings of the indigenous people around here. Elms were plentiful in the river basins were crops were grown.

DSC_0144What a good year to reflect on the remnants of the last Ice Age! Most of the lakes around here formed when the last one receded, of course. The steeply eroded hills of till moraine create an abrupt juxtaposition between forest and pond ecosystems. Just think, under the blanket of snow and the layer of ice, creatures in the pond can move around in the liquid water beneath.

DSC_0110Boak Wiesner is a Minnesota Naturalist volunteer.

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