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Lichens remain exposed to winter

A clump of antler lichen (Pseudevernia) on a tamarack branch. (Photo by Larry Weber)1 / 2
A growth of beard lichen (Usnea) grows on a thin twig. (Photo by Larry Weber)2 / 2

The light snow that fell last night happened before midnight. So when I step outside this morning, I see a new covering that reveals the movements of the wildlife during the rest of the winter night. Temperatures are in the 20s and most of the wintering critters are likely to be active.

On the driveway, I see tracks of a couple of deer that have been passing between the woods, where they spend much of the day, and the birdfeeders, where they snack on fallen sunflower seeds at night. Nearby are the tracks of squirrels that are going to the feeders to take some breakfast seeds. We are now at midwinter and both of these common wild mammals have been doing well throughout this season. By this time they have formed regular routes and trails where they go daily. And I have been seeing their tracks just as often.

Dawn starts to light up the day, but I can still see the waning quarter moon in the west. Both Jupiter and Venus linger with the glow as well. With the rising sun, the planets Mercury, Saturn and Mars are now too dim to see.

I walk through the woods where I pass a few tracks of deer mice hopping over the snow and an abandoned grouse shelter, recently dug in the snow. From here I pass along the edge of the lake to the swamp. I'm surprised to find some slush on the lake. I'm also surprised to not see the coyote tracks that I have seen almost daily.

A snowshoe hare has been active on its trail and I find a couple of vole holes at the swamp. Voles (meadow mice) move freely in the subnivean zone under the 6-8-inch snowpack. Occasionally they dig to the surface, making finger-sized openings in the snow.

The sunlight now illuminates the swamp as I walk over it. Crows and ravens are calling in the distance while a woodpecker, either hairy or downy, drums in some nearby tree. Wandering through the swamp in winter is always an interesting walk.

Though we often tend to look for animal signs during a walk, I find the plants offer much to see as well. The snowpack covers many of the lower plants, but others are above. Alders and willows grow along the edge. I'm sure they'll be growing and opening buds in coming weeks. Here, too, I find spirea plants that held flowers late last summer and irises that now hold pods from their delightful purple flowers of last spring.

Out in the wetter part of the swamp, I walk over the snow-covered ice. Cattails abound in this site and now have their hotdog-shaped brown seeds. Sedges, mostly bur-reeds, are bent by the snow and patches of leatherleaf plants stick out from the snow, many still with leaves.

I pause to look at a tamarack growing out here in the middle of the swamp. This conifer, unlike the others, drops its needles in the fall. As I look closer, I see that though there are no needles, there is much more here. The tree has many miniature cones, only about a half-inch long. And the tree's trunk and branches are crowded with lichens.

Right out in the open, the tree is exposed to the cold conditions of winter. But it also gets the sunlight that these hardy lichens need, and they thrive here. The lichens (the ch is pronounced like a k) hardly look alive now, but a close look shows that they are composed of both algae and fungi. While the algae use the sunlight to make food, the fungi hold the needed moisture. Both go dormant now in the winter chill. They are not growing much now but these lichens are easy to see. I note several kinds.

The various kinds fall into three large groups, determined by the shape of their growth. Crustose lichens grow flat on the substrate, rocks and trees. Foliose lichens are leaflike, often on trees, especially the stump. Fruticose lichens look like little bushes, frequently on tree branches.

Though I see all kinds here, it is the fruticose, the little bushes, that I take a closer look at on this tamarack. Unimpeded, these lichens are able to grow quite well on the branches. I see dozens of them. Most are in clumps of 1-2 inches. With many branches, the flattened growths superficially resemble antlers. Indeed, this group is often called antler lichen.

Some of the clumps, however, are made up of more thin parts and do not look like antlers. This kind, beard lichen, is common on many local trees, sometimes growing quite long. The growths I see are also about 1-2 inches. These fruticose lichens blend with the other abundant ones here. The hardy lichens make use of these exposed branches of a tamarack in the swamp. In a couple of months I'll be seeing red-winged blackbirds on this tree, but now it is interesting to note the lichens that winter here.

Retired teacher Larry Weber is the author of several books, including “Butterflies of the North Woods,” “Spiders of the North Woods” and “Webwood.” Contact him c/o budgeteer@duluthbudgeteer.com.

Larry Weber

Retired teacher Larry Weber is the author of several books, including “Butterflies of the North Woods,” “Spiders of the North Woods,” “Webwood” and “In a Patch of Goldenrods.” Contact him c/o budgeteer@duluthbudgeteer.com.

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