I’ve written before about the subnivean zone, the space under the snow but above the soil. Lots of stuff goes on there when we have snow. What happens when we don’t have this zone for most of the winter? Well, I guess we are about to find out.
Consider the weasel. You probably didn’t know that the color of their coats changes from brown to white based on the length of days. It is automatic. By the time winter arrives, weasels are white and able to work on top of snow, camouflaged, as well as below the snow.
Not this year. Weasels turned white, but there is no camouflaging snow. To you and me, a weasel now might look like a bit of Kleenex blowing across the lawn. Unfortunately, as fast as it can move, it is vulnerable to its enemies without snow cover.
How about foxes? They listen for the movement of mice and voles in the snow. Then they jump into the air and dive into the snow at 10 mph in order to catch their prey. Just the other day, I saw an article as to why they don’t hurt themselves catching subnivean prey. Their snouts are designed to slice through the snow.
You can guess what happens when there is no snow into which to dive: Fox populations go down, as it is more difficult to catch food. Without snow, it takes a bit more luck for an arctic or red fox to eat.
Voles, on the other hand, are OK without snow cover. They make perfectly adequate tunnels and dens in the lawn without snow cover, as we all know. These are good enough to keep voles protected. When there is snow cover, however, it is easier for them to tunnel. They are fine until the snow melts, which can cause drowning of vole pups.
Then there are all those spring-flowering bulbs I tell you to plant every fall. I can tell you that when I started writing columns, I did not recommend mulching over them. I sure do now. One winter without snow cover taught me an important lesson.
Then, too, when we don’t have snow cover, there is probably less decay in the yard. Normally the snow traps in a layer of heat just above the soil, right at the leaf zone, and this enables microbes that decay to thrive.
Obviously, when there is no snow cover, the heat is not trapped and the decaying microbes do not operate as efficiently as they would. Bummer. The solution, of course, is to have a thick layer of mulch just in case there isn’t snow.
And then there are the humans who greatly appreciate the snow cover. They ski over the subnivean layer. We hear plenty of griping among them of late due to the lack of snow. Ah, but those animals who normally live down there are the ones I really worry about. Hopefully we will get some more snow — did I really write that? — and all will return to normal. We shall see.
Jeff’s Alaska Garden Calendar:
Alaska Botanical Garden: The Garden is not just for the summer! Brighter Winter Nights, Fridays and Saturdays, 5-8 p.m., through Feb. 22. Experience the magic! Ice sculptures, kick-sledding, model train, luminarias, and more lights than ever! Get info at www.alaskabg.org
Grow lights: Got yours set up yet?
Pelargoniums: If yours are indoors, pick off flowers to keep them coming.