Midwinter Snow Is a Boon For Plants and Animals

Shoveling last weekend's white stuff may have been a chore but, along with skiers and snowboarders, plants and animals benefit from snow cover in the dead of winter.

For about a month after the shortest day of the year, the earth below us continues to lose heat energy it has stored up during the warm months, reaching a nadir just about now. Although other factors are involved, the heat loss cycle means that the coldest time of winter generally begins near the end of January. Not to say that severe cold snaps cannot occur at any time but, in terms of energy loss, now is the big chill. Saturday's snow came just in time, because cold temperatures without snow cover can be damaging for many plants and animals.

While the surface of the snow can be truly frigid, losing immense amounts of heat through radiation, temperatures underneath may be several degrees warmer. The top of snow cover, not its bottom, has the lowest temperatures. One study of temperatures  just below the surface of soil in winter showed a difference of about 30 degrees Farenheit between times when the ground was bare and when it was covered with snow.

The surface of snow is so cold because it reflects all wavelenths of solar radiation equally well, which his why snow looks white. If it reflected the orange in sunlight's spectrum, that is the color it would project.

The insulating effect of snow arises from the fact that it is filled with air pockets, like a feather down comforter, and thus prevents against the escape of heat. As snowflakes form from water vapor condensed by freezing temperatures, air is trapped in their crystaline structure. When it piles up on the ground the air is held between the crystals, providing a feather bed effect.  

The benefits of snow may not be particularly apparent when it loads the branches of shrubs to the breaking point. Clearing fallen snow off tender shrubs to keep branches from breaking, however, may cause more harm than good because the snow can prevent freeze damage.

Without snow cover, severely low temperatures can devastate worms, insects and other creatures inhabiting the soil. Shrews and other small mammals that live on the ground or just beneath the surface benefit greatly from snow. Even with only an inch or two of snow on the ground, the  ridges of their tunnels can be plainly seen meandering over lawns and other open areas. Shrews and small rodents not only find protection from predators under the snow but enjoy its comforting warmth as well. When the wind really howls and temperatures plummet, even birds will find refuge in deep snow.

So, as far as plants and animals are concerned, snow is a boon, as long as it's not too much of a good thing.

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Rod building classes at Rivers End Tackle in Old Saybrook begin the last weekend of January. For information, call 860-388-2283

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The CT Fly Fishermen's Association will hold its AnnualFly Fishing Expo from 9 a.m. to 3 p.m. Feb. 4 at Maneeley's in South Windsor. For information call 860-467-6514.