Ok, we finally got some snow! It was the very beautiful type of snow that lined all the trees and bushes. What does that mean for the Lake? Is snow environmentally beneficial? (I’ll explore that in today’s blog post.) And as the stewards responsible for the Lake’s health, what can we do to remove snow and ice in ways that are healthy for the lake? (We’ll look at that in the next blog post.)
The kind of weather we’ve been having recently — freezing temperatures without snow — isn’t so great for the Lake. The ground gets very hard, and the soil freezes deeper and deeper. This hard ground cannot as effectively absorb or filter any stormwater runoff. As a result, contaminants carried by the stormwater can find their way more easily into the Lake and its tributaries.
Our all-important vegetative buffers, (the trees, bushes and plants that line the watershed and keep the soil from eroding in the spring, summer and fall), depend upon snow cover in the winter to provide necessary insulation. The snow keeps their root systems from freezing. Fresh un-compacted snow is typically 90 to 95 percent trapped air. This air barely moves, and the flow of heat from the warm ground to the cold air above is reduced. A study done at minus 14 degrees Fahrenheit found that the surface temperature of soil under a 9-inch deep snow cover was a relatively balmy 28 degrees!
The Lake’s vegetative buffers and forest also depend upon the snow for moisture; the snow prevents the plants from drying out during the cold months. Even dormant plants lose moisture in the winter as water evaporates through their branches. Evergreen plants, which keep their foliage throughout winter, are at even greater risk of injury from lack of moisture.
(For more on why buffers and trees are so crucial to the wellbeing of the Lake, check out the stories in the following two LGA newsletters: Nov/Dec 2010 and June/July 2010.)
Looking from a more global perspective, we really do want the snow. According to a report from US News and World Report, research from the University of Michigan shows that decreases in the Earth’s snow and ice cover over the past 30 years have exacerbated global warming more than models predicted they should have. Snow helps to reflect the sun’s light and heat back to space. But when less snow falls, more ground is exposed to the sun and that ground absorbs more heat; this is a main contributor to the planet’s warming trend.