you see this towards spring when snows are starting to thin. in a stand of birch saplings the ground around the base of the trees is always the first to be exposed. why is this?
3 guesses
1)Birch has a light colored bark, reflecting the sun’s rays
2)The foliage prevents snow for accumulating around the base of the trees, less snow equals less weight, less compaction, and eventually the snow under the trees is less dense
3)The breaking down of organic matter under the stems creates heat, like a compost pile
I think that’s true of most trees*, not just birch.
The ground around the trunk of my maple trees is usually the first to reappear as the snow melts here in Minnesota. The ground is a bit higher around the trunks, but not much. And I think the snow is just as deep & dense as elsewhere – there are no leaves left to prevent accumulation, and no foliage around the trunks.
*Except evergreens – the branch cover means that snow accumulates around them later in the fall, and then it also means that snow underneath them is usually the last to melt in the spring.
sunlight seems to get collected by (and producing heat) or reflected by objects. i see snow melt depressions around trees and other objects.
I’ve also noticed the grass tends to be greener under trees in the winter (we don’t get a lot of snow down here, but the grass goes brown). I think this lends credence to the theory that somehow heat is being held in.