I’m sure you’ve all noticed this if you’ve been in the woods in winter: as the season goes on (and on and on, if you live where I do), the first place snow starts to retreat a little is often around the bases of the trees. Why?
The answer is actually not all that exciting. A few plants, such as skunk cabbage, actually do generate their own heat early in the spring, but as far as I know that’s not the case for the sugar maples and other common trees here. The most likely explanation is just that the relatively dark color of the tree bark absorbs more heat and, as a result, melts the surrounding snow. Still, any sign of spring is cause for celebration at this point!