I've been keeping a circular area of my backyard clear of snow under a maple tree by using a snow blower to concentrate the snow closer to the trunk of the tree. I've probably gone overboard doing it. The pile is roughly 4 feet in radius and about 5 feet high. Now because this is snowblower-blown snow, it becomes more dense when it's piled up, so this is becoming quite a heavy and dense pack of snow. The tree is about 18
- 20 inches diameter at the base, and about 12" diameter at the level where the snow is currently piled up. This is a sugar maple, if that matters, and (naturally) there is no road salt or other chemicals in the snow.
The canopy of this tree (and hence it's roots) extends far beyond where the snow has been piled up, so I don't think that oxygen availability will be an issue.
I'm wondering if this snow pack can cause any harm to the bark of the tree - perhaps not for the next month or so, but come april if the snow pack is still in contact with the trunk. This tree doesn't really leaf out until early may, if that's a factor.
Along the same lines, there are 3 shade-master locusts in the circular boulevard of our court. Their trunks are 3 to 4 inches in diameter. The circle is 50 ft diameter and is currently covered with an average of about 2 feet of snow-blower-blown snow. So these trees also have snow packed around their trunks. There is no salt used on our court - only sand, and only occassionally.
So my question about snow packed around tree trunks applies to those trees as well.