wall constructed around a tree to maintain the original grade between the trunk and the wall. with a raised grade beyond the wall. Used to maintain adequate oxygen levels in the root zone and to protect the trunk from burial.
A tree well, also known as a spruce trap, is the space around a tree under its branches that does not get the same amount of snow as the surrounding open space. This creates a void or area of loose snow below the branches and around the trunk that is dangerous to any hikers, snowshoers, skiers, and snowboarders who fall into them. If someone lands in such a well, often as a result of a fall, it can be too deep for them to climb up the surrounding loose snow before they are buried. Making the situation more dangerous, they often fall into the well head-first and as the result of an accident which could leave them injured or unconscious.