Trees represent the grove, which is a very ancient sacred place in most native tribes. Also known as Asherim, forests and trees represent Mother, and I believe Walter knew this.

Basically Mother Nature is God, and the tree/ forest motif is one of Her many symbols.

I see the bandages meaning to preserve or protect God, aka Mother. It's hard to describe this, but it makes sense to me.

An interesting note on Asherah, are the asherah poles..these are made by cutting off all the branches of a tree, just leaving the trunk..these asherah poles are found in the Forest World.