It called my attention that in South Finland there are pine trees which apparently are able to grow with their roots barely covered with soil. Some sit directly on hard rock with all their roots visible. I took two photos of this on 2006: http://pix.hamoid.com/finland2006/nature_is_a_huge_canvas.jp... http://pix.hamoid.com/finland2006/going_back_to_my_roots.jpg Those trees survive winter winds at -22F (-30C) with very little sunlight, although sometimes winds knock them down making a vertical wall out of the exposed roots.