Water flows in a film over rock. When it strikes dry faces, it breaks into rivers. Then it reforms and becomes a lake again.
It is a story of water tension and its relationship to gravity. In other words, moss lives within water tension, which it becomes the lake.
Or both together.
Snow buckwheat forms lakes as well, and extends them in rivers into the air until they disappear at that point that the evaporative power of the sun is stronger than the water tension itself.
In other words, life lives within an energy field, and extends it.
There is no life outside the field.