Okay, time for a myth and history lesson:
1. The Aryans (of which the Norse culture is a part) are descended from the ancient Persians, and their lore reflects this. The Persians were well know for their wise men (magicians), who were extremely well educated and versed in a wide range of mystic/religious concepts. Most notably, Daniel (the guy from the Bible) left them with a lot of Jewish lore and some writings he instructed them to keep.
2. The tree of life is another name for the Sephirot. It's not a physical tree, but a concept of how an almighty being we can't comprehend manifests in a manner to help finite beings understand something about itself. Think of it something like
Flatland: A Romance of Many Dimensions.
Fascinating stuff really. Guess what? It's a
ring/cycle.
3. As of one of the upcoming Thor comics, they've shown the tree of life with the appropriate dots representing the Sephirot around it, so it's clear that Marvel writers are associating the tree of life with the Sephirot.