There is usually four phases of a Miao wedding:
Before the wedding:
The Welcoming ceremony
Wedding ceremony
Marriage crying
The tree burial is a kind of funeral custom that the person y would be wrapped in tree bark and hung on the tree after death.
cave burial is also a common burial style for Miao people (Many other Chinese minorities also have the tradition of cave burial).
Now, interment have become the main burial style used by the Miao people.
How did this tradition came from?