The "sacred grove" is another mythic motif; it represents an enclosure where the hero is changed. Ancient peoples widely believed the tree to be infused with creative energy. Forests came to symbolize mystery and transformation, and they were home to sorcerers and enchanters.
When Luke leaves Hoth, he travels to the planet Dagobah to undergo training with the Jedi Master, Yoda. The hallmark of Dagobah is its large, oddly shaped trees.
Forests can also symbolize the unconscious mind, where there are secrets to be discovered and perhaps dark emotions or memories to be faced. In this forest Luke battles an image of Vader, prefiguring his combat with the Dark Lord later in the story.
Into the Belly of the Beast || EMPIRE STRIKES BACK || Sacrifices