In "Okay For Now," what does the metaphor "dark woods" represent?

In the book, the Yellow Shank bird is associated with the dark woods. However, the metaphor "dark woods" represents the defining moment of confrontation between Doug and his abusive father. To Doug, the "woods" is a treacherous and frightening place; to confront his abusive father, he must venture into this dark place alone, as no one else in his family dares to accompany him.
In Chapter Five, we learn that Doug's father has appropriated the hundred dollars and signed baseball that Doug won at the Trivia Contest. Later, Doug confronts him, despite knowing that he's putting himself in physical danger by doing so. Mr. Swieteck lies about having received the prizes, but Doug knows what Mr. Ballard told him.
At this time, Doug is ready to call his father a liar (because that's what Mr. Swieteck is), but he's afraid. Doug has never openly challenged his father before. Suddenly, in a moment of inspiration, he remembers the Yellow Shank and how the bird stands facing the dark woods ahead of him. Doug imagines that the Yellow Shank will eventually walk towards the woods, despite the uncertainty that awaits him.

He's staring into this dark place, and he's just about to cross the river that divides him from it...he knows what he's getting into, but he does it anyway, calm and smooth and straight. He's going to step into the middle of the picture, where he should be, with the light in back of him and the dark ahead. His whole world is waiting for him to do that.

He's so inspired by the Yellow Shank that he goes ahead and tells Mr. Swieteck that he's a liar. Mr. Swieteck lunges at Doug, but he misses him three times; he only manages to clip Doug slightly when the boy pushes through Ernie Eco's arms. Apparently, Ernie Eco isn't too successful either in his efforts to help Mr. Swieteck corner Doug. For his part, Doug counts the confrontation a victory. Despite his fears, he has braved the "dark woods," and he's justifiably proud of himself for confronting his abusive father.