If you ask me I think the shadows and sunlight are inverted. In other words: That what is shadow should be a bright patch of sunlight coming through the leafs. The sunlight should be shadows from the trees, that separate the various area's.
At least that is how I think about it. And when the shadows come from the sides, you can make them bigger to make it darker. You can also make a bridge with a shadow from one end to another.