I don't quite see what you mean by the smear you mention. Can you elaborate?
It's looking good. I'd suggest moving the drop shadow to just below the forest rather than a universal all around glow. I'd also suggest darkening the vertical edge of the trees. At the moment the canopy looks like a flat layer on top of the trunks. You need to give it body. You could do this by having the pen texture just on the edges towards the viewer, or by running a darker green brush around the bottom edges.
Nevertheless, good stuff so far.