>>2520more atmospheric perspective, make shadow areas take the color of the sky, the perspective is fucked up in the lower left corner, all the trees look like they are on the same plane (saturation and level of detail too unified), ugly tangent between the top and bottom leftmost trees.
In short, separate the planes more.
Also the composition looks unfinished, nothing is happening in this piece. Show scale by repeating design elements. The bottom right corner begs for something to be put there