comments and suggestions welcome
You need some other plants placed near or around your tree. It looks naked. :)
Clear your atmosphere.
Get some fill lights (at least a couple), since I see a lot of dark contrasty (and to me, uncomely) shadows. Maybe some light up front to fill in the really big shadow in front.
I really like the perspective on this and the terrain looks pretty well developed, though I'm finding there's so much to terrain development.