I like the background you have set up and the overall layout of the map.
Some points of criticism/questions:
- The river splitting doesn't look really natural (but you have to wonder does it have to be?).
- I don't think you should have put any trees on the hills. In between and around is ok, but right on top of them looks weird.
- What's that brown line? It looks line another river or maybe a border...
- Did you chose not to put any effects on the trees? Like them dropping a shadow?
Keep up the good work!