I've figured out what the problem is with the trees!
Its a tree texture all right, but you can't actually identify the individual trees when you look at the map full size because the texture is waaaay too large!
I only realised why it looked so wrong when I glanced again at the thumbnail. If you just look at that for a moment without clicking it, you can see the shapes of the individual trees, but... each tree in that texture is about the size of a whole block of houses in your city.
If you reduce the scale of your tree fill to about 1/4 the size it is (or even less than that), then it should look a whole lot better
It would look even better than that if you also carefully carved out roadways and small clearings for at least a few fields. Falconius is right about the need for roads, gates and nearby farmland, or the residents of your city will soon die of starvation. I know you are trying to recreate someone else's map, but surely it would be ok to improve the believability of the setup?