Map in first post - well done, and welcome! We always appreciate those willing to pitch right in. Therefore worth a bit of starter reputation (the little squares beneath peoples' names in posts).

Initial reaction - nothing necessarily wrong with great swaths of forest. It is said that when Europeans first showed up in North America, a squirrel could run tree to tree from the Atlantic to the Mississippi. Ain't hyperbole The Best Thing Ever?!?!?! :-) In any case - there's plenty of reasons forests could exist in broad areas alongside human-developed lands. Soil too crummy for agriculture? Holy areas not to be touched? Crown lands held for hunting? Critters too tenacious & dangerous to permit clearing? Abandoned farmsteads from a hundred years before (remembering big forests need not necessarily have been there forever, and regrowth happens startlingly quickly)? Plantations (maple syrup and turpentine being the trade goods of choice??) Simple rugged terrain? Bet you can devise a dozen more - and better!

Do you LIKE those various landcover types where they are? I see nothing inherently implausible going on. Especially since you wisely say those watercourses are rivers AND canals :-).

Is the map for your purposes, as a writing aid? Or will a version be published with the book(s)? If the latter - paper or digital? Color maps in paper books take a lot of selling....