to be honest, I like the trees....or rather the forest
While it is logical that you have individual shapes for the mountains, it is also logical that you wouldn't be drawing individual trees...esp. by hand. You might want to try drawing small individual trees, if you REALLY want hand cramps... but I really like your Forest. If you want to add some extra "iso" to the trees, I would do some ore of what you did to the southern part of the east forest (add some darker green as a shadow) to all of the forest that faces south....either that or add some small vertical black lines as trunks (but no longer than the shadow you have as mentioned above). I would go with the shadow as that definitely creates a sense of canopy....If you are going to be showing the different types of trees, I would suggest for Pine types working with a "less bushy and more pointy" style of forest.
I do have a little crit on the western mountain range though...it looks like more of a wall with very little height difference between the peaks....and it doesn't really match the style of the colored ones already done.
Good job and have some rep for the hand drawn map