Congrats on making your first map. I'd suggest to, instead of doing 'periodic taller trees' which as pointed out resemble your wave markers, add in a few clearings to break up the tree mass. It's a lovely first try. I can tell that the east is dunes but I'd suggest doing sand ridges around them to finish the effect. I'm sure your players would be very happy with this as a handout intended to be drawn by someone in universe!