This has always puzzled me as I look at both antique map collections and user created maps. Do clumps of trees represent specific forests, or woods or what?

I used to think specific clumps of trees on a map represented forests like the "Cherokee National Forest" but that doesn't seem to make much sense on a map from the 1500s. It would seem there are huge tracts of lands covered in forests, so what is the motivation to only show 'some' trees on specific parts of a map?

I understand that different geographic areas have 'more' or 'less' forests, but on a map they often appear right next to each other.

Also, mountains are often covered in forests, but on a map they are not really represented this way.

I think I'm clearly misunderstanding the intent of the representation of "trees" on a hand drawn map.

Can anyone shed some light on this for me?