Ok, so I seem to remember reading a sign/information board there that said the Highlands used to be forested. I can see looking at pictures here on Whiteblaze that there are small trees (pines, mainly) growing amid the meadows. Why haven't they taken over? Obviously the ponies' grazing would limit regrowth, but they aren't everywhere in the Highlands, are they? Why don't the trees grow back?

I guess this question applies to the southern balds, as well...