Trees & Vegetation

[I of the Storm]

I'm pretty sure that in Europe north of the alps there were large forests of really huge trees. Primeval forest, you know. REAL primeval forest. It had been there since the ice of the last ice age withdrew to the north, i.e. some thousands of years, and the few people living there couldn't do much about it. It wasn't only large and tall but impenetrable.
From space, Europe would - in general - have looked like the Sahara, only the other way round. A vast desert of trees and vegetation with only some "oasises" of habitable areas.
It was only during the middle ages that this changed (earlier in the west, later in the east). The travel accounts we have from northern french 10th century clergymen are terrifying. You had to know the area or have a good guide who did, else you were lost and never found again.