"nothing has been able to reestablish in the harsh conditions" AFAIK the main factor in those "harsh conditions" is sheep farming. Sheep on Iceland are kept pr

"nothing has been able to reestablish in the harsh conditions" AFAIK the main factor in those "harsh conditions" is sheep farming. Sheep on Iceland are kept pretty much without any fences. They will eat saplings and small tees. There is an amazing photo somewhere of a little island in a river that's in essence covered in forest. Everything around it is mostly moss as you call out. Another factor, especially on the Rejkyanes peninsula towards the airport is that this is also a very young part of the island. It's mostly still lava rock. This isn't representative of other parts of Iceland. Source: visited 5 times and travelled the island extensively.=