|Heather, Calluna vulgaris in bloom|
Pleistocene glaciations wiped out Icelandic Boreal Forests. Succeeding glaciations left fewer and fewer species of flora. Iceland is far from Europe and North America, so species were not easily reintroduced onto the island. The only forest forming tree to return to the present interglacial was the downy birch.
Other tree species native to Iceland are the uncommon Rowan (Sorbus aucuparia), the extremely rare aspen (populus tremula) and abundant shrubby willows.
Human settlement, begining about 1140, served to decimate the remaining birch forests. The grazing of sheep, an important source of wool and food for Icelanders, prevented the regeneration of the birchwoods, even after human clearing had begun to decline.
|Downy Birch leaves|
|Nearly a million sheep roam Iceland freely in the summer. |
They are rounded up come fall.