A Moosring

In colder climates several species of the genus "Racomitrium" often cover huge areas more or less monotonically - sometimes many square kilometres. In such locations one can find black rings of dead moss, such as can be seen on the picture. Sometimes there are even several concentric rings. They are caused by a fungus, which obviously kills the moss, when ist develops its fruits. I took the pictures in the þorsmork in Iceland.

The inner ring has a diameter of about 20cm. In the lower right corner of the picture one can see an arctic poplar species.