This habitat comprises sparsely vegetated volcanic features such as active volcanos, recently formed lava streams, and older lava fields and rocks, as well as volcanic slopes and plains in the subarctic and arctic regions of Europe, mostly on Iceland and parts of Jan Mayen. The rock surfaces and volcanic soils are only slowly colonised, are nutrient-poor and subject to continuing effects of wind erosion and desiccation. Vascular plants and few and cryptogams are generally sparse but accumulating soil and deptressions benefiting from snow-lie may sustain more extensive vegetation.