The area of alvars in the 1950ies was approximately 44 000 ha and they situated mainly in the eastern part of Saaremaa Island, Muhu Island and in the north-western part of Estonia. In the end of the 1990ies the area had decreased to 5000 ha but part of this was seriously overgrown with junipers. There are about 300 ha of alvars that are under protection – in the national parks of Vilsandi and Lahemaa, in the nature reserves of Matsalu, islets of Hiiumaa, Sarve peninsula and Kostivere.