Alvars can be found on the islands of the Baltic Sea (Gotland and Öland Island in Sweden, Saaremaa, Muhu and smaller islands in Estonia) also on the coastal areas of western and northern Estonia. Smaller patches of alvars are spread also in the mainland part of Sweden in Västergötaland, Ahvenamaa and in the surroundings of St. Petersburg. Communities familiar to alvars have been described in Canada and North America in the vicinity of the Great Lakes.
Alvars formed the inseparable part of traditional cultural landscapes in Estonia as well as in Sweden. Changes in the land-use in the middle of the 20th century have strongly influenced these communities. Animal husbandry ceased in the fringe areas and unfertile alvars, and the former pastures were overgrown as a result of that. Until the 1930ies the area of alvars was estimably over 40 000 ha, fifty years later about 16 000 ha was left, of which approximately a quarter was almost overgrown. The disappearance of alvars was promoted by preterit campaigns of afforestation – the purpose was to plant trees into the limestone at any cost. However, the quality of the timber in such growing conditions is questionable, even if the trees started to grow. At present we lack the authoritative data about the actual area of alvars. Fortunately, studies have shown that an alvar is a dour community and preserves on areas that are already quite overgrown. There are good chances for a recovery, if it is possible to clean a partly overgrown community from brushwood and to use it as a pasture.