A long coastline with both low and dune beaches, low bays with small islets and holms and thousands of years of land use has formed the structure of the islands' forests, meadows, arable land and pastures, the result of which is a mosaic landscape and the diverse nature of the islands. Terrestrial habitats contain pine forests, mixed spruce and deciduous woodlands, juniper and coastal meadows, swamps and peat bogs. The alvar forests (spruce, pine or birch forest on limestone plains with thin soils) are of particular interest. Parts of the area are designated as wetlands considered important according to Ramsar specifications.