Belgian Journal of Botany vol:138 issue:1 pages:24-38
In Belgium, most calcareous grassland relics are associated with Devonian limestone substrates in the Viroin valley, which is part of the Calestienne region. Previously grazed by sheep, these grasslands are characterised by an extremely high species richness and many rare plant species. Despite their high biodiversity, a detailed phytosociological. classification and an ecological description of the relics of these grasslands do not exist.