Chalk grassland along The Ridgeway was created thousands of years ago, probably by grazing animals that created gaps in the tree-covered downs which were then cleared further by early man. Livestock grazing kept it clear of woody plants until this declined in the mid-19th century after which wild rabbits took over the grazing role. Their numbers have reduced in many places because of myxomatosis but chalk grassland still needs to be managed, otherwise it is invaded by shrubs and trees and the rare plants are shaded out and lost forever.
The soil consists of a thin layer of topsoil over chalk. It is dry and poor in nutrients which discourage the common, fast-growing plants from dominating. As a result, chalk grasslands support many species that would not be able to compete in more nutritious soils and is one of the richest habitats for plants and associated insects in Britain.