Downland
A downland is an area of open chalk upland. This term is especially used to describe the chalk countryside in southern England. Areas of downland are often referred to as downs.
Downland is formed when chalk formations are forced above the sea level. Over centuries the chalk is slowly eroded to form sloping hills. Chalk deposits are very porous so the height of the water table in chalk hills rises in winter and falls in summer.
In temperate regions chalk downland is typically calcareous grassland, a habitat formed by grazing farm animals. Prior to farming, these areas would probably have been covered with forest. Chalk downland is often unspoilt because it is often unsuitable for modern arable farming, horticulture and housing, due to the poor shallow soil and difficult slopes. Many of the downland ranges have been protected against future development, due to their unique biodiversity.
Where the downs are being erroded quickly steep white chalk cliffs are formed such as the White cliffs of Dover.
Chalk downland can be found in many places, including:
There are extensive Chalk Formations under southern England;
- Berkshire Downs
- Chiltern Hills (Dunstable Downs)
- Cranborne Chase
- Dorset Downs (Hambledon Hill, Hodd Hill, Maiden Castle)
- Isle of Wight (The Needles)
- North Downs
- Purbeck Hills (Ballard Down, Lulworth Cove, Old Harry Rocks, White Nothe)
- Salisbury Plain
- South Downs (Beachy Head, Eastbourne,)
- White cliffs of Dover
In the United States:
- In the extensive Austin Chalk formation, which underlies much of central Texas