Lowland Calcareous Grassland

Lowland calcareous grasslands develop on shallow lime-rich soils generally overlying limestone rocks – in Sussex it occurs exclusively on chalk.

Chalk grassland sward

Photo: Sussex Wildlife Trust

Why is it important?

  • Chalk grassland can support over 50 species of flowering plant per square metre, including a number of nationally scarce species.
  • Many species of rare invertebrates are found including hoverflies, molluscs and moths.
  • Rare assemblages of mosses and lichens can be found on some chalk grasslands.
  • The grasslands and associated patches of scrub provide breeding and feeding habitat for many birds including scarce species such as Stone Curlew.

Lowland Calcareous Grassland in Sussex

Around 2600 hectares of calcareous grassland remains in Sussex, with the South Downs representing one of the major areas in the UK. It is estimated chalk grassland now covers only around 3% of the South Downs, where it is predominantly confined to steeper slopes. It continues to support a rich diversity of animals and plants including many rare species.

What are the threats?

  • Agricultural intensification by use of fertilisers, liming, reseeding and ploughing.
  • Lack of grazing stock results in dominance of coarse grasses and scrub, and a decline in overall botanical diversity.
  • Recreation effects including disturbance of wildlife, compaction of soil, trampling and increased nutrients in soil. High public access can also cause conflicts where grazing animals are present.
  • Isolation and fragmentation of sites reduces dispersal opportunities making species more susceptible to extinction.
  • Losses can result from development including redevelopment of abandoned chalk quarries which can develop good quality grassland.

Some associated species

  • Linnet Carduelis cannabina
  • Whitethroat Sylvia communis
  • Adonis Blue Polyommatus bellargus
  • Glow-worm Lampyris noctiluca
  • Round-headed Rampion Phyteuma orbiculare
  • Yellow-wort Blackstonia perfoliata

Small Blue

Photo: Paul Marten/Sussex Wildlife Trust

Advice on lowland calcareous grassland

After Minerals
Buglife
Natural England
The Grasslands Trust
The Grazing Advice Partnership

Sussex Targets

Biodiversity Action Reporting System Website

Download the Lowland Calcareous Grassland Habitat Action Plan