General site character
Shingle, Sea cliffs, Islets (40%)
Heath, Scrub, Maquis and Garrigue, Phygrana (5%)
Dry grassland, Steppes (55%)
Habitats that are a primary reason for selection of this site:
Vegetated sea cliffs of the Atlantic and Baltic Coasts
Isle of Portland to Studland Cliffs, including the detached peninsula of Portland, with St Albans (St Adhelm's) Head to Durlston Head, forms a single unit of cliffed coastline some 40 kilometres in length. The cliffs are formed of hard limestones, with chalk at the eastern end, interspersed with slumped sections of soft cliff of sand and clays. The cliffs support species-rich calcareous grassland with species that are rare in the UK, such as wild cabbage Brassica oleracea var. oleracea, early spider-orchid Ophrys sphegodes and Nottingham catchfly Silene nutans. The Portland peninsula, extending 8 kilmetres south of the mainland, demonstrates very clearly the contrast between the exposed western and southern coasts, with sheer rock faces and sparse maritime vegetation, and the sheltered eastern side, with sloping cliffs supporting scrub communities, where wood spurge Euphorbia amygdaloides grows in grassland.
Semi-natural dry grasslands and scrubland facies on calcareous substrates (Festuco-Brometalia) (* important orchid sites)
Semi-natural dry grassland occurs at this site in both inland and coastal situations on both chalk and Jurassic limestone. The site contains extensive species-rich examples of Brachypodium pinnatum grassland in the southern part of its UK range. Smaller areas of Festuca ovina – Avenula pratensis grassland occur on shallow soils on steeper slopes. Transitions from calcareous grassland to both chalk heath and acid grassland are also present. The site has well-developed terricolous and saxicolous lichen and bryophyte communities associated with open turf, chalk rock and pebbles, and flinty soils.
Habitats present as a qualifying feature, but not a primary reason for selection of this site:
Annual vegetation of drift lines.
Species that are a primary reason for selection of this site:
Early gentian Gentianella anglica.
This site on the Dorset coast, together with St Albans (St Adhelm’s) Head to Durlston Head, supports important long-standing populations of early gentian Gentianella anglica numbering several thousands of plants in floristically-rich calcareous grassland.