|IPA Factsheet - Dorset Coast - Isle of Portland to Studland Cliffs|
Site Description The Dorset coast runs West from Studland Cliffs for 40 Kilometres, up to and including the detached peninsula of Portland This whole section has recently become a World Heritage site known as the Jurassic Coast, with exceptional fossil and geological interest. The cliffs are largely formed of hard limestone, with chalk at the eastern end, interspersed with slumped sections of soft cliff of sand and clays. Cliff top habitats and the fields nearby 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, Nottingham catchfly Silene nutans, and the English endemic, early gentian, Gentianella anglica. The Portland peninsula, extending 8 km 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 rich scrub communities. 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 CG4 Brachypodium pinnatum grassland in the southern part of its UK range. Smaller areas of CG2 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. Eurhynchium meridionale occurs in both Portland and in one Purbeck site, the only UK locations. The coastal areas have superb calcicolous communities, with probably the richest site in Dorset at the east of the chalk ridge. Here Scapania aspera has its only recent Dorset site. Studland Dunes are of national importance as the only large dune heath site in the south and south-west of Britain. The site represents shifting dunes along the southern English shore and the lichen communities are of particular interest. The seaward dune ridge supports marram Ammophila arenaria vegetation mainly of NVC type SD6e Ammophila arenaria mobile dune, Festuca rubra sub-community, though three other types are represented. There are transitions to embryonic dunes, which are rare on the south coast partly because of intense recreational pressure, and extensive transitions to decalcified fixed dunes and dune heath. The area around Studland is the second richest for lichen species in Dorset, with 363 species found in modern times. Little Sea, the shallow lake within Studland Dunes holds notable bird populations, and has interesting marginal vegetation. The acidic, oligotrophic water makes it ideal for marine algae.
Botanical Significance UK’s largest population of Early spider orchid, exceptionally rich sites across varied habitats, rich lichen communities in dry calcicolous grassland and dune heath. Noted for bryophyte, lichen and marine algae interest.
General Habitat Description Coastal, Mire, Bog and Fen, Grassland and Tall Forb, Heathland Scrub and Tundra, Woodland and Forest, Regular or recently cultivated agriculture, horticulture and domestic.