Mediterranean and Black Sea soft sea cliff

This habitat is formed by coastal soft cliffs and rocks (clays, friable sands, shales and glacial deposits) that are poorly resistant to the natural processes of erosion on the coasts of the Mediterranean and Black Sea, and in the southern Atlantic parts of Europe (northwards up to Porto, Portugal). These cliffs are subject to frequent slumps and land slips caused by erosion (e.g. waves, rain, winter storms, and groundwater percolating through the cliffs). The soft-sea cliffs frequently form borders with hard cliffs, giving rise to more complex habitats. On most soft cliff sites there are a range of micro-habitats formed by the fracture water streaming down the rocks, plus mosaics from open rocks and small patches of grassland and shrubs. In comparison to many coastal cliffs formed by granite, limestone and chalk, soft lithologies often form low, shallow, sloping cliffs which are more easily colonized by vegetation. However, the soft cliffs also erode much quicker than hard cliffs and vegetation is therefore restricted to pioneer stages in many places. Soft cliffs may support scrub similar to that on dunes with species like Hippophae rhamnoides, Juniperus spp. and Crataegus monogyna. On the western Black Sea coast many steppe and halophytic species, like Camphorosma monspeliaca, Matthiola odoratissima and Peganum harmala, may inhabit the chalk deposits over the sea. The single Black Sea locality of Hippophae rhamnoides outside the Danube Delta also occurs on soft sea-cliffs. Soft-sea cliffs are threatened by some natural causes such as slumping and landslips, which are sometimes of a cyclical nature. They can also be damaged through insensitive cliff top management and artificial drainage. Other threats include tourist development of the coastal area, pollution and nitrification of the coastal cliffs, and increase of non-typical ruderal species.

Indicators of quality:

• High species and micro-habitat richness
• Presence of rare and/or threatened species
• Low number of nitrophilous ruderals and alien species
• Absence of human infrastructure on the top of coastal cliffs

Synthesis of Red List assessment

Confidence in the assessment

Pressures and threats