Temperate, lowland to montane siliceous inland cliff

Siliceous (rich in quartz and silicate minerals such as mica or feldspar) rock walls and cliffs in the nemoral biogeographic domain except those in the high mountains and in the sea spray coastal zone. Siliceous cliffs consist chiefly of metamorphic more or less acid rocks such as slate, schist, gneiss and quartzite, sedimentary rock such as sandstone, or of igneous rocks such as granite, porphyry and diorite. Non-calcareous but more or less base-rich igneous volcanic rocks such as andesite, trachyte and basalt are also included. The vegetation in the rock fissures and crevices consists of vascular plants such as small ferns, succulents and rosulate herbs, on the rock surface also mosses and hepatics, crustose (e.g. Aspicilia, Lecanora, Lecidea s.l., Lepraria, Pertusaria, Rhizocarpon, Rinodina, Trapelia) and foliose lichens (e.g. Parmelia s.l. Umbilicaria), further epi- and endolithic micro-algae and other micro-organisms. Asplenium, Dianthus, Saxifraga, Sedum and Silene are important vascular plant genera in extra-alpine temperate siliceous cliffs. Among the mosses the genera Hedwigia, Grimmia, Racomitrium and Schistidium are particularly common on siliceous rocks, the latter three are species-rich.

Temperate lowland to montane siliceous cliffs are generally rather poor in plant species (but may be rich in lichens). The species composition depends on the biogeographic (thermic and oceanic) position, on rock type, humidity and water availability. Several species are considered glacial relicts.

The habitat type occurs throughout nemoral Europe from the British Isles and Northwest Spain to the Caucasus and the Ural Mountains and probably much further into Central Asia. It is particularly well-known in Galicia (Spain), the Massif Central, the slate-dominated suboceanic Rhenish Massif and generally in the Central European Uplands, where it is represented by gneiss and granitic rocks of the Rheno-Hercynian zone. The slate-dominated parts of the Carpathian Mountains are another main area of temperate montane siliceous cliffs.

Indicators of good quality:

Temperate lowland to montane siliceous cliffs is a habitat of high phytogeographical significance. Although not species-rich it harbours rare species and disjunct populations including many relict cryptogams of nordic-alpine distribution. There are also a few narrow endemics such as in the northwest Iberian Peninsula and in the Carpathians.  Habitat quality must be assessed at regional level and in view of the ecoregional variation. It is crucial to consider bryophytes and lichens. The occurrence of rare and relict species is a main criterion.

The following characteristics may be used as indicators of favourable quality:

• Occurrence of rare species of lichens, bryophytes, ferns and phytogeographically significant vascular plant taxa,
• Presence of sizable open exposed rock and of different aspects of rock walls, different exposure to insolation, moisture and rock structures such as vertical rock faces, overhangs, cavities, rock shelters, and ledges
• Contact with natural habitats such as screes, boulder fields, rock shrubs and pioneer grasslands
• Absence of quarrying and control structures
• Absence of garbage dumping and nutrient input from above the cliff
• Absence of rock climbing facilities

Synthesis of Red List assessment

Confidence in the assessment

Pressures and threats