Unvegetated, sparsely vegetated, and bryophyte or lichen vegetated cliffs, rock faces and rock pavements, not presently adjacent to the sea, and not resulting from recent volcanic activity. Parts of seacliffs free from the influence of wave or wind transported marine salt are included. Rock accumulations resulting from depositional processes are excluded and listed under U2 or U5.
Chytrý M., Tichý L., Hennekens S.M., Knollová I., Janssen J.A.M., Rodwell J.S. … Schaminée J.H.J. (2020) EUNIS Habitat Classification: expert system, characteristic species combinations and distribution maps of European habitats. Applied Vegetation Science 23: 648–675. https://doi.org/10.1111/avsc.12519
Version 2021-06-01, https://doi.org/10.5281/zenodo.4812736.
For the official presentation of the EUNIS Habitat Classification from the European Environment Agency, please see: EUNIS Terrestrial Habitat Classification 2021. The FloraVeg.EU presentation may show modifications and partial updates to the habitat classification.