IBEROATLANTICA

Description

Patchy plant communities, rich in ferns and crassulaceans, colonising crevices and ledges of solid siliceous outcrops and cliffs.

Protection

Communities colonising crevices are protected under code 8220 ("Siliceous rocky slopes with chasmophytic vegetation") by the EU Habitat Directive; those on regolith, under the code 8230 ("Siliceous rock with pioneer vegetation of the Sedo-Scleranthion or of the Sedo albi-Veronicion dillenii").

Floristic Composition

Frequent species

Sedum brevifolium 73%, Sedum hirsutum 49%, Umbilicus rupestris 42%, Asplenium obovatum 29%, Allosorus tinaei 20%, Neoschischkinia truncatula 18%, Anarrhinum bellidifolium 17%, Linaria saxatilis 17%, Saxifraga fragosoi 14%, Allosorus hispanicus 13%, Asplenium trichomanes 13%, Anogramma leptophylla 12%, Rumex acetosella 11%, Plantago holosteum 11%, Avenella flexuosa 11%, Festuca summilusitana 10%, Polypodium vulgare 9%, Sedum anglicum 9%, Phalacrocarpum oppositifolium 7%, Asplenium adiantum-nigrum aggr. 7%, Murbeckiella boryi 7%, Micropyrum tenellum 6%, Ornithogalum concinnum 6%, Phagnalon saxatile 6%, Molineriella laevis 6%, Sedum album 6%, Anarrhinum duriminium 6%, Sedum forsterianum 6%, Dianthus laricifolius 6%, Teesdalia nudicaulis 6% view more...

Indicator species

Sedum brevifolium 0.7, Sedum hirsutum 0.47, Umbilicus rupestris 0.41, Asplenium obovatum 0.29, Allosorus tinaei 0.19, Neoschischkinia truncatula 0.17, Linaria saxatilis 0.16, Anarrhinum bellidifolium 0.16, Saxifraga fragosoi 0.14, Allosorus hispanicus 0.13, Anogramma leptophylla 0.12, Plantago holosteum 0.11, Rumex acetosella 0.1, Polypodium vulgare 0.09, Festuca summilusitana 0.08, Sedum anglicum 0.07, Asplenium adiantum-nigrum aggr. 0.07, Ornithogalum concinnum 0.06, Micropyrum tenellum 0.06, Avenella flexuosa 0.06, Phalacrocarpum oppositifolium 0.06, Teesdalia nudicaulis 0.06, Dianthus laricifolius 0.06, Molineriella laevis 0.06, Anarrhinum duriminium 0.06, Sedum forsterianum 0.05, Dianthus langeanus 0.04, Phagnalon saxatile 0.04, Sedum arenarium 0.03, Erysimum linifolium 0.03, Helictochloa marginata 0.03, Rumex induratus 0.03, Armeria humilis 0.03, Festuca elegans 0.03, Sagina procumbens 0.03, Arenaria montana 0.03, Cardamine hirsuta 0.03, Phyteuma hemisphaericum 0.03, Silene nutans 0.03, Hypochaeris radicata 0.02, Festuca ovina 0.02, Ceratocapnos claviculata 0.02, Aira praecox 0.02, Tuberaria guttata 0.02, Armeria transmontana 0.02, Agrostis curtisii 0.02, Glandora prostrata 0.02, Filago minima 0.02, Saxifraga granulata 0.02, Sesamoides purpurascens 0.02 view more...

Phytosociology

Agrostio durieui-Sedetum pyrenaici
Asplenietum corunnensis
Linario glabrescentis-Cheilanthetum tinaei
Murbeckiello boryi-Saxifragetum willkommianae
Murbeckiello boryi-Sperguletum pourretii
Phagnalo saxatilis-Rumicetum indurati
Phalacrocarpo oppositifolii-Saxifragetum fragosoi
Sedo anglici-Thymetum caespititii
Sedo pruinati-Thymetum caespititii
Sesamoido suffruticosae-Anarrhinetum bellidifolii
Sesamoido suffruticosae-Anarrhinetum durimini

Relations with other habitat types

Rupicolous vegetation analogous to U381, but on siliceous outcrops which, on top of the direct chemical and nutritional difference with limestones, are less soluble and produce a lesser amount of suitable crevices, these communities being therefore less diverse. Since most of the associated species (including a few endemics, as often in this island-like biotopes, clustered along recent orogens) grow on ledges retaining locally originated regolith, an alternative typification of some of these formations might make use of the EUNIS unit R122 (“Sparsely vegetated weathered rock and outcrop habitats"), but they intermix with truly rupicolous communities at very small spatial scales (apparently smaller than those typically used in the rélévés that constitute our primary data source), the distinction thus becoming inoperative for most purposes. Similarly, a regional umbrella unit is created in order to join together at level IV the thermophilous, submediterranean, lowland communities of U345 (“Western Iberian siliceous cliffs") and the orophilous ones of unit U3411 (“Ibero-Carpetanian siliceous cliffs"), whose floristic delimitation, for the existence of many transitions, is too weak as to justify the recognition of two units at that level.