Description of biotope or habitat type
Yellow and grey lichens on supralittoral rock
Habitat (physical) description
|Salinity||Full (30-35 ppt), Variable (18-35 ppt)|
|Wave exposure||Very exposed, Exposed, Moderately exposed, Sheltered, Very sheltered|
|Substratum||Bedrock; stable boulders|
Download comparative physical and biological data. The comparative tables enable a rapid comparison of the species composition and principal physical characteristics between a given set of biotopes.
- Records used to define the biotope (core records)
- Other records assigned to this biotope, marked as 'certain'
- Other records assigned to this biotope, marked as 'uncertain'
Point data based on records in the UK Marine Recorder Snapshot.
Vertical to gently sloping bedrock and stable boulders in the supralittoral (or splash zone) of the majority of rocky shores are typically characterised by a diverse maritime community of yellow and grey lichens, such as Xanthoria parietina, Caloplaca marina, Lecanora atra and Ramalina spp. The black lichen Verrucaria maura is also present, but usually in lower abundance than in the littoral fringe zone. In wave exposed conditions, where the effects of sea-spray extend further up the shore, the lichens generally form a wide and distinct band. This band then becomes less distinct as wave exposure decreases, and in sheltered locations, cobbles and pebbles may also support the biotope. Pools, damp pits and crevices in the rock are occasionally occupied by winkles such as Littorina saxatilis and halacarid mites may also be present.
This biotope is usually found at the top of the shore, immediately above a zone of the black lichen V. maura (Ver.Ver; Ver.B). Above the band of YG, and occasionally in crevices in the rock alongside the lichens, terrestrial plants such as the thrift Armeria maritima and other angiosperms often occur. In sheltered areas the transition from YG to Ver.Ver is often indistinct and a mixed zone of YG and Ver.Ver may occur. In estuaries, this biotope is often restricted to artificial substrata such as sea defences.
|Taxon||Relative importance of taxon for defining this community (%)||Typical abundance - SACFOR scale||% of core records where taxon was recorded|
|Caloplaca marina||12||Occasional||41-60 %|
|Caloplaca thallincola||4||Occasional||21-40 %|
|Lecanora atra||4||Frequent||21-40 %|
|Verrucaria maura||21||Frequent||61-80 %|
|Xanthoria parietina||27||Frequent||61-80 %|
|Grey lichens||17||Frequent||41-60 %|