Identification

Identifier

NRW_DS87152

Alternative Title

• Arolwg o Gennau Uwch-lanwol Arforol Pentir Portmeirion, yACA Pen Llyn a'r Sarnau/SoDdGA/GNG Morfa Harlech

Metadata Language

English

Lineage

Observations were made by experienced surveyors following standard methodology. The coastline was systematically walked and stops made at promising localities. The survey focussed on supralittoral lichen communities, i.e. those occurring at and above mean high water (MHW). Frequently submerged lower shore eu-littoral lichen communities, dominated by filmy Verrucaria species (‘oil lichens’), were not examined in any detail. The upper survey boundary was set at the terrestrial – xeric-supralittoral interface. In practice, because of the low elevation of the shore exposures, this was where cliff-top rock terminated and terrestrial woody and coastal scrub vegetation commenced. An exception was made for one essentially terrestrial dry dwarf shrub heath formation, with coastal character, on the cliff-top a short distance inland from Trwynypenrhyn, which supported an interesting mix of hard upland acid and coastal rock species, including the rare Pertusaria monogona. Notable species and assemblages were logged in the field with a Garmin 12-channel Global Positioning System (GPS) unit, delivering grid references accurate to 1-15m (maximum ten-figure resolution), the performance depending on satellite reception and topographic shadowing. GPS locations form spatial reference points for the location target notes as detailed below.

Dataset Reference Date (Publication)

2004-11-30

Extent

Extent

Geographic Extent

GWYNEDD - GWYNEDD

N

W

E

S

 

Distribution

Quality

Keywords

Spatial Reference System

Content

Constraints