CYNGOR CEFN GWLAD CYMRU
SITE OF SPECIAL SCIENTIFIC INTEREST: CITATION
Local Planning Authority: Anglesey/Ynys Môn
Date of Notification 1971,1987
National Grid Reference SH 359936
OS Maps 1:50000 Sheet Number : 114
1:25000 Sheet Number :SH39
Site Area 10.1 hectares (25 acres)
This site has been selected for it's biological interest, in particular as a representative example of rich fen habitat in north-west Wales.
The fen has developed in a basin above Cemaes Bay on the north Anglesey coast, and the vegetation present consists of a mosaic of rich-fen and associated communities. There are stands of fen meadows in which blunt-flowered rush (Juncus subnodulosus) and other jointed rushes are abundant; these grade into a variety of other communities in which fen species such as fen sedge (Cladium mariscus), black bog rush (Schoenus nigricans) and common reed (Phragmites communis) are locally dominant. Swamp vegetation with stands of greater reedmace (Typha latifolia), and fen scrub occur in places.
The variable structure of the vegetation at this site probably reflects a chequered management history as well as other environmental gradients. A wide range of wetland plant species occur in the various communities, and of particular interest is the presence of a population of the marsh fern (Thelypteris thelypteroides) which is a scarce fen plant in Britain where it appears to be declining over much of it's range.
The site boundary has been revised in 1987.