Llyn Eiddwen

Site of Special Scientific Interest · 52.2867, -4.0426

Also within

Dyfed County

Climate exposure

This is about exposure to a nationwide pressure this habitat type carries — not a verdict on this site's own management.

Peatland

Peat habitats store centuries of carbon and depend on a stable, waterlogged water table. Warmer, drier summers dry out peat, making it far more vulnerable to wildfire and to carbon release — a pressure that can undo years of restoration work regardless of how well the site is otherwise managed.

Geology & landscape

Geological Period: Silurian

Landscape processes: Peatland / Mire

Description

Description This natural lake is situated in a small hollow at an altitude of about 300 metres in an area of upland Silurian Aberystwyth Grits known as Mynydd Bach. The lake, which extends to 10.5 ha and reaches a maximum depth of about 4 metres, is noted for its remarkable flora. The unpolluted oligotrophic-mesotrophic waters support abundant stands of water lobelia Lobelia dortmanna, along with carpets of shoreweed Littorella uniflora and quillwort Isoetes lacustris. It is one of the most southerly sites known in Britain for awlwort Subularia aquatica, which forms an unusual association with floating water-plantain Luronium natans. The lake and its surrounds support a variety of insects (particularly dragonflies), and the site is frequented by waterfowl, especially in winter. To the south of the lake there is an actively growing basin mire which grades into drier heathland-grassland communities. These communities comprise most of the catchment, which is included in the site, and are typical of many of the acid uplands of Mid-Wales. In the northern part of the catchment, there is another developing mire, Cors Pwll-yr-ŷch.

Species mentioned

English name
search for this in other sites
Latin name
search with Google
IUCN / Red List Type Family
lake quillwort Isoetes lacustris LC fern isoetaceae
shoreweed Littorella uniflora LC herb plantaginaceae
water lobelia Lobelia dortmanna LC herb campanulaceae
floating water plantain Luronium natans LC herb alismataceae
awlwort Subularia aquatica LC herb brassicaceae