Report Cover Vol I - Clare County Library

The County Clare Wetlands Survey Patrick Crushell & Peter Foss 2008
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(Phragmites australis), sedges (Carex spp.), rushes (Juncus effusus, J. maritimus) and broadleaved
wetland herbs such as Common Marsh-bedstraw (Galium palustre), Water Mint (Mentha aquatica),
Silverweed (Potentilla anserina) and Bog Pimpernel (Anagallis tenella). Orchids such as Dactylorhiza
incarnata, Gymnadenia conopsea and Epipactis palustris are common. Dune slacks that remain
permanently wet are characterised by Mare's-tail (Hippuris vulgaris) and Water Horsetail (Equisetum
fluviatile). Note that open bodies of standing brackish water should be considered under lagoons and
saline lakes - CW1.
Links with Annex I: This category corresponds to the annexed habitat, 'humid dune slacks (2190)'; those
with Creeping Willow (Salix repens) may also fit in a second annexed category, 'dunes with Salix repens
ssp. argentea (Salicion arenariae) (2170)'.
F Freshwater
This section includes all bodies of freshwater that may be either natural, modified or entirely artificial,
and that are either permanent or seasonal. Areas of land that flood temporarily in winter or during very
wet periods are excluded if there is no differentiation or evidence of a shoreline or draw-down zone, and
if there are no aquatic plants. Springs that are maintained by a more or less continual supply of moving
water are included in this section, as are swamps. Swamps are an integral part of many freshwater
bodies but may also occur in brackish waters and tidal situations. Note, however, that apart from
swamps, all other brackish water and tidal habitats are excluded.
FL Lakes and Ponds
Lakes and ponds include all bodies of open or standing freshwater that lack a strong unidirectional flow of
water. These can be either natural, modified or entirely artificial, as in the case of some reservoirs,
ornamental lakes, or flooded quarries and gravel pits, and may be either temporary or seasonal as in the
case of turloughs and some ponds. Artificial linear water bodies with no obvious connection to a wider
drainage network are also included here. To distinguish a lake from a wide stretch of river, most of the
water in the former should be either standing, moving imperceptibly or circulating within the basin, as
opposed to moving with a strong unidirectional flow. Note that no distinction is made between lakes and
ponds.
Only the area of open water, with or without floating or submerged aquatic vegetation, is included here.
This is taken as the area normally occupied by a water body in situations where water levels fluctuate, or
as the normal limit of flooding in the case of seasonal or temporary lakes and ponds. Swamps (FS1-2),
which may include floating mats or surface scraws of vegetation, and any other peripheral wetland
habitats, are excluded. Note that some tall reeds die back in winter and have a late but vigorous growing
season; their full extent may not be evident before about mid-May. Any fish farming operations should be
categorised separately under fish cages and rafts - CC2.
The classification of most open water bodies is largely based on the trophic, or nutrient status of the
water. The concentrations of phosphorus and phytoplankton, which require measurements in the
laboratory, have well defined categories to recognise oligotrophic, mesotrophic and eutrophic water
bodies. Because the present classification is based on vegetation and not actual values of water quality
parameters, this approach is only loosely applied here. Turloughs - FL6, reservoirs - FL7 and other
artificial lakes and ponds - FL8 are considered separately but may also differ in terms of their trophic
status.
FL1 Dystrophic lakes
This category includes lakes and ponds that are highly acidic (pH 3.5-5.5), base-poor and low in
nutrients, and where the water is brown in colour owing to inputs of humic and other acids from peat.
They are usually associated with blanket bogs, mainly the lowland type, and are characterised by peaty
rather than rocky margins and substrata. The transition from bog to open water is often abrupt. Among
the aquatic plants that colonise these lakes are bladderworts (Utricularia spp.), pondweeds (Potamogeton
natans, P. polygonifolius) and Bogbean (Menyanthes trifoliata). Aquatic Sphagnum mosses such as S.
auriculatum and S. cuspidatum may also be present.
Links with Annex I: Corresponds to the annexed habitat, 'natural dystrophic lakes and ponds (3160)'.
FL2 Acid oligotrophic lakes
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