Red List habitat classification > RLC - Freshwater habitats > RLC1.1b Permanent oligotrophic to mesotrophic waterbody with soft-water species

Permanent oligotrophic to mesotrophic waterbody with soft-water species

Quick facts

Red List habitat type code RLC1.1b
Threat status
Europe Least Concern
EU Least Concern
Relation to
Source European Red List habitat factsheet
European Red List of habitats reports
European Red List of habitats (Excel table)

Summary

Oligotrophic to mesotrophic waters of sandy plains and rocky substrates (granites, gravel, stones, till, moraine, clay) containing few minerals. Over large parts of the lake the sediment is covered by a thin layer of detritus and accumulation of mud is sparse. The water layer is carbon deficient and poorly buffered (low alkalinity). The water is weakly acid to circumneutral. Concentrations of nitrogen and phosphorous are low and in the oligotrophic to mesotrophic range. The water is clear, sometimes humic (brown) with a low concentration of chlorophyll. The vegetation is low to moderate in species diversity and is dominated by soft-water species. This soft-water vegetation consists mainly of communities dominated by the isoetid species Plantago uniflora and other soft-water species with other growth forms like Myriophyllum alterniflorum, Potamogeton polygonifolius and P. gramineus. Several soft-water species including Baldellia ranunculoides subsp. ranunculoides, B. ranunculoides subsp. repens and Luronium natans are atlantic and are absent from the boreal zone. In the temperate Atlantic zone boreal and atlantic species overlap. As a consequence, soft-water lakes are relatively richer in species in the temperate atlantic zone. Similar habitats in coastal dune slacks, with Plantago uniflora (= Littorella uniflora) as characteristic species, are considered part of habitat B1.8a. In soft-water lakes the vegetated layer extends from the littoral to lower parts of the sub-littoral zone. The littoral zone has fluctuating water levels and the littoral vegetation might be semi-permanent in the summer period. The vegetation and its substrate are mechanically influenced by water movement, ice sheets and wind exposition. Many large lakes in northern Europe represent this type or the more oligotrophic type C1.1a in terms of water chemistry and abundant isoetid vegetation. Occurrence and abundance of other growth forms (elodeids, aquatic mosses, sometimes also Nitella stands, nymphaeids and helophytes) vary according to shore and bottom material, topography, exposition and lake area exposed to wind and subsurface currents. Exposed shores have sparse stands of aquatic vegetation, in sheltered bays vegetation has clear zonation, but the stands are still open. The lower limit of submerged vegetation reaches typically the depth of 3-6 meters, sometimes close to 10 meters. Due to postglacial history deeper lakes host some glacial relict crustaceans and vertebrates, including salmonid fish and a critically endangered fresh water seal (Pusa hispida subsp. saimensis). Large lakes have diverse waterfowl populations and are important parts of migration routes. This habitat type must not be confused with oligotrophic to mesotrophic ponds only periodically flooded, which is instead typical of the Mediterranean area and dominated by isoetid species of Isoëtetalia and Nano-Cyperetalia (class Isoëto-Nanojuncetea). The vegetation of these habitats is composed of a contribution of annual and ephemeral species. These drier habitats are not part of the habitat described here, but belong to types C1.6b "Mediterranean temporary waters" and C3.5b "Periodically exposed shores with stable, mainly mesotrophic sediments with pioneer and ephemeral vegetation".

Indicators of good quality:

  • Large stands of soft-water species
  • Absence or very low abundance of peat mosses
  • Absence or very low abundance of water plants from eutrophic and alkaline waters
  • Low abundance of water plants with large floating leaves (Nymphaeids) or emergent plants (e.g. Phragmites australis, Typha spp., Equisetum fluviatile, Carex spp.)
  • Long-term habitat stability, with no rapid successional trends (e.g. no trends in acidification or eutrophication)
  • Low concentrations of nutrients and chlorophyll (approximately P < 40 μg/L and chlorophyll < 5 μg/L)
  • pH weakly acid to circumneutral ( pH 5.5 - 7.5)
  • Alkalinity 0.1 – 2 meq/L
  • Thin layer of detritus (no accumulation of organic mud) over large parts of the lake
  • Occurrence of conspicuous populations of salmonid fish, but population of roach (Rutilus rutilus) and other Cyprinidae low

Note: Chemical and physical parameters are only indicative, they may change in different geographical area and climatic conditions.

Characteristic species
For full habitat description, please download the habitat factsheet.

Threat status

Synthesis of Red List assessment

This habitat reaches the qualification of Least Concern (LC) for the whole of Europe, due to a widespread distribution and relatively small declines in quality and qauntity over the last 50 years. However, the overall assessment is strongly influenced by the countries having the largest area of this soft-water habitat, Finland and Sweden, where the habitat is in rather good condition. For the rest of Europe the habitat qualifies as Near Threatened (NT) because of a strong decline in quality, and also declines in area are much larger with some countries reporting 90% decline. Quantitative and qualitative data are missing for Norway and Iceland, but based on some assumptions a similar score is reached for the EU28+ as for EU28.
EU
Red List Category Red List Criteria
Least Concern -
Europe
Red List Category Red List Criteria
Least Concern -

Confidence in the assessment

medium
Red List of habitat categories and criteria descriptions

Pressures and threats

  • Agriculture
    • Cultivation
    • Fertilisation
  • Pollution
    • Diffuse pollution to surface waters due to agricultural and forestry activities
    • Nutrient enrichment (N, P, organic matter)
  • Invasive, other problematic species and genes
    • Invasive non-native species
  • Natural System modifications
    • Human induced changes in hydraulic conditions
    • Modification of hydrographic functioning, general
    • Modifying structures of inland water courses
    • Small hydropower projects, weirs
  • Climate change
    • Changes in abiotic conditions
    • Temperature changes (e.g. rise of temperature & extremes)
    • pH-changes

Habitat restoration potential

Experience from North-Western Atlantic Europe has shown that the vegetation can be restored from the diaspores left in the sediment. Restoration can be achieved within a period of 2-5 years.

Trends in extent

Average current trend in quantity

Decreasing Decreasing
EU28 EU28+

Trends in quality

Average current trend in quality

Decreasing Decreasing
EU28 EU28+

Conservation and management needs

The main current approaches to conservation, management and restoration of this habitat are: 1. Restore the hydrology; 2. Limit nutrient input from surrounding agricultural areas; 3. Restore the sediment conditions and remove organic layers; 4. Remove dominating shore vegetation like reed beds and shrubs.

List of conservation and management needs

  • Measures related to wetland, freshwater and coastal habitats
    • Other wetland related measures
    • Restoring/Improving water quality
    • Restoring/Improving the hydrological regime
    • Managing water abstraction
  • Measures related to hunting, taking and fishing and species management
    • Specific single species or species group management measures

Distribution

For each habitat a distribution map was produced from a wide variety of sources indicating known and potential occurrences of the habitat in 10x10 km grids within Europe. Occurrences in grid cells were given in two classes: actual distribution from relatively reliable sources (surveys, expert knowledge), and potential distribution based on models or less reliable indicators. Please download the fact sheet to see the map.

Geographic occurrence and trends

EU28 Present or presence uncertain Current area of habitat (Km2) Recent trend in quantity (last 50 years) Recent trend in quality (last 50 years)
Austria Present 64 Decreasing Decreasing
Belgium Present 11 Decreasing Decreasing
Bulgaria Present 6.9 Decreasing Decreasing
Czech Republic Present 0.6 Decreasing Decreasing
Estonia Present 2 Decreasing Decreasing
Finland mainland Present 21000 Decreasing Stable
Aland Islands Uncertain 21000 Decreasing Stable
France mainland Present 80 Decreasing Decreasing
Corsica Uncertain 80 Decreasing Decreasing
Germany Present 52 Decreasing Decreasing
Greece (mainland and other islands) Present 15 Stable Stable
Crete Present 15 Stable Stable
East Aegean Present 15 Stable Stable
Ireland Present 558 Unknown Stable
Italy mainland Present 222 Decreasing Decreasing
Sardinia Present 222 Decreasing Decreasing
Sicily Present 222 Decreasing Decreasing
Lithuania Present 4 Decreasing Decreasing
Netherlands Present 4.2 Decreasing Decreasing
Portugal mainland Present 0.2 Unknown Decreasing
Portugal Azores Present 0.2 Unknown Decreasing
Slovakia Present 1 Decreasing Decreasing
Slovenia Present 2.6 Stable Stable
Spain mainland Present 77 Decreasing Decreasing
Sweden Present 4865 Decreasing Stable
Romania Present unknown Decreasing Decreasing
United Kingdom Present 705 Decreasing Stable
Northern Island Present 705 Decreasing Stable
Gibraltar Uncertain 705 Decreasing Stable
Croatia Uncertain Unknown Unknown Unknown
Cyprus Uncertain Unknown Unknown Unknown
Denmark Present Unknown Unknown Unknown
Hungary Uncertain Unknown Unknown Unknown
Latvia Present Unknown Unknown Unknown
Luxembourg Present Unknown Unknown Unknown
Malta Uncertain Unknown Unknown Unknown
Poland Present Unknown Unknown Unknown
EU28 + Present or presence uncertain Current area of habitat (Km2) Recent trend in quantity (last 50 years) Recent trend in quality (last 50 years)
Switzerland Present 0.1 Decreasing Decreasing
Bosnia and Herzegovina Present 1 Decreasing Stable
Norway Mainland Present 3000 Unknown Unknown
Albania Uncertain Unknown Unknown Unknown
Andorra Uncertain Unknown Unknown Unknown
Faroe Islands Uncertain Unknown Unknown Unknown
Guernsey Uncertain Unknown Unknown Unknown
Iceland Uncertain Unknown Unknown Unknown
Isle of Man Uncertain Unknown Unknown Unknown
Jersey Uncertain Unknown Unknown Unknown
Kaliningrad Uncertain Unknown Unknown Unknown
Kosovo Uncertain Unknown Unknown Unknown
Liechtestein Uncertain Unknown Unknown Unknown
Former Yugoslavian Republic of Macedonia (FYROM) Uncertain Unknown Unknown Unknown
Monaco Uncertain Unknown Unknown Unknown
Montenegro Uncertain Unknown Unknown Unknown
San Marino Uncertain Unknown Unknown Unknown
Serbia Uncertain Unknown Unknown Unknown
Vatican City Uncertain Unknown Unknown Unknown

Extent of Occurrence, Area of Occupancy and habitat area

Extent of Occurrence (EOO) (Km2) Area of Occupancy (AOO) Current estimated Total Area Comment
EU28 6834050 5151 27687
EU28+ 5348 30688 For EU28+ only data from Switzerland, Norway and Bosnie Herzegovina are available.
AOO = the area occupied by a habitat measured in number of 10x10 km grid cells.
EOO = the area (km2) of the envelope around all occurrences of a habitat (calculated by a minimum convex polygon).

Characteristic species

The full list of characteristic species and genus are available above from the Summary. The species available in the EUNIS database are shown here.
Birds Bucephala clangula
Birds Gavia arctica
Birds Larus fuscus
Birds Melanitta nigra
Birds Mergus merganser
Ferns Equisetum fluviatile
Ferns Lycopodiella inundata
Ferns Pilularia globulifera
Fishes Lota lota
Fishes Osmerus eperlanus
Fishes Perca fluviatilis
Fishes Rutilus rutilus
Fishes Sander lucioperca
Flowering Plants Antinoria agrostidea
Flowering Plants Baldellia alpestris
Flowering Plants Baldellia ranunculoides
Flowering Plants Callitriche hamulata
Flowering Plants Deschampsia setacea
Flowering Plants Eleocharis acicularis
Flowering Plants Eleogiton fluitans
Flowering Plants Hydrocotyle vulgaris
Flowering Plants Juncus bulbosus
Flowering Plants Juncus heterophyllus
Flowering Plants Littorella uniflora
Flowering Plants Lobelia dortmanna
Flowering Plants Luronium natans
Flowering Plants Myriophyllum alterniflorum
Flowering Plants Phragmites australis
Flowering Plants Potamogeton gramineus
Flowering Plants Potamogeton polygonifolius
Flowering Plants Ranunculus flammula
Flowering Plants Ranunculus ololeucos
Flowering Plants Samolus valerandi
Flowering Plants Sparganium angustifolium
Flowering Plants Subularia aquatica
Invertebrates Arctocorisa germari
Invertebrates Chaoborus flavicans
Invertebrates Dicrotendipes tritomus
Invertebrates Gammaracanthus lacustris
Invertebrates Gammarus lacustris
Invertebrates Glaenocorisa propinqua
Invertebrates Hygrotus novemlineatus
Invertebrates Lestes dryas
Invertebrates Limnodrilus hoffmeisteri
Invertebrates Molanna albicans
Invertebrates Mysis relicta
Invertebrates Pagastiella orophila
Invertebrates Parakiefferiella bathophila
Invertebrates Psectrocladius psilopterus
Invertebrates Sigara scotti
Invertebrates Spirosperma ferox
Mammals Lutra lutra
Mosses & Liverworts Calliergon megalophyllum
Mosses & Liverworts Fontinalis hypnoides
Mosses & Liverworts Scorpidium scorpioides
Mosses & Liverworts Warnstorfia exannulata
Species scientific name English common name Species group
Bucephala clangula Goldeneye Birds
Gavia arctica Black-throated Diver Birds
Larus fuscus Lesser Black-backed Gull Birds
Melanitta nigra Common Scoter Birds
Mergus merganser Goosander Birds
Equisetum fluviatile Ferns
Lycopodiella inundata Ferns
Pilularia globulifera Ferns
Lota lota Burbot Fishes
Osmerus eperlanus European smelt Fishes
Perca fluviatilis European perch Fishes
Rutilus rutilus Roach Fishes
Sander lucioperca European pike-perch Fishes
Antinoria agrostidea Flowering Plants
Baldellia alpestris Flowering Plants
Baldellia ranunculoides Flowering Plants
Callitriche hamulata Flowering Plants
Deschampsia setacea Flowering Plants
Eleocharis acicularis Flowering Plants
Eleogiton fluitans Flowering Plants
Hydrocotyle vulgaris Flowering Plants
Juncus bulbosus Flowering Plants
Juncus heterophyllus Flowering Plants
Littorella uniflora Flowering Plants
Lobelia dortmanna Flowering Plants
Luronium natans Water-Plantain Flowering Plants
Myriophyllum alterniflorum Flowering Plants
Phragmites australis Flowering Plants
Potamogeton gramineus Flowering Plants
Potamogeton polygonifolius Flowering Plants
Ranunculus flammula Flowering Plants
Ranunculus ololeucos Flowering Plants
Samolus valerandi Flowering Plants
Sparganium angustifolium Flowering Plants
Subularia aquatica Flowering Plants
Arctocorisa germari Invertebrates
Chaoborus flavicans Invertebrates
Dicrotendipes tritomus Invertebrates
Gammaracanthus lacustris Invertebrates
Gammarus lacustris Invertebrates
Glaenocorisa propinqua Invertebrates
Hygrotus novemlineatus Invertebrates
Lestes dryas Invertebrates
Limnodrilus hoffmeisteri Invertebrates
Molanna albicans Invertebrates
Mysis relicta Invertebrates
Pagastiella orophila Invertebrates
Parakiefferiella bathophila Invertebrates
Psectrocladius psilopterus Invertebrates
Sigara scotti Invertebrates
Spirosperma ferox Invertebrates
Lutra lutra Eurasian otter Mammals
Calliergon megalophyllum Mosses & Liverworts
Fontinalis hypnoides Mosses & Liverworts
Scorpidium scorpioides Mosses & Liverworts
Warnstorfia exannulata Mosses & Liverworts

Vegetation types

Relation to vegetation types (syntaxa)

Not available

Other classifications

This habitat may be equivalent to, or broather than, or narrower than the habitats or ecosystems in the following typologies.
Classification Code Habitat type name Relationship type
EUNIS Habitat Classification 200711 C1.3 Permanent eutrophic lakes, ponds and pools overlap
EUNIS Habitat Classification 200711 C1.1 Permanent oligotrophic lakes, ponds and pools overlap
EUNIS Habitat Classification 200711 C1.2 Permanent mesotrophic lakes, ponds and pools overlap
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