Red List habitat classification > RLC - Freshwater habitats > RLC1.4 Permanent dystrophic waterbody

Permanent dystrophic waterbody

Quick facts

Red List habitat type code RLC1.4
Threat status
Europe Near Threatened
EU Near Threatened
Relation to
Source European Red List habitat factsheet
European Red List of habitats reports
European Red List of habitats (Excel table)

Summary

The term 'dystrophic' is applied to a water body that is usually shallow, rich in humus giving its water a brown colour, with variable amounts of nutrients (though the availability of nutrients in most cases is low), and with the deeper water often depleted of oxygen. Most boreal lakes and ponds have humic substances in the water, but only polyhumic ones (with colour >90 Pt mg/L) are recognized as dystrophic here, the humic substances in the water being derived from mires, wetlands or paludified forests. Oligo- (< 30) and mesohumic (30 – 90 Pt mg/L) lakes and ponds are included in types based on their trophic state (habitats C1.1a, C1.1b and C1.2a, C1.2b).  In most dystrophic lakes and ponds the water is acid, (pH 3-6), but some have a higher pH, often caused by eutrophication. Bottom sediments consist of organogenic mud and debris, and the soft bottom can be some metres thick. Shores consist usually at least partially of peat, representing bog and fen communities, often quaking due to overgrowth from pond margins to the open water. Dystrophic pools with a similar appearance occur also in raised bog systems but as the origin of those pools is usually related to the development of mire complexes, they are included in the D habitats. Small dystrophic ponds (usually <10 hectares) and pools are often in contact with swamps and mires, therefore the water near the shores is often characterized by overgrowth of fen and bog vegetation. Floating-leaved plants are constant, elodeids and isoetids sparse. Potamogeton species are often missing, due to low nutrient status and pH. Freely floating and drifting aquatic mosses (Sphagnum spp., Warnstorfia spp., Drepanocladus spp., Fontinalis spp.) can be abundant. Utricularia minor and U. intermedia are characteristic species. The cover of helophytes and vascular shore plants varies, typical species being Carex lasiocarpa, C. rostrata, Phragmites australis, Equisetum fluviatile, Menyanthes trifoliata, Comarum palustre, Calla palustris etc. Moss cover, often dominated by Sphagnum spp., is well developed on shores.

In boreal regions there are many larger lakes with polyhumic water. Beside peaty shores they have mineral bottoms and shores, often of till or glacifluvial origin. Floristically these lakes are close to habitat C1.1b maintaining sparse stands of helophytes (Phragmites, Equisetum fluviatile, Schoenoplectus lacustris, Eleocharis palustris, Carex rostrata, C. lasiocarpa), floating-leaved macrophytes (Nymphaea alba, Nuphar lutea, N. pumila, Sparganium spp.), elodeids (Potamogeton perfoliatus, Myriophyllum alterniflorum) and isoetids (Isoëtes spp., Subularia aquatica, Eleocharis acicularis). Aquatic mosses are common. The vegetation of Lobelion dortmannae is typically occurring in this habitat type in oceanic Europe (e.g. Scandinavia and Ireland) but is absent in north-west European lowlands. Dystrophic water bodies are abundant in the boreal region with large mire areas, occurring typically on watersheds. They occur commonly in oceanic NW Europe as well but in continental Europe and southern Europe they are rare. Due to slow peat formation they are rare in northern boreal, arctic and alpine areas. Dystrophic lakes have deteriorated largely by forestry activities and drainage of peatlands for forestry, peat excavation etc., resulting in increase of humic substances, and in lowering of the water table. This has changed the bottom quality and depleted oxygen. Many lakes and ponds have also eutrophicated because of human habitation, construction activities and air-born nitrogen.

Indicators of good quality:

  • Water body has natural hydrology and water chemistry,
  • The pH should be < 6, colour >90 Pt mg/L,
  • Catchment area has undisturbed hydrology and natural land cover,
  • Typical structure of vegetation and co-existence of Utricularids, aquatic mosses, floating-leaved plants,
  • Intact shore vegetation,
  • Low anthropogenic influence, in terms of drainage, construction activities, forestry, water exploitation, and eutrophication,
  • Absence of invasive alien species.

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

Threat status

Synthesis of Red List assessment

The quantity of the habitat declined severely in historical times, largely by large-scale land reclamation, suggesting category Vulnerable (VU) according to the criterion A3. However, the situation has since stabilized, therefore data from 50 last years have been used for the assessment. In the recent past the quality of the habitat has degraded clearly, severity of degradation being 30 %, affecting 75 % of current area. This is based on data from 7 countries with quantitative data from both extent of degraded area and severity of degradation. This data covers most of the habitat area. Criterion C/D1 qualifies the habitat to the category Near-Threatened (NT). Most area of the habitat in EU28+ occur in the EU28 area, therefore NT category may be used also for EU28+
EU
Red List Category Red List Criteria
Near Threatened C/D1
Europe
Red List Category Red List Criteria
Near Threatened C/D1

Confidence in the assessment

medium
Red List of habitat categories and criteria descriptions

Pressures and threats

  • Agriculture
    • Cultivation
  • Mining, extraction of materials and energy production
    • Mining and quarrying
    • Peat extraction
  • Pollution
    • Pollution to surface waters (limnic, terrestrial, marine & brackish)
    • Diffuse pollution to surface waters due to agricultural and forestry activities
    • Nutrient enrichment (N, P, organic matter)
    • Air pollution, air-borne pollutants
    • Nitrogen-input
  • Natural System modifications
    • Landfill, land reclamation and drying out, general
    • Polderisation
    • Modification of hydrographic functioning, general
    • Water abstractions from surface waters
    • Anthropogenic reduction of habitat connectivity

Habitat restoration potential

Many sites are able to recover after some ten of years. In sites with heavy eutrophication and/or changes in the hydrological regime, active intervention is needed. Natural recovery of the habitat can take place after intervention if pressures from land use in catchment areas are controlled. Restoration measures include changes in hydrology (often need to fill ditches etc.), management of littoral vegetation, removal of sediments etc.

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

Water protection measures decreasing nutrient and contaminant loading from the catchment areas are needed in many areas with intensive land use. That means in many cases changes in agricultural and forestry practices, resulting in lower loads of nutrients and humic substances. Another main approach is maintaining natural hydrology of the waters, meaning ecologically sound regulation regimes, maintaining natural flooding etc. Most representative sites should by protected (e.g. as Natura 2000 sites), and in some cases managed actively. Restoration activities are needed, including changes to natural hydrology, reduction of eutrophication, management of littoral communities, in extreme cases also removal of sediment.

List of conservation and management needs

  • Measures related to forests and wooded habitats
    • Restoring/Improving forest habitats
  • Measures related to wetland, freshwater and coastal habitats
    • Restoring/Improving water quality
    • Restoring/Improving the hydrological regime
  • Measures related to spatial planning
    • Establish protected areas/sites
    • Establishing wilderness areas/allowing succession

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 11 Decreasing Decreasing
Belgium Present 0.8 Decreasing Decreasing
Bulgaria Present 0.3 Decreasing Decreasing
Croatia Present Unknown Unknown Unknown
Czech Republic Present 0.3 Unknown Decreasing
Denmark Present Unknown Unknown Unknown
Estonia Present 15.6 Unknown Increasing
Finland mainland Present 3200 Decreasing Stable
Aland Islands Present 3200 Decreasing Stable
France mainland Present 7.5 Decreasing Decreasing
Germany Present 20 Decreasing Decreasing
Greece (mainland and other islands) Present Unknown Unknown Unknown
Hungary Present 2 Unknown Decreasing
Ireland Present 32 Unknown Unknown
Italy mainland Present 5.8 Decreasing Decreasing
Latvia Present Unknown Unknown Unknown
Lithuania Present 17 Decreasing Decreasing
Luxembourg Present Unknown Unknown Unknown
Netherlands Present 7 Stable Stable
Poland Present Unknown Unknown Unknown
Portugal mainland Present 5.9 Unknown Stable
Romania Present 10 Decreasing Decreasing
Slovakia Present marginal Decreasing Decreasing
Slovenia Present marginal Stable Stable
Spain mainland Present 31 Decreasing Decreasing
Sweden Present Unknown Unknown Unknown
United Kingdom Present 16 Stable Stable
Northern Island Present 16 Stable Stable
EU28 + Present or presence uncertain Current area of habitat (Km2) Recent trend in quantity (last 50 years) Recent trend in quality (last 50 years)
Albania Present Unknown Unknown Unknown
Faroe Islands Present Unknown Unknown Unknown
Iceland Present Unknown Unknown Unknown
Former Yugoslavian Republic of Macedonia (FYROM) Uncertain Unknown Unknown Unknown
Montenegro Uncertain Unknown Unknown Unknown
Norway Mainland Present Unknown Unknown Unknown
Serbia Uncertain Unknown Unknown Unknown
Switzerland Present 10 Decreasing Decreasing

Extent of Occurrence, Area of Occupancy and habitat area

Extent of Occurrence (EOO) (Km2) Area of Occupancy (AOO) Current estimated Total Area Comment
EU28 10592350 10853 3289 might be 20-25 % higher due to gaps of data from countries
EU28+ 10903 Unknown data insufficient, Norway and Iceland are missing
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 Anas crecca
Birds Cygnus cygnus
Birds Gavia stellata
Ferns Equisetum fluviatile
Ferns Thelypteris palustris
Fishes Perca fluviatilis
Flowering Plants Calla palustris
Flowering Plants Carex lasiocarpa
Flowering Plants Carex limosa
Flowering Plants Carex rostrata
Flowering Plants Comarum palustre
Flowering Plants Drosera longifolia
Flowering Plants Eleocharis acicularis
Flowering Plants Eleocharis palustris
Flowering Plants Juncus bulbosus
Flowering Plants Menyanthes trifoliata
Flowering Plants Myriophyllum alterniflorum
Flowering Plants Nuphar lutea
Flowering Plants Nymphaea alba
Flowering Plants Phragmites australis
Flowering Plants Potamogeton alpinus
Flowering Plants Potamogeton natans
Flowering Plants Potamogeton perfoliatus
Flowering Plants Rhynchospora alba
Flowering Plants Schoenoplectus lacustris
Flowering Plants Sparganium minimum
Flowering Plants Subularia aquatica
Flowering Plants Typha angustifolia
Flowering Plants Utricularia minor
Mammals Castor fiber
Mammals Lutra lutra
Mosses & Liverworts Fontinalis antipyretica
Mosses & Liverworts Sphagnum cuspidatum
Species scientific name English common name Species group
Anas crecca Teal Birds
Cygnus cygnus Whooper Swan Birds
Gavia stellata Red-throated Diver Birds
Equisetum fluviatile Ferns
Thelypteris palustris Ferns
Perca fluviatilis European perch Fishes
Calla palustris Flowering Plants
Carex lasiocarpa Flowering Plants
Carex limosa Flowering Plants
Carex rostrata Flowering Plants
Comarum palustre Flowering Plants
Drosera longifolia Flowering Plants
Eleocharis acicularis Flowering Plants
Eleocharis palustris Flowering Plants
Juncus bulbosus Flowering Plants
Menyanthes trifoliata Flowering Plants
Myriophyllum alterniflorum Flowering Plants
Nuphar lutea Flowering Plants
Nymphaea alba Flowering Plants
Phragmites australis Flowering Plants
Potamogeton alpinus Flowering Plants
Potamogeton natans Flowering Plants
Potamogeton perfoliatus Flowering Plants
Rhynchospora alba Flowering Plants
Schoenoplectus lacustris Flowering Plants
Sparganium minimum Flowering Plants
Subularia aquatica Flowering Plants
Typha angustifolia Flowering Plants
Utricularia minor Flowering Plants
Castor fiber European beaver Mammals
Lutra lutra Eurasian otter Mammals
Fontinalis antipyretica Mosses & Liverworts
Sphagnum cuspidatum 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 C1.4 Permanent dystrophic lakes, ponds and pools same
European Environment Agency (EEA)
Kongens Nytorv 6
1050 Copenhagen K
Denmark
Phone: +45 3336 7100