Red List habitat classification > RLD - Mires and bogs > RLD4.1a Small-sedge base-rich fen and calcareous spring mire

Small-sedge base-rich fen and calcareous spring mire

Quick facts

Red List habitat type code RLD4.1a
Threat status
Europe Endangered
EU Endangered
Relation to
Source European Red List habitat factsheet
European Red List of habitats reports
European Red List of habitats (Excel table)

Summary

This habitat includes calcareous fen vegetation of the lowlands and mountains of the European nemoral zone, and it also occurs more rarely in the boreal zone where calcareous substrates and the influence of base-rich water are scarce. Calcareous fens occur at sites with a permanently high water table, often near springs, and they are particularly common in areas with calcareous bedrock, especially in the mountain systems of central Europe. Water is rich in calcium, magnesium and bicarbonates and precipitation of calcium-carbonate and tufa formation is common, and also accumulation of organic matter due to permanently wet conditions which reduce decomposition processes. The soil has a high proportion of organic matter and is base-rich, but with limited availability of nutrients.

The vegetation of base-rich fens is dominated by small sedges such as Carex davalliana, C.  flava, C. hostiana, C. lepidocarpa and other short or medium-tall Cyperaceae such as Blysmus compressus, Eleocharis quinqueflora, Eriophorum angustifolium and E. latifolium. In some places these species typical of fens grow together with species characteristic of wet meadows on mineral soil such as Anthoxanthum odoratum, Briza media, Caltha palustris, Cirsium palustre, C. rivulare, Cynosurus cristatus, Festuca rubra agg., Holcus lanatus, Lychnis flos-cuculi, Plantago lanceolata and Ranunculus acris. Bryophytes are common, in some stands reaching a cover close to 100% and, in the moss layer, species of fens (e.g. Bryum pseudotriquetrum, Campylium stellatum, Hamatocaulis vernicosus, Palustriella commutata and Scorpidium cossonii) can grow together with species typical of mineral soils (e.g. Cirriphyllum piliferum, Climacium dendroides, Plagiomnium affine agg., Rhytidiadelphus squarrosus), although the latter may be absent at some sites, especially in primary fens.

Small-sedge calcareous fens can be primary habitats developed around springs and seepages of calcium-rich water. Some of them can be several thousand years old and the long-term habitat continuity can be indicated by the occurrence of species such as Primula farinosa, Salix rosmarinifolia or Triglochin maritimum. At some sites, however, fens can be natural but only a few centuries old, and in other sites they can be secondary, developed on formerly forested land and be dependent on regular mowing. Many of them have been mown once a year without input of fertilizers for several centuries. Export of nutrients with hay has led to partial elimination of nutrient-demanding tall-growing species of wet meadows. Many of these species are still growing in these grasslands but their competitive ability is too weak to outcompete short-growing fen species. Small-sedge fens are most common and most diverse in the limestone massifs of the central European mountain systems, especially the Alps and the Carpathians.

In many places calcareous fen meadows have been damaged or destroyed by artificial drainage, which has caused mineralization of nutrients in the fen sediment and the spread of nutrient-demanding species of wet meadows or species of strongly-drained mesic meadows. To some extent they can be negatively influenced by livestock grazing as well.

Indicators of good quality:

In general, primary fens without species of wet meadows are more valuable than secondary fens. However, in some areas, especially in the lowlands, primary fens may not occur and in that case the secondary fens with meadow species have the highest conservation value.

·      Stable hydrological regime

·      Continued traditional management at secondary habitats

·      Absence of overgrazing

·      No encroachment of trees or shrubs

·      No spread of tall-growing nutrient-demanding herbs

·      Absence or low incidence of neophytes

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

Threat status

Synthesis of Red List assessment

The category Endangered (EN) is indicated by A1 and A3 categories describing declines in extent over respectively the last 50 years and a longer time frame. In addition, the total area (based on territorial data) is very low, as the habitat almost everywhere occurs in small stands. The subtypes that cover smaller areas and occur outside Sweden, Ireland and Estonia are even more threatened and if assessed separately, the Critically Endangered category should be expected. Considering still continuing and even accelerating degradation, loss of habitat specialists and bad restoration prospects reported by several regional studies, the resulting Endangered category has a high reliability.
EU
Red List Category Red List Criteria
Endangered A1, A3
Europe
Red List Category Red List Criteria
Endangered A3

Confidence in the assessment

high
Red List of habitat categories and criteria descriptions

Pressures and threats

  • Agriculture
    • Cultivation
    • Modification of cultivation practices
    • Agricultural intensification
    • Mowing / Cutting of grassland
    • Abandonment / Lack of  mowing
    • Grazing
    • Abandonment of pastoral systems, lack of grazing
  • Sylviculture, forestry
    • Forestry activities not referred to above
  • Human intrusions and disturbances
    • Outdoor sports and leisure activities, recreational activities
    • Sport and leisure structures
  • Pollution
    • Pollution to surface waters (limnic, terrestrial, marine & brackish)
    • Pollution to groundwater (point sources and diffuse sources)
    • Diffuse groundwater pollution due to agricultural and forestry activities
    • Other forms of pollution
  • Natural System modifications
    • Human induced changes in hydraulic conditions
    • Modification of hydrographic functioning, general
    • Water abstractions from groundwater
    • Other human induced changes in hydraulic conditions
    • Anthropogenic reduction of habitat connectivity
  • Natural biotic and abiotic processes (without catastrophes)
    • Biocenotic evolution, succession
    • Species composition change (succession)

Habitat restoration potential

Naturally only if habitat specialists survived at site, nutrient availability is not increased and water regime is unaffected.
Through intervention restoration is extremely difficult as demonstrated by several studies, especially because of problems with nutrient oversupply, iron toxicity and cessation of carbonate precipitation during water level manipulations

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 following procedures are advised:
No intervention - in boreal or high mountain fens, with stable high water level, no extra supply of nutrients and no invasive species.
Mowing - in fens enriched in nutrients or with declining water level, typically in young habitats with shallow peat level that has developed since Middle Ages. Also in fens invaded by Molinia, Phragmites, Calamagrostis, Filipendula or tall willows. Additional spring mowing can supress invasive grasses such as Molinia or Phragmites, should not be applied permanently
Grazing - with caution only, may bring extra nutrients.
Artificial disturbances - if acidicole, late-successional Sphagnum species invade, disturbances without nutrient input (e.g., removal of expanding peat mosses) may be applied to support original brown-moss vegetation.
Extensive restoration measures (blocking drainage channels, sod removal) - in heavily damaged fens.

List of conservation and management needs

  • No measures
    • No measures needed for the conservation of the habitat/species
    • Measures needed, but not implemented
  • Measures related to agriculture and open habitats
    • Maintaining grasslands and other open habitats
  • Measures related to wetland, freshwater and coastal habitats
    • Restoring/Improving water quality
    • Restoring/Improving the hydrological regime
    • Managing water abstraction
  • Measures related to spatial planning
    • Establish protected areas/sites
    • Legal protection of habitats and species
  • 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 85 Decreasing Decreasing
Belgium Present 0.2 - -
Bulgaria Present 5 Decreasing Decreasing
Croatia Present Unknown - -
Czech Republic Present 0.5 Decreasing Decreasing
Denmark Present 90 Decreasing Decreasing
Estonia Present 130 Decreasing Unknown
Finland mainland Present 370 Decreasing Decreasing
France mainland Present 93 Decreasing Decreasing
Germany Present 50 Decreasing Decreasing
Greece (mainland and other islands) Present 1.5 Stable -
Hungary Present 3.5 - Decreasing
Ireland Present 130 Decreasing Decreasing
Italy mainland Present 62 Decreasing Decreasing
Latvia Present 9 Decreasing Decreasing
Lithuania Present 10 Decreasing Decreasing
Netherlands Present 0.1 Decreasing Decreasing
Poland Present 90 Decreasing Decreasing
Romania Present 15 Decreasing Decreasing
Slovakia Present 0.4 Decreasing Decreasing
Slovenia Present 1.3 Decreasing Decreasing
Spain mainland Present 27 Decreasing Decreasing
United Kingdom Present 30 Decreasing Unknown
Sweden Present 1000 Decreasing Decreasing
EU28 + Present or presence uncertain Current area of habitat (Km2) Recent trend in quantity (last 50 years) Recent trend in quality (last 50 years)
Former Yugoslavian Republic of Macedonia (FYROM) Present Unknown Decreasing Decreasing
Switzerland Present 100 Decreasing Decreasing
Bosnia and Herzegovina Present 20 Decreasing Decreasing
Norway Mainland Present 1250 - 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 7447400 7446 2203
EU28+ 7621 2323
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.
Ferns Selaginella selaginoides
Flowering Plants Anthoxanthum odoratum
Flowering Plants Aster bellidiastrum
Flowering Plants Bartsia alpina
Flowering Plants Blysmus compressus
Flowering Plants Briza media
Flowering Plants Caltha palustris
Flowering Plants Carex davalliana
Flowering Plants Carex flava
Flowering Plants Carex hostiana
Flowering Plants Carex lepidocarpa
Flowering Plants Cirsium palustre
Flowering Plants Cirsium rivulare
Flowering Plants Crepis paludosa
Flowering Plants Cruciata glabra
Flowering Plants Cynosurus cristatus
Flowering Plants Dactylorhiza incarnata
Flowering Plants Dactylorhiza majalis
Flowering Plants Eleocharis quinqueflora
Flowering Plants Epipactis palustris
Flowering Plants Eriophorum angustifolium
Flowering Plants Eriophorum latifolium
Flowering Plants Festuca rubra
Flowering Plants Galium uliginosum
Flowering Plants Holcus lanatus
Flowering Plants Juncus alpinoarticulatus
Flowering Plants Juncus effusus
Flowering Plants Lathyrus pratensis
Flowering Plants Lychnis flos-cuculi
Flowering Plants Menyanthes trifoliata
Flowering Plants Parnassia palustris
Flowering Plants Pinguicula vulgaris
Flowering Plants Plantago lanceolata
Flowering Plants Primula elatior
Flowering Plants Primula farinosa
Flowering Plants Prunella vulgaris
Flowering Plants Ranunculus acris
Flowering Plants Salix rosmarinifolia
Flowering Plants Scirpus sylvaticus
Flowering Plants Tofieldia calyculata
Flowering Plants Trichophorum cespitosum
Flowering Plants Triglochin palustris
Flowering Plants Valeriana dioica
Flowering Plants Valeriana simplicifolia
Mosses & Liverworts Bryum pseudotriquetrum
Mosses & Liverworts Calliergonella cuspidata
Mosses & Liverworts Campylium stellatum
Mosses & Liverworts Cirriphyllum piliferum
Mosses & Liverworts Climacium dendroides
Mosses & Liverworts Cratoneuron filicinum
Mosses & Liverworts Hamatocaulis vernicosus
Mosses & Liverworts Palustriella commutata
Mosses & Liverworts Palustriella falcata
Mosses & Liverworts Plagiomnium affine
Mosses & Liverworts Rhytidiadelphus squarrosus
Mosses & Liverworts Scorpidium cossoni
Mosses & Liverworts Scorpidium cossonii
Mosses & Liverworts Thuidium philibertii
Species scientific name English common name Species group
Selaginella selaginoides Ferns
Anthoxanthum odoratum Flowering Plants
Aster bellidiastrum Flowering Plants
Bartsia alpina Flowering Plants
Blysmus compressus Flowering Plants
Briza media Flowering Plants
Caltha palustris Flowering Plants
Carex davalliana Flowering Plants
Carex flava Flowering Plants
Carex hostiana Flowering Plants
Carex lepidocarpa Flowering Plants
Cirsium palustre Flowering Plants
Cirsium rivulare Flowering Plants
Crepis paludosa Flowering Plants
Cruciata glabra Flowering Plants
Cynosurus cristatus Flowering Plants
Dactylorhiza incarnata Flowering Plants
Dactylorhiza majalis Flowering Plants
Eleocharis quinqueflora Flowering Plants
Epipactis palustris Flowering Plants
Eriophorum angustifolium Flowering Plants
Eriophorum latifolium Flowering Plants
Festuca rubra Flowering Plants
Galium uliginosum Flowering Plants
Holcus lanatus Flowering Plants
Juncus alpinoarticulatus Flowering Plants
Juncus effusus Flowering Plants
Lathyrus pratensis Flowering Plants
Lychnis flos-cuculi Flowering Plants
Menyanthes trifoliata Flowering Plants
Parnassia palustris Flowering Plants
Pinguicula vulgaris Flowering Plants
Plantago lanceolata Flowering Plants
Primula elatior Flowering Plants
Primula farinosa Flowering Plants
Prunella vulgaris Flowering Plants
Ranunculus acris Flowering Plants
Salix rosmarinifolia Flowering Plants
Scirpus sylvaticus Flowering Plants
Tofieldia calyculata Flowering Plants
Trichophorum cespitosum Flowering Plants
Triglochin palustris Flowering Plants
Valeriana dioica Flowering Plants
Valeriana simplicifolia Flowering Plants
Bryum pseudotriquetrum Mosses & Liverworts
Calliergonella cuspidata Mosses & Liverworts
Campylium stellatum Mosses & Liverworts
Cirriphyllum piliferum Mosses & Liverworts
Climacium dendroides Mosses & Liverworts
Cratoneuron filicinum Mosses & Liverworts
Hamatocaulis vernicosus Mosses & Liverworts
Palustriella commutata Mosses & Liverworts
Palustriella falcata Mosses & Liverworts
Plagiomnium affine Mosses & Liverworts
Rhytidiadelphus squarrosus Mosses & Liverworts
Scorpidium cossoni Mosses & Liverworts
Scorpidium cossonii Mosses & Liverworts
Thuidium philibertii 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 D4.1 Rich fens, including eutrophic tall-herb fens and calcareous flushes and soaks narrower
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