Red List habitat classification > RLD - Mires and bogs > RLD2.3a Non-calcareous quaking mire

Non-calcareous quaking mire

Quick facts

Red List habitat type code RLD2.3a
Threat status
Europe Vulnerable
EU Vulnerable
Relation to
Source European Red List habitat factsheet
European Red List of habitats reports
European Red List of habitats (Excel table)


Very wet mires with poor fen vegetation. Quaking mires include mires formed by terrestrialization of water bodies which involves formation of floating rafts of peat, typically proceeding from marginal areas towards basin centre, where primary open water pools can remain. Also included in this type are mires without neighbouring water bodies layer but similarly high water saturation leading to quaking conditions occurring in high water throughput percolation mires. The mire basin is always fed by minerotrophic ground water from the catchment area. There is no regular surface patterning connected to water flow. Water quality varies from acidic to moderately acidic. Vegetation is minerotrophic poor fen vegetation including intermediate fen communities (pH below 7). The lack of raised peat domes separate quaking mires from D1.1 Raised bogs, the lack of string patterning and slope from D3.2 Aapa mires and the lack of true rich fen indicator species (Scorpidium spp. et al.) from D4.1c Calcareous quaking mires.

Non-calcareous quaking mires are characterized by poor fen to medium rich vegetation including Calla palustris, Carex limosa, Carex rostrata, Carex aquatilis, Eriophorum angustifolium, Equisetum fluviatile, Menyanthes trifoliata, Potentilla palustris, Rhynchospora alba, Scheuchzeria palustris and Utricularia intermedia among vascular plants. Sphagnum cuspidatum, Sphagnum platyphyllum, Sphagnum subsecundum, Sphagnum majus and Warnstofia spp. are characteristic among bryophytes. Hepatics are sometimes abundant, most typically Cladopodiella fluitans. Floating peat rafts may also form surfaces elevated from water level with for example Sphagnum fallax and Eriophorum vaginatum or Molinia caerulea. When the floating peat raft becomes thick enough nearly ombrotrophic hummock like surfaces with e.g. Sphagnum magellanicum, Andromeda polifolia and Vaccinium oxycoccos can occurr. Even in such cases deep-rooted minerotrophic vascular plants like Menyanthes trifoliata can be found. Excluded are stands of vegetation fringing water bodies (see C3.2) unless the vegetation raft is sufficiently extensive to count as a habitat in its own right.

Indicators of good quality:

  • water table always at surface; it can always be readily observed

  • packing density of peat is low, walk-on leads to characteristic yielding (quaking)

  • drainage ditches may affect quaking mires by lowering water level either permanently or increasing fluctuation and, thus, the likeliness of temporal drought or flooding with polluted water

  • deteriorating quality is indicated by loss of wet mire area associated species e.g. among birds, increase of trees and bushes, and of hummock vegetation

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

Threat status

Synthesis of Red List assessment

There is a strong negative trend in large parts of Europe, especially in Central Europe, but this negative trend is overshadowed by a smaller trend and much larger remaining areas in the boreal countries. Although an assessment for Central Europe would possibly lead to the category Endangered, the average decline in Europe leads to the conclusion Least Concern. However, the trend in quality (assessed under criterion C/D1) is large in Sweden as well, leading to an overall conclusion of Vulnerable (VU) . Eutrophication of water bodys and drainage are the main threats to this habitat type.
Red List Category Red List Criteria
Vulnerable C/D1
Red List Category Red List Criteria
Vulnerable C/D1

Confidence in the assessment

Red List of habitat categories and criteria descriptions

Pressures and threats

  • Pollution
    • Pollution to surface waters (limnic, terrestrial, marine & brackish)
    • Nutrient enrichment (N, P, organic matter)
    • Pollution to groundwater (point sources and diffuse sources)
    • Diffuse groundwater pollution due to agricultural and forestry activities
  • Natural System modifications
    • Human induced changes in hydraulic conditions
    • Landfill, land reclamation and drying out, general
    • Polderisation
    • Modification of hydrographic functioning, general
    • Modifying structures of inland water courses
    • Modification of standing water bodies

Habitat restoration potential

Floating vegetation mats directly depend on water level and water quality of their lake and can be relatively easy be restored, if water chemistry and water level of the lake is restored. Quaking areas in percolation mires will need a very long time to regenerate after rewetting if the regulatory mechanism of the peat body are destroyed by drainage.

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

Efforts have been undertaken in the last decades to restore the hydrological systems of the respective mires. Floating vegetation mats directly depend on water level and water quality of their lake. Under optimal conditions mats of floating sphagnum mosses can grow rapidly. However, quaking areas in percolation mires (with much higher species richness) will need a very long time to regenerate after rewetting if the regulatory mechanism of the peat body has been destroyed by drainage.

List of conservation and management needs

  • 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
    • Legal protection of habitats and species


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 24 Decreasing Unknown
Belgium Present unknown Decreasing Decreasing
Bulgaria Present 0.5 Decreasing Decreasing
Czech Republic Present 10 Decreasing Decreasing
Denmark Present 20 Unknown Unknown
Estonia Present 50 Stable Unknown
Finland mainland Present 830 Decreasing Decreasing
Aland Islands Uncertain 830 Decreasing Decreasing
France mainland Present 12 Decreasing Decreasing
Corsica Uncertain 12 Decreasing Decreasing
Germany Present 2 Decreasing Decreasing
Hungary Present 0.1 Decreasing Decreasing
Ireland Present 94 Unknown Unknown
Italy mainland Present 30 Decreasing Decreasing
Sardinia Present 30 Decreasing Decreasing
Sicily Present 30 Decreasing Decreasing
Latvia Present unknown Decreasing Decreasing
Lithuania Present 7 Decreasing Decreasing
Netherlands Present 11 Stable Increasing
Poland Present 60 Stable Decreasing
Romania Present 1 Decreasing Stable
Slovakia Present 0.5 Stable Decreasing
Spain mainland Present 65 Decreasing Decreasing
Sweden Present 4500 Decreasing Decreasing
Portugal mainland Present 0.2 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)
Bosnia and Herzegovina Present 0.3 Stable Stable
Switzerland Present 12 Stable Stable

Extent of Occurrence, Area of Occupancy and habitat area

Extent of Occurrence (EOO) (Km2) Area of Occupancy (AOO) Current estimated Total Area Comment
EU28 9973750 13693 about 5500 AOO and EOO incl. potential distribution
EU28+ 13711 > 5500 AOO and EOO incl. potential distribution
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

Not available

Vegetation types

Relation to vegetation types (syntaxa)

Not available

Other classifications

Not available
European Environment Agency (EEA)
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