Poor fen
Quick facts
Red List habitat type | code RLD2.2a |
---|---|
Threat status | |
Europe | Least Concern |
EU | Vulnerable |
Relation to |
|
Source | European Red List habitat factsheet |
European Red List of habitats reports | |
European Red List of habitats (Excel table) |
Summary
Wide group of acidic (pH 3-5), minerotrophic mires, dominated by sedges and Sphagnum species. Poor fens occur in many different hydro-topographical situations and are typical components of the marginal lagg of raised bogs. In temperate Europe they also occur around mountain springs, in forest hollows, and in infertile fen-grassland complexes, but always on non-calcareous bedrock. Poor fens can also form the main type of usually small mire areas in weakly minerotrophic basins. Poor fens are the main transition type between D2.3a Quaking mires and D1.1 Raised bogs. Poor fens receive limited minerotrophic water input from upper catchments usually via non-distinct, diffuse flow paths. Poor fens can have unidirectional slope and lateral water flow but hummock-string patterning typical for D3.2 Aapa mires is missing.
Poor fens are characterized by continuous carpets of oligotrophic Sphagnum spp. combined with high abundance of sedges like Carex canescens, Carex echinata, Carex nigra, Carex lasiocarpa, Eriophorum scheuchzeri, Trichophorum cespitosum. Other abundant species are and Andromeda polifolia, Betula nana, Dactylorhiza maculata, Eriophorum vaginatum, Potentilla erecta, and Vaccinium oxycoccos. Also certain deep-rooted species more characteristic of D2.3a Quaking mires are frequent in poor fens, namely Eriophorum angustifolium, Carex rostrata and Menyanthes trifoliata. Ground layer is often dominated by Sphagnum angustifolium, Sphagnum fallax, Sphagnum flexuosum, Sphagnum papillosum and Sphagnum magellanicum, while other brown mosses can also be frequent, including Straminergon stramineum, Polytrichum commune and Warnstorfia fluitans. Higher degree of minerotrophic influence can be found only occasionally, as indicated by occurrence of e.g. Sphagnum subsecundum, Sphagnum obtusum or Sphagnum teres. In boreal zone, hummocks with Sphagnum fuscum, Polytrichum strictum, Calluna vulgaris and Empetrum nigrum are sometimes found in poor fens, with Salix spp., Rhamnus frangula, Betula pubescens or individual cranked pines (Pinus sylvestris).
Indicators of good quality:
Under natural conditions, water table is high also in summer and continuous carpets of mosses prevail with abundant sedges. Species diversity of vegetation is generally slightly higher than in D1.1 Raised bogs but clearly lower than in intermediate fens. In good hydrological condition there are no ditches that drain or disconnect water flow from the upper drainage area to the mire. Tree growth is limited to scattered individuals on hummocks or mire margins.
Threat status
Synthesis of Red List assessment
EU | |
Red List Category | Red List Criteria |
Vulnerable | A1 |
Europe | |
Red List Category | Red List Criteria |
Least Concern | - |
Confidence in the assessment
Pressures and threats
- Agriculture
- Agricultural intensification
- Pollution
- Pollution to surface waters (limnic, terrestrial, marine & brackish)
- Air pollution, air-borne pollutants
- Natural System modifications
- Modification of hydrographic functioning, general
- Water abstractions from groundwater
- Climate change
- Droughts and less precipitations
Habitat restoration potential
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
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
Distribution
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 | 13 | - | Decreasing |
Belgium | Present | 0.8 | Increasing | Decreasing |
Bulgaria | Present | 1 | Decreasing | Decreasing |
Croatia | Uncertain | - | - | |
Czech Republic | Present | 27 | Decreasing | Decreasing |
Denmark | Present | 20 | Stable | Decreasing |
Estonia | Present | 350 | Stable | Unknown |
Finland mainland | Present | 7050 | Decreasing | Decreasing |
Aland Islands | Uncertain | 7050 | Decreasing | Decreasing |
France mainland | Present | unknown | - | - |
Germany | Present | unknown | Decreasing | Decreasing |
Hungary | Present | 0.1 | Decreasing | Decreasing |
Ireland | Present | 560 | Unknown | Decreasing |
Italy mainland | Uncertain | - | - | |
Latvia | Present | unknown | Decreasing | Decreasing |
Lithuania | Present | 7.5 | Decreasing | Decreasing |
Luxembourg | Uncertain | - | - | |
Netherlands | Present | 1.1 | Stable | Decreasing |
Poland | Present | 300 | Decreasing | Decreasing |
Romania | Present | 2 | Decreasing | Stable |
Slovakia | Present | 6.2 | Stable | Decreasing |
Slovenia | Uncertain | - | - | |
Spain mainland | Present | 70 | Unknown | Decreasing |
Balearic Islands | Present | 70 | Unknown | Decreasing |
Sweden | Present | 12500 | Decreasing | Decreasing |
United Kingdom | Present | 75 | Unknown | Decreasing |
Northern Island | Present | 75 | Unknown | Decreasing |
Greece (mainland and other islands) | Uncertain | - | - |
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 | 0.7 | Stable | Decreasing |
Norway Mainland | Present | 15000 | 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 | 9973750 | 13692 | 13000 | AOO and EOO incl. potential distribution |
EU28+ | 13711 | 33000 | AOO and EOO incl. potential distribution |
EOO = the area (km2) of the envelope around all occurrences of a habitat (calculated by a minimum convex polygon).