Red List habitat classification > RLD - Mires and bogs > RLD2.2a Poor fen

Poor fen

Quick facts

Red List habitat type	code RLD2.2a
Threat status
Europe	Least Concern
EU	Vulnerable
Relation to	Annex I habitat types (EU Habitats Directive) Resolution 4 habitat type (Bern Convention) EUNIS habitat classification (2007)
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.

Characteristic species

For full habitat description, please download the habitat factsheet.

Threat status

Synthesis of Red List assessment

This habitat has been assessed as Vulnerable (VU) in the EU28, based on the decline in area over the last 50 years, and Least Concern for the EU28+. However, there is a massive reduction up to over 90% of its previous area in many European countries, and therefore the habitat is regionally much more threatened. However, in the countries of Scandinavia, where by far the largest areas of this mire type occur, the reductions are relatively low. The habitat is not as sensitive regarding reduction of quality as the calcareous counterpart Short-sedge base-rich fens. On the contrary, slight drainage often leads to acidification of mire surfaces due to the higher influence of rainfall and therefore to an expansion of poor fens at the expense of calcareous types.

EU
Red List Category	Red List Criteria
Vulnerable	A1

Europe
Red List Category	Red List Criteria
Least Concern	-

Confidence in the assessment

medium

Red List of habitat categories and criteria descriptions

European Red List of Habitats categories

Based on Scientific Foundations for an IUCN Red List of Ecosystems

European Red List of Habitats criteria

Reduction in quantity (area of distribution)	A	A1 Present decline (over last 50 years) A2a Future decline (over the next 50 years) A2b Future/present decline (over a 50-year period inclunding present and future) A3 Historic decline
Restricted geographic distribution	B	B1 Restricted Extent of Occurrence (EOO) B2 Restricted Area of Occupancy (AOO) B3 Present at few locations
Reduction in abiotic quality	C	C/D1 Reduction in quality over the last 50 years C/D2 Reduction in quality in the future or in a period including present and future C/D3 Historic reduction in quality
Reduction in biotic quality	D
Quantitative analysis of probability of collapse	E

From Scientific Foundations for an IUCN Red List of Ecosystems

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

Rewetting activities show that in general the hydrological regime of poor fens can be restored. However, depending on the status of the surrounding landscape, pollution with nutrients might have effect for a long time and regeneration of nutrient poor conditions at least in Central Europe can be expected only after decades to centuries after massive new peat accumulation or after top soil removal.

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

Huge efforts have been undertaken in the last decades to protect the last poor fen areas in Central and Southern Europe. Most important is the regeneration of the hydrological systems of the mires. In some areas and after eutrophication, poor fens depend on nutrient withdrawal by browsing or mowing.

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

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	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

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.

Conifers Pinus sylvestris

Ferns Equisetum fluviatile

Ferns Huperzia selago

Flowering Plants Andromeda polifolia

Flowering Plants Betula nana

Flowering Plants Betula pubescens

Flowering Plants Calluna vulgaris

Flowering Plants Carex canescens

Flowering Plants Carex chordorrhiza

Flowering Plants Carex diandra

Flowering Plants Carex echinata

Flowering Plants Carex lasiocarpa

Flowering Plants Carex limosa

Flowering Plants Carex nigra

Flowering Plants Carex rostrata

Flowering Plants Chamaedaphne calyculata

Flowering Plants Dactylorhiza maculata

Flowering Plants Drosera longifolia

Flowering Plants Drosera rotundifolia

Flowering Plants Empetrum nigrum

Flowering Plants Epilobium palustre

Flowering Plants Eriophorum angustifolium

Flowering Plants Eriophorum scheuchzeri

Flowering Plants Eriophorum vaginatum

Flowering Plants Juncus filiformis

Flowering Plants Ledum palustre

Flowering Plants Menyanthes trifoliata

Flowering Plants Pedicularis palustris

Flowering Plants Peucedanum palustre

Flowering Plants Potentilla erecta

Flowering Plants Rhamnus frangula

Flowering Plants Rubus chamaemorus

Flowering Plants Swertia perennis

Flowering Plants Trichophorum cespitosum

Flowering Plants Vaccinium oxycoccos

Mosses & Liverworts Aulacomnium palustre

Mosses & Liverworts Calliergonella cuspidata

Mosses & Liverworts Polytrichum commune

Mosses & Liverworts Polytrichum strictum

Mosses & Liverworts Sphagnum angustifolium

Mosses & Liverworts Sphagnum aongstroemii

Mosses & Liverworts Sphagnum fallax

Mosses & Liverworts Sphagnum fimbriatum

Mosses & Liverworts Sphagnum flexuosum

Mosses & Liverworts Sphagnum fuscum

Mosses & Liverworts Sphagnum magellanicum

Mosses & Liverworts Sphagnum obtusum

Mosses & Liverworts Sphagnum palustre

Mosses & Liverworts Sphagnum papillosum

Mosses & Liverworts Sphagnum pulchrum

Mosses & Liverworts Sphagnum riparium

Mosses & Liverworts Sphagnum subnitens

Mosses & Liverworts Sphagnum subsecundum

Mosses & Liverworts Sphagnum teres

Mosses & Liverworts Straminergon stramineum

Mosses & Liverworts Warnstorfia fluitans

Species scientific name	English common name	Species group
Pinus sylvestris		Conifers
Equisetum fluviatile		Ferns
Huperzia selago		Ferns
Andromeda polifolia		Flowering Plants
Betula nana		Flowering Plants
Betula pubescens		Flowering Plants
Calluna vulgaris		Flowering Plants
Carex canescens		Flowering Plants
Carex chordorrhiza		Flowering Plants
Carex diandra		Flowering Plants
Carex echinata		Flowering Plants
Carex lasiocarpa		Flowering Plants
Carex limosa		Flowering Plants
Carex nigra		Flowering Plants
Carex rostrata		Flowering Plants
Chamaedaphne calyculata		Flowering Plants
Dactylorhiza maculata		Flowering Plants
Drosera longifolia		Flowering Plants
Drosera rotundifolia		Flowering Plants
Empetrum nigrum		Flowering Plants
Epilobium palustre		Flowering Plants
Eriophorum angustifolium		Flowering Plants
Eriophorum scheuchzeri		Flowering Plants
Eriophorum vaginatum		Flowering Plants
Juncus filiformis		Flowering Plants
Ledum palustre		Flowering Plants
Menyanthes trifoliata		Flowering Plants
Pedicularis palustris		Flowering Plants
Peucedanum palustre		Flowering Plants
Potentilla erecta		Flowering Plants
Rhamnus frangula		Flowering Plants
Rubus chamaemorus		Flowering Plants
Swertia perennis		Flowering Plants
Trichophorum cespitosum		Flowering Plants
Vaccinium oxycoccos		Flowering Plants
Aulacomnium palustre		Mosses & Liverworts
Calliergonella cuspidata		Mosses & Liverworts
Polytrichum commune		Mosses & Liverworts
Polytrichum strictum		Mosses & Liverworts
Sphagnum angustifolium		Mosses & Liverworts
Sphagnum aongstroemii		Mosses & Liverworts
Sphagnum fallax		Mosses & Liverworts
Sphagnum fimbriatum		Mosses & Liverworts
Sphagnum flexuosum		Mosses & Liverworts
Sphagnum fuscum		Mosses & Liverworts
Sphagnum magellanicum		Mosses & Liverworts
Sphagnum obtusum		Mosses & Liverworts
Sphagnum palustre		Mosses & Liverworts
Sphagnum papillosum		Mosses & Liverworts
Sphagnum pulchrum		Mosses & Liverworts
Sphagnum riparium		Mosses & Liverworts
Sphagnum subnitens		Mosses & Liverworts
Sphagnum subsecundum		Mosses & Liverworts
Sphagnum teres		Mosses & Liverworts
Straminergon stramineum		Mosses & Liverworts
Warnstorfia fluitans		Mosses & Liverworts

Legal status

Relation to other habitat types mentioned in legal instruments

Legal text	Annex	Name in legal text	Code in legal text	Habitat type relationship	More information
Council Directive 92/43/EEC of 21 May 1992 on the conservation of natural habitats and of wild fauna and flora - consolidated version 01/01/2007	Annex I: natural habitat types of community interest whose conservation requires the designation of special areas of conservation	Transition mires and quaking bogs	7140	Overlap	http://ec.europa.eu/environm...rective/index_en.htm
Council Directive 92/43/EEC of 21 May 1992 on the conservation of natural habitats and of wild fauna and flora - consolidated version 01/01/2007	Annex I: natural habitat types of community interest whose conservation requires the designation of special areas of conservation	Depressions on peat substrates of the Rhynchosporion	7150	Overlap
Convention on the conservation of European wildlife and natural habitats	Revised Annex I of Resolution 4 (1996) of the Bern Convention on endangered natural habitats types using the EUNIS habitat classification (year of revision 2010)	Poor fens and soft-water spring mires	D2.2	Narrower	https://wcd.coe.int/ViewDoc....ckColorLogged=FDC864 Resolution No. 4 (1996) of the Bern Convention lists endangered natural habitats requiring specific conservation measures [and the designation of Areas of Special Conservation Interest (ASCIs) forming the Emerald network]

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	D2.2	Poor fens and soft-water spring mires	narrower

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Sections

Poor fen

Quick facts

Summary

Threat status

Synthesis of Red List assessment

Confidence in the assessment

European Red List of Habitats categories

European Red List of Habitats criteria

Pressures and threats

Habitat restoration potential

Trends in extent

Average current trend in quantity

Trends in quality

Average current trend in quality

Conservation and management needs

List of conservation and management needs

Distribution

Geographic occurrence and trends

Extent of Occurrence, Area of Occupancy and habitat area

Characteristic species

Legal status

Relation to other habitat types mentioned in legal instruments

Vegetation types

Relation to vegetation types (syntaxa)

Other classifications