Red List habitat classification > RLG - Forests > RLG1.5 Broadleaved bog woodland on acid peat

Broadleaved bog woodland on acid peat

Quick facts

Red List habitat type code RLG1.5
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)


This habitat is broadleaved deciduous woodland on wet acid, oligotrophic peat on the surfaces of bogs or transition mires, around pools and along laggs throughout the Atlantic and into the Boreal zones; more locally, where ground water conditions permit, it occurs also in the Continental zone. The woodland is typically dominated by Betula pubescens, the canopy is often only a few metres tall and the trees sometimes have a naturally decrepit appearance, infected early with Piptoporus. Alnus glutinosa is generally excluded from the canopy because of nutrient shortage. There is never more than a minority component of conifers, though Pinus sylvestris increasingly replaces Betula as the dominant in similar situations in the colder Boreal zone and as a pioneer species in Massif central. Deciduous woody associates, such as shrubby Salix spp. and Frangula alnus can occur, though typically at low cover and never forming an extensive understorey. The field layer generally shows strong continuity with the adjacent bog vegetation and can be quite luxuriant but more shade-tolerant species gain the ascendancy under the birch canopy, sometimes producing a rather species-poor cover of, for example, tussocks of Molinia caerulea. The often extensive carpets of Sphagnum on lower wetter ground between the trees include some distinctive species such as S. fimbriatum and S. russowii. Only naturally developed stands should be included here (primary stands and secondary stands due to older/ former changes in hydrology) and drying or cut-over bogs onto which Betula and other tree species spread in the past should be considered as poorer-quality examples of bog forests. Young succession stages or stages without stabilized hydrology are not considered under this type.

Indicators of quality:

  • Intact (semi)natural hydrology
  • Absence of forest exploitation
  • Typical structure and composition of canopy with an open or patchy cover with dying and keeling birch trees are natural
  • Typical flora and fauna composition of the region, especially a field layer typical of wet acid peat without any indication of drying, eutrophicaqtion or pollution, for example the overwhelming spread of Molinia caerulea
  • Absence of non-native tree species and absence of invasive aliens in all layers (fauna, flora), such as conifers or non-native Rhododendron such as happens where bogs have been drained.

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

Threat status

Synthesis of Red List assessment

The VU category is attained because of the reduction in quantity during the last 50 years, especially in Finland. Even if the area ouside Finland and Sweeden is much smaller, most other countries reports a similar decline. We lack data for Sweden, and a trend in quantity can only be calculated on about 60% of the area in EU28 and 28+. Even so, we assume that the trend in Sweeden must not be good enough to improve the average trend and make it go bellow the 30% decline required to qualify the VU category.
Red List Category Red List Criteria
Vulnerable A1
Red List Category Red List Criteria
Vulnerable A1

Confidence in the assessment

Red List of habitat categories and criteria descriptions

Pressures and threats

  • Sylviculture, forestry
    • Forest and Plantation management & use
    • Forest replanting
    • Forestry clearance
  • Mining, extraction of materials and energy production
    • Peat extraction
  • Pollution
    • Air pollution, air-borne pollutants
    • Nitrogen-input
  • Natural System modifications
    • Modification of hydrographic functioning, general
    • Water abstractions from groundwater
  • Climate change
    • Changes in abiotic conditions
    • Temperature changes (e.g. rise of temperature & extremes)
    • Droughts and less precipitations

Habitat restoration potential

The main intervention is to restore hygrological functioning of the habitat, both in quality and quantity. Species will be able to recolonize and planting is not necessary most of the time. Alien species (eg. Picea abies outside its natural range) must be removed. During late 20th - early 21st centuries, the restoration of former wet grasslands has been systematically choosed in some areas, and no balance between open land and wooded habitats was sought. Both habitat types deserves to be conserved, and a balance has to be found.

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

On damaged sites, the restoration of the abiotic and biotic condition is the most important approach in peatland conservation. This means good water supply in quantity by filling or putting dams on the drains, and also dealing with water quality. An increase of the water level with a bad quality water could completely damage the habitat, with very few chances to restore an oligotrophic vegetation. On a lot of sites, broadleaves swamp woodland on acid peat occurs on the wetter part of the bog, and water can come from the surroundings : the water supply should be protected from pollution, due for example to agriculture. Conservation measures cannot apply only on the bog itself but must also cover the surroundings. Extensive agriculture with no fertilization or forestry without large clearcuts (to protect soils and hydrological fonctioning) are possible measures. Changes on hydrology outside the site can also have important effects.
Grazing has to be prohibited because of regeneration problems and destruction of the Sphagnum layer. Even where the habitat covers large surfaces, a restoration of the hydrological conditions followed by strict protection (no forestry nor agriculture use) seems appropriate, because forestry on such wet soils implies drainage, and is not compatible with the habitat conservation. This approach is even more important in area where the habitat is rare (south-western part of the distribution area), and rare remaining sites have to be strictly protected.

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
    • 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 1 Unknown Unknown
Belgium Present 7.5 Increasing Increasing
Croatia Present Fragments Unknown Unknown
Czech Republic Present 18 Decreasing Decreasing
Finland mainland Present 1513 Decreasing Decreasing
Germany Present 200 Decreasing Decreasing
Ireland Present 1 Decreasing Unknown
Italy mainland Present unknown Decreasing Decreasing
Latvia Present unknown Decreasing Decreasing
Lithuania Present 200 Decreasing Stable
Slovakia Present 5.7 Unknown Decreasing
Sweden Present Unknown Unknown Unknown
United Kingdom Present 50 Stable Stable
Northern Island Present 50 Stable Stable
Bulgaria Uncertain unknown Unknown Unknown
Denmark Present 47 Decreasing Unknown
Estonia Present unknown Unknown Unknown
France mainland Present 30 Increasing Increasing
Netherlands Present 17 Increasing Increasing
Poland Present unknown Unknown Unknown
Romania Uncertain unknown Unknown Unknown
Aland Islands Uncertain 1513 Decreasing Decreasing
Luxembourg Uncertain - -
Slovenia Present 0.03 Unknown 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 0.2 Decreasing Decreasing
Norway Mainland Present unknown Unknown Unknown
Switzerland Present 3 Unknown Decreasing
Kaliningrad Present unknown Unknown Unknown
Serbia Uncertain unknown Unknown Unknown

Extent of Occurrence, Area of Occupancy and habitat area

Extent of Occurrence (EOO) (Km2) Area of Occupancy (AOO) Current estimated Total Area Comment
EU28 8713550 12648 3500 AOO and EOO incl. potential distribution
EU28+ 12667 3550 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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1050 Copenhagen K
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