|Red List habitat type||code RLD1.1|
|Source||European Red List habitat factsheet|
|European Red List of habitats reports|
|European Red List of habitats (Excel table)|
In raised bogs, the water table level is elevated by a few centimeters to metres above that of mineral rich ground water of surrounding areas and consequently there is an ombrotrophic (rain-fed) nutrient regime. The peat layer is often several metres thick and mainly composed of Sphagnum remains, highly water saturated with the water table close to the surface. High acidity (pH < 4.5) and low mineral content characterize the peat and pore water. Typically there is a pattern of alternation between micro habitats (hummocks, lawns, carpets, hollows) that relate to topography, hydrology and peat formation. Hummock-hollow patterning can be irregular in flat plateau bogs, where hummocks remain low. In concentric and eccentric raised bog complexes, hummock-hollow patterning shows a distinct orientation perpendicular to the slope and water flow. Open water pools of secondary origin, i.e. developed on the peat after hummock ridge formation, are often found and provide important aquatic microhabitats. Raised bog habitats are most typical in central parts of raised bog complexes (EUNIS habitat X04) but they are also found in mixed complexes with D3.2 Aapa mires. Mire complex patterns may also be completely missing and often raised bog habitats are found as small undrained remnants of historically degraded bog complexes. Raised bogs differ from D1.2 Blanket bogs by being restricted to basins rather than blanketing over variable terrain. The lagg zones of raised bog complexes are considered under D2.2a Poor Fens.
Trees (Pinus sylvestris, Betula pubescens) are found only sparsely on hummocks and Sphagnum mosses dominate the ground layer of vegetation. In hummocks, Sphagnum fuscum is the most characteristic species, especially in boreal and continental areas. Other typical hummock species are S. rubellum, S. magellanicum, S. capillifolium, S. angustifolium, Dicranum bergeri and Polytrichum strictum. Dwarf-shrub species Andromeda polifolia, Betula nana, Calluna vulgaris, Empetrum nigrum, Erica tetralix, Ledum palustre, Vaccinium microcarpon, V. oxycoccos, V. uliginosum are characteristic on hummocks, while only few herbs (Drosera rotundifolia, Rubus chamaemorus) and sedges (Carex pauciflora, Eriophorum vaginatum) are found. The wet hollows may have continuous carpets of Sphagnum or sometimes muddy peat surfaces void of mosses or with some cover of hepatics or Warnstorfia fluitans. Typical species include Sphagnum cuspidatum, S. balticum, S. jensenii, S. majus, S. tenellum among mosses and Carex limosa, Scheuchzeria palustris, Rhynchospora alba among vascular plants. Also forest mosses like Pleurozium schreberi, Hylocomium splendens, Dicranum polysetum and lichens like Cladonia spp. and Certraria islandica are found on hummocks.
Raised bogs are widely distributed from central European mountain areas to north-boreal regions, being most prominent in the hemi-boreal to south-boreal zones. The pattern of dominance and features of micro-habitat patterning vary over different climatic zonation belts.
Indicators of good quality:
- Under natural conditions, the water table is close to surface in hollows and it can be readily observed in small pit dug in peat surface except during prolonged drought.
- There is a gradual and logical continuum between dominant vegetation and the composition of recently (decades to centennial) formed peat, indicating that modern vegetation is forming typical Sphagnum peat.
- Species composition differs between hummocks and hollows in a regionally characteristic way and there are no large patches of lichens or hummock mosses such as Polytrichum strictum in the hollows.
- Ombrotrophic and acidophilic Sphagnum mosses and other characteristic species comprise substantial elements in vegetation.
- Number of species or diversity indices of vegetation are not good indicators since raised bogs are naturally species poor habitats, while harboring unique species assemblages.
- Occurrence of trees is limited to scattered individuals on hummocks. Drainage ditches are one main factor to cause decline of quality of raised bogs but their occurrence alone does not always indicate poor quality.
Synthesis of Red List assessment
|Red List Category||Red List Criteria|
|Red List Category||Red List Criteria|
Confidence in the assessment
Pressures and threats
- Sylviculture, forestry
- Forest planting on open ground
- Forest planting on open ground (native trees)
- Artificial planting on open ground (non-native trees)
- Mining, extraction of materials and energy production
- Peat extraction
- Mechanical removal of peat
- Human intrusions and disturbances
- Other human intrusions and disturbances
- Air pollution, air-borne pollutants
- other air pollution
- Natural System modifications
- Human induced changes in hydraulic conditions
- Canalisation & water deviation
- Modification of hydrographic functioning, general
- Water abstractions from groundwater
- Other human induced changes in hydraulic conditions
- Other ecosystem modifications
- Anthropogenic reduction of habitat connectivity
- Natural biotic and abiotic processes (without catastrophes)
- Biocenotic evolution, succession
- Species composition change (succession)
- Eutrophication (natural)
- Climate change
- Changes in abiotic conditions
- Droughts and less precipitations
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
- Measures related to wetland, freshwater and coastal habitats
- Restoring/Improving the hydrological regime
- Managing water abstraction
- Measures related to spatial planning
- Establish protected areas/sites
- Establishing wilderness areas/allowing succession
- Legal protection of habitats and species
- Manage landscape features
- Measures related to hunting, taking and fishing and species management
- Regulation/Management of hunting and taking
- Measures related to urban areas, industry, energy and transport
- Specific management of traffic and energy transport systems
- Measures related to special resouce use
- Other resource use measures
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)|
|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|
Extent of Occurrence, Area of Occupancy and habitat area
|Extent of Occurrence (EOO) (Km2)||Area of Occupancy (AOO)||Current estimated Total Area||Comment|
EOO = the area (km2) of the envelope around all occurrences of a habitat (calculated by a minimum convex polygon).