Yanal Bog () is a 1.6

hectare The hectare (; SI symbol: ha) is a non-SI metric unit of area equal to a square with 100-metre sides (1 hm2), that is, square metres (), and is primarily used in the measurement of land. There are 100 hectares in one square kilometre. ...

biological Site of Special Scientific Interest A Site of Special Scientific Interest (SSSI) in Great Britain, or an Area of Special Scientific Interest (ASSI) in the Isle of Man and Northern Ireland, is a conservation designation denoting a protected area in the United Kingdom and Isle ...

on the southern edge of the

North Somerset Levels The North Somerset Levels is a coastal plain, an expanse of low-lying flat ground, which occupies an area between Weston-super-Mare and Bristol in North Somerset, England. The River Banwell, River Kenn, River Yeo and Land Yeo are the three pri ...

, just north of the village of Sandford,

North Somerset North Somerset is a unitary authorities of England, unitary authority in the ceremonial county of Somerset, England. The council is based in Weston-super-Mare, the area's largest town. The district also contains the towns of Clevedon, Nailsea ...

. It was notified as an SSSI in 1988.

Site description

Yanal Bog is a calcicolous lowland mire. Underlying the site are

gravel Gravel () is a loose aggregation of rock fragments. Gravel occurs naturally on Earth as a result of sedimentation, sedimentary and erosion, erosive geological processes; it is also produced in large quantities commercially as crushed stone. Gr ...

s and

clay alluvium Clay is a type of fine-grained natural soil material containing clay minerals (hydrous aluminium phyllosilicates, e.g. kaolinite, ). Most pure clay minerals are white or light-coloured, but natural clays show a variety of colours from impuriti ...

. Above this sits a layer of

peat Peat is an accumulation of partially Decomposition, decayed vegetation or organic matter. It is unique to natural areas called peatlands, bogs, mires, Moorland, moors, or muskegs. ''Sphagnum'' moss, also called peat moss, is one of the most ...

. This results in a high

water table The water table is the upper surface of the phreatic zone or zone of saturation. The zone of saturation is where the pores and fractures of the ground are saturated with groundwater, which may be fresh, saline, or brackish, depending on the loc ...

, creating a distinct domed landscape feature.

Biological interest

The

plant communities A plant community is a collection or Association (ecology), association of plant species within a designated geographical unit, which forms a relatively uniform patch, distinguishable from neighboring patches of different vegetation types. The comp ...

of the mire are nationally rare in Britain, and support two species, Black Bog-rush (''

Schoenus nigricans ''Schoenus nigricans'' is a species of sedge known by the common names black bog-rush''Schoenus ni ...

'') and Blunt-flowered Rush (''

Juncus subnodulosus ''Juncus subnodulosus'', the blunt-flowered rush, is a species of Juncaceae, rush. It natively occurs from the Mediterranean region across temperate Europe, but it does not range far into Scandinavia. Introduced populations exist in New Zealand a ...

''), that have restricted distributions in south-west England, and a number of species that are localised in the North Somerset area. Surrounding the raised mire is a belt of grassland; although this is included within the SSSI, it is largely made up of common grass and herb species. In the community in the western part of the mire, Blunt-flowered Rush, Purple Moor-grass (''

Molinia caerulea ''Molinia caerulea'', known by the common name purple moor-grass, is a species of grass that is native to Europe, west Asia, and north Africa. It grows in locations from the lowlands up to in the Alps. Like most grasses, it grows best in acid s ...

'') and Carnation Sedge (''

Carex panicea ''Carex panicea'', commonly known as carnation sedge, is a plant species in the sedge family, Cyperaceae. It is known as grass-like sedge and can be found in Northern and Western Europe, and also in north-eastern North America. The plant produce ...

'') are abundant species, and this part of the mire is characterised by the presence of a number of species that favour

base-rich In ecology, base-richness is the level of chemical bases in water or soil, such as calcium or magnesium ions. Many organisms prefer base-rich environments. Chemical bases are alkalis, hence base-rich environments are either neutral or alkaline. ...

conditions. Black Bog-rush is locally abundant along a wet drainage ditch in this western part of the site. In the eastern part of the mire Purple Moor-grass and Blunt-flowered Rush are again abundant, but the abundant sedge species are Lesser Pond-sedge (''

Carex acutiformis ''Carex acutiformis'', the lesser pond-sedge, is a species of plant in the ''Carex'', or sedge family. Description Carex acutiformis is a tuft-forming, rhizomatous plant growing up to tall. Stems are slender and three angled. Leaves are narrow, ...

'') and Greater Pond-sedge (''

Carex riparia ''Carex riparia'', the greater pond sedge, is a species of sedge found across Europe and Asia. It grows in a variety of wet habitats, and can be a dominant species in some swamps. It is Britain's largest ''Carex'', growing up to tall, with glau ...

''). Common Reed (''

Phragmites australis ''Phragmites australis'', known as the common reed, is a species of flowering plant in the grass family Poaceae. It is a wetland grass that can grow up to tall and has a cosmopolitan distribution worldwide. Description ''Phragmites australis' ...

'') and Marsh Horsetail (''

Equisetum palustre ''Equisetum palustre'', the marsh horsetail, is a perennial herbaceous pteridophyte belonging to the subclass of horsetails (Equisetidae). It is widespread in cooler regions of Eurasia and North America. Description ''Equisetum palustre'' has ...

'') are also frequent. This part of the site supports plant species associated with more neutral conditions. The site has a species-rich flora; species that occur here but are localised or confined to specialised habitats in North Somerset are Flea Sedge (''

Carex pulicaris ''Carex'' is a vast genus of over 2,000 species of grass-like plants in the family Cyperaceae, commonly known as sedges (or seg, in older books). Other members of the family Cyperaceae are also called sedges, however those of genus ''Carex'' may ...

''), Saw-wort (''

Serratula tinctoria ''Serratula tinctoria'', commonly known as dyer's plumeless saw-wort or saw-wort, is a species of flowering plant in the family Asteraceae. Description Saw-wort is a spineless hairless perennial herb with wiry branched erect grooved stems. It ...

''), Meadow Thistle (''

Cirsium dissectum ''Cirsium dissectum'', also known as meadow thistle, is an erect perennial herb. It is found in Great Britain, Ireland, France, the Netherlands, Germany, Italy, Spain, Hungary, Norway, etc. It is found in fens and less acidic peat bogs i.e. it p ...

''), Marsh Valerian (''

Valeriana dioica ''Valeriana dioica'', the marsh valerian, is a species of flowering plant in the family Caprifoliaceae, native to North America, Europe and Anatolia. It is typically found in calcareous fens. It is a dioecious species, with male and female flower ...

''), Dyer’s Greenweed (''

Genista tinctoria ''Genista tinctoria'', the dyer's greenweed or dyer's broom, is a species of flowering plant in the family Fabaceae. Its other common names include dyer's whin, waxen woad and waxen wood. The Latin specific epithet ''tinctoria'' means "used as a ...

''), Marsh Arrowgrass ('' Triglochin palustris''), Southern Marsh-orchid (''

Dactylorhiza praetermissa ''Dactylorhiza majalis'' subsp. ''praetermissa'', the southern marsh orchid or leopard marsh orchid, is a commonly occurring species of European orchid. Description ''Dactylorhiza majalis'' subsp. ''praetermissa'' grows to tall, with leaves g ...

''), Fen Bedstraw (''

Galium uliginosum ''Galium'' is a large genus of annual and perennial herbaceous plants in the family Rubiaceae, occurring in the temperate zones of both the Northern and Southern Hemispheres. Some species are informally known as bedstraw. Over 600 species of ' ...

''), Devil’s-bit Scabious (''

Succisa pratensis ''Succisa pratensis'', also known as devil's-bit or devil's-bit scabious, is a flowering plant in the honeysuckle family Caprifoliaceae. It differs from other similar species in that it has four-lobed flowers, whereas '' Scabiosa columbaria'' ( ...

'') and Tawny Sedge (''

Carex hostiana ''Carex hostiana'', the tawny sedge, is a species of flowering plant in the genus ''Carex'', native to Europe and northeast Canada, and extinct in Massachusetts. It is a member of the ''Carex flava'' species complex. Description The rhizome, rhi ...

'') and Tufted-sedge ('' Carex elata'').

Sources

English Nature citation sheet for the site
(accessed 15 July 2006)

External links

English Nature (SSSI information)Site boundary at "Nature on the Map" website
{{SSSIs Avon biological Bogs of England Sites of Special Scientific Interest in North Somerset Sites of Special Scientific Interest notified in 1988

Site description

Biological interest

See also

Sources

External links