Geding-Kasted Mose is a bog about 7 kilometers north-west of Aarhus, in the western section of the

Egå Egå is a both a suburban district and a stream in the Municipality of Aarhus in Denmark. Name Egå means 'Oak-stream' in English. The Egå stream The Egå stream runs north of the city of Aarhus, in the bottom of the flat valley of Egå ...

river valley though which the river Egå runs. The bog covers about 30 hectares of which a sizable portion is used as meadows for grazing cattle. Other parts are cultivated but as the area is low-lying it is more or less flooded during winter. The bog has some waterholes and old

peat Peat (), also known as turf (), is an accumulation of partially decayed vegetation or organic matter. It is unique to natural areas called peatlands, bogs, mires, moors, or muskegs. The peatland ecosystem covers and is the most efficient ...

pits which are now mostly concealed by thickets of primarily

downy birch ''Betula pubescens'' (syn. ''Betula alba''), commonly known as downy birch and also as moor birch, white birch, European white birch or hairy birch, is a species of deciduous tree, native and abundant throughout northern Europe and northern Asia ...

and

grey willow Grey willow or gray willow may refer to: *'' Salix atrocinerea'', a species of willow native to Europe commonly called grey willow *'' Salix cinerea'', a species of willow native to Europe and western Asia, also occasionally called grey sallow *''S ...

. Geding-Kasted Bog is one of the most important catchment areas for the water supply in

Aarhus Municipality Aarhus Municipality ( da, Aarhus Kommune), known as Århus Municipality ( da, Århus Kommune) until 2011, is a municipality in Central Denmark Region, on the east coast of the Jutland peninsula in central Denmark. The municipality covers an area ...

and the city of Aarhus.

Flora and fauna

Geding-Kasted Bog has a major biodiversity with many different plant and animal species. Especially downy birch and grey willow dominate but on the meadows there is also globeflower, branched bur-reed, western marsh orchid,

saw-wort ''Serratula tinctoria'', commonly known as dyer's plumeless saw-wort or saw-wort, is a species of flowering plant in the family Asteraceae. It is a native of Europe with a thistle-like flower head. It grows in moist soil, full sun to part shade, ...

and Irish fleabane. Insects are important pollinators for the flowers in bog and as prey for toads, reptiles and birds. Due to the location between the nesting grounds

Egå Engsø Egå Engsø is an artificial lake and wetland site located in the north of the town of Aarhus between Vejlby, Risskov and Lystrup. Engsø means 'meadow lake' and Egå means 'oak stream', referring to the stream that drains the lake into the Aar ...

and

Brabrand Lake Brabrand Lake ( da, Brabrand-søen or Brabrand Sø) is a lake in the district of Brabrand (Gellerup), west of Aarhus city, Denmark. The Aarhus River passes through Brabrand Lake and it is possible to canoe all the way to the inner city from he ...

there's an especially varied population of birds including

thrush nightingale The thrush nightingale (''Luscinia luscinia''), also known as the sprosser, is a small passerine bird that was formerly classed as a member of the thrush family Turdidae, but is now more generally considered to be an Old World flycatcher, Musci ...

eurasian penduline tit The Eurasian penduline tit or European penduline tit (''Remiz pendulinus'') is a passerine bird of the genus ''Remiz''. It is relatively widespread throughout the western Palearctic. It is migratory in the northern part of its range but resident ...

water rail The water rail (''Rallus aquaticus'') is a bird of the Rallidae, rail family which breeds in well-vegetated wetlands across Europe, Asia and North Africa. Northern and eastern populations are bird migration, migratory, but this species is a perma ...

western marsh harrier The western marsh harrier (''Circus aeruginosus'') is a large harrier, a bird of prey from temperate and subtropical western Eurasia and adjacent Africa. It is also known as the Eurasian marsh harrier. Formerly, a number of relatives were includ ...

common kestrel The common kestrel (''Falco tinnunculus'') is a bird of prey species belonging to the kestrel group of the falcon family Falconidae. It is also known as the European kestrel, Eurasian kestrel, or Old World kestrel. In the United Kingdom, where n ...

and

grey heron The grey heron (''Ardea cinerea'') is a long-legged wading bird of the heron family, Ardeidae, native throughout temperate Europe and Asia and also parts of Africa. It is resident in much of its range, but some populations from the more norther ...

. The bog was used for grazing cattle for many years which was maintained by a local group of volunteers. In the 2010s the bog will undergo a rewilding project that will introduce

Galloway cattle The Galloway is a Scottish breed of beef cattle, named after the Galloway region of Scotland, where it originated during the seventeenth century. It is usually black, is of average size, is naturally polled and has a thick coat suitable for ...

and later possibly

water buffalo The water buffalo (''Bubalus bubalis''), also called the domestic water buffalo or Asian water buffalo, is a large bovid originating in the Indian subcontinent and Southeast Asia. Today, it is also found in Europe, Australia, North America, So ...

and wild horses.

Environmental conditions

Pollution with heavy metals was discovered by coincidence in 1966. Botanists found a species of

liverwort The Marchantiophyta () are a division of non-vascular land plants commonly referred to as hepatics or liverworts. Like mosses and hornworts, they have a gametophyte-dominant life cycle, in which cells of the plant carry only a single set of ...

which at the time was not known from other places in Denmark. Further examinations of the plant led to the discovery of a connection between this particular species and heavy metals or sulphur in the ground. Excavation revealed buried industry waste consisting of, among other things,

copper Copper is a chemical element with the symbol Cu (from la, cuprum) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkis ...

from a former production of sulphuric acid. The bog has received polluted water through the stream of ''Moseåen'' between 1870 and the 1970s, mostly heavy metals such as

arsenic Arsenic is a chemical element with the symbol As and atomic number 33. Arsenic occurs in many minerals, usually in combination with sulfur and metals, but also as a pure elemental crystal. Arsenic is a metalloid. It has various allotropes, ...

lead Lead is a chemical element with the symbol Pb (from the Latin ) and atomic number 82. It is a heavy metal that is denser than most common materials. Lead is soft and malleable, and also has a relatively low melting point. When freshly cu ...

, and a smaller amount of

cadmium Cadmium is a chemical element with the symbol Cd and atomic number 48. This soft, silvery-white metal is chemically similar to the two other stable metals in group 12, zinc and mercury. Like zinc, it demonstrates oxidation state +2 in most of ...

, but also

and

zinc Zinc is a chemical element with the symbol Zn and atomic number 30. Zinc is a slightly brittle metal at room temperature and has a shiny-greyish appearance when oxidation is removed. It is the first element in group 12 (IIB) of the periodi ...

. The pollution originated from a fertilizer factory in Mundelstrup Stationsby at

Tilst Tilst is a suburban area of Aarhus, Denmark, situated some 10 km to the west of Aarhus. The Tilst area is marked by big city blocks and large traditional suburban areas. In the surrounding area are several superstores, which mainly serve the inn ...

. The factory closed in the 1970s, the emissions stopped, and a major cleanup project was undertaken around the factory in 1991-1993. The upper section of the Egå valley is still polluted, although the pollution is mostly in the

top soil Topsoil is the upper layer of soil. It has the highest concentration of organic matter and microorganisms and is where most of the Earth's biological soil activity occurs. Description Topsoil is composed of mineral particles and organic matte ...

layer and it has been assessed that it won't affect the

ground water Groundwater is the water present beneath Earth's surface in rock and soil pore spaces and in the fractures of rock formations. About 30 percent of all readily available freshwater in the world is groundwater. A unit of rock or an unconsolidate ...

. The water in Kasted Vandværk (Kasted Waterworks) in Kasted is continuously tested for heavy metals.

Gallery

Tilst Mose.jpg, The bog is heavily overgrown with grey willow (''

Salix cinerea ''Salix cinerea'' (common sallow, grey sallow, grey willow, grey-leaved sallow, large grey willow, pussy willow, rusty sallow) is a species of willow native to Europe and western Asia.Meikle, R. D. (1984). ''Willows and Poplars of Great Britain ...

'') Mosetræ.jpg, The wet and damp bog provides a good environment for mosses Dyreveksel i mosen.jpg, An animal track leading into the bogland thickets Hulkravet Kodriver.jpg, Cowslip (''

Primula veris ''Primula veris'', the cowslip, common cowslip, or cowslip primrose ( syn. ''Primula officinalis'' ), is a herbaceous perennial flowering plant in the primrose family Primulaceae. The species is native throughout most of temperate Europe and ...

'') Trollius-europaeus-Kasted.jpg, Globeflower ('' Trollius europaeus'')

References

;Publications *

External links

* * {{url, http://www.spor.dk/Sporene/Midtjylland/Kasted.aspx, ''Spor i landskabet'' page for hiking route in Kasted Bog Bogs of Denmark Aarhus Municipality