Difference between revisions of "Bog" - New World Encyclopedia

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[[Image:Lütt-Witt Moor-2.jpg|thumb|250px|right|[[Lütt-Witt Moor]], a bog in [[Henstedt-Ulzburg]] in northern [[Germany]].]]
 
[[Image:Lütt-Witt Moor-2.jpg|thumb|250px|right|[[Lütt-Witt Moor]], a bog in [[Henstedt-Ulzburg]] in northern [[Germany]].]]
  
A '''bog''' is a freshwater [[wetland]] characterized by [[acid]]ic [[peat]] deposits and by moisture provided by precipitation (rain and snow) rather than groundwater or interior drainage. The precipitation leaches nutrients from the [[soil]], while acid is produced from the decomposing organic material (Finlayson and Moser 1991). The United Stated Environmental Protection Agency (EPA) considers the bog one of the four general categories of wetlands, the others being [[marsh]]es, [[swamp]]s, and [[fen]]s (EPA 2004), although categorization of wetlands varies widely.  
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A '''bog''' is a freshwater [[wetland]] characterized by [[acid]]ic [[peat]] deposits and by moisture provided by [[precipitation]] ([[rain]] and [[snow]]) rather than groundwater or interior drainage. The precipitation leaches nutrients from the [[soil]], while acid is produced from the decomposing organic material (Finlayson and Moser 1991). The United States [[Environmental Protection Agency]] (EPA) considers the bog one of the four general categories of wetlands, the others being [[marsh]]es, [[swamp]]s, and [[fen]]s (EPA 2004), although categorization of wetlands varies widely.  
  
Importance
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Bogs provide many [[ecology|ecological]], commercial, archaeological, and recreational benefits. As a unique habitat, they serve as a biogenetic reservoir for many rare and protected plant and animal species. They are a source of peat, which can be dried and burned as an energy source and alternatively used as a soil amendment. Bogs are also a very early stage in the formation of coal deposits. Bogs serve as a [[carbon]] store, and afford aesthetic enrichment and renewal. Archaeologically, they have been known to preserve [[mammal]]ian bodies extremely well for millennia.
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{{toc}}
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Despite these valuable aspects of bogs, many people consider them to be wastelands that can better be converted to some "useful" purpose, such as reclaimed land for intensive agricultural or residential use. Many bogs have been lost, including an estimated 94 percent of the original bogs in the [[United Kingdom]] (RSPB 2007).
  
==Overview==
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==Overview and description==
[[Image:Brown Lake Bog OH.jpg|thumb|240px|right|Virgin [[boreal]] acid bogs at Brown's Lake Bog, Ohio. The tree cover is not typical of a bog.]]
 
 
A bog is a type of '''wetland'''. A wetland is a transitional environment between permanently aquatic and terrestrial environments that shares characteristics of both environments and where [[water]], which covers the [[soil]] or is near the surface for substantial parts of the year, is the key factor in determining the nature of the [[ecosystem]] and soil. Although wetlands have aspects similar to both wet and and dry environments, they cannot be classified unambiguously as either aquatic or terrestrial (Barbier et al. 1997).  
 
A bog is a type of '''wetland'''. A wetland is a transitional environment between permanently aquatic and terrestrial environments that shares characteristics of both environments and where [[water]], which covers the [[soil]] or is near the surface for substantial parts of the year, is the key factor in determining the nature of the [[ecosystem]] and soil. Although wetlands have aspects similar to both wet and and dry environments, they cannot be classified unambiguously as either aquatic or terrestrial (Barbier et al. 1997).  
  
[[Image:Raselink.jpg|thumb|250px|left|[[Sphagnum]] bog vegetation, ''Tříjezerní slať'', [[Šumava]].]]
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A bog is a wetland type that accumulates [[acid]]ic [[peat]]. Peat is the dark, fibrous accumulation of partially decomposed and disintegrated [[organic]] [[biological tissue|matter]] found in wet areas, usually residues of [[plant]]s such as [[moss]]es, but also including [[sedge]]s, [[tree]]s, and other plant and even animal matter. It is generally light and spongy in consistency and dark brown or black in [[color]]. Many [[North America]]n bogs are characterized by ''[[Sphagnum]]'' moss.
A bog is a wetland type that accumulates [[acid]]ic [[peat]]. Peat is the dark, fibrous accumulation of partially decomposed and disintegrated [[organic]] [[biological tissue|matter]] found in wet areas, usually residues of [[plant]]s such as [[moss]]es, but also including [[sedge]]s, [[tree]]s, and other plant and even animal matter. It is generally light and spongy in consistency and dark brown or black in color. Many North American bogs are characterized by ''[[Sphagnum]]'' moss.
 
  
Bogs are not the only peat-forming wetland. For example, a [[fen]] is a freshwater, peat-forming wetland with chemically [[Base (chemistry)|basic]] (which roughly means [[Alkali|alkaline]]) ground water. This means that it contains a moderate or high proportion of [[hydroxyl]] ions ([[pH]] value greater than 7).
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[[Image:Raselink.jpg|thumb|250px|left|[[Sphagnum]] bog vegetation]]
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Bogs are not the only peat-forming wetland. For example, a fen is a freshwater, peat-forming wetland with chemically [[Base (chemistry)|basic]] (which roughly means [[Alkali|alkaline]]) ground water. This means that it contains a moderate or high proportion of [[hydroxyl]] ions ([[pH]] value greater than seven).
  
In bogs, [[moisture]] is provided essentially by [[precipitation (meteorology)|precipitation]], and for this reason bog waters are acidic and termed [[ombrotrophic]] (or [[ombrotrophic|cloud-fed]]), which accounts for their low plant nutrient status. Excess rainfall outflows, with dissolved [[tannin]]s from the plant matter giving a distinctive tan color to bog waters.
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In bogs, [[moisture]] is provided essentially by [[precipitation (meteorology)|precipitation]], and for this reason bog waters are acidic and termed [[ombrotrophic]] (or cloud-fed), which accounts for their low plant nutrient status. Excess rainfall outflows, with dissolved [[tannin]]s from the plant matter giving a distinctive tan color to bog waters.
  
In the [[United States]], the four general categories of wetlands, according to the Environmental Protection Agency, are marshes, swamps, bogs, and fens. (EPA 2004) The term 'mires'' is sometimes used for a type of complex, wetland [[ecosystem]]s that includes [[bog]]s and [[fen]]s. Finlayson and Moser (1991) state that bogs are formed when rain and snow feed directly into an already high watertable, with nutrients leached from the soil and acid produced as organic material slowly decomposes. They distinguish bogs from fens by stating that fens are fed by ground water or by interior drainage into hollow rather than precipitation; they are higher in nutrients and lower in acidity, but can still produce peat.
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In the [[United States]], the four general categories of wetlands, according to the Environmental Protection Agency, are marshes, swamps, bogs, and fens. (EPA 2004) The term ''mires'' is sometimes used for a type of complex, wetland [[ecosystem]]s that includes bogs and fens. Finlayson and Moser (1991) state that bogs are formed when rain and snow feed directly into an area with an already high watertable, with nutrients being leached from the soil and acid being produced as organic material slowly decomposes. They distinguish bogs from fens by stating that fens are fed by ground water or by interior drainage into a hollow rather than by precipitation; fens are higher in nutrients and lower in acidity than bogs, but can still produce peat.
  
 
The EPA notes that bogs often are formed in old glacial lakes and characterized by spongy peat deposits, evergreen trees and shrubs, and a floor covered by a thick carpet of [[sphagnum]] moss (EPA 2004).
 
The EPA notes that bogs often are formed in old glacial lakes and characterized by spongy peat deposits, evergreen trees and shrubs, and a floor covered by a thick carpet of [[sphagnum]] moss (EPA 2004).
  
Bogs are recognized as a significant habitat type by a number of governmental and conservation agencies. For example, the [[United Kingdom]] in its [[Biodiversity Action Plan]] establishes bog habitats as a priority for conservation. Bogs are challenging environments for plant life because they are low in nutrients and very acidic. Furthermore, the absorption of water by sphagnum moss reduces the amount of water available for plants. As a result of these unique conditions, many unique flora and fauna may be found. [[Carnivorous plant]]s have adapted to the low nutrient conditions by using [[insect]]s as a nutrient source. Some bog plants, such as [[Chamaedaphne|Leatherleaf]], have waxy leaves to help retain moisture. [[England|English]] bogs give a home to the [[boghopper beetle]] and a yellow [[fly]] called the [[hairy canary]].
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==Distribution and extent==
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Bogs are widely distributed in cold, temperate climates, mostly in the northern hemisphere ([[Boreal]]). The world's largest wetlands are the bogs of the Western [[Siberia]]n Lowlands in [[Russia]], which cover more than [[1 E11 m²|600,000 square kilometers]]. [[Sphagnum]] bogs historically were widespread in northern [[Europe]], and [[Ireland]] once was more than 15 percent bog. [[Achill Island]] off Ireland remains 87 percent bog.  
  
==Distribution and extent==
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There are extensive bogs in [[Canada]] and [[Alaska]] (labeled [[muskeg]]), [[Scotland]], [[Denmark]], [[Estonia]] (20 percent boglands), [[Finland]] (26 percent), northern [[Germany]], the [[Netherlands]], and [[Sweden]]. There are also bogs in the [[Falkland Islands]].  
Bogs are widely distributed in cold, temperate climes, mostly in the northern hemisphere ([[Boreal]]). The world's largest wetlands are the bogs of the Western  [[Siberia]]n Lowlands in [[Russia]],  which cover more than [[1 E11 m²|600,000 square kilometres]].  Sphagnum bogs were widespread in northern [[Europe]]. [[Ireland]] was more than 15% bog; [[Achill Island]] off Ireland is 87% bog. There are extensive bogs in [[Canada]] and [[Alaska]] (called [[muskeg]]), [[Scotland]], [[Denmark]], [[Estonia]] (20% boglands), [[Finland]] (26%), northern [[Germany]], the [[Netherlands]], [[Ireland]], and [[Sweden]]. There are also bogs in the [[Falkland Islands]]. [[Ombrotrophic]] wetlands - that is, bogs - are also found in the tropics, with notable areas documented in [[Kalimantan]]; these habitats are forested so would be better called [[swamp]]s.  Extensive bogs cover the northern areas of the [[U.S. state]]s of [[Minnesota]] and [[Michigan]], most notably on [[Isle Royale]] in [[Lake Superior]]. The [[pocosin]] of the southeastern United States is like a bog in that it is an acidic wetland but it has its own unusual combination of features.  In certain areas such as Ireland and Scotland, coastal bogs are frequently intruded upon by low lying dunes called ''[[Machair (geography)|Machairs]]''.
 
  
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[[Ombrotrophic]] wetlands (that is, bogs) are also found in the tropics, with notable areas documented in [[Kalimantan]]; these habitats are forested so would be better called [[swamp]]s. Extensive bogs cover the northern areas of the [[U.S. state]]s of [[Minnesota]] and [[Michigan]], most notably on [[Isle Royale]] in [[Lake Superior]]. The [[pocosin]] of the southeastern United States is like a bog in that it is an acidic wetland but it has its own unusual combination of features. In certain areas such as Ireland and Scotland, coastal bogs are frequently intruded upon by low lying dunes called ''[[Machair (geography)|Machairs]]''.
  
 
==Importance==
 
==Importance==
===Industrial uses===
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Bogs provide innumerable benefits. Nonetheless, many have been drained or otherwise converted to intensive agricultural, residential, or commercial use. It is estimated that more than 90 percent of the United Kingdom's lowland peat bogs have been damaged or destroyed (BBC 2004; RSPB 2007).
A bog is a very early stage in the formation of [[coal]] deposits. In fact, bogs can catch fire and often sustain long-lasting smouldering blazes, producing smoke and [[carbon dioxide]], thus causing health and environmental problems. After drying, peat is used as a [[fossil fuel|fuel]]. More than 20% of home heat in Ireland comes from peat, and it is also used for fuel in Finland, Scotland, Germany, and Russia. Russia is the leading producer of peat for fuel at more than 90 million metric tons per year. Ireland's [[Bord na Móna]] (peat board) was one of the first companies to mechanically harvest peat.
 
  
The other major use of dried peat is as a [[soil amendment]] (sold as ''moss peat'' or ''sphagnum'') to increase the soil's capacity to retain moisture and enrich the soil. It is also used as a [[mulch]]. Some [[distillation|distilleries]], notably [[Laphroaig]], use peat fires to smoke the [[barley]] used in making [[scotch whisky]]. More than 90% of the bogs in England have been destroyed.<ref>[http://news.bbc.co.uk/1/hi/england/cumbria/3942167.stm BBC NEWS | England | Cumbria | Insight into threatened peat bogs<!-- Bot generated title —>]</ref><ref>[http://www.rspb.org.uk/ourwork/policy/water/water/peat_bogs/index.asp The RSPB: Policy<!-- Bot generated title —>]</ref>
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====Biodiversity====
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Bogs are recognized as a significant habitat type by a number of governmental and conservation agencies. For example, the [[United Kingdom]] in its [[Biodiversity Action Plan]] establishes bog habitats as a priority for conservation. Bogs are challenging environments for plant life because they are low in nutrients and very acidic. Furthermore, the absorption of water by sphagnum moss reduces the amount of water available for plants. As a result of these unique conditions, many unique flora and fauna may be found. [[Carnivorous plant]]s have adapted to the low nutrient conditions by using [[insect]]s as a nutrient source. Some bog plants, such as [[Chamaedaphne|Leatherleaf]], have waxy leaves to help retain moisture. [[England|English]] bogs are home to the [[boghopper beetle]] and a yellow [[fly]] called the [[hairy canary]].
  
===Other uses===
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Many rare and protected plant and animal species are found on bogs. These include the Greenland white-fronted goose, which relies on bogs for feeding and roosting, and the bog moss ''Sphagnum imbricatum'' is entirely restricted to bogs (IPCC 1996).  
[[Image:BogHBy.jpg|thumb|150px|right|Bog [[Huckleberry]] at Polly's Cove, [[Nova Scotia]]]]
 
[[blueberry|Blueberries]], [[cranberry|cranberries]], [[cloudberry|cloudberries]], [[huckleberry|huckleberries]], [[strawberries|wild strawberries]] and [[cowberry|lingonberries]]  are harvested from the wild in bogs. [[Bog oak]], wood that has been partially preserved by bogs, has been used in manufacture of [[furniture]].
 
  
Sphagnum bogs are also used for sport, but this can be damaging. [[All-terrain vehicle]]s are especially damaging to bogs. [[Bog snorkelling]] is popular in England and [[Wales]].[[Llanwrtyd Wells]], the smallest town in Wales, hosts the World Bog Snorkeling Championships. In this event, competitors with mask, snorkel, and [[Scuba set|scuba]] fins swim along a 60-meter trench cut through a peat bog.
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====Commercial uses====
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Peat, which is characteristic of bogs, is a very early stage in the formation of [[coal]] deposits. Indeed, peat can be dried and burned and thus is used as an energy source, such as for home heating or even for power stations. More than 20 percent of home heat in Ireland comes from peat, and peat is also used for fuel in [[Finland]], [[Scotland]], [[Germany]], and [[Russia]]. Russia is the leading producer of peat for fuel at more than 90 million metric tons per year.
  
==Archaeology==
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The other major use of dried peat is as a [[soil amendment]] (sold as ''moss peat'' or ''sphagnum'') to increase the soil's capacity to retain moisture and enrich the soil. It is also used as a [[mulch]], although this generally is not advisable since it can repel water when dried. Some [[distillation|distilleries]], notably [[Laphroaig]], use peat fires to smoke the [[barley]] used in making [[scotch whiskey]]. This gives Scotch whiskey its distinctive smoky flavor, often called "peatiness" by its [[aficionado]]s.
  
In parts of Denmark, Germany, Ireland and the United Kingdom, peat bog conditions exist where the subsurface chemistry of moisture combined with an anaerobic environment, such that remarkable preservation of animal organisms can result.<ref>C.M.Hogan, ''Haraldskaer Woman'', Lumina Technologies Press, July, 2005</ref> Some bogs have preserved ancient [[oak]] logs useful in [[dendrochronology]], and they have yielded extremely well-preserved [[bog body|bog bodies]], with organs, skin, and hair intact, buried there thousands of years ago after apparent Germanic and [[Celts and human sacrifice|Celtic human sacrifice]].  Excellent examples of such human specimens are [[Haraldskær Woman]] and [[Tollund Man]] in Denmark. In the [[Iron Age]] culture of Denmark, a discovery of several victims of ritual sacrifice by strangulation was recorded.<ref>P.V. Glob, ''The Bog People: Iron Age Man Preserved''</ref> The corpses were thrown into peat bogs where they were discovered after 2000 years, perfectly preserved down to their facial expressions, although well-tanned by the acidic environment of the Danish bogs.  The Germanic culture has similarities to the characteristics of the probably Celtic [[Lindow man]] found at [[Lindow Common]] and with the [[Frisia]]n culture described in the story of [[Wulfram of Sens|St. Wulfram]].  In Ireland, at Ceide fields in County Mayo, a 5000 year old [[neolithic]] farming landscape complete with field walls and hut sites has been found preserved under a raised [[blanket bog]].
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[[blueberry|Blueberries]], [[cranberry|cranberries]], [[cloudberry|cloudberries]], [[huckleberry|huckleberries]], [[strawberries|wild strawberries]], and [[cowberry|lingonberries]] are harvested from the wild in bogs. [[Bog oak]], wood that has been partially preserved by bogs, has been used in manufacture of [[furniture]].
  
==Fiction and song==
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====Archeology====
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The anaerobic acidic bogs are known to preserve [[mammal]]ian bodies extremely well for millennia, making them a valuable archaeological resource.
  
[[Gothic Fiction]] is commonly set on a [[moorland|moor]], a type of landscape common in [[Great Britain]] and Ireland which often has extensive bogs. One example is "[[The Hound of the Baskervilles]]", a [[Sherlock Holmes]] story by [[Arthur Conan Doyle]] which is largely set on [[Dartmoor]] and contains the fictional bog ''Grimpen Mire'', said to have been based on [[Fox Tor]] in [[Devon]].
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During prehistoric times, peat bogs had considerable ritual significance to [[Bronze Age]] and [[Iron Age]] peoples, who considered them to be home to (or at least associated with) nature gods or spirits. The bodies of the victims of ritual sacrifices have been found in a number of locations in [[England]], [[Ireland]], and especially northern [[Germany]] and [[Denmark]], almost perfectly preserved by the tanning properties of the acidic water. Some bogs have preserved ancient [[oak]] logs useful in [[dendrochronology]], and they have yielded extremely well-preserved [[bog body|bog bodies]], with organs, skin, and hair intact, buried there thousands of years ago after apparent Germanic and [[Celts and human sacrifice|Celtic human sacrifice]]. Excellent examples of such human specimens are [[Haraldskær Woman]] and [[Tollund Man]] in Denmark. Both of these specimens retained remarkably intact skin, internal organs, and skeletons.
  
Several [[comic book]] characters are based on the idea of a half-plant/half-human creature living in a bog, notably [[The Heap]], [[Swamp Thing]], [[Man-Thing]], and [[Solomon Grundy (comics)|Solomon Grundy]].
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The discovery of several victims of ritual sacrifice by strangulation during the [[Iron Age]] culture of Denmark has been recorded (Glob 1969). The corpses were thrown into peat bogs where they were discovered after 2000 years, perfectly preserved down to their facial expressions, although well-tanned by the acidic environment of the Danish bogs. The Germanic culture has similarities to the characteristics of the probably Celtic [[Lindow man]] found at [[Lindow Common]] and with the [[Frisia]]n culture described in the story of [[Wulfram of Sens|St. Wulfram]]. In Ireland, at Ceide fields in County Mayo, a 5000 year old [[neolithic]] farming landscape complete with field walls and hut sites has been found preserved under a raised [[blanket bog]].
  
German [[Industrial music|industrial]] band [[Bigod 20]] had their biggest hit with 1990s "[http://www.testube.com/bigod20/lyrics/bog.html The Bog]", in which the narrator, a fell creature living within the bog or perhaps the bog itself, describes how he's swallowing the listener's body.  American [[post-punk]] band [[be your own PET]] also has a song called "Bog", where the singer mentions having drowned her boyfriend in a bog.
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====Other uses====
  
One of Europe's best-known protest songs, "[[Peat Bog Soldiers (song)|Peat Bog Soldiers]]", was written by prisoners in [[Nazi Party|Nazi]] moorland [[Nazi concentration camps|labour camps]] in the [[Emsland]] and describes their [[penal labour]] in [[drainage|bog drainage]].
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'''Carbon store'''. Worldwide, peat contains an estimated 550 gigatons (one gigaton = one billion metric tons) of [[carbon]], which is equivalent to 30 percent of all global soil carbon, 75 percent of all atmospheric carbon, and twice the carbon stock of the world's forest biomass (Joosten 2007).
  
==Trivia==
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'''Recreational'''. [[Sphagnum]] bogs are used for sport, but this can be damaging. [[All-terrain vehicle]]s are especially damaging to bogs. [[Bog snorkeling]] is popular in England and [[Wales]]. [[Llanwrtyd Wells]], which claims to be the smallest town in Wales, hosts the World Bog Snorkeling Championships. In this event, competitors with mask, snorkel, and [[Scuba set|scuba]] fins swim along a 60-meter trench cut through a peat bog.
{{Trivia|date=June 2007}}
 
  
* The last Sunday in July is International Bog Day [http://www.wildlifetrusts.org/index.php?section=places:events:bogday]
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'''Aesthetic'''. The value of bogs as an aesthetic resource is difficult to quantify, but for many people bogs' uniqueness and biodiversity helps to make them places of beauty.  
* ''Bog'' is also a [[British English|British]] and [[Irish English|Irish]] [[slang]] word for [[toilet]].  Toilet paper is called a ''bog roll''
 
* The phrase ''bog standard'' is often used to describe something that is ordinary or regular issue
 
* ''The Mysterious Bog People'' is a travelling museum exhibition organized by the [[Drents Museum]], Assen, The Netherlands, the [[Niedersachsisches Landesmuseum]], Hannover, Germany, the [[Canadian Museum of Civilization]], Gatineau-Ottawa, Canada and the [[Glenbow Museum]], Calgary, Canada
 
* [[Bog Snorkelling]] is a tongue-in-cheek [[extreme sport]] with competitors swimming through murky water-filled trenches cut into a bog.
 
* The [[UK|British]] town of [[Blackpool]] is believed to get its name from a long gone drainage channel which ran over a [[bog|peat bog]].[http://www.blackpool-stay.co.uk/html/blackpool_history.php] The water which ran into the sea at Blackpool was black from the [[peat]] and formed a "black pool" in waters of the [[Irish Sea]]
 
  
== See also ==
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'''Agriculture'''. The blanket bogs of the west of Ireland have been used year round for grazing cattle and sheep (IPCC). Blanket bog habitats cover about ten million hectares of the earth's surface with Ireland claiming about eight percent of the total (IPCC).
{{Commons|Bog}}
 
{{wiktionary|bog}}
 
{|
 
|-valign=top
 
|
 
*[[List of bogs]]
 
*[[String bog]]
 
*[[Blanket bog]]
 
*[[Bog body]]
 
*[[Bog butter]]
 
*[[Blackwater river]]
 
|
 
*[[Wetland#Types|Differences between bogs and other wetlands]]
 
*[[Irish Peatland Conservation Council]]
 
*[[Marsh]]
 
*[[Poor fen]]
 
*[[Swamp]]
 
*[[Wetland]]
 
*[[Will-o'-the-wisp]]
 
|}
 
  
 
== References==
 
== References==
 
* Barbier, E. B., M. Mike Acreman, and D. Knowler. 1997. ''Economic Valuation of Wetlands: A Guide for Policy Makers and Planners''. Gland, Switzerland: Ramsar Convention Bureau. ISBN 294007321X.
 
* Barbier, E. B., M. Mike Acreman, and D. Knowler. 1997. ''Economic Valuation of Wetlands: A Guide for Policy Makers and Planners''. Gland, Switzerland: Ramsar Convention Bureau. ISBN 294007321X.
 +
* BBC. 2004. [http://news.bbc.co.uk/1/hi/england/cumbria/3942167.stm Insight into threatened peat bogs] ''BBC News'' July 31, 2004. Retrieved May 4, 2008.
 +
* Environmental Protection Agency. 2006a. [http://www.epa.gov/owow/wetlands/vital/what.html What are wetlands?] ''U.S. Environmental Protection Agency''. Retrieved May 3, 2008.
 +
* Environmental Protection Agency. 2006b. [http://www.epa.gov/owow/wetlands/what/definitions.html Wetlands definitions] ''U.S. Environmental Protection Agency''. Retrieved May 3, 2008.
 +
* Environmental Protection Agency. 2004. Wetlands overview. ''U.S. Environmental Protection Agency'' EPA 843-F-04-011a (December 2004).
 +
* Finlayson, M., and M. Moser. 1991. [http://www.uow.edu.au/arts/sts/sbeder/wingecarribee/peatlands/what.html What is peat?]'' International Waterfowl and Wetlands Research Bureau (IWRB)''. Reprinted in ''Wetlands Australia'' 6: 7. Retrieved May 4, 2008.
 +
* Glob, P. V. 1969. ''The Bog People: Iron Age Man Preserved''. Ithaca, N.Y.: Cornell University Press.
 +
* Joosten, H. 2007. Peat should not be treated as a renewable energy source ''International Mire Conservation Group''.
 +
* Royal Society for the Protection of Birds (RSPB). 2007. Destruction of peat bogs ''Royal Society for the Protection of Birds''.
  
* Environmental Protection Agency. 2006a. [http://www.epa.gov/owow/wetlands/vital/what.html What are wetlands?]. ''U.S. Environmental Protection Agency''. Retrieved May 3, 2008.
 
* Environmental Protection Agency. 2006b. [http://www.epa.gov/owow/wetlands/what/definitions.html Wetlands definitions]. ''U.S. Environmental Protection Agency''. Retrieved May 3, 2008.
 
* Environmental Protection Agency. 2004. Wetlands overview. ''U.S. Environmental Protection Agency'' EPA 843-F-04-011a (December 2004). Retrieved May 3, 2008.
 
 
* Finlayson, M., and M. Moser. 1991. [http://www.uow.edu.au/arts/sts/sbeder/wingecarribee/peatlands/what.html What is peat?] ''International Waterfowl and Wetlands Research Bureau (IWRB)''. Reprinted in ''Wetlands Australia'' 6: 7. Retrieved May 4, 2008.
 
  
http://www7.nationalgeographic.com/ngm/0709/bog-bodies/bog-bodies-photos.html?email=Focus24Aug07
 
  
==External links==
 
*[http://www.geographyinaction.co.uk/Landscapes/Landscapes_bog.html Ballynahone Bog]
 
*[http://pages.cthome.net/rwinkler/bog.htm Black Spruce Bog] Describes a forested bog type of North America
 
  
 
[[Category:Life sciences]]
 
[[Category:Life sciences]]

Latest revision as of 00:02, 12 January 2023

Lütt-Witt Moor, a bog in Henstedt-Ulzburg in northern Germany.

A bog is a freshwater wetland characterized by acidic peat deposits and by moisture provided by precipitation (rain and snow) rather than groundwater or interior drainage. The precipitation leaches nutrients from the soil, while acid is produced from the decomposing organic material (Finlayson and Moser 1991). The United States Environmental Protection Agency (EPA) considers the bog one of the four general categories of wetlands, the others being marshes, swamps, and fens (EPA 2004), although categorization of wetlands varies widely.

Bogs provide many ecological, commercial, archaeological, and recreational benefits. As a unique habitat, they serve as a biogenetic reservoir for many rare and protected plant and animal species. They are a source of peat, which can be dried and burned as an energy source and alternatively used as a soil amendment. Bogs are also a very early stage in the formation of coal deposits. Bogs serve as a carbon store, and afford aesthetic enrichment and renewal. Archaeologically, they have been known to preserve mammalian bodies extremely well for millennia.

Despite these valuable aspects of bogs, many people consider them to be wastelands that can better be converted to some "useful" purpose, such as reclaimed land for intensive agricultural or residential use. Many bogs have been lost, including an estimated 94 percent of the original bogs in the United Kingdom (RSPB 2007).

Overview and description

A bog is a type of wetland. A wetland is a transitional environment between permanently aquatic and terrestrial environments that shares characteristics of both environments and where water, which covers the soil or is near the surface for substantial parts of the year, is the key factor in determining the nature of the ecosystem and soil. Although wetlands have aspects similar to both wet and and dry environments, they cannot be classified unambiguously as either aquatic or terrestrial (Barbier et al. 1997).

A bog is a wetland type that accumulates acidic peat. Peat is the dark, fibrous accumulation of partially decomposed and disintegrated organic matter found in wet areas, usually residues of plants such as mosses, but also including sedges, trees, and other plant and even animal matter. It is generally light and spongy in consistency and dark brown or black in color. Many North American bogs are characterized by Sphagnum moss.

Sphagnum bog vegetation

Bogs are not the only peat-forming wetland. For example, a fen is a freshwater, peat-forming wetland with chemically basic (which roughly means alkaline) ground water. This means that it contains a moderate or high proportion of hydroxyl ions (pH value greater than seven).

In bogs, moisture is provided essentially by precipitation, and for this reason bog waters are acidic and termed ombrotrophic (or cloud-fed), which accounts for their low plant nutrient status. Excess rainfall outflows, with dissolved tannins from the plant matter giving a distinctive tan color to bog waters.

In the United States, the four general categories of wetlands, according to the Environmental Protection Agency, are marshes, swamps, bogs, and fens. (EPA 2004) The term mires is sometimes used for a type of complex, wetland ecosystems that includes bogs and fens. Finlayson and Moser (1991) state that bogs are formed when rain and snow feed directly into an area with an already high watertable, with nutrients being leached from the soil and acid being produced as organic material slowly decomposes. They distinguish bogs from fens by stating that fens are fed by ground water or by interior drainage into a hollow rather than by precipitation; fens are higher in nutrients and lower in acidity than bogs, but can still produce peat.

The EPA notes that bogs often are formed in old glacial lakes and characterized by spongy peat deposits, evergreen trees and shrubs, and a floor covered by a thick carpet of sphagnum moss (EPA 2004).

Distribution and extent

Bogs are widely distributed in cold, temperate climates, mostly in the northern hemisphere (Boreal). The world's largest wetlands are the bogs of the Western Siberian Lowlands in Russia, which cover more than 600,000 square kilometers. Sphagnum bogs historically were widespread in northern Europe, and Ireland once was more than 15 percent bog. Achill Island off Ireland remains 87 percent bog.

There are extensive bogs in Canada and Alaska (labeled muskeg), Scotland, Denmark, Estonia (20 percent boglands), Finland (26 percent), northern Germany, the Netherlands, and Sweden. There are also bogs in the Falkland Islands.

Ombrotrophic wetlands (that is, bogs) are also found in the tropics, with notable areas documented in Kalimantan; these habitats are forested so would be better called swamps. Extensive bogs cover the northern areas of the U.S. states of Minnesota and Michigan, most notably on Isle Royale in Lake Superior. The pocosin of the southeastern United States is like a bog in that it is an acidic wetland but it has its own unusual combination of features. In certain areas such as Ireland and Scotland, coastal bogs are frequently intruded upon by low lying dunes called Machairs.

Importance

Bogs provide innumerable benefits. Nonetheless, many have been drained or otherwise converted to intensive agricultural, residential, or commercial use. It is estimated that more than 90 percent of the United Kingdom's lowland peat bogs have been damaged or destroyed (BBC 2004; RSPB 2007).

Biodiversity

Bogs are recognized as a significant habitat type by a number of governmental and conservation agencies. For example, the United Kingdom in its Biodiversity Action Plan establishes bog habitats as a priority for conservation. Bogs are challenging environments for plant life because they are low in nutrients and very acidic. Furthermore, the absorption of water by sphagnum moss reduces the amount of water available for plants. As a result of these unique conditions, many unique flora and fauna may be found. Carnivorous plants have adapted to the low nutrient conditions by using insects as a nutrient source. Some bog plants, such as Leatherleaf, have waxy leaves to help retain moisture. English bogs are home to the boghopper beetle and a yellow fly called the hairy canary.

Many rare and protected plant and animal species are found on bogs. These include the Greenland white-fronted goose, which relies on bogs for feeding and roosting, and the bog moss Sphagnum imbricatum is entirely restricted to bogs (IPCC 1996).

Commercial uses

Peat, which is characteristic of bogs, is a very early stage in the formation of coal deposits. Indeed, peat can be dried and burned and thus is used as an energy source, such as for home heating or even for power stations. More than 20 percent of home heat in Ireland comes from peat, and peat is also used for fuel in Finland, Scotland, Germany, and Russia. Russia is the leading producer of peat for fuel at more than 90 million metric tons per year.

The other major use of dried peat is as a soil amendment (sold as moss peat or sphagnum) to increase the soil's capacity to retain moisture and enrich the soil. It is also used as a mulch, although this generally is not advisable since it can repel water when dried. Some distilleries, notably Laphroaig, use peat fires to smoke the barley used in making scotch whiskey. This gives Scotch whiskey its distinctive smoky flavor, often called "peatiness" by its aficionados.

Blueberries, cranberries, cloudberries, huckleberries, wild strawberries, and lingonberries are harvested from the wild in bogs. Bog oak, wood that has been partially preserved by bogs, has been used in manufacture of furniture.

Archeology

The anaerobic acidic bogs are known to preserve mammalian bodies extremely well for millennia, making them a valuable archaeological resource.

During prehistoric times, peat bogs had considerable ritual significance to Bronze Age and Iron Age peoples, who considered them to be home to (or at least associated with) nature gods or spirits. The bodies of the victims of ritual sacrifices have been found in a number of locations in England, Ireland, and especially northern Germany and Denmark, almost perfectly preserved by the tanning properties of the acidic water. Some bogs have preserved ancient oak logs useful in dendrochronology, and they have yielded extremely well-preserved bog bodies, with organs, skin, and hair intact, buried there thousands of years ago after apparent Germanic and Celtic human sacrifice. Excellent examples of such human specimens are Haraldskær Woman and Tollund Man in Denmark. Both of these specimens retained remarkably intact skin, internal organs, and skeletons.

The discovery of several victims of ritual sacrifice by strangulation during the Iron Age culture of Denmark has been recorded (Glob 1969). The corpses were thrown into peat bogs where they were discovered after 2000 years, perfectly preserved down to their facial expressions, although well-tanned by the acidic environment of the Danish bogs. The Germanic culture has similarities to the characteristics of the probably Celtic Lindow man found at Lindow Common and with the Frisian culture described in the story of St. Wulfram. In Ireland, at Ceide fields in County Mayo, a 5000 year old neolithic farming landscape complete with field walls and hut sites has been found preserved under a raised blanket bog.

Other uses

Carbon store. Worldwide, peat contains an estimated 550 gigatons (one gigaton = one billion metric tons) of carbon, which is equivalent to 30 percent of all global soil carbon, 75 percent of all atmospheric carbon, and twice the carbon stock of the world's forest biomass (Joosten 2007).

Recreational. Sphagnum bogs are used for sport, but this can be damaging. All-terrain vehicles are especially damaging to bogs. Bog snorkeling is popular in England and Wales. Llanwrtyd Wells, which claims to be the smallest town in Wales, hosts the World Bog Snorkeling Championships. In this event, competitors with mask, snorkel, and scuba fins swim along a 60-meter trench cut through a peat bog.

Aesthetic. The value of bogs as an aesthetic resource is difficult to quantify, but for many people bogs' uniqueness and biodiversity helps to make them places of beauty.

Agriculture. The blanket bogs of the west of Ireland have been used year round for grazing cattle and sheep (IPCC). Blanket bog habitats cover about ten million hectares of the earth's surface with Ireland claiming about eight percent of the total (IPCC).

References
ISBN links support NWE through referral fees

  • Barbier, E. B., M. Mike Acreman, and D. Knowler. 1997. Economic Valuation of Wetlands: A Guide for Policy Makers and Planners. Gland, Switzerland: Ramsar Convention Bureau. ISBN 294007321X.
  • BBC. 2004. Insight into threatened peat bogs BBC News July 31, 2004. Retrieved May 4, 2008.
  • Environmental Protection Agency. 2006a. What are wetlands? U.S. Environmental Protection Agency. Retrieved May 3, 2008.
  • Environmental Protection Agency. 2006b. Wetlands definitions U.S. Environmental Protection Agency. Retrieved May 3, 2008.
  • Environmental Protection Agency. 2004. Wetlands overview. U.S. Environmental Protection Agency EPA 843-F-04-011a (December 2004).
  • Finlayson, M., and M. Moser. 1991. What is peat? International Waterfowl and Wetlands Research Bureau (IWRB). Reprinted in Wetlands Australia 6: 7. Retrieved May 4, 2008.
  • Glob, P. V. 1969. The Bog People: Iron Age Man Preserved. Ithaca, N.Y.: Cornell University Press.
  • Joosten, H. 2007. Peat should not be treated as a renewable energy source International Mire Conservation Group.
  • Royal Society for the Protection of Birds (RSPB). 2007. Destruction of peat bogs Royal Society for the Protection of Birds.

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