is a genus
of approximately 380 accepted species
, commonly known as "peat moss
", although that term is also sometimes used for peat
. Accumulations of Sphagnum
can store water, since both living and dead plants can hold large quantities of water inside their cells; plants may hold 16 to 26 times as much water as their dry weight, depending on the species.
The empty cells help retain water in drier conditions.
Hence, as sphagnum moss grows, it can slowly spread into drier conditions, forming larger mires
, both raised bogs
and blanket bogs
Thus, sphagnum can influence the composition of such habitats, with some describing sphagnum as 'habitat manipulators'.
accumulations then provide habitat for a wide array of peatland plants, including sedges and ericaceous
shrubs, as well as orchids and carnivorous plants.
and the peat
formed from it do not decay readily because of the phenolic compounds
embedded in the moss's cell walls
. In addition, bogs, like all wetlands, develop anaerobic soil conditions, which produces slower anaerobic decay
rather than aerobic microbial action. Peat moss can also acidify its surroundings by taking up cations
, such as calcium
, and releasing hydrogen
Under the right conditions, peat can accumulate to a depth of many meters. Different species of Sphagnum
have different tolerance limits for flooding and pH, so any one peatland may have a number of different Sphagnum
Individual peat moss plants consist of a main stem, with tightly arranged clusters of branch fascicles
usually consisting of two or three spreading branches and two to four hanging branches. The top of the plant, or capitulum, has compact clusters of young branches. Along the stem are scattered leaves of various shapes, named stem leaves; the shape varies according to species. The leaves consist of two kinds of cells: small, green, living cells (chlorophyllose
cells), and large, clear, structural, dead cells (hyaline
cells). The latter have the large water-holding capacity.
have a distinct structure adapted to the watery habitats they live in. The water supports Sphagnum plants, making other strengthening structures unnecessary. The top of the plant is called the capitulum
, a rosette of leaves which gather the majority of the plant's energy through photosynthesis
. The main body consists of a stem and branches, with leaves also protruding from both the stem and the branches. The lowermost parts of the plant are dead and decomposing underground.
has a distinctive cellular structure. Mosses have no vascular system to move water and nutrients around the plant. Thus tissues are thin and usually one cell thick to allow these to diffuse easily. Sphagnum
mosses have two distinct cell types. There are normal photosynthesising cells with chlorophyll
. Additionally there are larger Aline or retort cells. These are barrel shaped. They have pores and soak up water like a sponge. These unique cells mean Sphagnum
can keep the habitat watery by releasing water to keep bogs waterlogged.
Walker (2019) describes Sphagnum
thus as 'habitat manipulators'.
, like all other land plants, has an alternation of generations
; like other bryophytes
, the haploid gametophyte generation is dominant and persistent. Unlike other mosses, the long-lived gametophytes do not rely upon rhizoids to assist in water uptake.
species can be unisexual (male or female, dioecious) or bisexual (male and female gametes produced from the same plant; monoecious
); In North America, 80% of Sphagnum
species are unisexual.
Gametophytes have substantial asexual reproduction by fragmentation
, producing much of the living material in sphagnum peatlands.
fertilize eggs contained in archegonia
that remain attached to the female gametophyte
. The sporophyte
is relatively short-lived, and consists almost entirely of a shiny green, spherical spore capsule that becomes black with spores. Sporophytes are raised on stalks to facilitate spore dispersal, but unlike other mosses, Sphagnum
stalks are produced by the maternal gametophyte. Tetrahedral haploid spores are produced in the sporophyte by meiosis, which are then dispersed when the capsule explosively discharges its cap, called an operculum
, and shoots the spores some distance. The spores germinate to produce minute protonemae
, which start as filaments, can become thalloid, and can produce a few rhizoids. Soon afterwards, the protonema develops buds and these differentiate into its characteristic, erect, leafy, branched gametophyte with chlorophyllose
cells and hyaline
This stage dominates the environment where Sphagnum
grows, obliterating and burying the protonema and eventually building up into layers of dead moss called peat.
Carpets of living Sphagnum
may be attacked by various fungi
, and one fungus that is also a mushroom
, Sphagnurus paluster
, produces conspicuous dead patches. When this fungus and other agarics
attack the protonema
is induced to produce nonphotosynthetic gemmae
that can survive the fungal attack and months later germinate to produce new protonema and leafy gametophytes.
It is unknown whether the leafy stage can produce such gemmae.
Taxonomy and phylogeny
Peat moss can be distinguished from other moss species by its unique branch clusters. The plant and stem color, the shape of the branch and stem leaves, and the shape of the green cells are all characteristics used to identify peat moss to species. Sphagnum
taxonomy has been very contentious since the early 1900s; most species require microscopic dissection to be identified. In the field, most Sphagnum
species can be identified to one of four major sections of the genus—classification and descriptions follow Andrus 2007 (Flora North America):
Red sphagnum closeup
- Sphagnum sect. Acutifolia plants generally form hummocks above the water line, usually colored orange or red. Examples: Sphagnum fuscum and Sphagnum warnstorfii.
- Sphagnum sect. Cuspidata plants are usually found in hollows, lawns, or are aquatic, and are green. Examples: Sphagnum cuspidatum and Sphagnum flexuosum.
- Sphagnum sect. Sphagnum plants have the largest gametophytes among the sections, forming large hummocks, their leaves form cuculate (hood-shaped) apices, and are green, except for Sphagnum magellanicum Example: Sphagnum austinii.
- Sphagnum sect. Subsecunda plants vary in color from green to yellow and orange (but never red), and are found in hollows, lawns, or are aquatic. Species always with unisexual gametophytes. Examples: Sphagnum lescurii and Sphagnum pylaesii.
The reciprocal monophyly
of these sections and two other minor ones (Rigida
) has been clarified using molecular phylogenetics
All but two species normally identified as Sphagnum
reside in one clade; two other species have recently been separated into new families within the Sphagnales
reflecting an ancestral relationship with the Tasmanian
and long phylogenetic distance to the rest of Sphagnum
Within main clade of Sphagnum
, phylogenetic distance is relatively short, and molecular dating methods suggest nearly all current Sphagnum
species are descended from a radiation that occurred just 14 million years ago.
As with many other mosses
species disperse spores through the wind. The tops of spore capsules are only about 1 cm above ground, and where wind is weak. As the spherical spore capsule dries, the operculum
is forced off, followed by a cloud of spores. The exact mechanism has traditionally attributed to a "pop gun" method using air compressed in the capsule, reaching a maximum velocity of 3.6 meters per second,
but alternative mechanisms have been recently proposed.
High-speed photography has shown vortex rings
are created during the discharge, which enable the spores to reach a height of 10 to 20 cm, further than would be expected by ballistics alone. The acceleration of the spores is about 36,000G
Spores are extremely important in establishment of new populations in disturbed habitats and on islands.
Peat moss soil amendment, made of partly decayed, dried sphagnum moss
Decayed, dried sphagnum moss has the name of peat or peat moss. This is used as a soil conditioner
which increases the soil's capacity to hold water and nutrients by increasing capillary forces
and cation exchange capacity
– uses that are particularly useful in gardening. This is often necessary when dealing with very sandy
soil, or plants that need increased or steady moisture content to flourish. A distinction is sometimes made between sphagnum moss, the live moss growing on top of a peat bog, and 'sphagnum peat moss' (North American usage) or 'sphagnum peat' (British usage), the latter being the slowly decaying matter underneath.
Anaerobic acidic sphagnum bogs have low rates of decay, and hence preserve plant fragments and pollen to allow reconstruction of past environments.
They even preserve human bodies for millennia; examples of these preserved specimens are Tollund Man
, Haraldskær Woman
, Clonycavan Man
and Lindow Man
. Such bogs can also preserve human hair and clothing, one of the most noteworthy examples being Egtved Girl
. Because of the acidity of peat, however, bones are dissolved rather than preserved. These bogs have also been used to preserve food.
Up to 2000-year-old containers of butter
have been found.
moss has also been used for centuries as a dressing for wounds, including through World War I.
Since it is absorptive and extremely acidic, it inhibits growth of bacteria and fungi, so it is used for shipping seeds and live plants.
Peat moss is used to dispose of the clarified liquid output (effluent) from septic tanks
in areas that lack the proper conditions for ordinary disposal means. It is also used as an environmentally friendly alternative to chlorine
in swimming pool sanitation
The moss inhibits the growth of microbes
and reduces the need for chlorine in swimming pools.
Several of the world's largest wetlands are sphagnum-dominated bogs
, including the West Siberian Lowland, the Hudson Bay Lowland and the Mackenzie River Valley. These areas provide habitat for common and rare species. They also store large amounts of carbon, which helps reduce global warming.
The U.S. gets up to 80% of sphagnum peat moss it uses from Canada. In Canada, the peat bog mass harvested each year is an estimated 1/60th of the mass that accumulates. About 0.02% of the 1.1 million km2
(422,000 square miles) of Canadian peat bog are used for peat moss mining.
Some efforts are being made to restore peat bogs after peat mining, and some debate exists as to whether the peat bogs can be restored to their premining condition and how long the process takes. "The North American Wetlands Conservation Council estimates that harvested peatlands can be restored to 'ecologically balanced systems' within five to 20 years after peat harvesting." Some wetlands scientists assert that "a managed bog bears little resemblance to a natural one. Like tree farms, these peatlands tend toward monoculture, lacking the biodiversity of an unharvested bog."
PittMoss, a peat moss alternative made from recycled newspaper, has emerged as a sustainable substitute in growing media. Coir
has also been touted as a sustainable alternative to peat moss in growing media.
Another peat moss alternative is manufactured in California from sustainably harvested redwood
fiber. Semi-open cell polyurethane materials available in flaked and sheet stock are also finding application as sphagnum replacements with typical usage in green wall and roof garden substrates.
In the 2010s, Sphagnum
peat in Chile
has begun to be harvested at a large scale for export to countries like Japan, South Korea, Taiwan and the United States. Given Sphagnum
’s property to absorb excess water and release it during dry months harvesting of Sphagnum
, means that overexploitation
may threaten the water supply in the fjords and channels of Chile
Extraction of Sphagnum
in Chile is regulated by law since 2 August 2018.
Since 2018 Chilean law allows only for the manual extraction of Sphagnum
using only pitchforks or similar tools as an aid.
In a given area (polygon) at least 30% of Sphagnum
coverage has to be left unharvested.
fibers may not exceed 15 cm in length and the remaining Sphagnum
after harvest may never have a length less than 5 cm over the water table.
In the regions of Los Ríos
(40°S) and Los Lagos
(41–43°S) the same plots may be harvested after 12 years, while further south in Aysén
(44–48°S) and Magallanes
(49–56°S) 85 years have to pass before the same area is harvested again.
Europe has a long history of the exploitation of peatlands. The Netherlands
, for example, once had large areas of peatland, both fen and bog. Between 100 AD and the present, they were drained and converted to agricultural land.:Fig. 14.2
The English broadlands have small lakes that originated as peat mines.
More than 90% of the bogs in England have been damaged or destroyed.
A handful of bogs has been preserved through government buyouts of peat-mining interests.
Over longer time scales, however, some parts of England, Ireland, Scotland, and Wales have seen expansion of bogs, particularly blanket bogs, in response to deforestation and abandonment of agricultural land.:Fig. 11.8
has, like other parts of the world, lost large areas of peatland
. The latest estimates for wetland loss in New Zealand are 90% over 150 years.
In some cases, better care is taken during the harvesting of Sphagnum
to ensure enough moss is remaining to allow regrowth. An 8-year cycle is suggested, but some sites require a longer cycle of 11 to 32 years for full recovery of biomass, depending on factors including whether reseeding is done, the light intensity, and the water table.
This "farming" is based on a sustainable management program approved by New Zealand's Department of Conservation
; it ensures the regeneration of the moss, while protecting the wildlife and the environment. Most harvesting in New Zealand swamps is done only using pitchforks without the use of heavy machinery. During transportation, helicopters are commonly employed to transfer the newly harvested moss from the swamp to the nearest road.
- ^ Tropicos, Isocladus Lindb.
- ^ "Dierk Michaelis (2019): The Sphagnum Species of the World (Sphagnum bible: keys for all peat moss species by continents, and Sphagnum species lists for 20 phytogeographic regions of the world)". Schweizerbart.
- ^ "Sphagnum on theplantlist". Theplantlist.org. Retrieved 17 September 2016.
- ^ a b c Bold, H. C. 1967. Morphology of Plants. second ed. Harper and Row, New York. p. 225-229.
- ^ Gorham E. (1957). "The development of peatlands". Quarterly Review of Biology. 32 (2): 145–66. doi:10.1086/401755. S2CID 129085635.
- ^ Walker, M. D. 2019. Sphagnum: the biology of a habitat manipulator. Sicklebrook Publishing, Sheffield, U.K.
- ^ a b O'Neill, Alexander; et al. (25 February 2020). "Establishing Ecological Baselines Around a Temperate Himalayan Peatland". Wetlands Ecology & Management. 28 (2): 375–388. doi:10.1007/s11273-020-09710-7. S2CID 211081106.
- ^ a b c d Keddy, P. A. (2010). Wetland Ecology: Principles and Conservation (2nd edition). Cambridge University Press, Cambridge, UK. 397 pp.
- ^ Vitt D. H., Slack N. G. (1984). "Niche diversification of Sphagnum relative to environmental factors in northern Minnesota peatlands". Canadian Journal of Botany. 62 (7): 1409–30. doi:10.1139/b84-192.
- ^ a b Andrus, Richard. Sphagnum. Flora of North America. 2007
- ^ Rydin, Hakan and Jeglum, John K. 2006. Biology of Peatlands. Oxford University Press, Oxford.
- ^ Schofield, W. B. 1985. Introduction to Bryology. Macmillan Publ. Co., N.Y. & London
- ^ Redhead, S.A. (1981). "Parasitism of bryophytes by agarics". Can. J. Bot. 59 (1): 63–67. doi:10.1139/b81-011.
- ^ Shaw, A.J.; Cox, C.; Boles, S.B. (2003). "Polarity of peatmoss (Sphagnum) evolution: who says bryophytes have no roots?". American Journal of Botany. 90 (12): 1777–1787. doi:10.3732/ajb.90.12.1777. PMID 21653354.
- ^ Shaw A.J.; et al. (2010). "Newly resolved relationships in an early land plant lineage: Bryophyta class Sphagnopsida (peat mosses)". American Journal of Botany. 97 (9): 1511–1531. doi:10.3732/ajb.1000055. hdl:10161/4194. PMID 21616905.
- ^ Shaw A.J.; et al. (2010). "Peatmoss (Sphagnum) diversification associated with Miocene Northern Hemisphere climatic cooling?". Molecular Phylogenetics and Evolution. 55 (3): 1139–1145. doi:10.1016/j.ympev.2010.01.020. PMID 20102745.
- ^ Arroyo, M.T.K., P. Mihoc, P. Pliscoff and M. Arroyo-Kalin. (2005). The Magellanic moorland. P. 424-445 in L.H. Fraser and P.A. Keddy (eds.). The World's Largest Wetlands: Ecology and Conservation. Cambridge University Press, Cambridge, UK.
- ^ Crum H (1991). "Two new species of Sphagnum from Brazil". The Bryologist. 94 (3): 301–303. doi:10.2307/3243970. JSTOR 3243970.
- ^ Sebastian Sundberg (2010). "Size matters for violent discharge height and settling speed of Sphagnum spores: important attributes for dispersal potential". Annals of Botany. 105 (2): 291–300. doi:10.1093/aob/mcp288. PMC 2814761. PMID 20123930.
- ^ Jeff Duckett; Pressel, Silvia; P’ng, Ken M. Y.; Renzaglia, Karen S. (2009). "Exploding a myth: the capsule dehiscence mechanism and the function of pseudostomata in Sphagnum". New Phytologist. 183 (4): 1053–63. doi:10.1111/j.1469-8137.2009.02905.x. PMID 19552695.
- ^ Johan L. van Leeuwen (23 July 2010). "Launched at 36,000g". Science. 329 (5990): 395–6. doi:10.1126/science.1193047. PMID 20651138.
- ^ Dwight L. Whitaker and Joan Edwards (23 July 2010). "Sphagnum Moss Disperses Spores with Vortex Rings". Science. 329 (5990): 406. Bibcode:2010Sci...329..406W. doi:10.1126/science.1190179. PMID 20651145. S2CID 206526774.
- ^ Sundberg, S (2005). "Larger capsules enhance short-range spore dispersal in Sphagnum, but what happens further away?". Oikos. 108 (1): 115–124. doi:10.1111/j.0030-1299.2005.12916.x.
- ^ Hood, Gerry (January 1995). "Don't Confuse Sphagnum Moss with Peat Moss". African Violet Magazine, p. 34
- ^ Madrigal, Alexis. Bogosphere: The Strangest Things Pulled Out of Peat Bogs. Wired Magazine. 21 August 2009
- ^ Bog Butter Test. New Scientist. 20 March 2004.
- ^ "Facts about Peat Moss (Sphagnum) – Encyclopedia of Life". Eol.org. Retrieved 11 September 2013.
- ^ Moss Proving An Alternative To Chlorine In Pools. Archived 21 August 2008 at the Wayback Machine WCCO. 15 August 2008.
- ^ Hill, Catey. Time to fire the pool boy? Moss helps pools stay clean. Daily News. 29 October 2009.
- ^ Engman, Max; D. G. Kirby (1989). Finland: people, nation, state. C. Hurst & Co. p. 45. ISBN 0-253-32067-4.
- ^ Fraser, L. H. and P. A. Keddy (eds.). 2005. The World's Largest Wetlands: Ecology and Conservation. Cambridge University Press, Cambridge, UK. p. 488
- ^ Trail, Jesse Vernon. The truth about peat moss. The Ecologist. 25 January 2013.
- ^ Priesnitz, Wendy. "Ask Natural Life: Does Peat Moss Have a Place In the Ecological Garden". Natural Life Magazine. 1 July 2012.
- ^ Cellulose Based Soil Medium as a Peat Moss Substitute EPA/SBIR Sponsored (Contract No. 68D60035)(C) 1997 Wabash Vallet Products, Inc. Crown Point, Indiana.
- ^ Richards, Davi. Coir is sustainable alternative to peat moss in the garden. Oregon State University Extension Service.
- ^ Raviv, Michael. Soilless Culture: Theory and Practice: Theory and Practice. Elsevier.
- ^ Molinet, Carlos; Solari, María Eugenia; Díaz, Manuel; Marticorena, Francisca; Díaz, Patricio A.; Navarro, Magdalena; Niklitschek, Edwin (2018). "Fragmentos de la historia ambiental del sistema de fiordos y canales nor-patagónicos, Sur de Chile: Dos siglos de explotación". Magallania (in Spanish). 46 (2): 107–128. doi:10.4067/S0718-22442018000200107.
- ^ "Ministerio de Agricultura dicta decreto que regula extracción de musgo de turberas". Chile Sustentable (in Spanish). 18 February 2018. Retrieved 14 July 2019.
- ^ a b c d "Dispone Medidas Para La Protección Del Musgo Sphagnum magellanicum". leychile.cl (in Spanish). Biblioteca del Congreso Nacional. 2 August 2017. Retrieved 17 July 2019.
- ^ a b Durán, Vanessa; Moncada, Eduardo; Natho, Federico (2018). "Megaparques eólicos, destrucción de turberas y conflictividad sociopolítica". Archipiélago de Chiloé: nuevas lecturas de un territorio en movimiento (in Spanish). CESCH. pp. 7–17. ISBN 978-956-09219-0-1.
- ^ Moss B (1984). "Medieval man-made lakes: progeny and casualties of English social history, patients of twentieth century ecology". Transactions of the Royal Society of South Africa. 45 (2): 115–28. doi:10.1080/00359198409519477.
- ^ Insight into threatened peat bogs. BBC News.
- ^ The RSPB: Policy
- ^ Jeffery, Simon. Bogs to be preserved for peat's sake. The Guardian. 27 February 2002.
- ^ Peters, M. and Clarkson, B. 2010. Wetland Restoration: A Handbook for New Zealand Freshwater Systems. Manaaki Whenua Press, Lincoln, N.Z. ISBN 978-0-478-34707-4 (online)
- ^ Sphagnum research programme: the ecological effects of commercial harvesting Department of Conservation R. P. Buxton, P. N. Johnson and P. R. Espie. Wellington, N.Z. Department of Conservation, 1996 ISBN 0478017871http://www.doc.govt.nz/documents/science-and-technical/sfc025.pdf (Retrieved 10 January 2013)
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