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'Papyrus sedge', also known as 'Bulrush' or 'Paper reed' (''Cyperus papyrus'') is a monocot belonging to the sedge family Cyperaceae. It is a herbaceous perennial native to Africa.
This tall, robust, leafless aquatic can grow 4-5 m high. It features a grass-like clump of triangular green stems that rise up from thick, woody rhizomes. Each stem is topped by a dense cluster of thin, bright green, thread-like rays around 10-30 cm in length. This cluster resembles a feather duster when the plant is young. Greenish-brown flower clusters appear at the ends of the rays. The flowers give way to brown, nut-like fruits.
The younger parts of the rhizome are covered by red-brown, papery, triangular scales, which also cover the base of the culms and represent reduced leaves. It is therefore untrue to call this plant "leafless".
Papyrus is estimated to range from subtropical to tropical desert to wet forests, tolerating annual temperatures of 20-30°C and pH of 6.0 - 8.5. Papyrus flowers in late summer, and prefers full sun to partly-shady conditions. Like most tropical plants, it is sensitive to frost.
The papyrus sedges form vast stands in swamps, shallow lakes, and along stream banks throughout the wetter parts of Africa, but has become rare in the Nile Delta. In deeper waters it is the chief constituent of the floating, tangled masses of vegetation known as ''sudd''. It also occurs in Madagascar, and some Mediterranean regions such as Sicily and the Levant.
The 'feather-duster' flowering heads make ideal nesting sites for many social species of birds. As in most sedges, pollination is effected by wind, not insects, and the mature fruits after release are distributed by water.
Today, papyrus is mainly cultivated as an aquatic ornamental plant. A dwarf relative of this plant, designated as ''C. nanus'' or ''C. profiler'', typically grows to only 1 m tall.

Contents

Papyrus in history

Ecology

See also

Further reading

External links

Papyrus in history

:''See also the main article'' 'Papyrus'.
Egyptians used the plant for many purposes, most famously for making papyrus paper. Its name in Greek and in English is widely believed to have come from Egyptian, but this is likely a folk etymology. ''Cyperus papyrus'' is now used mainly for decoration, as it is nearly extinct in its native habitat in the Nile Delta, where in ancient times it was widely cultivated. Theophrastus' "History of Plants" (Book iv. 10) states that it grew in Syria; and, according to Pliny's ''Natural History'', it was also a native plant of the Niger River and the Euphrates.
Aside from papyrus, several other members of the genus ''Cyperus'' may actually have been involved in the multiple uses Egyptians found for the plant. Its flowering heads were linked to make garlands for the gods in gratitude. The pith of young shoots was eaten both cooked and raw. Its woody root made bowls and other utensils and was burned for fuel. From the stems were made reed boats (seen in bas-reliefs of the Fourth Dynasty showing men cutting papyrus to build a boat; similar boats are still made in the southern Sudan), sails, mats, cloth, cordage, and sandals. Theophrastus states that King Antigonus made the rigging of his fleet of papyrus, an old practice illustrated by the ship's cable, wherewith the doors were fastened when Odysseus slew the suitors in his hall (''Odyssey'' xxi. 390).

Ecology

In recent years papyrus has been the subject of intense ecological studies centered around its prodigious growth rate and ability to recycle nutrients. Much of this research was begun at Makerere University in Uganda in the early 70’s in the swamps on the edge of Lake Victoria and continued in Kenya (University of Nairobi) on Lake Naivasha. John Gaudet’s work in Africa, supported by a National Geographic Society grant, appeared in various scientific journals over the period 1975-1991. In addition, other pioneer researchers of papyrus at Makerere in the 70’s were: Keith Thompson, T. R. Milburn, and Mike Jones. Thompson’s studies of papyrus swamp development throughout Africa (1976-1985) later formed the basis for management and conservation at national levels.
Extensive research on the productive physiology of papyrus were carried out by Jones from the 70's onward. He started his work in Uganda and later continued his research on Lake Naivasha in Kenya where he was joined by a new generation of African researchers including, Frank Muthuri. Jones's latest research (2002) found that papyrus is a C4 sedge which forms highly productive monotypic stands over large areas of wetland in Africa. Jones and others measured eddy covariance from a stand of the C4 emergent sedge Cyperus papyrus (papyrus), which formed a fringing swamp on the north-west shore of Lake Naivasha, Kenya. They determined that fluxes of CO2 and H2O vapor between the papyrus swamp and the atmosphere were large but variable, depending on the hydrology of the wetland system and the condition of the vegetation. These measurements, combined with simulation modeling of annual fluxes of CO2, show that papyrus swamps have the potential to sequester large amounts of the carbon (1.6 kg C m-2 y-1) when detritus accumulates under water in anaerobic conditions, but they are a net source of carbon release to the atmosphere (1.0 kg C m-2 y-1) when water levels fall to expose detritus and rhizomes to aerobic conditions. Evapotranspiration from papyrus swamps (E) was frequently lower than evaporation from open water surfaces (E o) and plant factors have a strong influence on the flux of water to the atmosphere.
Research on the papyrus swamp habitat has in recent years attracted the attention of many more African biologists, such as A. O. Owino, K. M. Mavuti, S. M. Muchiri and S. Njuguna. Increasingly the value of papyrus to other species is being recognized. Papyrus swamps provide hypoxic and structural refugia for cichlids from predatory fish Nile Perch and are an important habitat for several endangered bird species (Chapman et al. 1996; 2003; Maclean et al. 2003a; 2006).
The late 90s also saw the rise in research on the papyrus swamps of Lake Naivasha in Kenya by teams from English Universities (Universities of Leicester and East Anglia) notably led by David Harper. Harper's extensive recent studies on the swamps and lakes have led to a world-wide awareness of the problems facing papyrus swamps in Africa today.

See also

★ Cyperus haspan

Further reading

★ Boar, R. R., D. M. Harper and C. S. Adams. 1999. Biomass Allocation in Cyperus papyrus in a Tropical Wetland, Lake Naivasha, Kenya. 1999. ''Biotropica'' 3: 411.

★ Chapman, L.J., C.A. Chapman, R. Ogutu-Ohwayo, M. Chandler, L. Kaufman and A.E. Keiter. 1996. Refugia for endangered fishes from an introduced predator in Lake Nabugabo, Uganda. ''Conservation Biology'' 10: 554-561.

★ Chapman, L.J., C.A. Chapman, P.J. Schofield, J.P. Olowo, L. Kaufman, O. Seehausen and R. Ogutu-Ohwayo. 2003. Fish faunal resurgence in Lake Nabugabo, East Africa. ''Conservation Biology'' 17: 500-511.

★ Gaudet, John. 1975. Mineral concentrations in papyrus in various African swamps. ''Journal of Ecology'' 63: 483-491.

★ Gaudet, John. 1976. Nutrient relationships in the detritus of a tropical swamp.''Archiv fur Hydrobiologie'' 78: 213-239.

★ Gaudet, John. 1977. Natural drawdown on Lake Naivasha, Kenya and the formation of papyrus swamps. ''Aquatic Botany'' 3: 1-47.

★ Gaudet, John. 1977. Uptake and loss of mineral nutrients by papyrus in tropical swamps. ''Ecology'' 58: 415-422.

★ Gaudet, John. 1978. Effect of a tropical swamp on water quality. ''Verh. Internat. Ver. Limnol.'' 20: 2202-2206.

★ Gaudet, John. 1978. Seasonal changes in nutrients in a tropical swamp. ''Journal of Ecology'' 67: 953-981.

★ Gaudet, John. 1980. Papyrus and the ecology of Lake Naivasha. ''National Geographic Society Research Reports''. 12: 267-272.

★ Gaudet, J. and J. Melack. 1981. Major ion chemistry in a tropical African lake basin. ''Freshwater Biology'' 11: 309-333.

★ Gaudet, J. and C. Howard-Williams. 1985. “The structure and functioning of African swamps.” In (ed. Denny) ''The Ecology and Management of African Wetland Vegetation.'' Dr.w.Junk, Pub., Dordrecht (pp.154-175).

★ Gaudet, John. 1991. Structure and function of African floodplains. ''Journal of the East African Natural Historical Society''. 82(199): 1-32.

★ Harper, D.M., K.M. Mavuti and S. M. Muchiri. 1990: Ecology and management of Lake Naivasha, Kenya, in relation to climatic change, alien species introductions and agricultural development. ''Environmental Conservation'' 17: 328–336.

★ Harper, D. 1992. The ecological relationships of aquatic plants at Lake Naivasha, Kenya. ''Journal Hydrobiologia''. 232: 65-71.

★ Howard-Williams, C. and K. Thompson. 1985. ''The conservation and management of African wetlands.'' In (ed. Denny) The Ecology and Management of African Wetland Vegetation. Dr.w.Junk, Pub., Dordrecht (pp.203-230).

★ Jones, M.B. and T. R. Milburn. 1978. Photosynthesis in Papyrus (Cyperus papyrus L.), ''Photosynthetica''. 12: 197 - 199.

★ Jones, M. B. and F. M. Muthuri. 1997. Standing biomass and carbon distribution in a papyrus (Cyperus Papyrus L) swamp on Lake Naivasha, Kenya. ''Journal of Tropical Ecology''. 13: 347 – 356.

★ Jones M.B. and S. W. Humphries. 2002. Impacts of the C4 sedge Cyperus papyrus L. on carbon and water fluxes in an African wetland. ''Hydrobiologia'', Volume 488, pp. 107-113.

★ Maclean, I.M.D. 2004. An ecological and socio-economic analysis of biodiversity conservation in East African wetlands. Unpublished PhD thesis, University of East Anglia, Norwich.

★ Maclean, I.M.D., M. Hassall, M. R. Boar and I. Lake. 2006. Effects of disturbance and habitat loss on papyrus-dwelling passerines. ''Biological Conservation.'', 131: 349-358.

★ Maclean, I.M.D., M. Hassall, R. Boar, R. and O. Nasirwa. 2003a. Effects of habitat degradation on avian guilds in East African papyrus Cyperus papyrus L. swamps. ''Bird Conservation International'', 13: 283-297.

★ Maclean, I.M.D., R. Tinch, M. Hassall and R.R. Boar, R.R. 2003b. Social and economic use of wetland resources: a case study from Lake Bunyonyi, Uganda. Environmental Change and Management Working Paper No. 2003-09, Centre for Social and Economic Research into the Global Environment, University of East Anglia, Norwich.

★ Maclean, I.M.D., R. Tinch, M. Hassall and R.R. Boar. 2003c. Towards optimal use of tropical wetlands: an economic evaluation of goods derived from papyrus swamps in southwest Uganda. Environmental Change and Management Working Paper No. 2003-10, Centre for Social and Economic Research into the Global Environment, University of East Anglia, Norwich.

★ Messenger Dally. 1908 How papyrus defeated South Sydney and assisted in making Eastern Suburbs great

★ Muthuri, F. M., M. B. Jones, and S.K. Imbamba. 1989. Primary productivity of papyrus (Cyperus papyrus) in a tropical swamp - Lake Naivasha, Kenya, ''Biomass'', 18: 1 - 14.

★ Muthuri, F. M. and M. B. Jones. 1997 . Nutrient distribution in a papyrus swamp: Lake Naivasha, Kenya. ''Aquatic Botany'', 56: 35 – 50.

★ Owino, A. O. and P. G. Ryan. 2006. Habitat associations of papyrus specialist birds at three papyrus swamps in western Kenya. ''African Journal of Ecology'' 44: 438-443.

★ Thompson , K. 1976. Swamp development in the head waters of the White Nile. In (ed.J. Rzoska) ‘‘The Nile. Biology of an Ancient River.’’Monographiae Biologicae, 29. Dr.W. Junk b.v., The Hague.

★ Thompson, K., P.R. Shewry & H.W. Woolhouse. 1979. Papyrus swamp development in the Upemba Basin, Zaire: Studies of population structure in Cyperus papyrus stands. ''Botanical Journal of the Linn. Soc.'' 78: 299-316.

External links

★ Purdue University: ''Cyperus papyrus'' factsheet

★ Floridata

★ University of Connecticut Ecology & Evolutionary Biology Conservatory