Rwenzori Mountains

The Rwenzori, also spelled Ruwenzori and Rwenjura, is a mountain in eastern equatorial Africa, located on the border between Uganda and the Democratic Republic of the Congo. Mount Stanley, the highest massif of the Ruwenzori reaches 5,109 metres (16,762 ft), and the range's upper regions are permanently snow-capped and glaciated. Rivers fed by mountain streams form one of the sources of the Nile.[1] Because of this, European explorers linked the Ruwenzori with the legendary Mountains of the Moon, claimed by the Greek scholar Ptolemy as the source of the Nile. Virunga National Park in eastern DR Congo and Rwenzori Mountains National Park in southwestern Uganda are located within the range.

Ruwenzori
Highest point
PeakMount Stanley
Elevation5,109 m (16,762 ft)
Listing
Coordinates00°23′09″N 29°52′18″E
Dimensions
Length120 km (75 mi)
Geography
Ruwenzori
CountryUganda, Democratic Republic of the Congo

Geology

Margherita Peak on Mount Stanley is the highest point in the range.

The mountains formed about three million years ago in the late Pliocene epoch and are the result of an uplifted block of crystalline rocks including gneiss, amphibolite, granite and quartzite.[2]

This uplift divided the paleolake Obweruka and created three of the present-day African Great Lakes: Lake Albert, Lake Edward,[2] and Lake George.[3]

The range is about 120 kilometres (75 mi) long and 65 kilometres (40 mi) wide. It consists of six massifs separated by deep gorges: Mount Stanley (5,109 metres (16,762 ft)), Mount Speke (4,890 metres (16,040 ft)), Mount Baker (4,843 metres (15,889 ft)), Mount Emin (4,798 metres (15,741 ft)), Mount Gessi (4,715 metres (15,469 ft)) and Mount Luigi di Savoia (4,627 metres (15,180 ft)).[4] Mount Stanley has several subsidiary summits, with Margherita Peak being the highest point.

Human history

House and people in Kasese District, Uganda

The mountains are occasionally identified with the legendary "Mountains of the Moon", depicted in antiquity as the source of the Nile River.[1]

Photographer Vittorio Sella took a number of photographs of the Ruwenzori Mountains during the late 19th and early 20th centuries, documenting the retreat of the range's glaciers.[5] Sella's photographic work is conserved at the Museo Nazionale della Montagna in Turin and at the Istituto di Fotografia Alpina Vittorio Sella in Biella, both in Italy. The Makerere University, Uganda, also has a selection of his images.[6]

The first traverse of the six massifs of the Ruwenzori was done in 1975, starting on 27 January and ending on 13 February. The traverse was done by Polish climbers Janusz Chalecki, Stanisław Cholewa and Leszek Czarnecki, with Mirosław Kuraś accompanying them on the last half of the traverse.[7]

Natural history

Flora

Lower Bigo Bog at 3400 m in the Ruwenzori, with giant lobelia in foreground

The Ruwenzori are known for their vegetation, ranging from tropical rainforest through alpine meadows to snow. The range supports its own species and varieties of giant groundsel and giant lobelia and even has a 6 metres (20 ft) tall heather covered in moss that lives on one of its peaks. Most of the range is now a World Heritage Site and is covered jointly by Rwenzori Mountains National Park in southwestern Uganda and the Virunga National Park in the eastern Congo.[4]

There is no water shortage in the Ruwenzori; yet, several members of the afro-alpine family resemble species that normally thrive in desert climates. The reason lies in their similar water economy. Water is not always readily available to the afroalpine plants when they need it. In addition, nightly frosts affect the sap transport in the plants and the intake of water by its roots. As the day begins, the air temperature and radiation level rise rapidly, putting strenuous demands on the exposed parts of the plants as they try to meet the transpiration demands of the leaves and maintain a proper water balance. To counter the effects of freezing, the afro-alpine plants have developed the insulation systems that give them such a striking appearance. These adaptations become more prominent as the elevation increases.[6]

There are five overlapping vegetation zones in the Ruwenzori: the evergreen forest zone (up to 2,800 metres (9,200 ft)); the bamboo zone (2,800 to 3,300 metres (9,200 to 10,800 ft)); the heather zone (3,000 to 3,800 metres (9,800 to 12,500 ft)); the alpine zone (3,500 to 4,500 metres (11,500 to 14,800 ft)); and, the nival zone (4,400 to 5,000 metres (14,400 to 16,400 ft)). At higher elevations, some plants reach an unusually large size, such as lobelia and groundsels. The vegetation in the Ruwenzori is unique to equatorial alpine Africa.[8]

Flora vs elevation
Meters
Order
150020002500300032003400360038004000420044004600480050005100
Lamiales Mimulopsis elliotii
Mimulopsis arborescens
Rosales Prunus africanaHagenia abyssinica
Alchemilla subnivalis
Alchemilla stuhlmanii
Alchemilla triphylla
Alchemilla johnstonii
Alchemilla argyrophylla
Fabales Albizia gummifera
Cornales Alangium chinense
Malpighiales Casearia battiscombei
Croton macrostachyus
Neoboutonia macrocalyx
Symphonia globulifera
Hypericum sp
Hypericum revolutum
Hypericum bequaertii
Asparagales Scadoxus cyrtanthiflorus
Disa stairsii
Asterales Dendrosenecio erici-rosenii
Dendrosenecio adnivalis
Helichrysum sp.
Lobelia bequaertii
Lobelia wollastonii
Helichchrysum guilelmii
Helichchrysum stuhlmanii
Senecio transmarinus
Senecio mattirolii
Apiales Peucedanum kerstenii
Myrtales Syzygium guineense
Sapindales Allophylus abyssinicus
Gentianales Tabernaemontana sp.Galium ruwenzoriense
Ericales Pouteria adolfi-friedericiiErica arborea
Erica trimera
Erica silvatica
Erica johnstonii
Brassicales Subularia monticola
Primulales Rapanea rhododendroides
Ranunculales Ranunculus oreophytus
Arabis alpina
Santalales Strombosia scheffleri
Poales Yushania alpinaCarex runssoroensis
Festuca abyssinica
Poa ruwenzoriensis
Lecanorales Usnea
Order
Meters
150020002500300032003400360038004000420044004600480050005100

Sources: [8][9][10]

Glacial recession

Ornithologist James P. Chapin on a Ruwenzori expedition under flag of The Explorers Club, 1925

An ongoing concern is the impact of climate change on the Ruwenzori's glaciers. In 1906, forty-three named glaciers were distributed over six mountains with a total area of 7.5 square kilometres (2.9 sq mi), about half the total glacier area in Africa. By 2005, less than half of these were still present, on only three mountains, with an area of about 1.5 square kilometres (0.58 sq mi). Recent scientific studies, such as those by Richard Taylor of University College London, have attributed this retreat to global climate change and have investigated the impact of this change on the mountain's vegetation and biodiversity.[11][12][13]

See also

Notes

  1. Scheffel, Richard L.; Wernet, Susan J., eds. (1980). Natural Wonders of the World. United States of America: Reader's Digest Association, Inc. p. 327. ISBN 0-89577-087-3.
  2. "Climate Change and the Aquatic Ecosystems of the Rwenzori Mountains". Makerere University and University College London. 15 September 2007. Retrieved 2 February 2014.
  3. Wayland, E. J. (July–December 1934). "Rifts, Rivers, Rains and Early Man in Uganda". Journal of the Royal Anthropological Institute. Royal Anthropological Institute of Great Britain and Ireland. 64: 333–352. doi:10.2307/2843813. JSTOR 2843813.
  4. "Rwenzori Mountains National Park". Rwenzori Abruzzi. 27 May 2006. Archived from the original on 5 March 2008. Retrieved 6 May 2008.
  5. "Vittorio Sella". Rwenzori Abruzzi Centenary Celebrations. 2006. Archived from the original on 8 May 2008. Retrieved 9 August 2008.
  6. Flowers of the Moon, Afroalpine vegetation of the Rwenzori Mountains, Schutyser S., 2007, 5 Continents Editions, ISBN 978-88-7439-423-4.
  7. Wielka Grań Ruwenzori 1975, Wojtera T., Taternik iss 3. 1976.
  8. Linder, H. Peter; Gehrke, Berit (2 March 2006). "Common plants of the Rwenzori, particularly the upper zones" (PDF). Institute for Systematic Botany, University of Zurich. Archived from the original (PDF) on 30 May 2008. Retrieved 6 June 2017.
  9. "RWENZORI MOUNTAINS NATIONAL PARK, UGANDA". Protected Areas and World Heritage. United Nations Environment Programme. March 1994. Archived from the original on 25 March 2008. Retrieved 8 May 2008.
  10. "Forest Resources of Tropical Africa". Tropical Forest Resources Assessment Project (reprint ed.). Food and Agriculture Organization of the United Nations. 1984. UN 32/6.1301–78–04. Retrieved 12 May 2008.
  11. Taylor, R. G.; Mileham, L.; Tindimugaya, C.; Majugu, A.; Muwanga, A.; Nakileza, B. (2006). "Recent glacial recession in the Rwenzori Mountains of East Africa due to rising air temperature" (PDF). Geophysical Research Letters. 33 (10): L10402. Bibcode:2006GeoRL..3310402T. doi:10.1029/2006GL025962.
  12. Tom Knudson, In the Mountains of the Moon, A Trek to Africa’s Last Glaciers, Yale Environment 360 Report, 4 Feb 2010
  13. [Rwenzori Glaciers (East Africa)], Tropical Glaciology Group, Innsbruck University

References

This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.