Polylepis is a genus of trees and shrubs restricted to the
AndesThe Andes are the world's longest exposed mountain range. They lie as a continuous chain of highland along the western coast of South America...
of
South AmericaSouth America is the southern continent of the Americas, situated entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere...
. The genus belongs to the
RosaceaeThe Rosaceae or rose family is a large family of plants, with about 3000 species in 100 genera . The name is derived from the genus Rosa...
family and to the tribe
SanguisorbeaeSanguisorbeae is a tribe of the rose family, Rosaceae. It contains 16 genera in two subtribes, Agrimoniinae and Sanguisorbinae.-References:*Eriksson, Torsten; Malin S. Hibbs, Anne D. Yoder, Charles F. Delwiche, Michael J. Donoghue...
. It is wind-pollinated and can be recognized by its pinnate leaves and a multi-layered, papery bark, the latter feature also prompting its scientific name, a combination of Greek and Latin meaning "many-scales".
The
Polylepis species frequently grows at or above the natural tree line in the Andes.
Polylepis tarapacanaPolylepis tarapacana is a species of plant in the Rosaceae family. It is found in Bolivia, Chile, Peru, and possibly Argentina. It is threatened by habitat loss.-Source:* World Conservation Monitoring Centre 1998. . Downloaded on 23 August 2007....
is especially remarkable for being the woody plant occurring at the highest elevations worldwide.
Polylepis is a genus of trees and shrubs restricted to the
AndesThe Andes are the world's longest exposed mountain range. They lie as a continuous chain of highland along the western coast of South America...
of
South AmericaSouth America is the southern continent of the Americas, situated entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere...
. The genus belongs to the
RosaceaeThe Rosaceae or rose family is a large family of plants, with about 3000 species in 100 genera . The name is derived from the genus Rosa...
family and to the tribe
SanguisorbeaeSanguisorbeae is a tribe of the rose family, Rosaceae. It contains 16 genera in two subtribes, Agrimoniinae and Sanguisorbinae.-References:*Eriksson, Torsten; Malin S. Hibbs, Anne D. Yoder, Charles F. Delwiche, Michael J. Donoghue...
. It is wind-pollinated and can be recognized by its pinnate leaves and a multi-layered, papery bark, the latter feature also prompting its scientific name, a combination of Greek and Latin meaning "many-scales".
Distribution
The
Polylepis species frequently grows at or above the natural tree line in the Andes.
Polylepis tarapacanaPolylepis tarapacana is a species of plant in the Rosaceae family. It is found in Bolivia, Chile, Peru, and possibly Argentina. It is threatened by habitat loss.-Source:* World Conservation Monitoring Centre 1998. . Downloaded on 23 August 2007....
is especially remarkable for being the woody plant occurring at the highest elevations worldwide. It forms monotypic stands at 3,800 - 4,600 m.a.s.l. (12,000-15,000 feet above sea level), far above the natural treeline which is typically between 3,200-3,500 m.a.s.l (10,000-11,000 feet above sea level). These
Polylepis forests are separated by the true treeline of the forests of the humid
yungasThe Yungas is a stretch of forest along the eastern slope of the Andes Mountains from southeastern Peru through central Bolivia. It is a transitional zone between the Andean highlands and the eastern forests. Like the surrounding areas, it has characteristics of the Neotropic ecozone...
or dry
Interandean vallesDry valleys in the central Andes of Peru, Bolivia, and Argentina, known as "valles", are marked by a rain shadow effect of the surrounding mountains, and thus rainfall is limited, and mostly falls in a brief rainy season...
by shrubs or grasses of the
punaPuna may refer to:* Puna , one of the eight physiographic regions of Peru* Puna , the king of Hiti-marama or of Vavau in the Tuamotu legend of Rata* Puna , a type of wind in the Andes...
.
Controversy exists between tropical ecologists whether its currently fragmented distribution is natural or the result of human land-use. Some scientists believe that much of the open grasslands of the Andean
altiplanoThe Altiplano , in central South America, where the Andes are at their widest, is the most extensive area of high plateau on earth outside of Tibet. Lake Titicaca is its best known geographical feature....
that currently separate isolated
Polylepis forests were in fact one continuous forests before early native Andean peoples cleared or burned the ancient forests.
Conservation issues
Polylepis forests exist primarily as small, widely isolated fragments, which are being rapidly depleted by rural communities. Remaining
Polylepis forests are used for firewood and building material and provide protection against
erosionErosion is a gravity driven process that moves solids in the natural environment or their source and deposits them elsewhere...
and habitats for endangered animals. In some countries,
conservationConservation is an ethic of resource use, allocation, and protection. Its primary focus is upon maintaining the health of the natural world: its forests, fisheries, habitats, and biological diversity. Secondary focus is on materials conservation and energy conservation, which are seen as important...
and
reforestationReforestation is the restocking of existing forests and woodlands which have been depleted.Leaves from trees emit oxygen as well as absorb carbon dioxide and other pollutants from our atmosphere. The demand of reforestation is increasing both for quality of human life reasons, biosphere support...
measures are underway.
Taxonomic History
The genus has a complicated taxonomic history. Researchers have variously regarded it as comprising 15 to more than 30 species. The last treatment recognizes 28 species.
Species include
- Polylepis australis
Polylepis australis, also known locally as Tabaquillo or Queñoa is a tree endemic of central Argentina, member of the family Rosaceae. The genus Polylepis originated in the eastern South America, Andean forests . The plant has small, pinnate leaves, 7–10 cm long, normally composed of five or...
- Polylepis crista-galli
Polylepis crista-galli is a species of plant in the Rosaceae family. It is endemic to Bolivia. It is threatened by habitat loss.-Source:* World Conservation Monitoring Centre 1998. . Downloaded on 23 August 2007....
- Polylepis hieronymi
Polylepis hieronymi is a species of plant in the Rosaceae family. It is found in Argentina and Bolivia. It is threatened by habitat loss.-Source:* World Conservation Monitoring Centre 1998. . Downloaded on 23 August 2007....
- Polylepis incana
Polylepis incana is a species of plant in the Rosaceae family. It is found in Ecuador, Peru, and possibly Colombia. It is threatened by habitat loss.-Source:* World Conservation Monitoring Centre 1998. . Downloaded on 23 August 2007....
- Polylepis lanuginosa
Polylepis lanuginosa is a species of plant in the Rosaceae family. It is endemic to Ecuador.-Source:* Romoleroux, K. & Pitman, N. 2004. . Downloaded on 23 August 2007....
- Polylepis microphylla
Polylepis microphylla is a species of plant in the Rosaceae family. It is endemic to Ecuador.-Source:* Romoleroux, K. & Pitman, N. 2004. . Downloaded on 23 August 2007....
- Polylepis multijuga
Polylepis multijuga is a species of plant in the Rosaceae family. It is endemic to Peru. It is threatened by habitat loss.-Source:* World Conservation Monitoring Centre 1998. . Downloaded on 23 August 2007....
- Polylepis neglecta
Polylepis neglecta is a species of plant in the Rosaceae family. It is endemic to Bolivia. It is threatened by habitat loss.-Source:* World Conservation Monitoring Centre 1998. . Downloaded on 23 August 2007....
- Polylepis pauta
Polylepis pauta is a species of plant in the Rosaceae family. It is found in Ecuador and Peru. It is threatened by habitat loss.-Source:* World Conservation Monitoring Centre 1998. . Downloaded on 23 August 2007....
- Polylepis pepei
Polylepis pepei is a species of plant in the Rosaceae family. It is found in Bolivia and Peru. It is threatened by habitat loss.-Source:* World Conservation Monitoring Centre 1998. . Downloaded on 23 August 2007....
- Polylepis racemosa
Polylepis racemosa is a species of plant in the Rosaceae family. It is endemic to Peru. It is threatened by habitat loss.-Source:* World Conservation Monitoring Centre 1998. . Downloaded on 23 August 2007....
- Polylepis reticulata
Polylepis reticulata is a species of plant in the Rosaceae family. It is endemic to Ecuador.-Source:* Romoleroux, K. & Pitman, N. 2004. . Downloaded on 23 August 2007....
- Polylepis rugulosa
Polylepis rugulosa is a species of plant in the Rosaceae family. It is primarily found in the Andes region of South America in Bolivia, Chile and Peru. It is currently threatened by habitat loss....
- Polylepis subsericans
Polylepis subsericans is a species of plant in the Rosaceae family. It is endemic to Peru. It is threatened by habitat loss.-Source:* World Conservation Monitoring Centre 1998. . Downloaded on 23 August 2007....
- Polylepis tarapacana
Polylepis tarapacana is a species of plant in the Rosaceae family. It is found in Bolivia, Chile, Peru, and possibly Argentina. It is threatened by habitat loss.-Source:* World Conservation Monitoring Centre 1998. . Downloaded on 23 August 2007....
- Polylepis weberbaueri
Polylepis weberbaueri is a species of plant in the Rosaceae family. It is found in Ecuador and Peru. It is threatened by habitat loss.-Source:* World Conservation Monitoring Centre 1998. . Downloaded on 23 August 2007....