Pinus tecunumanii

from Wikipedia, the free encyclopedia
Pinus tecunumanii
Pinus tecunumanii.jpg

Pinus tecunumanii

Systematics
Order : Conifers (Coniferales)
Family : Pine family (Pinaceae)
Subfamily : Pinoideae
Genre : Pine ( Pinus )
Subgenus : Pinus
Type : Pinus tecunumanii
Scientific name
Pinus tecunumanii
F.Schwerdtf. ex Eguiluz & JPPerry

Pinus Tecunumanii is a plant from the genus of pine trees ( Pinus ) within the family of the Pinaceae (Pinaceae). The natural range extends from southern Mexico to Central America . It is in the red list of the IUCN classified "at risk" due to heavy use as. It is an important supplier of wood in its area of ​​distribution and is also planted in other tropical areas around the world.

description

Appearance

Pinus tecunumanii grows as an evergreen tree that usually reaches heights of 50 to 55 meters. The upright and straight trunk reaches diameters of 120 to 140 centimeters at chest height . The trunk bark in the lower part of the trunk is 5 centimeters thick and gray-brown, 3 to 4 meters above it becomes thinner and reddish brown. The branches are horizontal or slightly ascending. Higher-order branches are pliable but not drooping. The treetop is narrow and dense. Young shoots are rough, glabrous, reddish brown and often surrounded by a layer of wax.

Buds and needles

The vegetative buds are not resinous and ovate, oblong to cylindrical. Terminal buds are 15 to 20 millimeters long, lateral buds are smaller. Trained as bud scales Lower leaves are brown, subulate and have an irregular jagged edge and ciliated.

The needles usually grow in groups of four, less often in groups of three or five, in an initially orange-brown, up to 25 millimeters long, shortening to 12 to 18 millimeters, and later gray-brown needle sheath. The needles are light green, straight, thin, soft and slightly drooping, from 14 mostly 16 to 18 and rarely up to 25 centimeters long and 0.7 to 1 rarely up to 1.3 millimeters thick. The edge of the needle is finely sawn, the end pointed. There are evenly distributed stomata on all sides of the needle . Usually three or four, rarely two or five resin channels are formed. The needles stay on the tree for two to three years.

Cones and seeds

The pollen cones are yellowish, egg-shaped-oblong to cylindrical, when the pollen is released, 1.5 to 2 centimeters long with a diameter of 5 to 6 millimeters. The seed cones rarely grow individually, usually in whorls of two to four near the branch ends on mostly 20 to 25 millimeters, rarely only 15 millimeters long, thin stems that fall off with the cones. Fully grown cones are ovate to broadly ovate, symmetrical or almost symmetrical, and open usually 4 to 7 centimeters, rarely from 3.5 to 7.7 centimeters long, with diameters from 3 to 3.5 to 6 centimeters. The 75 to 100, rarely to 140, seed scales are elongated, straight or slightly curved and thinly woody. The apophysis is raised, transversely keeled, arched at the base of the cone, striped, matt light brown or slightly shiny. The umbo lies dorsally, it is gray, flat to slightly elevated and reinforced with a small, sloping spine . The cones fall from the tree about two to three years after the seeds have been released.

The dark-gray and black-spotted or black-gray seeds are oblique-egg-shaped with a length of 4 to 7 millimeters and a diameter of 2 to 4 millimeters. The seed wings are divided, 10 to 13 millimeters long, 4 to 8 millimeters wide and gray-brown.

Occurrence and endangerment

The natural range of Pinus tecunumanii extends from the southern Mexican states of Chiapas and Oaxaca to the Central American states of Belize , El Salvador , Guatemala , Honduras and northwestern Nicaragua .

Pinus tecunumanii grows in the mountains of Central America at altitudes of 550 to 2500 meters, rarely up to 2900 meters, in Belize this species is found at altitudes of 300 to 760 meters. The distribution area is assigned to winter hardiness zone 9 with mean annual minimum temperatures between −6.6 ° and −1.2 ° Celsius (20 to 30 ° Fahrenheit ). The annual rainfall is at least 1000 millimeters and ranges from 2500 to 3000 millimeters, the long dry period lasts from November to May. As a result, fires are frequent at lower and medium altitudes, but the frequency has been increased significantly by the presence of people. In these areas, open pine forests, together with bracken ( Pteridium aquilinum ) and representatives of the genera Rubus , Calliandra and Leucaena, are predominant as long as the human influence is not too strong. In less impaired areas, especially at higher altitudes, Pinus tecunumanii often grows together with other pine trees such as Pinus oocarpa , Pinus maximinoi and Pinus pseudostrobus , in drier areas with Pinus ayacahuite and Pinus strobus var. Chiapensis . The Guatemala fir ( Abies guatemalensis ) and the Mexican cypress ( Cupressus lusitanica ) can also be found in the coniferous forests at higher elevations . On the slopes of Chiapas facing the Atlantic, deciduous forests dominate with representatives of the genus of sweetgum trees ( Liquidambar ), magnolias ( Magnolia ), cinnamon trees ( Clethra ), hornbeams ( Carpinus ), symplocos and oaks ( Quercus ), Pinus tecunumanii and others Pine trees are restricted to nutrient-poor soils or as a pioneer species in areas that have been destroyed by drought.

In the Red List of the IUCN is Pinus Tecunumanii as "endangered" (= "Vulnerable") classified. However, it should be noted that a reassessment is necessary. There are still areas with sufficient stands and very large trees, but most of the stands have been separated into many small, disjoint areas by overexploitation , which are threatened with complete disappearance, especially in lower elevations.

Systematics and research history

The tree specimens have long been assigned to the species Pinus oocarpa , from 1940 the stocks in Chiapas were described as the variety Pinus oocarpa var. Ochoterenae Martínez . In 1953 Fritz Schwerdtfeger put the holdings in his own kind of Pinus tecunumanii , but the procedure did not meet the requirements of a valid initial description . These were not until 1983 with the description by Teobaldo Eguiluz Piedra and Jesse Parker Perry in Ciencia Forestal , 8, 41, pages 4-20, f. 1–9, Plates 1–2 fulfilled. International planting experiments with Pinus oocarpa , which were carried out from around 1970 , also contributed to the uncertainty . Plantations that developed particularly successfully had to be assigned to Pinus tecunumanii . The epithet tecunumanii reminiscent of Tecun Uman , a chieftain of the Quiché of the 16th century, who was killed in the Spanish conquest of Central America.

The species Pinus tecunumanii belongs to the Australes subsection from the Trifoliae section in the Pinus sub-genus within the genus ( Pinus ). Morphological and chemical studies show that Pinus tecunumanii is more closely related to Pinus patula than Pinus oocarpa . Some authors therefore see these specimens as representatives of the species Pinus patula or classify them as a subspecies Pinus patula subsp. tecunumanii (F.Schwerdtf. ex Eguiluz & JPPerry) styles of the species Pinus patula .

use

Pinus tecunumanii is an important supplier of wood in Central America, where this species forms large, straight trunks. It is used extensively as sawn timber and for other applications in its area of ​​distribution. Growing in plantations holds great promise for the production of pulp , and use in tropical areas outside the natural range is being considered. It has been planted in Africa, India, South America and Queensland , Australia, but the availability of seeds still limits large-scale use. It is not known to be used as an ornamental tree .

swell

literature

  • Aljos Farjon: A Handbook of the World's Conifers . tape 2 . Brill, Leiden-Boston 2010, ISBN 90-04-17718-3 , pp. 770-771 .
  • James E. Eckenwalder: Conifers of the World. The Complete Reference . Timber Press, Portland, OR / London 2009, ISBN 978-0-88192-974-4 , pp. 484-485 .

Individual evidence

  1. ^ A b Aljos Farjon: A Handbook of the World's Conifers , Volume 2, pp. 740-741
  2. ↑ a b c James E. Eckenwalder: Conifers of the World , p. 484
  3. ↑ a b c d e f Aljos Farjon: A Handbook of the World's Conifers , Volume 2, p. 741
  4. ↑ James E. Eckenwalder: Conifers of the World , pp. 484-485
  5. ↑ Pinus tecunumanii in the Germplasm Resources Information Network (GRIN), USDA , ARS , National Genetic Resources Program. National Germplasm Resources Laboratory, Beltsville, Maryland. Retrieved May 30, 2013.
  6. ↑ a b c James E. Eckenwalder: Conifers of the World , p. 485
  7. ↑ Pinus tecunumanii in the endangered Red List species the IUCN 2012. Posted by: Conifer Specialist Group, 1998. Accessed May 30, 2013.
  8. ↑ Pinus tecunumanii at Tropicos.org. Missouri Botanical Garden, St. Louis, accessed May 30, 2013.
  9. ↑ Christopher J. Earle: Pinus tecunumanii. In: The Gymnosperm Database. www.conifers.org, November 23, 2012, accessed May 30, 2013 (English).
  10. ^ Aljos Farjon: A Handbook of the World's Conifers , Volume 2, p. 740

Web links