Saxaul
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Saxaulbaum, Mongolia ( Haloxylon ammodendron ) |
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| Haloxylon ammodendron | ||||||||||||
| ( CAMey. ) Bunge |
The saxaul ( Haloxylon ammodendron ), also known as the black saxaul , is a species of the subfamily Salsoloideae in the foxtail family (Amaranthaceae). The Saxaul is a shrub or low tree of the arid steppes and deserts of Central Asia . It can be found from the Caspian Sea to the Gobi Desert in Mongolia . There he can train so-called “Saxaul forests”.
description
The Saxaul is a tall shrub or low tree that is one to nine meters (rarely up to 12 meters) tall. The gray-whitish trunk is usually 4–10 cm thick, but can reach a diameter of 50 cm at the base. Its wood is hard and brittle. The gray-brown to light yellowish-brown side branches are often torn open in a ring. This year's branches grow ascending or hanging, they are long, green and only about 1.5 mm thin.
The scale-shaped leaves are very small, so that the tree looks almost leafless. They sit at a distance of 0.4 to 1.2 cm on the young twigs, their shape is broadly triangular. The leaf axils are woolly hairy.
The Saxaul blooms in spring (in Iran from March to April, in China from May to July). The flowers are on short side shoots of the previous year's branches. Your broad-egg-shaped, skin-margined prophylls are about as long as the elongated bracts . The stamens protrude from the flower. The style has two (rarely three) very short scars.
At the time of fruiting, circular to kidney-shaped wings grow from the back of the bloom above the center. The winged fruit reaches 5-8 mm in diameter. The pericarp is not attached to the semen. The black seed has a diameter of up to 2.5 mm.
The chromosome number is 2n = 18.
Occurrence
The Saxaul is common in large areas of Asia. Its area extends from the Urals , Iran and Kazakhstan east to Mongolia and to China in the provinces and autonomous areas of western Gansu , Inner Mongolia , northwestern Ningxia , northern Qinghai and Xinjiang .
Saxaul trees grow in sandy deserts, on shifting dunes, in Artemisia steppe, in rocky valleys and on hill slopes.
ecology
The Saxaul is often found in mass populations, so that one can speak of "Saxaul forests". In southern Mongolia alone, these cover 45,000 square kilometers. This habitat is home to various animal species such as the Saxaul sparrow ( Passer ammodendri ). The plant acts against desertification several times. It is considered frugal, stores water and protects against the effects of sand and salt storms. Most of all, Saxaul is salt tolerant. The roots hold and stabilize slightly eroded soil and enrich it with phytomass and humus.
Systematics
It was first described in 1829 by Carl Anton von Meyer under the name Anabasis ammodendron (in Ledebour : Flora Altaica 1. p. 375). Alexander von Bunge placed the species in the genus Haloxylon in 1851 . Further synonyms are Arthrophytum ammodendron (CAMey.) Litw. , Arthrophytum ammodendron var. Aphyllum Minkw. , Arthrophytum haloxylon Litw. , Haloxylon aphyllum (Minkw.) Iljin and Haloxylon pachycladum M.Pop.
use
The water-storing bark offers the nomads an opportunity to supply water and at the same time the tree offers firewood . However, the latter has severely restricted its spread due to rising oil and coal prices.
The Saxaul is planted throughout Central Asia for soil reinforcement in order to stop the progressive desertification . Especially in Uzbekistan in the Aralkum (the dry lake bed) and in mountainous Afghanistan, the plant is suitable in the fight against erosion, where there is often no state aid and tenants have to help themselves.
A parasitic plant ( Cistanche deserticola ) on the roots of the saxaul tree is called "desert ginseng " by the Chinese and is used in traditional medicine.
literature
- Gelin Zhu, Sergei L. Mosyakin, Steven E. Clemants: Haloxylon ammodendron . In: Wu Zhengyi, Peter H. Raven, Deyuan Hong (Eds.): Flora of China . Volume 5: Ulmaceae through Basellaceae . Science Press / Missouri Botanical Garden Press, Beijing / St. Louis 2003, ISBN 1-930723-27-X , pp. 396 (English). , online (section description).
- Ian C. Hedge: Haloxylon ammodendron. In: Karl Heinz Rechinger et al. (Edit.): Flora Iranica , Vol. 172, Chenopodiaceae , Akad. Druck, Graz 1997: Pages 317-318. ISBN 3-201-00728-5 (sections description, occurrence, systematics)
Individual evidence
- ↑ Chromosome number in Tropicos
- ↑ a b Susanne Aigner: Our food (Telepolis): How does the agricultural and food industry work? Heise Medien GmbH & Co. KG, 2015. ISBN 3957880513 , ISBN 9783957880512 ( Chapter "Native plants can stop erosion" online at Google Books )
- ^ Edda Schlager: Aral Sea - News from an ecological catastrophe. Dossier, January 5, 2007
