Aralkum

from Wikipedia, the free encyclopedia
The making of the Aralkum
Silted up area of ​​the Aral Sea

The Aralkum is a desert created by the drying up of the Aral Sea , which borders the Kysylkum and Karakum . It offers a habitat for plants and animals, but with increasing regression of the shore zone and the onset of water scarcity, the vegetation retreats, leaving behind a dry desert area, which is the starting point for salt and sand storms. These affect both the flora and fauna in the wider area and people's health negatively.

So far there have been only a few research contributions on the Aralkum, especially as a habitat, as it represents a relatively new spatial unit, but many works on the subject of the Aral Sea also deal with the dry area.

Wind blows sand, salt and dust

Silted up area of ​​the Aral Sea

The retreating coastlines of the Aral Sea left behind huge areas of former seabed, which are predominantly covered by powdery salt crusts and to a lesser extent also by sand. These plains, often without vegetation, together with the dry climate, are the cause of the ever increasing frequency and intensity of sand and dust storms. Before the Aral Sea catastrophe, dust storms did not even occur 10 days a year, but at the turn of the millennium they did so on up to 90 days a year. In contrast to locally effective sandstorms, dust storms that transport particles of smaller grain sizes also reach higher levels in the atmosphere and are regionally effective. The resulting dust clouds can be up to 400 km long and 40 km wide. Every year around 150 Mt of silt , clay particles, salt dust, as well as herbicides , pesticides , heavy metals and radioactive material enter the atmosphere . These can be transported over many hundreds of kilometers and can even be detected in areas more than 2000 km away, including in Belarus , the Himalayas and the Pacific and Arctic Oceans. The salts contained in the storms accelerate the melting processes of nearby glaciers many times over.

Succession in the newly created Aralkum

The Aralkum desert , which consists of dry seabed and covers an area of ​​approximately 60,000 km 2 , is successively populated by different plant species.

A few weeks after an area has dried up, its still wet seabed, covered by remains of seagrass, is covered with blue-green cyanobacteria .

Next, salt-tolerant annual (annual) plants such as Salicornia , which are otherwise widespread in Central Asian salt soils in deserts and steppes because of their high climate tolerance , colonize the still moist areas. Salicornia can cover vast areas of thickets less than 30 cm high, which turn red in autumn.

After that, especially in dry years, vegetation-free “succession deserts ” can occur between the settlement of annual and perennial (perennial) plants. However, if several favorable, more humid years follow one another, perennials and with them bushes can establish themselves.

The final stage of the succession process will only be reached after 30 to 40 years and cannot be clearly predicted beforehand. In the meantime, many plants have migrated from neighboring areas through long-distance distribution: 368 vascular plant species from the adjacent Karakum and Kyzylkum deserts can now also be found in the Aralkum. And in the future too, the vegetation will resemble other Central Asian vegetation forms that have already been adapted to the climate .

literature

  • René Létolle, Monique Mainguet: The Aral Sea. An ecological disaster . Springer Verlag, Berlin, Heidelberg 1996, ISBN 978-3540587309
  • Christian Opp: From the Aral Sea to the Aralkum: causes, effects and consequences of the Aral Sea Syndrome . In: Glaser, R. & K. Kremb (eds.): Asia . (Planet Earth series) Wiss. Buchgesellschaft Darmstadt 2007, pp. 90-100

Web links

Commons : Aralkum  - album with pictures, videos and audio files

Individual evidence

  1. ^ Opp, C. & Darmstadt, A. (2007). From the Aral Sea to the Aralkum: causes, effects and consequences of the Aral Sea Syndrome. In R. Glaser & K. Kremb (eds.), Asia (pp. 90-100). Scientific book society.
  2. ↑ a b c d e f g h Breckle, S.-W. (2011). The lost Aral Sea - but 60,000 km 2 of new territory! In D. Anhuf, T. Fickert & G. Friederike (eds.), Passauer Kontaktstudium Geographie (Vol. 11, pp. 91-100). Passau: Self-published subject geography of the University of Passau.
  3. ↑ Létolle, R. & Mainguet, M. (1996). The Aral Sea . Berlin: Springer-Verlag Berlin Heidelberg.
  4. ↑ a b c Giese, E. (1998). The ecological crisis of the Aral Sea and the Aral Sea region: causes, effects, possible solutions. In environmental degradation in arid regions of Central Asia (West and East Turkestan). Causes, effects, measures (pp. 55–119). Stuttgart: Franz Steiner Verlag.
  5. ↑ Gaybullaev, B., Chen, S.-C. & Gaybullaev, G. (2014). The large Aral Sea water balance: a future prospective of the large Aral Sea depending on water volume alteration. Carbonates and Evaporites , 29 (2), 211-219.
  6. ↑ Michael, T. (Ed.). (2010). Diercke World Atlas . Braunschweig: Westermann.
  7. ↑ Isca, V., Seca, A., Pinto, D. & Silva, A. (2014). An overview of Salicornia genus: The phytochemical and pharmacological profile. Natural Products: Research Review , 2 , 145-176.

Coordinates: 45 ° 12 ′ 4.6 ″  N , 60 ° 31 ′ 27.7 ″  E