Vegetationsgrenzen im extremen und multizonalen Hochgebirge (Zentraler Himalaya)
DOI:
https://doi.org/10.3112/erdkunde.1984.04.03Keywords:
Himalaya, high mountains, vegetation geographyAbstract
Patterns of plant life-forms in the Central Himalayas (83°-84° E.) are presented together with remarks on the upper treeline of Mt. Everest and Nanga Parbat. In addition, causal aspects are discussed by comparing habitats with differing ecological conditions. The area of investigation, the Dhaulagiri- and Annapurna-Himalayas (28° 14'-29°N/83°14'-84°05' E.), has the greatest vertical distance of the continental earth's surface and a sharp decrease of precipitation from 6000 mm/p.a. in the Lower Himalayas to 300 mm/p.a. in the Tibetan Himalayas, an area spanning 50 km. These conditions produce extremely varied plant life-forms ranging from sub-tropical mountain forest to cloud forest, conifer forest and semi-desert dwarf scrublands. Between 28° 20' (Lower Himalayas) and 28°40' N (Tibetan Himalayas) the upper tree-line climbs up to 4400 m (Birch-woodlands on the shady slope only). Although deduction would lead one to conclude that north of the tropic the sunny slope maintains a higher tree-line than the shady slope, the upper tree-line in the Inner Himalayas between 83 and 84° E. lies up to 200 m higher on the northward- than on the southward-exposed slope. This is strictly due to the occurrence of thickets of moist alpine scrub at the southward-exposed upper tree-line. Where there are scarce and open alpine scrubs only, the tree-line on both slopes lies at 4200 m. The upper tree-line of Nanga Parbat and Mt. Everest is higher on the southward-exposed slope. This situation could be inverted by valley winds which depress the upper tree-line of junipers in the Dhaulagiri- and Annapurna-Himalayas some100 m and the upper border of sub-nival Rhododendron-woodlands in the Khumbu-Himal. In the Main Himalayan Range steep walls of v-shaped gorges are covered with tussocks, ascending from a sub-tropical 1500 m to a periglacial 4100 m. They seem to require a minimum amount of rainfall equal to 1200 m/p.a. and are found both in habitated valleys, where people still burn the grass, and in hitherto unexplored gorges.Downloads
Published
1984-12-31
How to Cite
Miehe, G. (1984). Vegetationsgrenzen im extremen und multizonalen Hochgebirge (Zentraler Himalaya). ERDKUNDE, 38(4), 268–277. https://doi.org/10.3112/erdkunde.1984.04.03
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