Palynological analysis of eight profiles from Nepal

In the Eastern Central Himalaya (Langtang Valley) and its southern declivity (Helambu), palynological and phytosociological studies were carried out with the aim of reconstructing the natural vegetation pattern and elucidating the development of replacement communities between the upper cloud forest belt (2000-4000 m a.s.l.), and the alpine belt (ca. 4000-5100 m a.s.l.). According to palynological studies and historical information, the remote area under study was first influenced by man during the 15th century, presumably by hunters who set fire to the forests which were dominated by Quercus semecarpifolia, Tsuga dumosa, Abies spectabilis and Betula utilis.

Pteridium aquilinum increased and Juniperus decreased as a result of the fires being set. The only permanent settlement of the upper Langtang Valley (Langtang village) is situated at 3450 m a.s.1. at the transition between the middle and upper cloud forest belt and was founded during the 17th century. A Rhododendron lepidotum dwarf shrub appeared as the first replacement community for the forest.