Populetum pamiricae ass. nova-an endemic forest association to Pamir in Tajikistan (Middle Asia)

Abstract

The floristic structure, distribution and habitat requirements of a forest syntaxon, Populetum pamiricae ass. nova is described. The potential range of the Populetum pamiricae association comprises the mountains of eastern Tajikistan (Pamir Alai Mts), Kashgaria in western China (Kunlun Shan Mts) and north-eastern Afghanistan (Hindu Kush Mts) in Middle Asia. The biotope of this community comprises of high mountain river valleys situated at elevations between 2,500 and 3,200 m above sea level. Phytocoenoses of the Populetum pamiricae association are characterized by the apparent domination in the tree layer of a diagnostic species, Populus pamirica. The tree stand has a mean cover around 55%. The layer of shrubs consists primarily of the willow including Salix linearifolia and S. wilhelmsiana, and Hippophaë rhamnoides, Rosa huntica and Lonicera stenantha. The herb layer is less developed and consists of species typical for Populetea laurifolio-suaveolentis; however, in juvenile stages of the community, taxa from riverbed vegetation (i.e. Salicion eleagni) also frequently occur. Populetum pamiricae grows in areas of flood inundations caused mainly by spring thaw where the humus layer in soils is very thin or even completely absent. The forest association of Populetum pamiricae ass. nova is one of the rarest and most rapidly disappearing wood communities in Tajikistan. High conservation priority and special management is recomended for this association.