Salicetum shugnanicae – a new plant association from alpine mires in the Pamir Alai Mts in Tajikistan (Middle Asia)

摘要

The paper discusses the floristic structure, distribution and habitat requirements of a shrubby community of Salicetum schugnanicae ass. nova. The potential range of the association is described within the Pamir Alai Mts in Middle Asia. The biotope of this community comprises alpine, humid tall-herbs with shrubby physiognomy on relatively flat slopes of mountain valleys. Th plots of the association were found at elevations between 2,500 and 3,500 m above sea level. Phytocoenoses of the Salicetum schugnanicae are characterised by an apparent domination of a characteristic species Salix schugnanicae in shrub layer. The density of the willow thicket is moderate, from 35 to 90%. The herb layer of the community is moderately rich in species and consists mainly of taxa typical for Mulgedio-Aconitetea class (Angelica komarovii, Codonopsis clematoides, Geranium collinum, G. regelii, Heracleum lehmannianum and Polygonum coriarium) and Nardion alliance (e.g. Blysmus compressus, Carex orbicularis subsp. hissaro-darvasica, Dactylorhiza umbrosa, Heleocharis meridionalis, Pedicularis peduncularis, Primula iljinii, Swertia juzepczukii). Also the moss layer is abundant as it is typically for peaty or boggy habitats similar to alpine mires. The most frequent bryophytes noted in the plots are: Brachythecium mildeanum, Calliergonella cuspidata or Cratoneuron commutatum. The described willow association is one of the rarest and most rapidly disappearing plant communit in Tajikistan. This makes the association of highest conservation priority and special management attention.