Vegetation of the ultramafic mountain massif Rai-Iz (upper reaches of the Enga-Yu River, the Polar Urals, Russia)

Abstract

The syntaxonomic diversity of vegetation in the upper reaches of the Enga-Yu River is described. The specificity of the vegetation in the study area was determined by the ubiquitous occurrence of ultramafic rocks, which contributed to an increase in the harshness of habitats due to the high concentration of heavy metals and the low calcium content. Unfavorable geochemical environments caused the absence of several common in this region species and in the same time the change of ecological preferences and ecological amplitude of other species. Within the lower and middle parts of the alpine belt, we distinguished and described for the first time 4 associations and 2 subassociations. Cladonio rangiferinae–Caricetum arctisibiricae ass. nov. with 2 subassociations (C. r.–C. a. typicum subass. nov., C. r.–C. a. dicranetosum acutifolii subass. nov.) we assigned to the class Loiseleurio procumbentis– Vaccinietea Eggler ex Schubert 1960. Asahineo chrysanthae–Racomitrietum lanuginosi ass. nov. is placed into the class Carici rupestris–Kobresietea bellardii Ohba 1974. Two associations were distinguished as provisional. Tephroserido tundricolae–Bistortetum ellipticae ass. prov. comprising snowbed vegetation, is not assigned yet to any higher unit. Festuco arcticae–Caricetum arctisibiricae ass. prov. comprises meadow communities, it is assigned to the class Juncetea trifidi Hadač in Klika et Hadač 1944 and order Juncetalia trifidi Daniёls 1994. It is not assigned to any alliance due to the shortage of data. The peculiarity of these provisional associations we explain by the influence of ultramafic rocks.