The 2 new associations, Carici stantis—Salicetum reptantis and Salico-Polemonietum acutiflori, are described within the all. Caricionstantis of the class Scheuchzerio-Caricetea fuscae R. Tx. 1937 for the northern belt of the typical tundra subzone of Taymyr. The diagnostic species group of the first syntaxon includes plants typical of sites with excessive watering. The ass. Carici stantis—Salicetum reptantis is restricted to bottoms or lower parts of the watershed and mountain terrace slopes. The ecological regime of these sites is subject to slight variations reflected in presence/ absence of certain species. Due to floristic differences, the association is subdivided into several subassociations which form a topographic-ecological series along the humidity gradient: epilobietosum palustris→ptilidietosum ciliaris→typicum→petasitetosum frigidi. The ass. Carici stantis—Salicetum reptantis is referred to the all. Caricionstantis which also includes the associations Meesiotriquetris—Caricetumstantis and Pooarcticae—Dupontietumfisheri (also described from the Ragozinka R. basin); the latter occur in the wet depressions between sloping hills and the flowing valleys, respectively. If compared to these two, the ass. Carici stantis—Salicetum reptantis is shown to hold an intermediate position between them.
The ass. Salico-Polemonietum acutiflori with the 2 variants, Salix lanata and S. reptans, represents various variants of mire vegetation which have undergone zoogenic transformation (by lemmings). The stands size 1—1.5 m2 in space. The diagnostic species group comprises plants common of the wet mossy stream banks. The association is referred to the all. Caricion stantis, although many diagnostic species of the alliance are not present in its composition. When the new data are available, the association is probable to be separated into an independent alliance.
Climatic warming and accompanying changes in the ecological regime of the Black Sea during 1990s
