Communities of the class Koelerio-Corynephoretea Klika in Klika et Novák 1941 in the Bryansk region of Russia

Abstract

Only few publications on the classification of vegetation of Koelerio–Corynephoretea canescentis Klika in Klika et Novák1941 class, that unites pioneer communities on sandy soils, dunes or an exposed sands, is known for Bryansk region of Russia (Bulokhov, 2001; Bulokhov, Kharin, 2008). This region is located in the western part of the East European plain, on the watershed of two large river (Dnieper and Volga) systems, occupying the central part of the Desna river pool and the woody watershed between Desna and Oka. The territory (34.9 thousand кm2) is extended from the west to the east on 270 km (between 31°10′ and 35°20′ E) and from the north to the south — on 190 km (between 54°05′ and 52°10′ N). The main item of this paper is to submit the results of the classification carried out upon thebasis of 57 releves made in 2003–2016 in Bryansk region and to characterize the composition, distribution and syntaxonomical position of thepioneer vege­tation of sandy and shallow soils communities within it. Three new associations are described according to Braun-Blanquet floristic classification. The syntaxon nomenclature of the higher ranks follows Mucina et al. (2016) The ass. Thymo serpylli–Koelerietum glaucae ass. nov. hoc loco, with synecological optimum on dry poor sandy soils, is diagnosed by character species Artemisia campestris, Koeleria glauca, Thymus serpyl­lum. Its communities occur on fringes of the lichen pine forests, sandy river terraces and outwash plains. Two subassociations are distinguished within the association: T. s.–K. g. typicum (with var. typica and Corynephorus canescens) and agrostietosum vinealis subass. nov. hoc loco (with var. typica and Calluna vulgaris) with Agrostis vinealis, Dianthus arenarius, Cladonia arbuscula as differential species. The ass. Koelerio glaucae–Plantaginetum arena­riae ass. nov. hoc loco, with synecological optimum on dry poor sandy soils or exposed sands, is diagnosed by Plantago arenaria and Koeleria glauca. Its communities occuron the exposed sands, fringes of lichen pine forests and not flooded sandy river crests. The ass. Diantho borbasii–Festucetum polesicae ass. nov. hoc loco with synecological optimum on dry, weekly acidic, poor of mineral nitrogen, sandy soils or the exposed sands, is diagnosed by Festuca pole­sica, Astragalus arenarius, Jurinea cyanoides, Otites parviflora. Communities occur on the exposed sands, fringes of lichen pine forests. Two variants are distinguished within association: Sempervivum ruthenicum (on dunes with dry, poor, weekly developed soils) and typica. These three associations are the early stages of the progressive succession of oligotrophic lichen pine fo­rests on the river terraces or of the heath meadows in flood river plains.