Populations of Cephalanthera damasonium (Mill.) Druce on the hills of the right bank of the River Dnieper (in Forest Steepe vegetation of Ukraine)

Abstract

As a result of studying the vegetation cover of artificial (possibly spontaneous) tree plantations on the hills of the right bank of the River Dnieper in the Forest-Steppe of Ukraine we discovered the formation of natural populations of Cephalanthera damasonium (Mill.) Druce. Information on the growth of this species was previously presented (more than 80 years ago) by F. Gryn (samples of which are in The National Herbarium of Ukraine, Kiev), who noted its distribution in these locations. The ecological and coenotic features of the distribution of this species as a part of available populations in the communities of classes CarpinoFagetea sylvaticae, Quercetea pubescentis, Crataego-Prunetea, Alno glutinosae-Populetea albae have been studied. The largest eight new populations of C. damasonium have been identified on the eastern border of Ukraine. Habitat conditions, number and structure of all new populations were determined. Micropopulations of the species occupy an area from several to 750 m2 with a total population of more than 1,200 specimens. The ontogenetic spectrum is right-sided, with a dominance of generative individuals, and their share is 4/5 of the total number of individuals. The peculiarity of this locality is the high number of individuals in most of these populations, which may be due to favourable ecological-coenotic conditions and the absence of intensive anthropogenic influences. The identified habitats of the study species need protection.