Ruderal vegetation in Kryvyi Rih (Ukraine) – the class of Robinietea

The present paper studies the ruderal vegetation of the class of Robinietea in Kryvyi Rih. We present the spontaneous woody vegetation of parks and other artificial plantations. Urban landscapes remain unstudied phytosociologically despite the highly diverse habitat niches. We have carried out the comparisons of communities from other regions of Ukraine and adjacent territories. In total, four associations and one derivate community, belonging to three alliances, were identified and categorized as follows: Chelidonio-Acerion negundi (synanthropic tree communities with Acer negundo), Chelidonio majoris-Robinion pseudoacaciae (artificial and spontaneous plantations of Robinia pseudoacacia), Geo-Acerion platanoidis (artificial plantations of broad-leaved tree species). The ordination analysis indicates ecological differentiation of syntaxa investigated in Kryvyi Rih. The most important of them are soil aeration (Ae), the cryo-climate (Cr) and nitrogen content in soil (Nt). Critical revision of the class Robinietea syntaxonomy demands further current research.