Dynamics of spontaneous flora of the Peter the Great BotanicaL Garden

About 30 years ago, the species composition of herbaceous plants on the territory of the Peter the Great Botanical Garden was studied. It has changed over the years, and it is necessary to give assessment to this process. Currently, the problem of the appearance and dispersal of invasive plant species, most of which are “escapees” from cultivation, is quite acute in Russia and beyond. The purpose of the research is to identify and analyze changes in the species composition of the spontaneous flora of herbaceous plants in the Peter the Great Botanical Garden over the past 30 years. The objectives of the study included assessing changes in the number of certain alien plant species and their invasive potential. As a result of the inventory, 355 species of vascular plants from 54 families were identified in the modern spontaneous flora of the botanical garden. Among them, the indigenous fraction comprises 248 plant species (70.3%). Compared to 1994, the number of species in the flora of the botanical garden increased by 20%. There was an increase in the group of species escaped from cultivation by 50%, but their abundance does not yet cause concern and only 4 species are recognized as potentially invasive on the territory of the botanical garden.