Spontaneous Dispersion of Species of the Genus Juglans L. in the Forests and Parks of Kyiv

Abstract

In 2016–2017, in the forests and parks of Kyiv, 22 points of spontaneous spread of selfsown plants of six species of Juglans L., namely, J. ailantifolia Carrière, J. cinerea L., J. mandshurica Maxim., J. nigra L., J. regia L., and J. subcordiformis Dode (Juglandaceae DC. ex Perleb), were found. In eight locations, 919 selfsown individuals and 45 maternal trees of these species were examined. Local populations are left-side in most cases; they have different spatial and ontogenetic structures and some of them contain young reproductive individuals. According to our data (abundance, size, and ontogenetic composition), the points of selfseeding spread are spontaneous self-reproducing populations. Schematic maps of distribution of Juglans species have been created. These results expand the concept of naturalization of representatives of the genus Juglans in urban forests and parks. The collected factual information and maps can serve as the basis for a strategy of monitoring the invasions of exotic trees.