INVASIVE CYCLE AND ASSESSMENT OF THE DEPTH OF INVASION OF REPRESENTATIVES OF DENDROFLORA OF UKRAINE IN THE SOME ECOSYSTEMS BY EUROPEAN MISTLETOE (VÍSCUM ÁLBUM L.)

Abstract

Research is related to the biology and ecology of white mistletoe (Víscum álbum L.), with an analysis of its impact on the dendroflora of natural and artificial ecosystems. The sequence of stages of the invasive cycle of mistletoe, starting from the stage of infection, the intensity of the invasion (the degree of its spread in the crown), the suppression of host trees, their death and biodegradation, as well as the mechanism of these processes. These stages have different durations in different species. A comparison of the full cycle of mistletoe infection for those species that are most often infected in Polissya, Eastern Podillya and in the coastal areas of the right bank of the Dnieper. The most sensitive species to the invasion were the following: Populus nigra L., Populus balsamifera L., Tilia cordata Mill, Salix babylonica L., Salix fragilis L., Juglans nigra L. and Juglans cinerea L., Sorbus aucuparia L., Betula pendula Roth , Acer saccharum Marshall, Acer saccharinum L., Fraxinus excelsior L. The intensity of the invasion by mistletoe also takes into account the degree of suppression aforementioned and some other species, have become particularly threatening today, so it requires finding ways to solve this biological and environmental problem. However, a number of tree species can resist to the spreading of mistletoe even under invasion due to mechanisms that ensure their high resistance, among them Populus pyramidalis Rozier, hybrids of poplars, Quércus rúbra L, some others. A number of species are able to resist to mistletoe spreading even under their conditions of infection due to the presence inner mechanisms that ensure their relatively high resistance to this parasite, among them: Populus pyramidalis Rozier, its hybrids, Quércus rúbra L., Prunus avium L., Prunus cerasifera Ehrh. A significant number of dendroflora species are outside of the influence of mistletoe. It is indicates on existing specific biological barriers which block following spreading and adaptation among Víscum album L. populations. The concept of resistance and sensitivity to mistletoe of representatives of dendroflora is offered. The algorithm for determining the tention of invasion by Víscum album, the processes of suppression, death and subsequent biodegradation of affected trees is optimized. The classification of the nature of the interaction of mistletoe and host trees is carried out. Strong invasion of mistletoe white require mutuals special efforts of scientists and state for restriction its spreading.