THE APPLIED ASPECTS OF ENVIRONMENTAL MANAGEMENT OF THE WHITE MISTLETOE (VISCUM ALBUM L.) POPULATION IN URBAN AREAS (IN CASE OF THE CITY OF KHARKIV)

Abstract

The problem of the population control of White Mistletoe (Viscum album L.) in of urban landscape was studied in order to improve the environmental management on urban areas. Nowadays, due to global climate change mistletoe becomes an active invasive plant. It effects on plantations in cities, dendrological parks with valuable woody vegetation, plantations along road, etc. Field survey was carried out in the city of Kharkiv (Ukraine). Sample plots were located within the north-eastern part of the town. We used semi-quantitative indices as a proxy of the White Mistletoe abundance at individual infested tree as follows: «1» was assigned for the range of the Mistletoe individual dwarves from 1 to 5, «2» – from 6 to 10, «3» – from 11 to 20, «4» – from 21 to 40, etc. For determination of the White Mistletoe populations’ age structure, 3 age classes determined visually were established. When the White Mistletoe did not produce fruits and its diameter was from 0 to 25 cm, the plant was considered as «juvenile», for the plants with flowers or fruits and diameter from 25 to 50 cm the «generative» age class was assigned, and the shrubs with diameters over 51 cm were considered as «senile». Depending on the actual age, structure of local populations their population trends («stable», «growing», «declining») were established. Mistletoe populations were mapped in sample plots at the scale 1:10 000. Based on the results of field research with the use of matrix model of the White Mistletoe population dynamics, the retrospective scenario of evolution of mistletoe popu­lation and scenario of changes of the number of mistletoe shrubs over time and its distribution by age in the future were introduced. Retrospective analysis revealed that mistletoe penetrated at sample plot «CR-61-39» in about 1979 and at sample plot «CR-61-40» in about 1950. Forecast scenario of mistletoe population evolution has shown that the number of mistletoe scrubs will grow over time rapidly. Thus, during fifteen years since the investigation has been carried out the number of mistletoe shrubs in sample plot «CR-61-39» will grow in almost two times, and in sample plot «CR-61-40» – almost 1.5 times. This fact is a cause of concern. Research results should be consi­dered when developing and reconstructing gardening of the city of Kharkiv.