Limiting factors of Viscum album L. spread and bioindication characteristics of alien species biomass in the Bryansk region

To clarify the role of environmental factors in the spread of the semi-parasite Viscum album L. in the habitats of the Bryansk region, long-term studies were carried out on the ecological-biological and ecological-chemical characteristics of woody phorophytes and mistletoe biomass. Mistletoe is an adventitious species with an expanding range, so the organization of biomonitoring work is an important condition for continuous biological control over the characteristics of the distribution of populations in favorable habitats of the Non-Black Earth Region of the Russian Federation. Using the route method, visual and metric techniques, laboratory and chemical instrumental surveys, more than 150 samples of plant biomass were processed, the locations of Viscum album were identified at 218 points. For the habitats of the urban and rural settlements, the leading environmental factors determining the spread of mistletoe were taken into account: acidity and density of the bark of substrate trees, which directly determine the rate of seed germination, prevent the formation of bark cracks. The trees most affected by mistletoe are soft-leaved trees with soft and almost neutral acidity bark: Betula pendula Roth, Sorbus aucuparia L., Populus tremula L., Prunus domestica L. Biochemical characteristics of mistletoe in terms of ascorbic acid and heavy metal content are recommended for ecological and geochemical mapping of territories and can indirectly characterize the state of phorophytes.