The flora of silver birch shelter belts in the vicinity of the Ufa city

The paper presents the results of a study of the flora of shelter belts comprised of: silver birch (Betula pendula Roth), silver birch and heart-shaped linden (Tilia cordata Mill.), silver birch and apple trees (Malus sylvestris Mill.), silver birch and Scots pine (Pinus sylvestris L.), silver birch and balsam poplar (Populus balsamifera L.) in the vicinity of the Ufa city. It was revealed that there exists a large species diversity of flora in shelter belts with silver birch, significantly exceeding the species diversity of shelter belts with balsam poplar in the same study area. The leading families in the flora of shelterbelts with silver birch were Asteraceae, Rosaceae, Fabaceae, Apiaceae, and Poaceae. The “ruderal” and “semi-ruderal” families are also well represented: Brassicaceae, Caryophyllaceae, Lamiaceae. The flora of shelter belts is dominated by meadow, meadow-ruderal species and species of broadleaved forests and their fringes. At the same time, in older, sparser and taller shelter belts, the number of meadow and ruderal species increases with an increase in the amount of light passing through the canopy. Under the conditions of low anthropogenic load, the proportion of broadleaved forest species and their synanthropized variants increases with the age of shelter belts. The predominance of species with a wide range of hemeroby accommodation — oligo-meso-β-euhemerobes — has also been established, but with the tree canopy getting sparser, the dominant position passes to species that are more resistant to anthropogenic influence — meso-euhemerobes. At high anthropogenic loads, the participation of euhemerobes increases. In shelter belts of pure birch, birch and linden, birch and apple trees, undergrowth and juvenile specimens of silver birch were found. There is no regeneration of birch in forest belts with birch and balsam poplar.