The influence of birch plantations on the formation of snow cover in the Middle Taiga subzone of Karelia

The thickness, density, and distribution of the snow cover affect the hydrothermal regime of the soil, the duration of microbiological and biochemical processes, and the productivity of the forest stand. The aim of this study was to assess the duration, thickness, and density of the snow cover in areas of a chronological series of birch plantations. The study was performed in the Middle Taiga subzone of Karelia (East Fennoscandia). In a long-term field experiment, the effect of the chronological sequence of Karelian birch plantings on the thickness and density of snow cover formation was studied. Based on 6 sample areas, the accumulation of winter precipitation under the canopy of Karelian birch trees of various ages was analyzed. Data on the height and density of snow cover were obtained on the basis of field snow measurement, which was performed in the period November-March. Stationary snow measuring rails and a weight snow meter (VS-43M) were used.

It was found that the average height of snow cover under the canopy of the Karelian birch in February (the month with the highest snow accumulation rate) varies from 40.4±1.1 to 50±1.5 cm, the density of snow cover varies from 102±4.2 in 19-year-old plantations to 130.9±9.5 g/cm3 in 69-year-old maximum values were 56 cm . The distribution of snow cover thickness depending on the age of the stand showed that the highest rates were recorded for trees aged 60 years, the lowest for 54 years. In the spruce stand, the accumulation of snow cover was 36.2± 2 cm, under the aspen tree – 50.7± 1.7 cm. In the arable land area, the change in snow cover height ranged from 37 to 52 cm, while here the snow cover density was 123.7 g/cm3. The data indicate that accumulation occurs to a lesser extent under the canopy of coniferous trees compared to deciduous plantings. Overall, when comparing the obtained data with long‑term meteorological data for Karelia, no general trend towards a sharp decline in the amount of snowfall is observed.