Evaluation of Heracleum sosnowskyi frost resistance after snow cover removal in early spring.
The development of environmentally safe and cost-effective methods for controlling invasive species Sosnowsky's hogweed (Heracleum sosnowskyi Manden.) is an urgent issue for the European part of Russia. The article presents findings of an experiment on the effect of snow cover removal from the areas occupied by H. sosnowskyi in the early spring period (the beginning of March 2018) in the vicinity of the city of Syktyvkar (Komi Republic, Russia). The snow depth reached 100 cm on the intact plots; the sum of below-zero air temperatures measured at 6 a.m. constituted -448°C, with a minimum of -29.0°C during the experiment. The number of H. sosnowskyi plants of all age groups at the experimental plots (with removed snow cover) was shown to be significantly decreased. The median seedling density (pcs. per square meter) was equal to zero. Most of the surviving plants were located along the sides and in the corners of experimental plots. This can be explained by the higher temperature of soil on the borders of plots with an intact snow cover. The results of the experiment may be used for development of invasive plant eradication technology by removal of the snow cover. This technology can be suitable for kindergartens, schools, hospitals, and water protection zones, where the use of chemical methods of plant control is limited or prohibited. The obtained data set with respect to H. sosnowskyi monitoring is available in the repository of Zenodo.