Sosnowski’s hogweed (Heracleum sosnowskyi Manden., Apiaceae) at the foot of Zelejowa Mountain in the Chęciny commune (Małopolska Upland)
Heracleum sosnowskyi Manden. (Sosnowski’s hogweed) is an invasive alien species, which is native to flora of Caucasus. It was brought into Poland in the mid-Fifties of the 20th century and it was cultivated as pasturage for cattle in holding of whole country. Unfortunately, a negative impact of the species on environment has been observed. Although its tillage was stopped, the species still spontaneously appeared on new locations.
Nowadays this phenomenon is still up to date.
In course of floristic studies conducted in year 2009 detailed siting of Sosnowski’s hogweed on new location was fixed. Population was divided into respective aggregations. Number of individuals in every cluster was counted. On selection area phytosociological record (relevé) using Braun-Blanquet’s method were completed for presenting type of community with H. sosnowskyi at the station.
New locality is situated at the foot of Zelejowa Mountain in the Chęciny commune (Małopolska Upland), (fig. 1a). Within confines of population of Sosnowski’s hogweed 8 aggregations along a road to an inactive quarry have been distinguished (fig. 1b). There are around 500 individuals of the species. The least numerous cluster counts 3 individuals (cluster number 7), the most numerous aggregation counts around 400 individuals (aggregation number 5), (fig. 2). In the whole the population contains 300 generative and 200 vegetative forms (fig. 3). On the investigated area H. sosnowskyi grows in synathropic communities of class Artemisietea vulgarisand in seminatural communities of the class Trifolio-Geranietea sanguinei. Dynamism of population of the species threaten to natural and economic environment of the Chęciny commune. Thus, there is a requirement to top off a right performance to eliminate or cut down an abundance of Sosnowski’s hogweed in this area.