Structure and growth dynamics of Heracleum sosnowskyi coenopopulations in the conditions of invasion

Complex studies of the coenopopulation structure of H. sosnowskyi Manden. in the middle taiga of the Komi Republic were carried out. The duration of vegetation of plants was 180–190 days. Coenopopulations were characterized by left-handed ontogenetic spectra and high recovery indices. The density of juvenile individuals was 1700 pcs/m², immature ones 4–7 pcs/m², virginial ones – 12–16 pcs/m², and generative ones – 1–3 pcs/m². Plants started flowering at the age of 2–6 full years. The main part of the assimilating surface of generative individuals was located in the upper layers and absorbed about 70 % of the incoming photosynthetically active radiation. The study of natural increase dynamics of H. sosnowskyi coenopopulation areas revealed the significance of anemochory for plant seed transport over long (up to 55 m) distances. Analysis of satellite images of model plots revealed an annual increase in the area of invasive coenopopulations by 20 %. The variability of invasion rate of the species depended on the initial conditions and stage of invasion, utilization regimes and ecological capacity of the plots.