Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

Seedling dynamics and population structure of invasive Heracleum sosnowskyi (Apiaceae) in Lithuania.

Abstract

We studied seedling dynamics and population structure of the invasive, monocarpic perennial Heracleum sosnowskyi (Apiaceae) in different habitats. The lowest seedling density was found in the managed anthropogenic herb stand, whereas in the unmanaged anthropogenic herb stand, mean seedling density was the highest and significantly different from that at the other studied sites. In all populations, a small fraction of the individuals were generative. In the managed anthropogenic herb stands, mature vegetative and generative individuals dominated in the population, whereas the unmanaged anthropogenic herb stands were dominated by immature vegetative plants. Our study confirmed that long-term abandonment of mesic meadows promotes development of denser stands of H. sosnowskyi. A short-time extensive management can reduce the density of monocarpic invasive species populations, especially their seedlings and immature vegetative plants. Significant reduction in seedling numbers occurred between April and May, with high seedling mortality rates in the following months until September. The mean seedling survival rate was 4.15%.