Heracleum sosnowskyi (Apiaceae) spread and phytotoxicity

Abstract

In the native range endemic species Heracleum sosnowskyi occurs in Caucasus region. Heracleum sosnowskyi is dangerous invader successfully spread along roads, riverbanks and has naturalized in Lithuanian habitats and plant communities. It outcompetes native species, thus changing ecosystems diversity, pushing autochthones species from native habitats, decreasing biodiversity and transforming landscape. This paper aims to evaluate H. sosnowskyi spread and establishment in habitat scale in Lithuania. Data on abundance, spatial distribution and contribution of H. sosnowskyi to plant biodiversity were collected from natural and anthropogenic habitats. Another objective was to evaluate the spread speed in infected landscape. Local assessments of the abundances of H. sosnowskyi by estimating variables of spatial penetrating and establishment in native plant communities at an individual block scale were carried out. Four population types with different density and coverage of species individuals were found. Species abundance was structured according to distance from highway and significantly correlated (r=0.7) with native plant community type. H. sosnowskyi find opportunities for colonization and reproduction resulting in decrease of natural diversity.