| Abstract [eng] |
The spread of alien plant species is a significant factor contributing to biodiversity loss; therefore, it is important to study areas where such species may establish and spread. Studies of botanical garden surroundings make it possible to assess which alien plant species may escape from living collections and spread into adjacent areas, revealing the role of botanical gardens in plant introduction and spread. The aim of this study was to assess the alien plant flora in the surroundings of botanical gardens in Lithuania. The objectives were to evaluate alien plant species occurring beyond botanical garden boundaries; to determine their life forms and status; to assess similarities among the studied botanical gardens based on alien plant diversity; and to evaluate the impact Toxicodendron radicans (L.) Kuntze, a species newly recorded in Lithuania, on native plants. The study was carried out in July–August 2025. Only spontaneously spreading alien plant species were recorded in the surroundings of the botanical gardens of Klaipėda University, Vilnius University Šiauliai Academy, Vytautas Magnus University, and Vilnius University. For each species, abundance, mode of reproduction, status, life form, and origin were assessed. During the study, two alien plant species were recorded in Lithuania for the first time: Veronicastrum virginicum (L.) Farw. and T. radicans. For the latter species, its cover and the diversity of other plant species were assessed in grassland and woodland habitats. In total, 108 alien plant taxa were recorded around Lithuanian botanical gardens, the largest proportion of which were phanerophytes, mainly ornamental trees, shrubs, and lianas. Casual plant species were the most frequently recorded, with 45 species, while potentially invasive plants were more numerous than naturalized ones. Based on alien plant diversity, the botanical gardens of Vilnius University and Klaipėda University, as well as those of Vytautas Magnus University and Vilnius University Šiauliai Academy, were the most similar to each other, whereas the greatest difference was observed between Vytautas Magnus University and Klaipėda University botanical gardens. The assessment of the T. radicans population revealed a statistically significant negative relationship between its cover and the projected cover of other herbaceous plants, suggesting that T. radicans is a potentially invasive plant species in Lithuania. |
