Invasion of Asclepias syriaca in grasslands in Hungary
Asclepias syriaca (Asclepiadaceae, Common milkweed) is native to North America and has invaded extensive areas in Europe forming novel ecosystems. In the current study, the impact of A. syriaca on native flora was studied in seven grasslands in Hungary. Within and between sites, the percentage cover of A. syriaca was highly variable and this allowed for an assessment of potential impacts relating to the cover of this invasive alien plant. Although no significant impact of A. syriaca cover was detected on total species richness and species richness of native grassland species, the cover of native grassland species decreased with increasing A. syriaca cover. The authors conclude that native, successional sandy grasslands invaded by A. syriaca form undesirable novel ecosystems because of significant negative impacts on the cover of native grassland species, especially those with low competitive ability. For these species, management of A. syriaca may be needed to ensure their persistence in sandy grasslands.
Lelemen A, Valkó O, Kröel-Dulay G, Deák B, Török P, Tóth K, Miglécz T, Tóthmérész B (2016) The invasion of common milkweed (Asclepias syriaca) in sandy old-fields – is it a threat to the native flora? Applied Vegetation Science 19, 218-224.