THE FIRST REPORT OF THE INVASIVE ALIEN WEED JERUSALEM ARTICHOKE (Helianthus tuberosus L.) IN THE REPUBLIC OF NORTH MACEDONIA

A population of Jerusalem artichoke (Helianthus tuberosus L.), an invasive plant A population of Jerusalem artichoke (Helianthus tuberosus L.), an invasive plant species native to North America, was recorded in 2016 near Gradište and along the regional road R 1204 (Gradište, Skačkovce, Dobrošane and Kumanovo) in the northern mountainous part of the Republic of North Macedonia. H. tuberosus is a new species that is alien to Macedonian flora. Surveys revealed intensive growth and low- to medium-density populations of H. tuberosus. The population density was not quantified, but several stands of different sizes were found. An ecological risk assessment based mainly on knowledge about historical invasions in north-western and central European countries showed that this species is a serious threat to Macedonia’s biodiversity. Biological invasion of H. tuberosus affects global biodiversity, and the invaded ecosystems may suffer from significant loss of economic and cultural value. Specifically, is a threat to biodiversity in wet habitats, natural and extensively managed habitats, riparian areas and swamps. It grows best in habitats that are repeatedly disturbed by floods (i.e. riparian areas), but it may also occur in ruderal and agricultural environments. Although many herbicides can be used to control H. tuberosus, their use is limited as the plants are often near waterways, where use of herbicides is not recommended. Other control methods are time-consuming and can be quite costly.