Biological control of the Tree-of-Heaven in endangered habitat types on the Bisamberg and in the Lobau

The invasive Tree-of-Heaven (Ailanthus altissima) is increasingly migrating into habitat types worthy of protection, where, due to its rapid growth, its low soil, site and climate requirements, its high capability of reproduction via root suckers and stump sprouts, its strong vegetative reproduction and massive production of seeds and due to its allelopathic properties, it endangers rare plant species and associated animal species. In the present project, an attempt is being made to combat invasive Tree-of-Heaven on the dry grassland site Dürrham (Heißlände) in the Lower Lobau, which is worthy of protection, and in the FFH habitat types 91G0 (Pannonian oak-hornbeam forest), 91H0 (Pannonian downy oak forest) and in the FFH habitat type 6210 (Trespen-fescue-limestone dry grassland) on the Bisamberg, respectively. Furthermore, soil as well as potentially susceptible dicotyledonous plants will be sampled and screened for the agent V. nonalfalfae (see below) on both sites in spring 2024 and 2025. The control is to be carried out using the biological control method developed at the Institute of Forest Entomology, Forest Pathology and Forest Protection (BOKU University) in 2011 on the basis of the native wilt fungus Verticillium nonalfalfae, which has already proven to be sustainable, cost-efficient, but also quickly and specifically effective in numerous series of experiments. The control is therefore also in line with the biodiversity strategy Austria 2030+ of the BMK.