Mapping the potential distribution of Ailanthus altissima in urban areas
Ailanthus altissima (Simaroubaceae - EPPO List of Invasive Alien Plants) commonly known as the tree of heaven is an invasive alien plant species in the EPPO region and native to Asia. Throughout the EPPO region, A. altissima can invade a variety of habitats including managed and unmanaged grasslands, forests, riverbanks/canal-sides, rail/roadsides, wastelands and urban areas. The management of this species can be problematic due to the type of areas where the plant grows and the need to identify and manage all individuals in an area. There currently remains a lack of tools to predict tree spread across urban landscapes and to predict invasion hotspots. A study was conducted in Poznań (Poland) and used floristic surveys, land-use maps, and field observations of the occurrence of A. altissima individuals. A simulation model was run and showed that the probability of A. altissima natural regeneration was positively associated with dense urban areas (10–50%), recreational areas, and water. Natural regeneration was negatively correlated with a high cover of forests, dense urban areas (50–100 %) and agricultural areas. It was also found that most of the naturally regenerated individuals occurred up to 20 m from parental trees, and densities of natural regeneration were five times higher in paved surfaces and ruderal vegetation compared to lawns and bare ground. Despite the limitations of the model, the patterns produced were consistent with other studies, revealing a set of rules that can facilitate prediction of A. altissima natural regeneration occurrence. Therefore, this approach can facilitate narrowing the area of fieldwork required for mapping invasive tree species in urban ecosystems, help to design effective policy and management of invasive species in urban areas, and reduce costs of monitoring.
Paź-Dyderska S, Ladach-Zajdler A, Jagodzinski AM, Gyderski MK (2020) Landscape and parental tree availability drive spread of Ailanthus altissima in the urban ecosystem of Poznań, Poland. Urban Forestry and Urban Greening. https://doi.org/10.1016/j.ufug.2020.126868