Ailanthus altissima habitat preferences in Switzerland
Ailanthus altissima (Simaroubaceae - EPPO List of Invasive Alien Plants) commonly known as tree of heaven is an invasive alien plant species in the EPPO region and native to North and Eastern China. 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. In these habitats, the species can have a negative impact on native biodiversity and ecosystem services. The species is very difficult to manage therefore, a combination of control methods is often needed for successful control. To evaluate the habitat preference of A. altissima in Switzerland, three study sites were selected which all comprised abandoned unmanaged stands of Castanea sativa. Sites selected were at the current front of the A. altissima invasion with no vegetation regeneration. All female trees of A. altissima bearing seed were recorded and the age of each tree was estimated. In addition, A. altissima saplings were identified and recorded within each site. Environmental variables were measured at each site. The spread of A. altissima was positively related to high rock cover, low litter cover and high light availability. The abundance of A. altissima was positively influenced by high light availability, low litter cover and high feeding pressure on competing species. High rock cover has not previously been identified as being beneficial for A. altissima in previous studies, though rock cover has been suggested to reduce competition and serve as a refuge for early successional species.
Knűsel S, Conedera M, Bugmann H, Wunder J (2019) Low litter cover, high light availability and rock cover favour the establishment of Ailanthus altissima in forests in southern Switzerland. NeoBiota 46, 91-116.