Using satellite imagery to assess Ailanthus altissima in Sardinia (IT)
Ailanthus altissima (Simaroubaceae: EPPO List of Invasive Alien Plants, List of (EU) Union concern) is native to Asia. It is a widespread species in the EPPO region where it can invade a variety of habitats including managed and unmanaged grasslands, forests, river/canal banks, rail/roadsides, wastelands, and urban areas. Remote sensing techniques have previously been used to detect and monitor populations of A. altissima in Mediterranean areas though its use to assess the eco-physiological traits of invaded vegetation is poorly researched. A study was conducted in Italy (Sardinia) and georeferenced occurrence of A. altissima were collected. Monthly satellite optical imagery at high spatial resolution were used to compare areas invaded by A. altissima to that of native vegetation. This imagery also captures the near-infrared and short-wave infrared sections of the electromagnetic spectrum which can be used to estimate eco-physiological traits of the vegetation, such as productivity and canopy biomass, photosynthetic activity, leaf water content and soil features, such as bare ground and organic content. The study showed that the differences between invaded and non-invaded vegetation were more pronounced in the summer indicating that A. altissima performs well under drought conditions. In invaded areas there was higher productivity, canopy biomass, leaf water content, and bare soil cover was lower. The study shows that remote sensing techniques can be used to study invasive alien plants.
Sources
Marzialetti F, Lozano V, Große-Stoltenberg A, Carranza ML, Innangi M, La Bella G, Bagella S, Rivieccio G, Bacchetta G, Podda L, Brundu G (2024) Assessing eco-physiological patterns of Ailanthus altissima (Mill.) Swingle and differences with native vegetation using Copernicus satellite data on a Mediterranean Island, Ecological Informatics, https://doi.org/10.1016/j.ecoinf.2025.103080