In the Mediterranean area, one the most threat tree to various ecosystems is Ailanthus altissima (Mill.)
Swingle. This is an aggressive invasive species common in natural and semi-natural habitat. Monitoring and
mapping of invasive species is an important information for the conservation and management of ecosystems.
The study of distribution and diffusion of invasive species are useful to assess their environmental impacts,
formulate effective control strategies, and forecast potential spread. The main target of this work is to
examine the feasibility of mapping the expansion of A. altissima using remote sensing techniques in a highly
complex urban forest setting. Remote sensing has been a useful tool to map the invasive plant. We mapped
the pattern of ailanthus expansion from 1990 to 2015 in a suburban area of Palermo, the Favorita park, using
time series of Landsat image. This images are nowadays available at no cost. We used that images to analyze
larger areas but the 30 m resolution does not permit mapping of individual trees; the combinations of dates
and medium spatial resolution with the phenology information allowed the detection of the species. Indeed,
the ailanthus is a deciduous tree that we compared with the other evergreen vegetation. Time series of
Normalized difference vegetation index (NDVI) and supervised classification were used as a dataset in the
classification process. These results provide a basis for more detailed investigations on invasive species and the
possibility to increase the spatial resolution with the new platforms might lead to further improvements plant
species identification and their distribution patterns recognition