Adil GÜNER, Vehbi ESER - optima

Posters
AILANTHUS ALTISSIMA (MILLER) SWINGLE IN SARDINIA (ITALY),
REMOTE SENSING AND GIS TO ASSESS INVADED HABITATS
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Luisa CARTA, Giuseppe BRUNDU, Antonello BRUNU, Sara MELITO,
Ignazio CAMARDA
Department of Botany, Ecology and Geology University of Sassari, Italy, lucarta@uniss.it
Ailanthus altissima, a deciduous tree commonly called Tree of Heaven, native in Taiwan and
central China, was first introduced in Italy (Padova botanical garden) in 1760 and planted
mainly as ornamental species. It can propagate by seeds but it spreads mainly vegetatively,
forming dense stands. At European level, it is generally described as common in urban areas,
old fields, along roadsides, woodland edges and forests. It is generally described as
polygamous, with perfect and male flowers in terminal or axillary panicles. We considered the
presence and abundance of Ailanthus altissima in the invaded habitats in Sardinia as a proxy
indicator for habitat environmental quality. Since 1991, the Italian Ministry of the
Environment, funded the "Carta della Natura" project. The Map of Nature is being realized
according to Corine Biotopes legend of habitats. The data collected with this project was
compared with the Ailanthus distribution evaluation obtained from previous works. Satellite
images (Landsat TM) represented the informative layer to provide a synoptic view of the
whole territory. The classification methodology used spectral features of the data and ground
control points (or areas) acquired by GPS positioning. Furthermore, in a second step,
classification was thematically enhanced by using logical niche models of species and habitats
derived from assessed relationships between species-habitats. The distribution patterns and
available predictors, i.e. GIS thematic layers (DTM, soil, geology and land-use) were also
considered to built the thematic map. In the final step, we compared by overlaying the Tree of
Heaven presence, using records from over 7,000 sites (presence/absence/abundance scores)
distributed on the whole Sardinia. Although this alien is mainly present in ruderal sites, we
detected a significant rate of invasion also in Mediterranean sub-nitrophilous grasslands,
dunes juniper thickets and woods, meso-Mediterranean calcicolous garrigues, showing its
spreading ability to colonize also semi-natural and natural habitats.
Keywords: Ailanthus, habitat, Map of Nature.
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