Rome has greatly expanded in the course of the last century, after it becam
e the capital of the Italian state in 1870. In this period, many areas were
built according to different urbanistic criteria. The city may now be divi
ded into urban units (Wards, Districts, Suburbs and Zones), which have an a
lmost concentric disposition. The changes of the whole urban landscape and
of the single urban units (UUs) have been analysed by studying the differen
t tree-species planted along the roads. A database has been created using t
he four censuses of the tree-lined roads made by the city administration in
1898, 1955, 1971 and 1998. This analysis has shown a strong link between t
he specific cultural and political period and the tree-species used. Moreov
er, for each year, the UUs have been classified according to the percentage
composition of the species. The results have been mapped using the Arcview
3.1 GIS program in order to integrate them with a more general project on
GIS-based cartography of the natural and anthropic vegetation of Rome. (C)
2000 Elsevier Science B.V. All rights reserved.