Landscape changes of Rome through tree-lined roads Fabio Attorre, Maurizio Bruno, Fabio Francesconi, Roberto Valenti, Franco Bruno * Dipartimento di Biologia Vegetale, Universita Á La Sapienza, P. le A. Moro 5, Rome, Italy Received 6 December 1999; received in revised form 29 February 2000; accepted 15 April 2000 Abstract Rome has greatly expanded in the course of the last century, after it became 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 divided into urban units (Wards, Districts, Suburbs and Zones), which have an almost concentric disposition. The changes of the whole urban landscape and of the single urban units (UUs) have been analysed by studying the different tree-species planted along the roads. A database has been created using the 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 the speci®c cultural and political period and the tree-species used. Moreover, for each year, the UUs have been classi®ed 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. # 2000 Elsevier Science B.V. All rights reserved. Keywords: Rome; Tree-lined roads; GIS 1. Introduction Speaking about the tree-lined roads of a city neces- sarily calls up the concept of urban sylviculture, a discipline which has not fully developed in Italy. Here, the relationship between urban development and the design and management of green open spaces has always been con¯ictual, to say the least. However, it seems almost super¯uous to point out the many and important functions performed by trees in a city; from their ecological functions, such as improving the micro- and meso-climatic conditions, capturing air pollutants and creating noise and visual barriers, to their positive psychological bene®ts to the citizens, as well as their aesthetic and historical value (Platt et al., 1994; Aavissar, 1995; Mage et al., 1996). At the same time, the peculiar characteristics of the city environment place trees in a dif®cult and precar- ious condition: buildings tend to concentrate solar radiation so as to hinder the normal leaf transpiration; asphalt rapidly conveys rain into the sewers, reducing the rate of regeneration of the soil water resources; air contains great quantities of pollutants which often reach concentrations harmful to plants (Kjelgren and Montague, 1998). A well-known case of the negative effect of pollutants is represented by the total disappearance of lichens in urban areas subject to strong alterations in the atmospheric composition (Nimis, 1989). To all this, the direct consequences of man's action must be added; damage caused by cars during parking manoeuvres, by road works around the trees, by acts of Landscape and Urban Planning 49 (2000) 115±128 * Corresponding author. Tel.: 39-6-49912818; fax: 39-6-49912901. E-mail address: franco.bruno@uniromal.it (F. Bruno) 0169-2046/00/$20.00 # 2000 Elsevier Science B.V. All rights reserved. PII:S0169-2046(00)00069-4