Abstract
Sofia is a large modern city with continuously increasing air pollution. Street landscaping is one of the opportunities for improving the urban environment, especially in the central urban areas. But how far in its present state could it perform such a function? Are the used tree species suitable and do they have a future? Do past technologies and those still used for street landscaping provide the necessary conditions for normal tree development? These are questions, the answers to which require a huge future work, since Sofia has no system for monitoring urban trees, including the street ones. The purpose of this research is to launch a more extensive and systematic study on the topic. Questions about the species or variety of the used tree species and some aspects of the general performance of the landscaping were tackled with at that stage. Based on data from literary sources, an attempt was made to assess the suitability of the species and forms that were found. Their health status was also commented on.
The established conclusions should support the future practice of planning and constructing street landscaping in the city and could be of use as a reference for the need for further research. As a result of a graphical measurement of the central city streets length, it was found that those of street landscaping were 48% of the total length and 52% of them were void of planted trees. Part of the non-landscaped streets belonged to the secondary street network. The common species of established taxons were 28, of which ash, linden and horse chestnut were the most commonly used, followed by Norway maple, silver birch, and silver linden. In the first-class network streets, horse chestnut, silver birch, and ash were most commonly used and in the second- class network streets – again ash and linden.
Keywords: street trees, street landscaping, urban tree, street tree, species selection