The contribution of urban road trees on improving the air quality in an urban area

Abstract

Landscape plantings in avenues, boulevards, and medians play a prominent role in the construction of outdoor green areas, and contribute both aesthetically and functionally. Roadside planting requires ecological, biological, aesthetic, and technical knowledge and is considered to be multidirectional. One of the most significant functions of roadside planting is the improvement of air quality caused by decreasing atmospheric pollution. Within this scope, the purpose of this study was to determine the metal accumulation of the roadside plants in Kastamonu city, Turkey. Metal accumulation was measured in 80 individual leaves belonging to 18 species inhabiting a 10.5 kilometer-long route in Kastamonu. Results showed that, between the measured elements, zinc (Zn) was accumulated at the highest levels, followed by copper (Cu), lead (Pb), nickel (Ni), and cadmium (Cd), in the given order. Highest Zn, Cd, and Cu levels were detected in Betula pendula, Elaeagnus angustifolia, Catalpa bignonioides, respectively, and the highest Ni and Pb levels were found in Acer campestre. These species are frequently used in urban green areas due to their aesthetic characteristics and their ability to accumulate heavy metals and improving the air quality. We suggest that these plants may be useful for monitoring air pollution.