Evaluating Spherical Trees in the Urban Environment in Budapest (Hungary)

The world's big cities, including Budapest, are becoming more crowded, with more and more people living in smaller and smaller spaces. There is an increasing demand for more green space and trees, with less vertical and less horizontal space. In addition, deteriorating environmental conditions are making it even more difficult for trees to grow and survive. Tree species in urban areas have multiple functions and high ecosystem services when in good health. Among taxa with diverse habits, sizes, crown shapes, growth vigor, longevity, urban tolerance, and canopy habit, our research aims to evaluate urban specimens of spherical species with smaller space requirements and sizes but have regular geometric crown shapes in public plantations in Budapest. In the restricted urban habitats, the city's cadastral records include 4676 specimens with spherical crowns. Among the species examined, eight species with globular crowns (Acer platanoides 'Globosum', Catalpa bignonioides 'Nana', Celtis occidentalis 'Globosa', Fraxinus excelsior 'Nana', Fraxinus ornus 'Mecsek', Platanus × hispanica 'Alphen's Globe', Prunus × eminens 'Umbraculifera' and Robinia pseudoacacia 'Umbraculifera') were evaluated in relation to age, health, wood type, crown size, and shade projection in order to show which species are or will be suitable in the future.