Response to fertilization of different tree species in the urban environment

The influence of fertilization on shoot growth, leaf gas exchange, leaf chlorophyll content, and mineral content was monitored on sweetgum (Liquidambar stryraciflua L.), Japanese pagoda tree (Styphnolobium japonicum Schott), and European ash (Fraxinus excelsior L.) over a 3-year period after planting in the urban environment. The research was carried out on newly planted trees that were placed in different urban sites and fertilized after planting. Fertilization was repeated for 2 years after planting at the beginning of the spring. There were contrasting results according to the species and the year of measurements. Fertilization was to a limited extent effective in the first year after planting but failed to provide better results in the following years. Thus, the results of this research do not support the utility of fertilizer application as a method to improve plant establishment, growth, or physiology after transplanting in the urban environment.