Street trees are important component of urban forest presenting a first barrier between air pollution
originated from vehicle traffic and pedestrians. It implies that an improvement of air quality in urban
areas greatly depends on green biomass, in short, the bigger and greener tree crown, better for human
health and wellbeing. Determination of Leaf Nitrogen Balance Index (LNBI) and chlorophyll
concentration (ChlC) by a non-invasive methodology and a user friendly instrument (Dualex 4,
Force), widely used in agronomy and horticulture, was tested here for the assessment of tree fitness in
urban zones. Investment of energy and resources either in growth or defence according to the tradeoff
strategy of plants may be indicated by LNBI, which approximately presents a Nitrogen/Carbon
ratio. We selected few tree species from Belgrade’s streets to determine those two parameters during
summer. We also presented the changes in those parameters of the introduced bamboo species within
ten years at several urban locations in Belgrade differing in air pollution aiming to evaluate
usefulness the LNBI parameter in access of multiyear exposure to the effect of intense vehicle traffic.
Numerous limiting factors for development of healthy tree crowns in urban ecosystem, such as low
capacity to cope with toxic pollutant, sensitivity to diseases, early senescence and etc., greatly depends
on tree species. We propose this methodology may also contribute in the process of choice of the
adequate tree species to be planted along streets
