Trees in big cities are adopted for the surrounded conditions more than the same species of wood put down their roots in the natural conditions. In other words, we are speaking again about influence of salt-affected soil, metal heavy, gases, etc.
Level of development for a tree was defined by the degree of its organs’ development, particularly leaves. We researched differences between the natural territory, for example, parks, green areas – the leaves were larger and contain less heavy metals there. Instead, leaves grown in the streets were not so.
We measured individual surface area. For this task we scanned leaves, put images into a PC software, it calculates shaded pixels, then these pixels were transferred to the area and this process took a lot of time.
By the way, we used unlicensed program. It seemed that it worked, brought some results but we cannot prove them and think that these results were accurate.