The influence of chemical characteristics of precipitation on tree health in Banjica Forest (Belgrade, Serbia)

Abstract

The most represented tree species in the Banjica Forest are Acer negundo, Quercus robur, Acer pseudoplatanus, Populus nigra, Fraxinus pennsylvanica, Fraxinus ornus and Robinia pseudoacacia. According to the ICP Forests combined assessment (degree of defoliation and decolorization), endangered species are Populus nigra (64.3% of heavily damaged trees), Quercus robur (45.5%), Fraxinus pennsylvanica (37.0%) and Acer negundo (26.6%), while the situation is much better for Acer pseudoplatanus and Fraxinus ornus. For Robinia pseudoacacia, 83% of trees are without decolorization, however, defoliation is established. In the period from April to October 2009, the average pH of rainwater was 5.46, and 5.18 in the period from November 2009 to March 2010. The concentration of SO42- in the period from April to October 2009 amounted to an average of 24.21 mg/l, and 28.87 mg/l in the period from November 2009 to March 2010. The concentration of SO42- and pH values is a possible explanation for the condition of the trees.