Effect of Species Composition on Polycyclic Aromatic Hydrocarbon (PAH) Accumulation in Urban Forest Soils of Krakow.

Polycyclic aromatic hydrocarbons (PAHs) are among the most hazardous organic pollutants due to their toxic, carcinogenic, mutagenic properties, wide distribution, recalcitrance and stability in the environment. The study objective is to determine the impact of the species composition of tree stands on PAH accumulation in urban forest soils of Krakow. The study compared the impact of deciduous and coniferous species on similar soils on PAH biodegradation. Basic physicochemical properties, activity of enzymes involved in the nutrient cycle and PAH content were measured in soil samples. Our study shows lower accumulation of PAHs in soils with deciduous tree stands, which are characterized by higher pH and higher biochemical activity expressed by enzymatic activity. There is statistically significant difference in the enzymatic activity in the soils of deciduous tree stands, which results in differences in PAH accumulation. Among the studied deciduous species, soils with Norway maple and locust were characterized by highest enzymatic activity. At the same time, soils under these species were characterized by the lowest PAH accumulation. Among the coniferous species, highest PAH accumulation was observed under pine and spruce, where low enzymatic activity was observed at the same time. [ABSTRACT FROM AUTHOR]