Csontos, P., Halbritter, A., Tamás, J., Szili-Kovács. T., Kalapos, T., Uzinger, N., Anton, A. (2012): Afforestation of dolomite rock grasslands with non-native Pinus nigra, and its effect on soil trace elements. Applied Ecology and Environmental Research 10: 405-415.
The non-native Pinus nigra has been widely planted on natural dolomite grasslands in Hungary, yet little is known on its influence on soil properties. We compared soil micro-element concentrations in rock grassland (RG) and under P. nigra plantation (PP), both grown on north facing slopes of dolomite bedrock. At PP sites, the original vegetation was RG prior to afforestation. For both vegetation types, five sampling sites were selected, and at each site soil samples were taken from three depths (0-5, 5-10 and 10-15 cm). Micro-element concentrations of corresponding soil layers in the two vegetation types were compared. Under the pine plantation, the concentration of a number of soil trace elements was altered compared to the original rock grassland soil, and this effect increased with soil depth. At the deepest layer, significant differences were found for 10 microelements (Al, Fe, Mn, Ba, Cd, Co, Ni, Pb, Sr, Zn), and in each case the concentration was higher in PP than in RG soil. In contrast, the concentration of Cr, Cu, Hg, Mo and Se was not different between the two habitats throughout the soil layers sampled. Values exceeding the Hungarian environmental limits of background concentrations were detected for lead and cadmium. In the RG soil, concentrations of Pb and Cd were highest in the topmost layer, while for the PP sites these elements showed concentrations higher in the 10-15 cm layer than in the 5-10 cm depth. Concentrations of some other micro-elements showed similar inversion at PP sites. The depth inversion of these, often airborne pollutant trace elements was explained as a consequence of afforestation with P. nigra and such phytostabilization effect of the pine stands is assumed to increase with stand age.
dolomite, heavy metals, Pinus nigra, rock grassland, soil pollution