DYNAMIC CHANGES IN THE CONTENT OF SELECTED CHEMICAL-ELEMENTS IN THE ABOVEGROUND BIOMASS OF DIFFERENT RED OAK (QUERCUS-RUBRA L.) AND BLACK-WALNUT (JUGLANS NIGRA L.) STAND TYPES

This contribution evaluates dynamic changes in the content of selected chemical elements (Ca, Mg, K, Na, Fe, Zn, Cu, Pb and Mn) in the above ground biomass components of 39-year-old red oak (Quercus rubra L.) an d black walnut (Juglans nigra L.) stand types from a series of PRAs at Ivanka near Nitra tended by mild crown thinnings. The results reveale d that under the effect of thinnings the Ca, K, Na and Zn contents dec reased and on the other hand the Pb contents increased.