Variability of nutritive macroelements in pedunculate oak (Quercus robur L.) leaves in Serbia

Abstract

Nowadays, the territory of pedunculate oak (Quercus robur L.) in Serbia is less widespread than in the past, primarily as the consequence of excessive exploitation and aggravated regeneration caused by the changed groundwater regime. The researches in this paper were aimed at the analysis of the variability of the content of macroelements in leaves, as well as of the soil characteristics in the pedunculate oak populations on the different sites, according to which the sites with the best conditions for the nutrition of pedunculate oak would be singled out. The analysed populations are of natural or artificial origin, and they occurred during the process of restitution. They are situated in the zone ranging from continental to moderate continental climate, at five different localities and five different types of soil. Foliar analyses of 150 individual-trees of pedunculate oak at five sites in Serbia and the respective soil analysis show that individual variability in macroelements among trees was not statistically significant, while the site effect was highly significant. Concentrations of elements, at all sites, in the decrease sequence were: N>Ca>K>Mg>P>Na. The highest individual variability was exhibited by Na, followed by Mg, Ca and K, and P as well as N had the lowest variability. The obtained results point to the conclusion that the variability of the content of macroelements in leaves is mainly the result of the environmental influence. Statistically significant intra-individual variability, as an indicator of the existence of genetic differences between trees within populations, was detected only for Ca concentration in leaves.