Varijabilnost makroelemenata ishrane u listu lužnjaka (Quercus robur L.) na području Srbije

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 analyzed 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.

Lužnjak (Quercus robur L.) je na području Srbije danas mnogo manje rasprostranjen nego nekada što je posledica prvenstveno preterane eksploatacije i otežanog obnavljanja usled promene režima podzemnih voda. Istraživanja u ovom radu su imala za cilj analizu varijabilnosti sadržaja makroelemenata u lišću lužnjaka (Quercus robur L.) i osobina zemljišta u populacijama lužnjaka na različitim staništima, na osnovu čega bi se izdvojila staništa koja imaju najbolje uslove za ishranu lužnjaka. Analizirane populacije su prirodnog ili veštačkog porekla, nastale u procesu restitucije. Nalaze se u zoni kontinentalne do umereno kontinentalne klime, na pet različitih lokaliteta i pet različitih tipova zemljišta. Folijarnom analizom 150 individua-stabala lužnjaka na 5 lokaliteta na području Srbije i analizom zemljišta sa istih lokaliteta ustanovljena individualna varijabilnost makroelemenata između stabala nije bila statistički opravdana dok su razlike između lokaliteta bile visoko značajne. Koncentracija elemenata, na svim lokalitetima, bila je u opadajućem nizu: N>Ca>K>Mg>P>Na. Najveću individualnu varijabilnost imao je Na, zatim Mg, Ca i K a najmanje varijabilni bili su P i N. Dobijeni rezultati upućuju na zaključak da je varijabilnost sadržaja makroelemenata u listu prvenstveno posledica sredinskog uticaja.