CONCENTRATIONS OF NUTRITIONAL AND TRACE-ELEMENTS IN NEEDLES OF NORWAYSPRUCE (PICEA-ABIES [L] KARST) AS FUNCTIONS OF THE NEEDLE AGE CLASS

The endogenous concentrations of the essential elements Ca, Cl, Cu, Fe , K, Mg, Mn, N, P and Zn, and of the nonessential elements Al, As, Ba, Br, Co, Cr, Cs, Hg, I, La, Na, Rb, Sb, Sc, Si and Sr were determined in 5 successive needle age classes. 40 mature spruce trees from 6 diff erent sites were investigated individually. A given element usually sh ows smooth changes with the needle age class t. Trees on a given site usually have a similar dynamic behaviour. The same holds for the diffe rent site means. The concentrations can be approximated by functions c = f(t). Three different types of functions are required to describe t he dynamic behaviour of 3 groups of elements that increase with t, and one for the elements that decrease with t. A given element usually ca n be described by the same type of function at all sites, even if its concentration differs widely. Exceptions are Mn, Co and Zn, which chan ge from a decreasing function at low concentrations to an increasing f unction at high concentrations. Further irregulatities are found at so me sites with Ca, Sr and Ba. These findings are corroborated by a mult ivariate statistical analysis.