ALUMINUM CONCENTRATION OF SPRUCE NEEDLES

Aluminium was determined in spruce needles (endogenic concentrations) and in the aerosol retained on the needle surface (exogenic concentrat ions). Individual trees of Norway spruce (Picea abies) on 9 different sites were investigated. Determinations were done by instrumental acti vation analysis with reactor neutrons. Removing the exogenous contribu tion prior to analysis proved to be essential for obtaining results wi th an unequivocal plant physiological meaning. Endogenous concentratio ns showed large differences between sites, what was partially due to s oil pH. Needle concentrations increased linearly with the needle age c lass at all sites.