EFFECTS OF ALUMINUM ON CALCIUM AND MAGNESIUM UPTAKE AND TRANSLOCATIONBY ROOT SEGMENTS OF WHOLE SEEDLINGS OF NORWAY SPRUCE (PICEA-ABIES KARST)

In the Ardennes, spruce decline is correlated with Mg deficiency cause d by acid rain leaching of soil nutrients, associated with solubilizat ion of Al-containing soil minerals. Laboratory experiments were carrie d out to measure the uptake and translocation of Ca-45 and Mg-28 by in tact roots of spruce seedlings in solutions containing various amounts of added AlCl3. Translocation rates in the various organs of the seed lings were higher for magnesium than for calcium. A 1 mM Al nutrient s olution had a much stronger inhibitory effect on uptake and translocat ion of Mg than it had on Ca. These rate differences result largely fro m differences in the chemical characteristics of these two elements.