Influence of aluminium of phosphate and calcium uptake in beech (Fagus sylvatica) grown in nutrient solution and soil solution.

The effects of AlCl3 on uptake of Ca2+ and phosphate in roots of intact beech (Fagus sylvatica L. provenance Maramures) plants were studied in nutrient solution and soil solution. Aluminium reduced the concentrations of Ca, Mg and P in plants and increased that of K. In short term experiments, uptake of Ca2+ (45Ca) was reduced by exposure of the roots to Al. The effect of aluminium on Ca2+(45Ca) uptake was immediate and primarily of a competitive nature, preventing Ca2+ from being adsorbed. Uptake of 32P-phosphate increased with increasing Al concentration up to 0.1 mM and then decreased at higher Al concentrations. The effect of Al on phosphate uptake was most pronounced during the first hours of exposure. Growth of plants for 15 days in soil solution, collected from the upper A horizon of a beech forest soil, had no effect on uptake of Ca2+(45Ca) and 32P-phosphate, probably because of a low concentration of labile bound monomeric Al and binding of Al to organic compounds. Soil solution from the deeper B horizon reduced Ca2+(45Ca) uptake and increased 32P-phosphate uptake in a manner similar to that with Al- treatment in nutrient solution. It is concluded that in soil solution from the deeper regions of the soil, mineral uptake by roots was affected by Al.