Interactions between calcium and copper or cadmium in Norway spruce

The accumulation of calcium (Ca), copper (Cu) and cadmium (Cd) in roots and stem of Norway spruce (Picea abies [L.] Karst) was examined. Two-year-old Norway spruce seedlings were treated with elevated concentrations of Ca, Cd or Cu, or as combinations of Ca with Cu or Cd in nutrient solutions for three months. The stem was divided into bark, wood formed during the treatment period (new wood), and wood formed before the treatment period (old wood). The accumulation of the metals in stem and roots increased with addition of the respective metal into nutrient solution. Addition of Cu decreased the accumulation of Ca in roots and wood, and Ca addition decreased the accumulation of Cu in the new wood. By adding Ca in combination with Cu the accumulation of Cu in the stem was decreased even more by Ca and the negative effect of Cu on the Ca content in the stem was diminished. Addition of Cd decreased the accumulation of Ca in wood, especially the old wood, and Ca addition decreased the accumulation of Cd in roots, bark and new wood. By adding Ca in combination with Cd the Ca content was reduced in the bark, instead of in the old wood.