Effect of ozone and aluminum on pitch pine (Pinusrigida) seedlings: growth and nutrient relations

Abstract

Newly germimated pitch pine (Pinusrigida Mill.) seedlings inoculated with a mycorrhizal fungus (Pisolithustinctorius (Pers.) Coker & Couch) were grown for 13 weeks in sand irrigated with nutrient solution (pH 4.0) containing 0, 12.5, 25, 50, or 100 mg/L of aluminum (Al) in growth chambers fumigated with 0, 50, 100, or 200 ppb ozone. Increasing the concentration of ozone or Al caused increasing reductions in needle length, seedling height, and biomass of needles, stems, and roots. Significant ozone × Al interactions indicated that ozone and Al were interacting synergistically in reducing growth. Effect of treatments on the root/shoot ratio demonstrated that shoot growth was more sensitive to Al than root growth, whereas root growth was more sensitive to ozone. The concentration of most mineral elements (P, K, Ca, Mg, Mn, Cu, Zn) in needles was reduced by ozone or Al. Iron was the only element that increased with increasing concentrations of ozone or Al.