Effects of acidic fog and ozone on the growth and physiological functions of Fagus crenata saplings

Abstract

The effects of simulated acid fog (SAF) and ozone (O3) stress on the growth and physiology of beech (Fagus crenata) saplings were investigated. Three-year-old beech saplings were exposed to SAFs of pH 3 and pH 5 (control) during May 2007 to July 2008. In each SAF treatment group, half of the saplings were exposed to 60 ppb of O3 during September 2007 to July 2008. In comparison to the control saplings, those from the pH 3 treatment had lower total plant biomasses, epicuticular wax amounts, Ca2+ concentrations in their leaves, and lower starch concentrations in their leaves and roots. The effect of O3 was significant only for the starch concentration in the roots, but the O3 exposure also negatively affected the growth and physiology of beech saplings. Results show that acid fog exerts various severe effects, and that both chronic acid fog and O3 exposure suppressed the physiological functions of beech saplings.