lésion

CONT: Elevated 03 was suspected to be the causal agent of needle injury and occasionally tree death in areas of relatively low (by European standards) S and N deposition, known as the ""clean air"" regions of southern Bavaria. Injured spruce needles had 50% to 80% less chlorophyll, which resulted in pigment bleaching (Elstner et al 1985).
OBS: On tree needles.