CHANGES IN PIGMENT CONCENTRATION AND COMPOSITION IN NORWAY SPRUCE INDUCED BY LONG-TERM EXPOSURE TO LOW-LEVELS OF OZONE

Rametes of Norway spruce were fumigated with 30 ppb (nl litre(-1)) ozo ne above ambient level for 4 years in open-top chambers. They were gro wn under different light conditions, because some of the chambers rece ived approximately 10% less light than the others. Samples from three age classes were analyzed for nitrogen and pigments using HPLC. it cou ld be demonstrated that the ozone treatment reduced the concentration of chlorophyll (a) and (b), alpha- and beta-carotene, but increased th e concentration of antheraxanthin. A significant decrease was found fo r the violaxanthin/antheraxanthin ratio following the ozone treatment. The concentration of all the pigments and of nitrogen were significan tly related to the age classes, and a similar relationship was found f or the light levels, except for antheraxanthin and total carotenoids. The ratio of chlorophyll a/b was only significantly related to the age classes.