Reaction of the assimilatory tissues of Norway spruce (Picea abies [L.] Karst.) and silver fir (Abies alba Mill.) to immission stress in regions under a long-term air pollution load

Bednarova. E.: Reaction of the assimilatory tissues of Norway spruce (Picea abies IL.] K a r s t.) and silver fir (Abies alba M i l l.) to immission s tress in regions under a long-term air pollution lend. Ekologia (Bratislava ). Vol. 20, Supplement 1/2001, p.36-45. in the presented study the reaction of the assimilatory tissues of Norway spruce (Picea abies [L.] K a r s t.) and silver fir (Abies alba M i l l.) to immission stress has been evaluated . A study method was used evaluating changes of epicuticular waxes which ha ve above all a protective function and are damaged by immissions as the fir st, even before the damage to assimilatory tissues is visible. The reaction of these two tree species was monitored on two localities under a long-ter m air pollution load and on three control plots in regions free of air poll ution. Epicuticular waxes of Norway spruce in the immission regions were da maged already with the first needle year-class, while those on the plots wi thout immissions only after three years. In silver fir no damage to epicuti cular waxes was found even in the regions under a Long-term air pollution l end. The structure and amount of epicuticular waxes of silver fir, compared to samples from the regions free of air pollution, did not differ. First n egative changes occurred only after three years. The epicuticular waxes of silver fir (Abies alba M i i I.) are more resistant to the immission stress , compared to those of Norway spruce (Picea abies [L] K a r s t.) and no de struction of them in the immission regions occurs as early as with the Norw ay spruce.