Tropospheric Ozone - a Stress Factor for Norway Spruce in Sweden


Nutrient and chlorophyll content, ultrastructural changes, photosynthesis, stem growth and biomass were studied in Norway Spruce, Pica abies, exposed to three different concentrations of ozone for five seasons (1985-89) in open-top chambers. The treatments were charcoal-filtered ambient air (CF), non-filtered ambient air (NF) and non-filtered air enriched with ozone (NF+). The results shows that ozone can change the ultrastructure of needles, decrease the content of chlorophyll and decrease the rate of photosynthesis, and that the extent of these changes depends on the length of exposure and the age of the needles and shoots. No significant effects of ozone on above-ground biomass were observed. Based on the results on photosynthesis, an attempt was made to model the canopy photosynthesis of 8 and 89 yr old trees. The results indicate that the ambient ozone concentrations in Sweden can reduce the canopy photosynthesis, and that the effect is small in young trees and becomes greater in old trees, mainly because of the different proportions of needle age classes. This paper is a summary document of the results some of which have already been published elsewhere

Medarbetare: Per_Erik Karlsson, Peringe Grennfelt

Nyckelord: ozon,Tropospheric Ozone, Norway Spruce

Typ: Artikel

År: 1995

Rapportnummer: A1027

Författare: Lena Skärby, Göran Wallin, Gun Selldén, Per_Erik Karlsson, Susanne Ottosson, Sirkka Sutinen, Peringe Grennfelt

Publicerad i: Ecological Bulletins 44: 133-146, 1995