Podatność sadzonek sosny zwyczajnej i świerka pospolitego na infekcję opieńką ciemną w warunkach podwyższonej koncentracji CO2 w powietrzu

Comparative cultivation experiment was carried out in the greenhouse to verify the assumption that increased air CO2 concentration (up to 1000 ppm) stimulates the infection intensity and mortality rate of Scots pine and Norway spruce seedlings subjected to the artificial inoculation with Armillaria ostoyae (Romagn.) Herink. It was found that increased air CO2 concentration reduces the intensity of pine and spruce seedlings infection by A. ostoyae, what was expressed both by the greater number of healthy and lower number of died seedlings at the end of 16−months−long experiment. However, the statistical significance of the observed differences was confirmed in case of only one out of three A. ostoyae isolates used in the experiment. It was also found that during the first 12 months of the experiment growth of pine and spruce seedlings was significantly stimulated by 1000 ppm air CO2 concentration compared to the ambient air conditions (approximately 380 ppm CO2) with not statistically significant effect of A. ostoyae presence. It was manifested for both tree species with significantly higher values of diameter at the stem base in all variants subjected to increased air CO2 concentration. No such difference was observed for the height of seedlings. All the findings suggest that elevated air CO2 concentration may compensate negative impact of disease on growth at the early stages of pathogen attack.