Significance of ozone exposure for inter-annual differences in primary metabolites of old-growth beech (Fagus sylvatica L.) and Norway spruce (Picea abies L.) trees in a mixed forest stand.

Significance of ozone exposure for inter-annual differences in primary metabolites of old-growth beech (Fagus sylvatica L.) and Norway spruce (Picea abies L.) trees in a mixed forest stand.