Needle carbohydrate concentrations in Norway spruce as affected by wood ash application to soil

Sandy soil in a tree nursery was treated with wood ash (0.25, 0.5, or 1.0 kg m -2 , untreated for control). The influence of different treatments on the carbohydrate concentration and dynamics in needles was estimated. The increase in the pH of soil due to wood ash application correlated with the reduction in the needle hexoses (glucose and fructose). The ratio of fructose to glucose in treated trees often exceeded 2-3 times the respective hexose ratio in untreated trees. The sucrose concentration was not significantly influenced by the soil pH and wood ash. The starch concentration tended to be smaller in treated trees. The results suggest that carbohydrate reserves in needles could be reduced by wood ash during the growing period. The accumulation of soluble carbohydrates by winter did not depend on the treatment.