Phytomass and nutrient partitioning of two Scots pine stands of the German northeastern lowland at Hubertusstock/Schorfheide (low atmogenic N-deposition) and Bayerswald/Schwedt (high atmogenic N-deposition) have been studied. The total tree phytomass was lower at Bayerswald than at Hubertusstock due to an ongoing dieback of trees at Bayerswald. However, this loss was found to be partly compensated for by a higher phytomass from forest floor vegetation which developed in the course of canopy thinning and increased nitrogen availability. Because of the loss of tree phytomass the nutrient content in the phytomass was lower in Bayerswald than in Hubertusstock for phosphorus, potassium, calcium and magnesium. In contrast, the total nitrogen content in plants was the same in Bayerswald as in Hubertusstock due to higher nitrogen concentrations in all tree phytomass compartments at Bayerswald, except for stem wood, and an increased forest floor vegetation phytomass. Hence, under conditions of increased atmogenic N-deposition the nitrogen pool appeared to shift towards phytomass compartments which are supposed to decompose more easily, i. e. the forest floor vegetation with a high annual phytomass production and mineral turnover rate.
