Above ground biomass and nutrient distribution in a limed and fertilized Norway spruce ( Picea abies) plantation : Part II. Accumulation of biomass and nutrients

Above ground biomass and nutrient distribution were determined in a combined liming and fertilization in a 59-year-old Norway spruce stand on a nutrient poor soil at Klosterhede, Denmark. Two types of lime (calcite and dolomite combined with additional kieserite and phosphate) were applied alone or in combination with conventional NPK fertilizer. Five sample trees of different size classes were felled in each treatment plot. The biomass was divided in seven compartments: stem wood, stem bark, living branches, dead branches, current year needles, older needles, and cones. The total above ground biomass and nutrient content in each tree were calculated and referenced to the ground surface area by solving regression equations relating the biomass or amount of nutrients to the tree height and breast height diameter (DBH) for all the trees in a given treatment. The biomass was closely correlated to the tree size (height × DBH 2) for stem wood, stem bark, living branches, and older needles( R 2 ≥ 0.70). The results show that biomass and stem volume growth were not affected ( P ≤ 0.05) by the different treatments. However, an increase of the above ground biomass caused by NPK fertilization was indicated. The stem wood and living branches contained the main part of the above ground biomass (approx. 80%, corresponding to 70 t ha −1 dry mass). The main part of the N, P, K, Mg, and S was in the living branches and needles (>60%), while stem bark, living branches, and needles contained a significant part of the Ca (>70%). The accumulation of nutrients in stem bark and needles increased significantly following fertilization and liming, especially in the current year needles. The calculated annual mean accumulation of P in the above ground biomass increased from 2.3 kg ha −1 for the control plot to more than 5 kg ha −1 for some of the treatments.