Nutrient uptake of a mixed oak/beech forest in Flanders (Belgium)

Abstract

A  72-year-old mixed oak/beech stand has been studied on the element (N, P, K,  Ca and Mg)    content in its woody biomass, in the wood increment and in the litter fall.  Crown leaching and nutrient uptake have been calculated respectively according to Ulrich (1983) and to Cole & Rapp    (1981). Eight oaks and six beeches have been sampled, regression equations  between the tree    element content and the stem volume have been calculated in order to scale  up from the tree to    the stand level.    The annual amount of elements taken up is 70 kg N, 4,9 kg P, 69,3 kg K, 43  kg Ca and 6,1 kg    Mg per ha. For K, Ca and Mg a large part of the nutrient uptake is due to  crown leaching. The    amount of N and P in the litter fall constituted the largest part of the  uptake of N and P. For the    elements K, Ca and Mg, crown leaching is very important in the nutrient  cycling: crown leaching    amounts respectively 63%, 21% and 43% of the annual return of these  elements from the    canopy to the forest floor.