Optimum nutrition and nitrogen saturation in Scots pine stands
Tamm, Carl Olof; Aronsson, Aron; Popovic, Budomir; Flower-Ellis, Jeremy
Long-term field experiments are described, in which nitrogen and other plant nutrients were added regularly to young Scots pine stands at two sites in Sweden, Lisselbo (1969-1988) and Norrliden (1971-1989; some treatments still in progress). A main aim was to establish a range of needle nitrogen concentration levels, as stable as possible, and to study the effects of these and of other factors (other added nutrients, soil acidity changes, irrigation) on tree growth and tree nutrient status. The results confirmed previous experience that nitrogen supply normally is a growth-limiting factor in boreal forest, but showed that regular nitrogen additions can induce boron and magnesium deficiency, and low internal concentrations in the trees, e.g. of potassium and phosphorus. Other aspects of ecosystem functioning at varied nitrogen supply-biomass production, nutrient balances for several elements; vegetation changes, soil acidity changes, nitrification, studied by ourselves or by cooperating research groups-are reviewed. The importance of long-term field experiments in the study of urgent environmental problems, such as nitrogen saturation and soil acidification, is discussed.
Pinus sylvestris; Picea abies; mineral nutrition; nutrient store; nutrient recovery; nutrient depletion; base saturation; exchange capacity; foliar sampling; litterfall
Studia Forestalia Suecica
Publisher: Swedish Univ. of Agricultural Sciences
Permanent link to this page (URI)