%0 Article
%T Spatial and age-related variation in nutrient concentrations of Pinus sylvestris needles.
%A Helmisaari, Heljä-Sisko
%D 1992
%J Silva Fennica
%V 26
%N 3
%R doi:10.14214/sf.a15643
%U https://silvafennica.fi/article/5482
%X <p>Spatial and age-related variation in nutrient concentrations of Scots pine (<em>Pinus sylvestris</em> L.) needles was studied during 1984–86 in three stands of different stages of development. The dry weight of current needles was significantly (p &lt; 0.05) higher in the tree top than in a composite sample representing the whole crown. However, there were no significant differences in the concentrations of nutrients in needles between upper and lower crown levels. The concentrations of mobile nutrients N, P, K and Mg decreased with increasing needle age whereas the concentrations of poorly mobile nutrients Ca, Mn and Fe increased during needle ageing. The coefficient of variation for nutrient concentrations varied irregularly when only a few trees were sampled but stabilized when tree number was ten or more. <br>The PDF includes an abstract in Finnish.</p>