%0 Research article
%T Reliability of foliar analyses of Norway spruce stands in a Nordic gradient
%A Brække, Finn H.
%A Salih, Nagwa
%D 2002
%J Silva Fennica
%V 36
%N 2
%R doi:10.14214/sf.540
%U https://silvafennica.fi/article/540
%X Norway spruce stands at eleven sites in Finland, Norway and Sweden have  been studied under various climates, atmospheric deposition of N and S  and fertilisation regimes. Nitrogen was growth restricting at eight  inland sites, while P was growth restricting at three coastal sites.  Liming and N fertilisation caused serious B deficiency on some of the  inland sites. It is likely that liming affects uptake of B, whereas N  fertilisation causes a dilution due to increased growth. Application of S  combined with N probably caused K deficiency at one of the sites. The  reliability of foliar analyses as a method to diagnose nutrient status  and the likely changes after nutrient input to spruce forests in the  Nordic countries, are discussed. The CR- and the DOP-method are  evaluated for diagnostic purposes. Both methods seem to give reliable  conclusions even if the CR-method often produces more specific results.  Interpretation based on both current and one year old foliage improved  the diagnostic prognoses. The accuracy of diagnosis also relies on  knowledge and ability of the interpreter. Based on the results it is  reason to be cautious about recommendations of single element  fertilisations, e.g. with N alone, because the demand of other elements  beyond available pools frequently occurs. Forest trees in the boreal  region are probably well adapted to N deficiency, which means that they  can handle the physiological consequences rather well, while  deficiencies of other elements usually are more detrimental to growth  vigour and stress related diseases.