Akumulacja makro- i mikroskładników w igliwiu sosny zwyczajnej na siedliskach borowych

This study was carried out in the Słowiński National Park (SNP; northern Poland) in Scots pine forest stands. The aim of the research was to compare the accumulation of nitrogen, phosphorus, potassium, magnesium, calcium, zinc, nickel, iron and manganese in needles of pines growing on in dry (Bs), fresh (Bw) and moist (Bw) habitats. The age of needles, soil moisture and the content of examined components in the soil were taken into account. Needles and soil samples were collected in September from 15 sites (Bs – 5, Bśw – 3, Bw – 7). The nitrogen was determined with Kiejdahl method, and the phosphorus by the molybdate method after digestion in the mixture of 98% H2SO4 and 30% H2O2. The content of K, Mg, Ca, Zn, Ni, Fe and Mn was assessed by atomic absorption spectrometry after digestion in the mixture of 65% HNO3 and 30% H2O2. The soils of SNP, developed from deep dune sands, were very poor in nutrients. The highest amounts of macro− and micronutrients were found in organic and humic levels. In mineral levels, the content of the ingredients decreased rapidly and in many cases was beyond the limit of determination. Extreme nitrogen, phosphorus and potassium deficiency was found in analysed needles, together with adequate amounts of magnesium, zinc, nickel, iron and manganese as well as an excess of calcium. Differences in the nutritional state of Scots pine in investigated habitats were apparent primarily in the sum of the components accumulated in the needles. Needles accumulated in total from 736.5 to 850.7 mmolc/kg of nutrients, with macronutrients ranging from 98.6 to 99.1%. The accumulation of macro− and micronutrients in the examined needles decreased in the series Bśw>Bw>Bs. Mn and Fe showed the largest share in the micronutrient pool. Zn and Ni were significantly less common. The comparison of the accumulation of macro− and micronutrients in the needles indicated that stands on Bśw have slightly better conditions for development under unfavourable soil and climatic conditions prevailing in the Łeba Spit than those in Bs and Bw habitats.