Current issue: 55(3)
Under compilation: 55(4)
Spatial and age-related variation in nutrient concentrations of Scots pine (Pinus sylvestris L.) needles was studied during 1984–86 in three stands of different stages of development. The dry weight of current needles was significantly (p < 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.
The PDF includes an abstract in Finnish.
The study was made in the Ivalojoki and Oulankajoki valleys, consisting of terraces of well sorted sandy material aged 9500–300 B.P. The vegetation is characterized by dry and moderately dry forest types with Scots pine (Pinus sylvestris L.) as the dominant tree species. The study included: forest types, particle size and sorting of mineral horizons, thickness of horizons, amount of organic material, pH, electrical conductivity, and NH4OAc (pH 4.56) extractable Fe, Al, P, K, Mg, Mn and Zn concentrations. The principal aim was to study the interrelationships between all these properties with special reference to the age of the soil.
The results allowed a distinction to be made between the following categories: (1) features typical of podsolization (e.g. increase in leaching of Fe and Al with age of soil from the A2), (2) certain factors showing higher values in the north (Ivalo) than in the south (Oulanka), principally Fe and Mg, (3) declining trends in P, Mg, Mn and Zn concentrations with age, which may partly be due to the geological history, and (4) declining trends in amount of organic material and electrical conductivity with age, these both being factors arising from the geological history rather than from podzolization.
The PDF includes a summary in Finnish.
Gravimetrically expressed nutrient concentrations of soil analysis were converted to volumetric values using dry bulk densities measured in the natural state and in the laboratory after air-drying and sieving the samples. The aim was to examine, using volumetric samples representing different soil classes, exactly how the converted nutrient values calculated by this laboratory method describe volumetric nutrient contents in undisturbed soil. In the fine soil classes undisturbed bulk density was higher than laboratory bulk density and converted nutrient concentrations were too small. In coarser soil classes the reverse was true, and the values were too high.
The PDF includes an abstract in English.