Abstract
The dominant litter samples Pinus sylvestris L. needle litter and Acer platanoides L. leaf litter were collected in the coniferous
mixed forest located at 54ş43‘ N 25ş19‘ E (Vilnius, Lithuania) in April 2010. Different heating temperatures (150, 250, 350, 450
and 550şC) and 2 hour heating duration were used to produce ashes. The selected heating temperatures affected mass loss, colour, pH, electrical conductivity (EC), C/N ratio, nutrient concentrations of the ash. The darkness of Munsell chroma values was
visible at 250°C and 350°C in both types of litter and additionally at 450°C in the needle litter ash. In contrast, the chroma values
increased in brightness mainly between 450 and 550°C. The general tendency of pH (p=0.01) increase was ranging at the 150–
550°C interval and the results did not include acid and extremely alkaline features but over the temperature of 350şC were
alkaline. Values of EC (p=0.01) showed similar differences in the same litters. EC reached the maximum value at 450°C in Acer
platanoides L. leaf litter. Likewise, heating temperatures affected litter ash nutrient composition. K, S, and P concentrations
particularly depended on heating temperature and litter type. Nutrient concentrations were in the order
Ca>K>Na>S>Mg>P>Zn>Fe for needle litter and Ca>K>S>Mg>P>Na>Fe>Zn for leaf litter samples. Significant differences in
C/N ratio between the litters were observed as temperatures increased.
In conclusion, this study provides significant information on how different heating temperatures affect ash properties of Pinus
sylvestris L. needle litter and Acer platanoides L. leaf litter of the coniferous mixed forest in Lithuania.