ZLV Online

Abstrakt

The calorific value (J g-1) of the dry matter of the Norway spruce Picea abies (L.) H. Karst. trees was evaluated. Experimental material was taken from five trees situated in Slovakia. Wood and bark samples were obtained from the discs, which were cut off from three locations, namely from the trunk, branches of tree crowns and needles. Calorific value (J g-1) of the dry matter of each sample was then determined. The impact of statistically significant factors on the calorific value capacity was determined by means of analysis of variance. The average values of the individual fractions are approximately in the range of 20,200–21,500 J g-1. Dry matter of wood and bark has the lowest calorific value, and then follows the dry matter of branches and twigs with needles. Calorific value variability is relatively low with its coefficient of variations of 0.7–2.9%. Calorific value of spruce is only 2–5% lower than calorific value of pine. Compared to deciduous trees, it is higher due to the presence of resin.