Utbyte av massaved och biobränsle i några typbestånd av Contorta
The aim of this study is to describe a number of type stands of lodge pole pine in Norrbotten with respect on stem volume and total biomass. Further questions to answer is if there is stand characteristics that make the stands more suitable for pulpwood in early thinning, or if it is better to apply whole tree harvest. The study shall also give an indication if bio energy can be an economical interesting alternative for Sveaskog.
Sampled trees represented the variation in the different stands. Five trees were selected from each stand to represent that stand. Stem volume and biomass (kg dry weight (DW) per hectare) for each fraction was calculated. In total 20 trees were sampled for destructive above ground biomass estimation. The study was done i Morjärv, in the province of Norrbotten, Northern Sweden.
It was concluded, that there is a strong connection between stem volume and dry weight (DW), which interpret that stem density does not vary between the different stands. There was a small variation between stem volume and diameter in breast height (DBH) between the different stands. The results interpret that the weight of the crown is the same for trees with the same diameter, while the stem weight in relation to diameter vary between stands. The explanation seems to be that the stem forms vary between stands. For that reason, the additional harvest that could be achieved by whole tree harvest compared to traditional harvest varied between 61-85%.
It is clear, that the pattern of allocation vary in different types of lodge pole pine stands. This study indicated that whole tree harvest for bio fuel energy could be more profitable in early thinning. Further, existing volume functions for lodge pole pine seems to work well to estimate stem volume. For estimating different fractions from lodge pole pine, more work need to be done to develop biomass functions for this tree species.