Browsing by Subject "kantojenkorjuu"

Because of European unions goals, direction of Finnish energy politics has been the increase of renewable energy. Stump harvesting has been in focus, because it is thought to be carbon neutral. Using stumps for energy has increased through the 2000s. It is better to harvest stumps than tree crowns, for they contain a lot of nutrients in the needles. On the other hand leaving stumps on the site will let them slowly decompose, and as they also collect nutrients they can decrease leaching. This study aimed to determine the long term effects of stump harvesting on soil disturbance and carbon and nitrogen storage. Study areas are in central Finland, where in 2013 there had been 9-13 years since stump harvesting. Soil surface disturbance was estimated both visually and with the point frequency method based on soil samples. For determination of soil carbon and nitrogen content there was a systematic line-assessment, where the soil samples were taken and divided to full 5cm layers that were dried and sieved. Carbon and nitrogen content and soil pH was analysed. Statistical analysis was made with variance analysis. Soil pH was between 4,2 and 5. At Honkola and Haukilahti in the stump harvesting areas the share of undisturbed soil surface was between 59-65% and where there was no stump harvesting this share was significantly larger, between 70-77%. The share of mounds was 18-23% in stump harvesting areas and where there was no stump harvesting 13-17%. Pits accounted for 15-17% in stump harvesting areas and where there was no stump harvesting 6-14%. The point frequency determination at one meter intervals was the best practical method for estimating soil surface disturbance.