Browsing by Subject "carbon cycle"

Climate change has been found to be one of the most serious challenges humankind has to face in the future. The link between climate change and forests is based on trees’ ability to use carbon dioxide as a raw material for growth. The growing stock sequesters carbon dioxide from the air to itself and ultimately as the forest is harvested the carbon stored is released and it moves from carbon pool of forests to another carbon pool. As the concept of emissions’ trading is applied to the investigation, a price for sequestered and released carbon can be determined. With the market price for carbon dioxide known, a net present value for the revenues and costs during the forest’s rotation period can be calculated. Using wood for different purposes, however, can result in various climatic benefits. These climatic benefits are described in this study by carbon displacement factors which can be used in determining how much the costs of releasing carbon from forests can be deducted. This study investigates the significance of forest management in a stand level from the climate change mitigation point of view in three Norway spruce (Picea abies, L.) and three Scots pine (Pinus Sylvestris, L.) stands as the previous carbon accounting aspects are taken into consideration. Stand Management Assistant (SMA) software is used in the optimization and simulation calculations. The SMA software is used for calculating the carbon accounting net present values and average carbon storages during the rotation periods of the stands included in the study with different intensities of bioenergy biomass harvesting. This way the level of biomass harvesting for bioenergy that returns with the highest net present value for carbon accounting and/or the highest average carbon storage can be calculated. The calculations are made with two interest rates, two carbon dioxide prices and with climatic benefits from bioenergy or with climatic benefits from bioenergy and forest products included. According to the results it can be stated that the intensification of forest biomass recovery for bioenergy production does not always result in the optimal climate change mitigation. The use of Norway spruce is considered of being the most potential forest-based bioenergy source in Finland. As the climatic benefits from bioenergy use were only taken into consideration, the intensification of recovery of Norway spruce biomass for bioenergy seemed to be most profitable. If, however, the climatic benefits from forest products are included in the investigation as well, the bioenergy use of Norway spruce is no longer optimal for the climate change mitigation. The climatic benefits from Norway spruce material use exceed the benefits from bioenergy use. This means that biomass recovery for bioenergy production does not necessarily result in optimal climate change mitigation.