Browsing by Subject "hiilensidonta"

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  • Hildén, Mikael; Soimakallio, Sampo; Seppälä, Jyri; Liski, Jari (Suomen ympäristökeskus, 2016)
    SYKE Policy Brief
  • Salo, Inkeri (Helsingin yliopisto, 2021)
    Recognizing and evaluating the benefits of trees is important for creating sustainable, safe and recreational urban spaces. i-Tree Eco software is developed by USDA for evaluation and valuation of ecosystem services of urban trees and forests. The objective of this research was to find out how does the quality of collected data affect i-Tree Eco modelling. Two different types of data and modelling results were compared in this research. All trees of the park Kupittaanpuisto in Turku were measured and evaluated according to the i-Tree guidance in late summer 2018 (later inventory). The contrasting data was selected from the tree register maintained by the city of Turku (later tree register). i-Tree Eco models several ecosystem services, of which carbon storage, carbon sequestration, avoided surface water runoff and pollution removal were analyzed in this research. The software estimates the structural value of the trees considering the land use and tree condition as well. The results show that the quality of data affects modelling results. Based on the total inventory data, the amounts of carbon sequestration, avoided surface water runoff and pollution removal were higher than the amounts modelled according to the tree register data. On the other hand, the structural value and carbon storage were bigger based on the register data than on the total inventory measurements. Lack of canopy dimensions and estimates of canopy condition had an impact on the modelling results. According to the total inventory, there were 1315 trees in the Kupittaanpuisto (ca. 34 ha), the structural value was approx. 2 430 000 €, carbon storage was 563 t, annual carbon sequestration 12 t, annual avoided surface water runoff 811 m3 and annual pollution removal 307 kg. On grounds of this research it can be stated that canopy measurements and canopy condition estimates are needed to make more accurate estimates of ecosystem services when using i-Tree Eco. This research showed that trees in the Kupittaanpuisto produce many ecosystem services and the trees are valuable. In the future, the results can be used as a reference for other research projects on ecosystem services of urban trees in the Nordic countries.
  • Hilden, Mikael; Soimakallio, Sampo; Seppälä, Jyri; Liski, Jari (Suomen ympäristökeskus, 2016)
    SYKE Policy Brief
  • Siivonen, Salla (Helsingin yliopisto, 2020)
    Finnish forests have a major impact on climate change at a national level, as approximately 86 % of Finland's surface area is forest and forests are a significant carbon sink. Continuous cover forestry is better from the point of view of carbon sequestration than even-age forestry. The Finnish Forest Act was reformed in 2014. Forest professionals and forest owners have had time to adapt to the new Act, to consider the use of alternative methods or, possibly, to take these methods into practice. Forest professionals have a clear position of power through information and communication to forest owners and the creation of a prevailing atmosphere of attitudes. Examination of the attitudes and the values of forest professionals are important as their attitudes and values have an impact on the recommendation of forest management methods. The purpose of this study was to examine how familiar continuous cover forestry was to forest professionals and forest owners as well as their perceptions of it. In addition, the values of forest professionals and how different factors influence their perceptions of continuous cover forestry were examined. The data used in this research was from a survey conducted in 2017. According to the results, forest professionals and forest owners are quite familiar with continuous cover forestry. The forest professionals’ perceptions of it were more negative compared to the forest owners’ perceptions. Gender and educational background were factors that were found to impact the attitudes of the forest professionals. Their perceptions of continuous cover forestry also affected the percentage of continuous cover forestry recommended by them. Forest professionals valued the sales proceeds of wood the most and the carbon sequestration of forests the least.
  • Salmela, Petri (Helsingin yliopisto, 2019)
    Hiilensidonnasta on tullut globaalin ilmastonmuutoksen johdosta hyvin ajankohtainen aihe. Boreaaliset metsät kattavat 22% maapallon maa-alasta. Tämän tutkimuksen tavoitteen on selvittää, vaikuttavatko metsähakkuut tasaikäisissä kuusimetsissä metsämaaperän hiilitaseeseen ja hiilivarastoihin verrattuna luonnontilaisiin metsiin pohjoismaissa (Suomi, Ruotsi ja Norja). Lisäksi tutkielmassa tarkastellaan tilannetta kahden eri ilmastoskenaarioiden valossa. Tutkimus on tehty käyttäen Yasso07 -mallia. Syötteet Yassoon on saatu FORMIT -mallista, joka hyödyntää kansallisista metsien inventoinneista saatua aineistoa. Tutkielman tulosten perusteella näyttäisi siltä, että metsähakkuut vaikuttavat merkittävästi maaperässä olevan hiilen kokonaismäärään sekä määrän muutokseen. Luonnontilaisissa metsissä hiilen määrän kasvu oli selvästi korkeampi, kuin tasaikäisissä talousmetsissä. Toinen merkittävä havainto saatujen tulosten perusteella on, että hiilen määrän kasvu hidastuu korkeammilla lämpötiloilla. Alhaisemman säteilypakotteen skenaario tuotti suuremman negatiivisen hiilivuon metsämaaperään, kuin korkeamman säteilypakotteen skenaario. Tulevaisuudessa hiilen määrän kertyminen maaperään tulee hidastumaan korkeamman lämpötilan vuoksi. Metsämaaperän hiilensidonta kasvaa merkittävästi, mikäli metsissä ei tehdä hakkuita.
  • Yrjölä, Hanna (Helsingin yliopisto, 2019)
    The study examines forest owners’ views on the profitability of forestry and their economic objectives. The aim is to find out how forest owners determine and evaluate profitability, and how the methods differ from those used by business enterprises. In addition to profitability perceptions, the study examines forest owners’ willingness to store carbon in their forests. The data for the study were collected by semi-structured interviews, which were undertaken with nine forest owners in spring 2019. The interviewees had participated in a training program called Metsänomistajan Talouskoulu that provides the forest owners with an opportunity to develop one’s understanding in forest management. Also, as the aim was to examine forest owners’ attitudes towards a hypothetical carbon offset program, the forest owners were asked to state their willingness to accept (WTA) presented in a questionnaire form. The results show that forest owners display diverse attitudes and the views on profitability differ from one owner to another. Even though the forest owners are familiar with different profitability assessment methods, utilizing them in one’s actions is relatively rare. While forest owners are generally interested in biodiversity protection, more information regarding carbon sequestration programs is still needed. According to the results, the actual participation rate would depend on factors such as the protocol requirements and the compensation amount. As a whole, majority of forest owners require financial incentives in order to participate in carbon sequestration programs.
  • Hänninen, Otso (Helsingin yliopisto, 2020)
    The use of biofuels has been considered as a carbon neutral activity. It is based to the assumption that after harvest grows new forest that sequester the carbon that was released earlier. In that case the new forest should grow very fast. The time frame between release and sequestration is however many decades. Also using forest biomass in energy production decreases forest carbon stock. There are numerous researches done of this subject that are natural science that haven’t taken in account the economic side. My aim is to examine and compare the studies with and without the economic point of view. The method is literature survey and comparison of practices in economics and natural science to study carbon neutrality in the use of forest resources. The literature of this subject are multidisclipinary and I have tried to separate economic studies from others according to most relevant analyses and theoretical framework. In the studies there were wide consenus that use of forest resources can’t be considered as a carbon neutral activity. Also there were solid consensus that carbon sequestration increases as forests grow, thus longer rotation period increases carbon sequestration. The studies of natural science was focused among other things for payback times and climate warming. In economics the studies focused for example political management instruments like tax and subsidies. It’s necessary to include economics to the studies because they give more realistic results and guidelines to politics. Without economic aspect it’s hard to make plausible statements to political decisions. The studies of natural science are yet beneficial although they wont alone help for making political decisions. Both economic and natural scientific studies can use information over the branch of science. That’s why it is important to adapt analysis and information to support studies in own branch of science.
  • Soimakallio, Sampo; Kalliokoski, Tuomo; Lehtonen, Aleksi; Salminen, Olli (Springer, 2021)
    Mitigation and Adaption Strategies for Global Change 26: 4
    Forest biomass can be used in two different ways to limit the growth of the atmospheric greenhouse gas (GHG) concentrations: (1) to provide negative emissions through sequestration of carbon into forests and harvested wood products or (2) to avoid GHG emissions through substitution of non-renewable raw materials with wood. We study the trade-offs and synergies between these strategies using three different Finnish national-level forest scenarios between 2015 and 2044 as examples. We demonstrate how GHG emissions change when wood harvest rates are increased. We take into account CO2 and other greenhouse gas flows in the forest, the decay rate of harvested wood products and fossil-based CO2 emissions that can be avoided by substituting alternative materials with wood derived from increased harvests. We considered uncertainties of key parameters by using stochastic simulation. According to our results, an increase in harvest rates in Finland increased the total net GHG flow to the atmosphere virtually certainly or very likely, given the uncertainties and time frame considered. This was because the increased biomass-based CO2 and other greenhouse gas emissions to the atmosphere together with decreased carbon sequestration into the forest were very likely higher than the avoided fossil-based CO2 emissions. The reverse of this conclusion would require that compared to what was studied in this paper, the share of long-living wood products in the product mix would be higher, carbon dioxide from bioenergy production would be captured and stored, and reduction in forest carbon equivalent net sink due to wood harvesting would be minimized.
  • Vilhonen, Enni (Helsingin yliopisto, 2021)
    Improving land management to mitigate climate change is important, especially in agriculture on soils with high organic content. Many studies have found evidence that increasing diversity can help to improve plant biomass production and soil carbon storage. This is attributed to complementarity which consists of more efficient resource use due to niche differences and facilitative interactions. For the total climate impact, the effect of greenhouse gas emissions from the soil needs to be considered. To find out if adding more species to a grass mixture could have similar benefits in boreal zone grass cultivation in Finland, an experiment was set up with four different species mixtures, and three levels of species richness were established under a nurse crop. It was additionally of interest if these effects can counter the emissions of cultivation on organic soils. Biomass samples were collected both before the nurse crop was removed and at the end of the growing season. Both species richness and Shannon diversity index were considered as explanatory factors. Carbon exchange, divided into respiration and photosynthetic capacity, as well as nitrous oxide and methane fluxes, were monitored monthly. There was no strong evidence that species richness affects biomass or greenhouse gas fluxes during the first year. The effect of species richness on the biomass was clearer when the diversity index was considered. These results were significant when the lowest biomass values were excluded from the analysis, probably because complementary resource use needs enough biomass to have an effect. The differences in carbon flux measurements may be sensitive to timing within the growing season since the results closest to significant were obtained at the start of the season. At the time, the measurement conditions were good and the nurse crop biomass was small enough not to obscure the effects of grass mixture. When it comes to other greenhouse gases, species richness had most impact on early nitrous oxide emissions, while methane flux probably needs significantly more time for any changes to appear. Overall, the effect of species richness needs to be studied over the full grass cultivation cycle to find out the full effect. Based on current results, increasing species richness may be an option when other methods cannot be used to reduce emissions and improve carbon sink of agriculture.
  • Siintola, Asko (Helsingfors universitet, 2012)
    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.