Browsing by Subject "ilmastovaikutus"

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  • Jyllilä, Lauri (Helsingin yliopisto, 2018)
    Maailman väkiluvun kasvaessa on ruuantuotantoa varten otettava käyttöön koko ajan enemmän pinta-alaa maanviljelyyn, rehuntuotantoon ja laidunnukseen. Tämä kehityskulku on kestämättömällä pohjalla ja ratkaisuksi on esitetty hyönteisten kasvattamista teollisen ruuantuotannon raaka-aineeksi. Hyönteissyönti on vasta nouseva trendi mutta trendin kasvu on voimakasta etenkin tällä hetkellä länsimaissa. Etuna hyönteistentuotannossa ovat merkittävästi pienemmät kasvihuonekaasupäästöt ja vedenkulutus sekä huomattavasti tehokkaampi rehuhyötysuhde kuin muilla tuotantoeläimillä. Hyönteisen ravintoarvot ovat myös erilaiset kuin muilla tuotantoeläimillä ja arvoihin voidaan vaikuttaa voimakkaasti. Kotisirkkojen kasvatuksen pilotointi tehtiin tämän lopputyön tiimoilta Etelä-Pohjanmaalaisella maatilalla, joka on tänä päivänä yksi Skandinavian suurimmista hyönteistuotantotiloista laajennuksien jälkeen. Koetilalla koostettiin tulokset laskelman pohjaksi, jolloin päästiin tarkastelemaan tuotannosta muodostuvia kokonaiskustannuksia tässä ensimmäisessä tuotantomallissa. Tämän ohella saatiin muodostettua hyönteistuotannon yhteiskunnalliselle kannattavuudelle lopputulos. Yhden tuotetun kotisirkkakilon kustannukset muodostettiin suhteutetuilla panosten hinnoilla. Käytettyinä panoksina huomioitiin rehun kulutus, lämmityskustannukset ja työvoimakustannus. Yhteiskunnallinen hyöty muodostettiin hyönteisten käytön syrjäyttäessä naudan ja sianlihan kulutusta ja tätä kautta kasvihuonekaasupäästöjä. Kasvihuonekaasupäästöt hinnoiteltiin markkinahintojen mukaan. Ilmastovaikutuksiltaan hyönteistuotantoa rinnastetaan hieman tehokkaammaksi kuin kalojen. Todellinen hyöty yhteiskunnalle muodostuu myös työllisyyden kehittymisen kautta tuotannossa ja prosessiteollisuudessa sekä loppumarkkinoinnissa.
  • Punkka, Eetu (Helsingin yliopisto, 2019)
    Substrate producers are interested in new climate-friendly alternatives due to the problematic nature of the peat life cycle and the uncertain status. The Sphagnum moss has good properties for substrate production and, due to its productivity, is a potential alternative to peat harvesting. Indeed, the Sphagnum moss has been harvested for this purpose for several years. Exploitation of the new natural resource involves many issues to take care of in order to consider sustainable use. One of these is the impact on climate. Of the greenhouse gases, carbon dioxide and me-thane play a role in the climate emissions of ombrotrophic mires. Nitrous oxide is not considered here. In the case of carbon dioxide, it is important to study the carbon stocks of the decaying material and, in the case of methane, vege-tation restoration and plant species relationships are considered carefully. The aim of this Master's thesis was to study observations on the climatic effects of Sphagnum harvesting for possi-ble further research. Climate effects were compared with untreated reference areas and, in addition, the differences in emissions between peatland types were provisionally investigated. The climatic effects of Sphagnum harvesting were also compared with the corresponding figures of horticultural peat. Carbon dioxide was studied by the carbon content of drilled peat samples. The climate impact of the peat that wasn’t formed as a result of the harvesting was also taken into account in the calculations. Methane emissions were examined on the basis of restoration of cover from vegetation analysis and plant species relationship data. The Sphagnum harvesting areas were also examined about general information of the harvesting area for example harvesting marks in the ground, tree stand and ditch conditions. Field work was carried out in summer 2019 in Kihniö area on 12 bogs. In general, the vegetation of the harvesting areas was characterized by a strong pioneer effect on Eriophorum vagi-natum. The most recent harvesting areas were still nearly plant-free, but at the time of the study, the harvesting areas that had recovered three growing seasons had already begun to clearly recover in terms of vegetation. Within 10 years, the vegetation had completely recovered. In relative terms, the proportion of Eriophorum vaginatum in the oldest areas was clearly higher than in the reference areas and the regenerated vegetation in the harvesting areas was poorer than in the reference areas. However, the presence of Eriophorum vaginatum also seems to contribute to the spread of Sphagnum sp. In addition, the harvesting marks of the harvesting seems to be important above all for the recovery of Sphagnum sp. The flat surface facilitates recovery, but also the unharvested spots within the harvesting areas. Based on the greenhouse gas calculations, the emission of the Sphagnum harvesting area was 10.26 kg/m2 CO2 in 13 years. Comparing the differences between the different bog types, it was found that the harvesting is more climate friendly in Sphagnum-bogs than in cottongrass-bogs. The Sphagnum harvesting is clearly a better alternative to harvesting peat from a climate point of view, when emissions are distributed on the dry masses of the growing media produced. When reducing climate emissions, the major part of total emissions is generated by the specific decontaminated substrate. The importance of the vegetation is less significant in the overall result. In this study, the climate effects of the Sphagnum harvesting were tentatively mapped, as the topic has not been studied previously in Finnish conditions. More research is needed with wider sampling and long-term follow-up.