Browsing by study line "Ympäristömuutos"

Permafrost peatlands have the capacity to store significant amounts of carbon, and thus they act as important controllers of the climate. Approximately 14% of the world’s soil organic carbon pool is stored in permafrost peatlands, which are sensitive to climatic fluctuations due to their location in the high latitudes of the subarctic zone. Permafrost peatlands also act as a habitat for a large number of moisture-sensitive organisms, such as bryophytes and testate amoebae, which can be used to study how the hydrology of peatlands has changed and will continue to change throughout time, giving us an opportunity to predict the future of peatlands under a changing climate. In this Master’s Thesis I examined the testate amoebae composition and used these species as indicators to study hydrological fluctuations from three subarctic permafrost peatland cores extracted from Taavavuoma and Abisko in northern Sweden. The species compositions were combined with radiocarbon (14C) and lead (210Pb) dates to reconstruct the past water table levels for the late Holocene, spanning four climatic periods. The reconstructions were then compared to past studies on testate amoebae to understand how permafrost peatlands and their species assemblages respond to changes in the hydrology of the active layer of the peat. Out of the study sites only the Taavavuoma cores spanned the Dark Age Cold Period (DACP) and Medieval Climate Anomaly (MCA). Species compositions in both cores indicated fluctuating water tables during the DACP, but during the MCA the results began to contradict with one site showing a wetter, and the other a drier MCA. Two out of three study sites indicated a wetter Little Ice Age and a drier Post-Industrial Warming, supporting past studies indicating similar results, whereas one study site gave opposite results. The results indicated large variability in testate amoebae assemblages throughout time, indicating that the hydrology of peatlands can change very abruptly and vary considerably even on a local scale. Modelling is however complicated by the poorly known ecology of testate amoebae, which is why a multi-proxy approach is essential to reliably predict the future fate of permafrost peatlands.

This study aimed to identify conservation landscapes with potential to be mutually beneficial for people and African savanna elephants (Loxodonta africana) in South Africa through spatial conservation planning analyses that integrate ecological and socioeconomic data. The research questions were: (i) what are the most ecologically suitable areas for the reintroduction of elephants, and (ii) which of these areas provide the best opportunities for also sustaining socioeconomic development of local people. The first question was answered with an ecological model that predicts habitat suitability for elephants, developed by a combination of literature review, expert opinion, and GIS-based methods. The second question was answered by combining the ecological model with socioeconomic criteria in Zonation spatial conservation planning software. The results show that the central part of South Africa holds most potential for elephant conservation as it has the largest uniform area of high-quality habitat, while the area also meets the socioeconomic criteria. The priority areas for the conservation of elephants were classified into top priority classes of 1%, 2%, 5%, 10% and 20%. The identified areas hold an unrealized opportunity in the wildlife and ecotourism sectors, and the reintroduction of elephants to those areas could provide the foundation for long-term economic activity of local communities e.g. in the form of elephant-based ecotourism, while contributing to the conservation of elephants. Conserving just the top 5% priority areas would grow South African protected area estate by approximately three million hectares and increase the current elephant range by approximately 75%. Ideally, the results of this study could be used to inform the on-going decision-making process on where to allocate resources for elephant conservation in South Africa.

Tässä tutkimuksessa selvitettiin, millaisia kehyksiä ilmastoahdistus saa kahdeksassa, vuonna 2021 julkaistussa suomalaisessa podcast-jaksossa. Näin pyritään lisäämään ymmärrystä ilmastoahdistuksen ilmiöstä, sekä siitä, millaisia kehystyksiä aihe mediassa saa. Tutkimus on tehty laadullisella kehysanalyysilla, joka perustuu Erwin Goffmanin (1974) kehittämään kehysteoriaan ja sen myöhempiin sovellutuksiin. Lyhyesti sanottuna, tutkimus pohjaa siihen olettamukseen, jossa median tavat kehystää ja esittää jokin aihe tai asia ohjaavat sitä, millä tavalla asiat meille esitetään ja millaisina me asiat näemme. Tutkimuksen aineisto kerättiin suoratoistopalvelu Spotifysta, Yle Areenasta ja Suplasta. Kehyksien muodostamisessa hyödynnettiin Robert Entmanin (1993) median kehysanalyysin periaatetta, jossa kehyksillä on neljä tarkoitusta: Ongelmien määritteleminen, ongelman aiheuttavien tekijöiden tunnistaminen, moraalisten arvioiden tekeminen sekä ratkaisujen ehdottaminen. Tutkimuksen tuloksena syntyi kolme kehystä, jotka nimettiin luonnollisen ilmastoahdistuksen, ilmastoahdistus sukupolvikysymyksenä sekä ilmastoahdistus tarvitsee vertaistukea, käsittelyä ja toimintaa kehyksiksi. Jokainen kehys kuvaa omalla tavallaan sitä, millaisena ilmastoahdistus nähdään viime aikaisissa podcast-keskusteluissa. Luonnollisen ilmastoahdistuksen kehyksessä korostuvat näkemykset siitä, kuinka ilmastoahdistus voidaan nähdä luonnollisena ja normaalina, sekä hyvänä reaktiona motivoivan vaikutuksensa kautta. Kaiken kaikkiaan kehys kuvaa ilmasto- ja ympäristöahdistuksen ilmiön monitahoisuutta ja yksilöllisyyttä, sekä pyrkii vahvistamaan näkemyksiä siitä, mitä ilmastoahdistus on ja mitä se ei ole. Lisäksi ilmastoahdistuksen sisältämä ahdistus sana kyseenalaistetaan. Ilmastoahdistus sukupolvikysymyksenä - kehys avaa puolestaan näkemyksiä nuorten ilmastoahdistuksen syihin ja korostumiseen, sekä ottaa kantaa aikaisempaan ilmastoahdistuskeskusteluun, joka joidenkin keskustelijoiden mielestä näyttäytyi ilmiötä vähättelevänä. Kokonaisuudessaan kehyksessä kuitenkin korostuu näkemys siitä, että ilmastoahdistus ei ole vain nuoria koskettava asia, vaikka se tällä hetkellä korostuu ja ilmenee eniten nuoremmissa sukupolvissa. Kehys ilmastoahdistus tarvitsee vertaistukea, käsittelyä ja toimintaa, tuo esiin keskustelijoiden näkemyksiä ja kokemuksia liittyen ilmastoahdistuksen käsittelyyn ja lievittämiseen, sekä osallistuu keskusteluun koskien ilmastotekojen merkityksellisyyttä. Tutkimuksen tulosten perusteella voidaan sanoa, että ilmastoahdistus saa vuonna 2021 julkaistuissa, suomalaisissa podcastkeskusteluissa monia eri sävyjä ja ilmastoahdistusta käsitellään niissä laajasti. Ja vaikka keskustelijoiden näkemykset ovat pitkälti linjassa ilmastoahdistusta käsittelevien julkaisujen kanssa, muutamia kiinnostavia ja tutkimattomiakin näkökulmia ja kehystyksiä ilmenee. Osaltaan tutkimuksen tulokset täydentävät kuvaa siitä, miten valtavirtamediaa hitaammat lajityypit – kuten podcastit – mukautuvat muualla esitettyihin määritelmiin ja kehystyksiin, mutta myös täydentävät niitä. Tällöin podcast-keskustelujen voidaan nähdä tarjoavan vaihtoehtoisia kehyksiä, jotka osittain haastavat ja täydentävät julkisuudessa hallitsevia kehyksiä.

Peatlands are a significant carbon and nitrogen reservoirs, making them potential sources of carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) emissions. Variations in water table level change the oxygen content of peat, affecting the oxidation-reduction or redox state of the peat, which is known to influence the biochemical processes and thus greenhouse gas (GHG) emissions. The aim of this study was to assess the effect of controlled anoxic redox conditions and inorganic electron acceptors (TEAs) on redox potential (Eh), and N2O, CH4, and CO2 emissions. In this study during an anaerobic incubation experiment, the rates of formation of these GHGs and Eh values as a function of time were measured from drained (D) and undrained (UD) peat of three nutrient levels: mesotrophic (ME), oligotrophic (OL), and ombrotrophic (OM). Redox conditions were controlled to three levels by nitrate (NO3-), ferric iron (Fe3+), and sulphate (SO42-). In addition, measurements were performed on untreated (Ctrl) peat. The peat was in an anoxic state throughout the incubation (Eh < 300 mV) and the values were in the order of TEA reduction, even though they were mainly in the iron and manganese reduction zones, probably due to the naturally high iron content of the peat. As expected, N2O formation was highest in flasks with added NO3-, and N2O formation was weak and ceased without addition. CH4 formation was reduced in flasks with added NO3- or SO42-, and SO42- addition also inhibited CO2 formation on which NO3- addition had no effect. In contrast, the addition of Fe3+ increased both CO2 and CH4 formation compared to Ctrl treatment, and it is possible that methanogens were involved in the reduction of Fe3+. In Ctrl flask, the redox state did not decrease to the lowest level compared to the other treatments as expected, but the Ctrl treated UD ME peat had the highest CH4 formation at the end of incubation. For all treatments, GHG emissions were higher from nutrient-rich peat in the descending order ME > OL > OM. In general, UD peat also had higher gas formation than D peat. All GHGs were formed the most while Eh values were around 0 mV and the value was especially high for CH4 formation, probably due to the linkage between methanogens and iron. The poor ability of the Pt electrode to detect NO3- or oxygen was the most likely reason for the variable and low Eh values of the flasks with NO3- addition. For the same reason, oxygen leakage of the anaerobic chamber was most likely responsible for the varying Eh values measured from Ctrl treated OM peat. This study suggests that Eh measurement is a useful predictor of the redox state and reactions, but it must be considered together with other measurements and analyses such as microbial analysis, nutrient analysis, and GHG measurements to predict redox processes and GHG emissions in anaerobic peatland. In particular, the role of iron on CH4 emissions requires further research.

The heath vegetation in the Jauristunturit study area is highly affected by the reindeer fence that was built in the mid-1950s between Finland and Norway, to prevent summer grazing in the Norwegian side. In the study area, the Finnish and Norwegian pastures are used during different seasons, causing differences in reindeer grazing history, and with time differences in vegetation. Additionally, local topography also impacts the vegetation composition and structure creating variation in local vegetation patterns. My research questions are: How vegetation patterns differ between summer- and winter- grazed areas, and which plant functional groups have the most significant difference? How local topography affects vegetation patterns, and does the effect of topography differ between summer and winter pastures? The data was collected from five 400 m long transects that crossed the fence and had vegetation plots with 10-m intervals. The %-cover and height of each vascular plant, bryophyte, and lichen species were estimated from 0.25 m2 plots. Later, species data was grouped into functional groups and general linear models were used to analyze differences in cover, height, species number, biomass, and leaf-area indices between countries. Topography indices were calculated in GIS for each plot and analyzed with random forest models to find out the most important topography indices explaining vegetation patterns. The vegetation data was collected by four teams, and therefore, the comparability in the collected data between teams was analyzed. Significant vegetation differences were found in the ground layer, with higher cover and biomass of bryophytes on the Finnish side (mean biomass 168.2 vs. 65.2 g m-2). Reindeer lichens were more abundant on the Norwegian side (mean biomass 197.0 vs. 2.9 g m-2) which is visible in aerial and satellite images and in the field. Among vascular plants, evergreen dwarf shrubs had higher biomass and leaf area index on the Finnish side and dwarf birch had higher cover and height on the Norwegian side. Topography indices had a higher level of variance explained on the Norwegian side, and higher at the ground layer compared to vascular plants. Elevation had the greatest impact on vegetation, and after that, topography protection index for 50 m and depth to water stream network for 2 and 10 ha. The differences between data collectors were not considered to have a major impact on the results. The results indicate that there are significant differences in vegetation between summer- and winter-grazed areas, mainly in the ground layer, and most differences are caused by differences in reindeer grazing history, but also local topography has an impact.

Kaikkien lauhkealla vyöhykkeellä elävien eliöiden täytyy sopeutua ympäristöolosuhteiden suureen vaihteluun vuodenaikojen mukaan. Vuodenaikaan liittyviin muutoksiin kuuluvat muun muassa lämpötilan ja valoisuuden vaihtelut, jotka ovat selkeitä myös järvissä veden alla. Lämpötilan, ravinteiden ja valon määrät vaikuttavat järven tuottavuuteen ja siten moniin muihin tekijöihin, myös kalojen ravinnon määrään. Eri kalalajit ovat sopeutuneet erilaisiin olosuhteisiin, joissa ne pärjäävät parhaiten, ja jokaisella lajilla on oma optimilämpötilansa. Kalat ovat aktiivisimmillaan niille sopivien olosuhteiden aikaan, mikä useimmilla lajeilla on kesä, jolloin ravintoakin on saatavilla enemmän. Suurin osa kalatutkimuksista tehdään yleensä kesällä avoveden aikaan, koska se on helpompaa ja talvella kalojen ei ajatella olevan tutkimuksen arvoisia. Suuri osa maailman järvistä kuitenkin on jääpeitteen alla osan vuodesta ja talvi on iso osa kalojen elämää, minkä vuoksi niiden tutkiminen vuoden ympäri on tärkeää. Tämän tutkimuksen neljä pääkysymystä olivat: 1. Millä tavalla eri kalalajien, lahkojen, sekä lämpötila- ja ravintokiltojen osuudet saaliista muuttuvat eri vuodenaikoina? 2. Kuinka paljon yksikkösaalis muuttuu vuoden aikana? 3. Miten kalojen koko ja kuntokerroin muuttuvat vuoden aikana? 4. Mitkä eri ympäristö- ja biologiset tekijät selittävät yksikkösaaliin muutoksia? Koekalastusta tehtiin vuosina 2020-2021 vuoden ajan koekalastusverkkosarjalla kolmessa habitaatissa: litoraalissa, profundaalissa ja pelagiaalissa. Joka kuukausi kalastettiin vähintään kolmen päivän ajan. Jokaiselle saadulle kalalle määritettiin laji, pituus, paino ja kuntokerroin ja jokaiselle yksittäiselle pyyntikerralle laskettiin yksikkösaalis. Kalastuksen lisäksi Pääjärvestä otettiin joka kuukausi fysikaaliskemiallisia mittauksia. Koekalastuksen tulosten mukaan selvästi runsain kala Pääjärvessä oli särki, toiseksi runsain kala oli kappalemääränä ahven ja biomassana kuha. Talvea kohti särjen ja ahvenen määrät laskivat, kun taas kuhan, kiisken ja mateen osuudet saaliista nousivat. Selvästi runsain kalalahko vuoden kokonaissaaliissa oli karppikalat, vaikka ahvenkalat olikin runsain lahko loppukesällä ja lopputalvella. Lämpimänveden kaloja oli muita lämpötilakiltoja enemmän koko vuoden saaliissa, vain helmikuussa viileänveden kaloja oli enemmän, kun kiiski oli kuukauden runsain kala. Petokalojen kappalemääräosuus saaliista oli jokaisena kuukautena muita ravintokiltoja pienempi, mutta talvella petokalojen biomassaosuus saaliista oli suurin. Yksikkösaalis oli alhaisimmillaan jääpeitteisinä kuukausina ja suurimmillaan kesällä. Kalojen keskikoko oli talvella kesää suurempi ja kuntokerroin alhaisempi. Kappaleyksikkösaaliin muutoksia eniten selittivät kuntokerroin, lämpötila, typpipitoisuus ja pH, kun taas biomassayksikkösaaliin muutoksia eniten selittivät kuntokerroin, lumensyvyys, lämpötila ja kokonaishiili. Pääjärven kalayhteisön rakenteessa tapahtui muutoksia vuodenaikojen välillä. Selkein muutos oli yksikkösaaliin muutos kesän ja talven välillä. Pääjärven lisäksi ympärivuotista kalatutkimusta pitäisi tehdä morfologisilta ja fysikaaliskemiallisilta piirteiltään erilaisissa järvissä, jotta saataisiin tietoa, miten kalayhteisö reagoi eri vuodenaikoihin eri olosuhteissa.

Climate change has exacerbated extreme weather events. According to climate scenarios, temperatures will rise and heat periods will become more common also in Finland. These heat periods worsen the urban heat island phenomenon which is known to have negative impacts on human well-being. The impacts of the urban heat island phenomenon can be reduced through careful urban planning, adaptation policies and economic investments. Adaptation to climate change can be monitored through indicators but research and development on adaptation indicators has been largely absent. The development of adaptation monitoring indicators is particularly important in order to ensure the long-term success of the city's adaptation efforts and whether adaptation is moving towards the desired goals. This thesis asks the following research question with the help of a literature review, a focus group discussion and a questionnaire: what kind of indicators can be used to monitor and evaluate adaptation to the urban heat island phenomenon in Helsinki? With the help of the literature review and New York Climate Change Panels framework “the seven steps to indicator selection”, 17 preliminary indicators were developed which were divided into six themes accounting the diverse nature of the urban heat island and its impacts. The indicators were specified in a focus group discussion which had six attendees from environment-, the technical-, social- and health sectors. After the group discussion, the indicators were further modified with the help of a questionnaire answered by ten municipal employees, mainly from the environmental, technical and social and health sectors. On average, respondents found each indicator useful, five indicators were found to be really useful on average, and three indicators were found to be useless among a couple of respondents. After the survey, 11 indicators were modified and one indicator was removed. The end result was 16 indicators for monitoring adaptation to the urban heat island phenomenon divided into the following themes: social vulnerability, state of environment, infrastructure, green-blue infrastructure, policy actions and communication. The development of indicators does not as such contribute to the development of urban adaptation to a desired level, but it is nevertheless an important step in the process of developing adaptation monitoring in the city of Helsinki. This work provides tools for the city to develop their adaptation monitoring strategy which should be systematic and comparable. If the city wants to develop its adaptation monitoring, it is essential to document decisions and programs to explore sufficient coverage. Decisions and programs should be compared against identified adaptation commitments, targets and needs. As a conclusion, this thesis is important step towards more diverse and effective adaptation monitoring. This thesis takes adaptation monitoring forward, developing ways to put adaptation monitoring into practice.

Local climatic interactions between ice, ocean and atmosphere in Northwest Atlantic are significant due to their impacts on global climate. Sea-surface conditions and their links to major climatic patterns during the late-Holocene offshore southeastern Newfoundland, Placentia Bay, were studied using diatoms as paleobioindicators. The record indicates moderate conditions with Arctic influence being little stronger than Atlantic influence during the time period between 5.8 and 4.75 ka BP. The time period between 4.75 and 2 ka BP is dominated by Atlantic influence, except for a cold pulse around 3.5 ka BP. There is a considerable increase in Arctic influence during the time period between 2 and 0.4 ka BP. The strength of the inner Labrador Current seems to be the most important factor affecting the conditions in Placentia Bay. It follows both the NAO index and the strength of AMOC being strongest when the NAO index is positive and AMOC is strong. Cold periods in the record match with positive NAO. Meltwater and sea ice content in the inner Labrador Current seems to be dependent on the conditions in Baffin Bay. The AO index and the orbitally driven HTM, Neoglacial cooling and Roman warm period events affected the dynamics in Baffin Bay during the late-Holocene. Also, the AMOC caused either additional cooling or melting in the region depending on its strength. The major shift at 2 ka BP matched with a recorded shift in the deep convection rate in the Labrador Sea.

City of Helsinki is aspiring towards carbon neutrality by 2050. Households play an important role in this matter, as their share of carbon dioxide emissions is substantial in the city-level. The energy efficiency of different household appliances is improving, but their usage is rising in tandem. Overall, it is recognized that there needs to be a change in household behaviour. In this thesis I examine what kinds of low carbon actions households are taking and what has motivated them to do so. The thesis is done in co-operation with Aalto University’s HAPPI project, which deals with carbon neutral living in Helsinki. The project studies possibilities to promote climate friendly actions on a residential level. Research was carried out in Mellunkylä, a residential area in eastern Helsinki. The contribution of this thesis is to recognize customs that advance and support low carbon actions on a residential level. The research question took shape as: “What are the low carbon actions that the households in Mellunkylä are taking and why are they taking them?” In order to answer both questions, I decided to use two methods: a survey and interviews. The survey aimed to provide quantitative information about the people living in Mellunkylä as well as a generalization on how they were acting, what they were interested in and what they saw as barriers to further behavior change. In order to better understand what these actions mean for the households and to gain information about their values and other motivations, qualitative interviews were a justified method to further assess the research problem. They aimed to specify the behavior changes that had already occurred and what kinds of motives lie behind these behaviors, as well as to assess the barriers to other behavior changes. Results from both studies indicate that most households were generally making mostly curtailment actions, such as reducing the use of lightning, household appliances and water consumption. There were also efficiency actions, which for the most part consisted of investing on new lightning and household appliances. The households were not fond of acquiring green electricity and were not generally trying to reduce their emissions through heating-related solutions. The households had a general idea of why they should reduce their energy consumption: energy use was commonly understood a societal problem and everyone’s responsibility. The interviewees mentioned altruistic values and biospheric concerns most often, which was fruitful in that these kinds of values are important in saving energy in the long run. Of the external motivators economic factors were mentioned repetitively. They were thought to have an effect on the individual as well as on the economy. It seemed that the households were hoping to be able to use energy without worries and with small expenses. This suggests that the motivations for low carbon actions lie within costs and ease of life rather than environmental concerns. Habits were often mentioned as a barrier to behavior change. Also costs and inability to follow one’s energy consumption were some of the barriers that stood out in the studies. This is in line with the fact that the participants were making more of the curtailment actions rather than efficiency actions, which can be more costly. The case study households showed interest in following their energy consumption, so some kind of feedback as well as personal recommendations for improvement could be in place. This is an important area where the city could take actions, for example, by supporting the households to commit in reducing their energy consumption. It should be noted that in reaching a low carbon lifestyle, there are various routes, of which living-related low carbon actions are only one piece. It is important to find the actions and interventions which can result in long lasting behavioral changes.

More meat is consumed in the world than ever before causing an intensifying number of social, environmental, and economic problems. Lately, consumers’ willingness for change has been examined by several scholars. Plenty of hope is placed on the consumers’ role as active participants in the sustainable nutrition transition. Therefore, many consumer-based strategies have been conceptualized to reduce meat consumption and thus enhance the transition to less animal-based proteins without taking it to the extreme (no meat/vegan ideology). “Less and better” is one of these strategies. It encourages, not only to eat less meat but also to replace the remaining meat with “better” meaning meat with positive outcomes and smaller negative environmental and social impacts. In this context “better meat” refers to extensively produced natural pasture-raised beef (luonnonlaidunliha) which has positive impacts on for instance animal wellbeing, biodiversity, and farmers’ livelihoods. This research aims to understand if buyers of “better meat” make linkages between “less” and “better” and whether they perceive the need for a sustainable protein transition. Being a relatively new approach, “less and better” has not been studied before from the perspective of consumers who already choose “better”. The data were collected in cooperation with Bosgård farm, which produces natural pasture-raised beef. Firstly, an email survey was sent out to the customers of the farm receiving 126 responses and secondly, six consumers were interviewed to gather a more in-depth understanding of the consumer perspectives. The results suggest that while a clear linkage between buying better and eating less exist, it also has a reverse side; many consumers are consuming more meat due to the access to what they perceive as better. The motives for meat reduction vary widely yet environmental and climate change reasons have not reached a significant position. It seems that meat reduction amongst the buyers of “better” meat is shadowed by pleasure orientation, lack of understanding of the scope of negative impacts of meat production and of the message “less meat”, high trust in Finnish meat production as such, and resistance to change caused by polarized information and attitudes. Even though many participants had found ways to incorporate more sustainable eating habits into their everyday lives and meat's position at the top of the food hierarchy is slowly changing, the results do not seem to correspond to high expectations held by the proponents of the concept. Though this is a small study, it questions a validity of the claim that “less and better” can be a sufficiently strong solution to support a sustainable nutrition transition in the way it is currently being presented.