Browsing by Subject "Master's Programme in Environmental Change and Global Sustainability"

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  • Katila, Anni-Sofia (Helsingin yliopisto, 2020)
    Meat consumption in the world is increasing, which has significant negative effects on the ongoing climate change. There is a need to make people change their diets towards more plant-based. One of the problems is that there is a negative atmosphere around veganism and vegans that prevents the change. In order to get people more plant-based, that negative atmosphere around veganism and vegans should be reduced. The aim of this study is to find out what kind of arguments are used against veganism and vegans, and what rhetorical strategies are used in these arguments. Previous studies have shown that there is still a strong belief that meat is a necessary part of the diet to keep one healthy. Studies also show, that the reason people do not change their diets can be attitudinal, for example that people think they are meant to eat meat, or practical, for example that there is not enough information available. The material for this study is from the Finnish online discussion forum Suomi24 and consists of messages that are against veganism and vegans. The Suomi24 data was retrieved from the KORP interface, where it was possible to search messages related to veganism. There is no information about the people behind the messages, because they are anonymous on the forum. The material was analysed with content analysis and strengthened with rhetorical analysis. Categorization was part of the analysis and categories were coded to the material in the Atlas.ti program. As a result, there were seven main categories and 28 sub-categories under two parent categories. The most common arguments against veganism and vegans were related to health, vegans as individuals and how vegans act. The most commonly used rhetorical strategies were factual argumentation, categorization, extreme expression and taking distance from one’s own interests. As a conclusion, to be able to increase plant-based food in people’s diets, more available information is needed, and positive encouragement without incrimination to build up an attractive atmosphere around veganism and vegans.
  • Korhonen, Henni (Helsingin yliopisto, 2021)
    The focus of this thesis is on environmental agency in two different video games, The Sims 4 Eco Lifestyle and Final Fantasy VII Remake. The research questions aim to answer how the player can act as an environmental agent in these two games and what are the key differences between these games. The study is executed in a form of qualitative two-case case study with the help of close reading. With close reading eight different types of agencies that form the typology of this study, will be analysed in order to answer the research questions. The data for this thesis was collected by playing both games and taking notes by following close reading. The notes were then analysed with the different types of agencies. The results showed clear overlapping of the types of agencies, and it could be said that environmental agency can be used better in the game when the overlapping is happening. The agencies complemented each other and made the possible learning process in the game more fulfilling. The main difference between the game seems to be that The Sims 4 Eco Lifestyle as a life simulation game offers more diverse possibilities for environmental player agency. The studies about environmental games are mainly focused on serious games and not so much on commercial games. Video games hold great potential to engage people in environmental things especially with the help of player agency. It offers the player the ability to make meaningful choices and if they are structure well, the player can see the consequences of their agency which serves as an effective feedback which could lead to positive learning. In this case, the environmental agency in the game could be transformed into real-life environmental agency. As video games have become more immersive and their environments more realistic, it could be worth considering that separating virtual environment from the real-life one might not be necessary anymore. Therefore, games like The Sims 4 Eco Lifestyle and Final Fantasy VII Remake could serve as an example of how environmental agency within them could be harnessed into wider use.
  • Hanstén, Magnus (Helsingin yliopisto, 2019)
    An increasing number of fisheries utilize rights-based management approaches for achieving economic, social and environmental sustainability. It is widely accepted that fisheries management is to a large extent about managing human behaviour, hence social acceptance is prerequisite for a successful management regime. Based on stakeholder interviews, this study analyses the opinions related to the recently implemented individual transferable quota (ITQ) system for the Finnish herring and sprat fisheries. Similarly, opinions were collected in 2007 by Kulmala et al. related to a possible implementation of ITQs, thus creating a unique opportunity to compile results from both a pre and post individual quota management implementation scenario. In 2007, it was suggested that fishers would largely support an ITQ system in Finland. Accordingly, this study implies that most of the Finnish stakeholders are content with the properties of the new system, however inequalities were perceived among fishers targeting fish for human consumption. In general, the system is expected to achieve its primary goal of improved economic efficiency within the fishery industry.
  • Azam, Gausul (Helsingin yliopisto, 2020)
    Dog activities (urination and defecation) can be a source of nitrogen accumulation in the snowpack of urban parks. Urban parks are commonly visited by urban residents and excessive buildup of nitrogen in snowpack can be a health concern. This accumulation of nitrogen in snowpack may wash away during spring with the runoff of melting snow, which can cause the eutrophication and deterioration of lake ecosystems. In this study, I investigated the concentration of some nitrogen-related compounds along with a few physical parameters in the snowpack of urban parks and compared these between areas with high dog activities and areas with no dog activities. I hypothesized that, nitrogen concentrations will be higher in areas with high dog activities, like snowpack beside paths than in areas with no dog activities. The study was performed in 10 parks of two cities in Finland; Helsinki and Lahti. In these parks, samples were collected from snowpack immediately next to walking paths (path edge), and in control areas 8 m away from these paths, where dogs were unlikely to visit. Samples were collected from February to April of 2019. The concentration nitrogen from snow samples of both parts of parks were compared. The study showed that, the concentration of most nitrogen species, e.g. Total Nitrogen (TN), ammonium (NH4+), Total Organic Nitrogen (TON), and electrical conductivity followed a similar pattern of having higher values in snow from path edges where dog activities were the highest. However, the concentration of NO3 – and pH values were both slightly lower in the path edge samples compared to control areas undisturbed by dogs, but differences were not statistically significant. Information from this study can be useful for understanding the connection between dog activities and nitrogen build up in snowpack of urban parks, and can also be helpful for designing urban parks by considering environmental and health effects of nitrogen accumulation in the snow from dog activities. My findings can also be useful to urban waterbody related studies, e.g. eutrophication, and the accumulation of nutrients in lakes.
  • Kivilompolo, Sanna-Kaisa (Helsingin yliopisto, 2021)
    Aims of this study. Previous studies have shown cyanobacterial dominance and harmful cyanobacterial blooms to increase due to recent climate warming. The increase of aggressively blooming species and toxin-producing strains of cyanobacteria has been predicted to further increase in the future. However, information on the response of cyanobacteria communities to environmental forcing in the Arctic region – which is experiencing warming at over twice the rate compared to the global average – has been insufficient. Thus, it is crucial to study how algal and cyanobacterial communities have developed after industrialization to better understand and predict future trends of subarctic algal communities as well as changes within cyanobacteria communities experiencing environmental forcing. This study aims to provide information on the effect of recent climate warming and lake browning on algal communities in subarctic lakes, with a special focus on cyanobacteria and cyanotoxins. Materials and methods. Modern and historical primary producer group abundances of 23 subarctic lakes located on an ideal temperature and vegetation gradient were studied using sedimentary algal pigments as a proxy. The top-bottom method was used to study both changes within algal communities during the last ca. 150 years and the broader trends in algal communities of subarctic lakes. Pigment data was analyzed together with environmental data using ordination analyses (principal component analysis (PCA) and redundancy analysis (RDA)) as well as other statistical analyses in order to determine possible trends of change and to reveal the environmental variables that have the strongest impact on cyanobacterial abundance. Results and conclusions. Algal communities have changed during the last ca. 150 years and show a general trend of increased primary production as well as lake browning in the spruce, pine and birch (SPB) vegetation zone. Siliceous algae generally dominate modern algal communities, and relative abundances of cyanobacteria have declined throughout the vegetation gradient. Within the Barren (Ba)- and mountain birch woodland (MBW) vegetation zones, cyanobacteria communities show a marked decline in the abundance of assumed benthic species based on pigment data, and low abundances of planktic picocyanobacteria. However, due to climate warming and lake browning, abundances of cyanobacteria have increased in several sites within the SPB vegetation zone and are suspected to indicate an increase of harmful planktic species. The most significant environmental variables controlling the abundance of cyanobacteria were total phosphorus, temperature and the amount of organic matter. The results highlight the urgent need to mitigate climate warming in order to preserve the unique biota and characteristics of Arctic and subarctic lake ecosystems, and to prevent the possible harmful increase of cyanotoxins in these sensitive ecosystems.
  • Raubenheimer, Marie-Claire (Helsingin yliopisto, 2020)
    Oil spillages represent a serious environmental hazard for flora and fauna of marine and coastal ecosystems. Though marine oil spills have decreased since the 1970s, the increasing production of petroleum goods remains a potential source of pollution due to its use and transportation. When aquatic organisms, including fish, are exposed to toxic oil compounds, this can cause sublethal morphological changes and increase mortality. In this context, herring have been frequently studied, and results suggest that particularly herrings eggs and larvae are highly susceptible to oil toxicity. In this thesis, a Bayesian meta-analysis was conducted to investigate the effects of crude and fuel oil on the mortality of herring eggs from the genus Clupea. Observations from laboratory studies, collected during a literature review, served as input for the statistical analysis. To this end, Bayesian inference modeling was applied to generate posterior probability distributions for additional mortality caused by exposure to oil mixtures. Also, oil concentration, oil type, exposure time, and temperature were analyzed to study possible correlations with mortality impacts. The results of this study suggest that acute mortality of exposed herring eggs is similar to mortality observed for individuals exposed to only small concentrations or none at all. Of all evaluated oil types, medium grade crude oil caused the most significant change in instantaneous mortality with increasing oil concentration. Generally, distinct oil types had a greater influence on mortality outcomes than temperatures at the given concentrations. For the lowest temperatures, some correlations for increased mortality were found. Overall, the unexplained variability between the reviewed studies has a relatively small influence on mortality outcomes. In conclusion, the mortality of exposed herrings eggs is most likely delayed due to sublethal effects, rather than immediate, at the modeled concentrations. Altogether, uncertainty amongst the posterior probability distributions is high, indicating a wide possibility range for the monitored parameters' actual values. The reasons for elevated uncertainty likely stem from diverse experimental setups, biological differences between tested species, relatively small sample sizes, and model-related issues. Thus, future research could consider additional variables, information from observational studies and other fish species to reduce uncertainty in mortality outcomes.
  • Luomaniemi, Virve Kaarina (Helsingin yliopisto, 2020)
    Behavior change can be seen as one cornerstone in transiting to more sustainable energy cultures. Various implemented behavioral intervention experiments have been popular and successful in creating behavioral change during and/or right after the intervention period, however follow-up research examining the persistence of changed behavior has been limited. The empirical material of this thesis builds on a set of data collected in a European research project ENERGISE. The analysis utilizes the data collected from two Finnish living lab experiments performed in 2018, focusing the examination on the closing interviews conducted by the research team and the participants’ self-reported practices in the follow-up survey three months after the intervention. The analysis examines the formation of new practices in relation to their persistence in everyday life. Answers to open questions presented in the follow-up survey are also examined in the analysis, to fuller the representation of events. The sample of the research is not enough to make comprehensive statistical generalizations, instead it gives interesting insight on the durability of the effects of one energy intervention. The research questions guiding this thesis are: How did household practices change when households participated in an intervention? How persistent are the observed changes in practices post-intervention? What contributes to the persistence of treatment effects? This examination observed persistence of behavioral change post-intervention. This examination suggests that these encouraging results may be supported by a number of different factors; the broad perspective of energy practices that the intervention designed on practice theory provided and the making of household routines visible to participants to question and experiment with. In addition, the intervention techniques used as making commitments, goal setting, social comparison elements and providing energy feedback, which corroborate with prior intervention follow-up studies that have noted the importance of a carefully thought intervention design with these techniques, to support creating permanent behavioral change. Intervention designs should also in-clude a longer-term evaluation and further study investigating the factors contributing to creating permanent change should be implemented.
  • Lahtela, Eero (Helsingin yliopisto, 2021)
    Municipal environmental authorities are required to conduct environmental monitoring. Unmanned aerial vehicles, UAVs, may be helpful in environmental monitoring but their applicability as a tool for municipal environmental monitoring has not been studied. In this thesis it was studied, how municipalities have been utilizing UAVs. Additionally, UAVs applicability for environmental monitoring and inspection work was tested using a litter monitoring experiment as an example. In the first part of the study, a questionnaire was sent to municipal environmental authorities in Finland, to municipalities in Sweden and to those participating in Eurocities WG Waste group (n = 512), covering the used applications, their utilization frequencies and successfulness, reasons for failures and future plans. The results were analyzed using descriptive statistics. In the second part of the study, a UAV was utilized in a litter monitoring experiment on four sites in Helsinki. Litter by category and leaves were counted based on visual observations from UAV imagery. The accuracy of UAV imagery detection was assessed by comparing its and ground assessment (GA) results. On one site, a control group also carried out UAV imagery detections in order to assess the magnitude of bias or offset occurring when both the GA and the litter detection from UAV imagery are conducted by a single individual. The Wilcoxon signed rank and Cronbach’s α reliability tests were used for statistical analysis of the results. Response rate of the questionnaire was low, 3.7% (n = 19). The pool of used applications was extensive and covered a variety of monitoring and inspecting targets with emphasis on the presumably manually piloted applications. Utilization was very successful. The most important reasons for failures were poor weather followed by lack of information and expertise. UAVs were included in the future plans of most participants for municipal environmental monitoring purposes. The UAV imagery detection accuracies of litter and leaves compared to the GA results were high, 90.5% for litter and 87.5% for litter and leaves, and no statistically significant differences existed between the assessment results. Especially leaves proved challenging to detect from UAV imagery. The control group’s detection accuracies were 67.9% without and 49.0% with leaves, and with leaves the results differed with statistical significance (p = 0.028). The internal reliability of the control group was relatively high, α = 0.776 without and α = 0.805 with leaves. UAVs are deemed sufficiently accurate and versatile as monitoring and inspecting tools for municipal environmental authorities. They have the capability to complement ground assessments or, with certain prerequisites, even function as an independent monitoring method. Further application and detection method development and research on municipal UAV utilization are needed.
  • Vikkula, Sami (Helsingin yliopisto, 2021)
    Oil spills in aquatic environments are devastating disasters with both biological and economic impacts. Fish populations are among the many subjects of these impacts. In literature, there are numerous assessments of oil spill impacts on fish populations. From all applied research methods, the focus of this thesis is on Bayesian methods. In prior research, several Bayesian models have been developed for assessing oil spill impacts on fish populations. These models, however, have focused on the assessment of impacts from past spills. They have not been used for predicting impacts of possible future oil spills. Furthermore, the models have not utilized data from laboratory studies. Some examples can be found of models assessing economic impacts of oil spills on fish populations however, none of them assess the economic impacts that follow from decreases in biomass. The aim of this thesis is to develop a Bayesian bioeconomic prediction model, which would be able to predict oil spill impacts on Baltic Sea main basin herring population, and the consequential economic impacts on fishermen. The idea is to predict the impacts of several hypothetical oil spill scenarios. As a result of this thesis, a bioeconomic prediction model was developed, which can predict both biological and economic impacts of oil spills on Baltic Sea main basin herring through additional oil induced mortality of herring eggs. The model can be applied to other fish populations in other regions as well. The model utilizes laboratory studies for assessing population level impacts. The model can be used for both assessing risks of the impacts of possible future oil spills, and for decision analysis after a spill has already occurred. Furthermore, the model can be used for assessing unknown aspects of past oil spills. The economic predictions can be used, for example, to estimate the compensations that could possibly be paid to fishermen. In the future, the prediction model should be developed further, especially regarding its stock-recruitment relationship assumptions. In addition, the model’s assumptions regarding the calculation of oil induced additional mortality and the economic impacts, should be expanded.
  • Ruippo, Lotta (Helsingin yliopisto, 2020)
    Innovation in food packaging interlinks many sustainability challenges ranging from food loss and waste through the value chains, to resource extraction and growing amounts of plastic waste globally. Food packaging innovations arising from regulation often focus on material waste and ignore other facets of sustainability such as food loss and waste. Simultaneously, conventional notions of innovations are focused on firm growth and competitiveness. This study investigates the perceptions of sustainability in food packaging among expert actors in Finland. Moreover, it examines how notions of Responsible Research and Innovation (RRI) are reflected in the research and development processes in the field. Here, RRI is understood as a framework for examining the role of socio-ethical considerations in research and development. The study aimed to find out which packaging attributes are considered sustainable, what motivations actors in the field have, what type of obstacles exist to innovation in the field, and which actor groups are perceived to be responsible for accelerating the food packaging transition towards sustainability. Semi-structured expert interviews were conducted with 14 participants, and the interview data were analyzed using qualitative content analysis (QCA). The results show that perceptions of sustainability in food packaging vary across the field. However, reducing food waste and loss was considered the most important facet of sustainability in food packaging. Actors in the field are motivated by personal reasons and the anticipated profitability of sustainable innovations. However, innovations in the field are slowed down because of regulatory issues, food safety requirements, unpredictable future changes, and technological lock-ins. Finally, the results of this study indicate that actors in the sector believe the Finnish government and brand owners in the food and beverage industries should be responsible for driving innovation towards improved sustainability. However, the qualitative approach taken here limits the generalizability of the results. The results suggest an ongoing narrative shift in innovation towards greater inclusion of social and ethical considerations in the research and development process.
  • Lehtonen, Ilmari (Helsingin yliopisto, 2020)
    In this paper, I examine the discussions around the concept of carbon sinks. From those discussion of Finnish forestry, I identify frames based on a media material of 108 news articles combining the methodologies of frame analysis and content analysis. I aim to contextualize the carbon sink discussions of the latter half of 2010s and examine how the natural science-based term is used to support varying policy agendas. Building from background literature on the media as a societal actor and a context around Finnish forest discussions and mismatches between science and forest policy, I reflect on the ways that Finnish media frames and contextualizes carbon sink-related forest discussions. Eventually, I identify three dominant and eight secondary frames that describe the ways of using and the transforming of carbon sink as a term in detail. The dominant frames divide the discussion into two clashing ways to communicate carbon sink issues and a third middle ground way of understanding and using the term. The middle ground frame identifies the conflict between the clashing frames and suggests reaching to an understanding as a priority goal in terms of optimal climate change policy. I discuss the results in terms of the frames' policy implications. In addition, I ask how they signal potential developments in forest and climate policy and discourse. The analysis shows that the clearest disagreements in the carbon sink conflicts raise from how forestry restricting policies are seen to affect carbon sink levels and how prominent a role should forest industry have in meeting national and international climate policy targets. The study confirms that carbon sink as a term transforms into altering forms to support distinct, even controversial policy goals because of both definitional and calculative uncertainties.
  • Courroux, Maxime (Helsingin yliopisto, 2021)
    The changes in lake diatom assemblages as a response to climate warming over the past three decades were examined in 26 lakes across Northwestern Finnish Lapland using multivariate statistical techniques. The lakes are distributed along a steep climatic and vegetational gradient, covering three distinct vegetation zones spanning boreal coniferous forest, mountain birch woodland, and treeless tundra. Lakes were selected following a study realised by Weckström and Korhola in 2001, who had sampled the same lakes for surface-sediment diatom assemblages, physical, and chemical limnological variables. Climate data from the past 30 years was retrieved, showing a slow and steady yearly increase in temperature, with strong seasonal fluctuation and fall months experiencing the strongest warming. Surface sediment samples were taken from the lakes and their diatom communities analysed. A total of 185 diatom taxa representing 27 genera were recorded. Ordination techniques (DCA, CCA) at the genus and species level were performed to identify the main patterns of variation between diatom data from the original data set and the current study, and their relationship to environmental variables. Strong changes were recorded in four of the lakes with major shifts in dominant diatom species. Moderate changes were recorded in eight lakes, where dominance changes were recorded for a few species while the majority remained unchanged. The remaining 14 lakes did not show noticeable changes over the 30-year period. Changes observed in the studied lakes did not follow a widely observed pattern in northern Hemisphere lakes. The results indicate that while climate change is a driving factor behind changing lake dynamics with increasing temperatures and decreasing lake ice cover duration, it cannot be the only force responsible.
  • Sarasma, Juho Johannes (Helsingin yliopisto, 2021)
    Ihmisten arkinen liikkuminen paikasta toiseen on tärkeä palanen laajemmassa kestävyysmurroksessa. Liikenne muodostaa Suomessa 20 % kansallisista kasvihuonekaasupäästöistä ja vaikka päästöt ovat tasaisesti vähentyneet, nykyinen tahti ei ole riittävä tämänhetkisten päästövähennystavoitteiden saavuttamiseksi. Kotitalouksien kulutuksen aiheuttamista kasvihuonekaasupäästöistä liikkuminen on suurin yksittäinen päästöjen aiheuttaja. Aikaisempi tutkimus on keskittynyt suurelta osin teknologisiin ratkaisuihin ja yksilöiden valintoihin syinä ja ratkaisuina kestävään liikkumiseen. Näitä lähestymistapoja on kritisoitu siitä, että ne eivät anna riittävää painoarvoa sosiaalisille tekijöille. Käytäntöteorioita on esitetty vaihtoehtona ja vallitsevien yksilökeskeisten lähestymistapojen haastajana arkisen liikkumisen ymmärtämiseen. Käytännöt ovat rutiininomaisia ihmisten käyttäytymismalleja, jotka koostuvat useista elementeistä: materiaaleista, merkityksistä ja kompetensseista. Tämä tutkielma analysoi ihmisten liikkumista ennen COVID-19-pandemiaa ja sen aikana käytäntöteoreettisesta näkökulmasta. Tavoite on selvittää mitä käytäntöteorioiden avulla voidaan oppia kestävästä liikkumisesta, sekä miten pandemia on vaikuttanut ihmisten liikkumiseen Suomessa. Tutkielmaa varten tehtiin yhdeksän puolistrukturoitua haastattelua, joissa osallistujilta kysyttiin heidän liikkumisestaan ennen pandemiaa ja sen aikana. Tulokset muodostavat kokonaisvaltaisen kuvan osallistujien elämästä liikkumisen näkökulmasta. Tulokset analysoitiin käyttäen kvalitatiivista teorialähtöistä sisällönanalyysia. Tuloksista selvisi, että ihmisten liikkuminen muodostaa monimutkaisen systeemin, johon pandemia vaikutti merkittävästi. Tutkimuksessa tunnistettiin lukuisia elementtejä, jotka joko mahdollistivat tai hankaloittivat eri liikkumismuotojen käyttöä. Käytäntöteorioita on usein käytetty tarkastelemaan yhtä liikkumismuotoa kerrallaan, ja tämän tutkielman laajempaa näkökulmaa voidaan pitää yhtenä sen tärkeimmistä ansioista liikkumisen tutkimukseen. Vaikka tutkielma ei tarjoa valmiita vastauksia siihen, miten ihmisten liikkumisesta saataisiin kestävämpää, se tarjoaa tärkeää uutta tietoa käytäntöteoreettiseen liikkumisen tutkimukseen, joka on Suomessa ollut todella vähäistä.
  • Heikkinen, Panu (Helsingin yliopisto, 2021)
    This thesis is a case study that examines the reasons for the lack of citizen participation in the planning process of Kalasataman keskus, and, more generally, in the planning of megaprojects. The main observation of this thesis is that there are several reasons for this. Based on the interviews of main characters taking part in the planning of Kalasataman keskus and the planning documents of Kalasataman keskus (as well as the previous research on the topic) the reasons for lack of citizen participation were: the location of planning area with few inhabitants, the large size of the planning project, technical difficulty of the planning project, the weight on the commercial aspects of the planning, and the view of the planners (relying on experts in the planning). When these results were viewed together with the previous research, it was noted that, as the previous research suggests, the traditional practices of urban planning hinder citizen participation in planning. (For example, seeing that urban planning relies on the technical knowledge of experts.) Moreover, based on the findings of the thesis as well as the previous research, it is possible to see that when the tradition, which emphasizes expert knowledge, is paired with a planning project where the city has a commercial partner, the structures and procedures of planning tend to exclude citizens’ views from the planning process. Partly based on such findings, the thesis suggests that, if the intention is to strengthen citizen participation in, especially large, planning projects, the city should aim to strengthen, for example, local community organizations.
  • Peters, Dana (Helsingin yliopisto, 2021)
    Concern about global warming can lead to climate change anxiety, a form of anxiety characterized by excessive worry about the climate crisis and associated consequences on the natural world and human society. It has been suggested by previous research that humor can be used to manage feelings of anxiety. This study seeks to determine if this phenomenon can be applied specifically to climate change anxiety. The research combines a comprehensive literature review with an online survey that leveraged climate change themed internet memes as a proxy for humor to gather opinions about the intersections between these two topics. The survey data supplemented claims made by existing literature, indicating that climate change themed internet memes and humor in general can be useful coping mechanisms to mitigate feelings of climate anxiety. The survey was completed by 93 respondents; most of these participants were women, located in the US, and/or between the ages of 20 and 29. Results from the survey showed that people tend to feel best about their environmental anxiety when they are taking active steps to solve the problem. Conscious decisions such as reducing waste or participating in activist movements are easier to recognize and self-report than more passive coping skills. Reliance on humor was reported as a supplementary coping skill, but many respondents indicated that looking at humorous climate change themed memes did influence their feelings about climate change overall. The scope of this study was relatively small in scale, therefore the results presented in this thesis may not be indicative of broader social trends and likely require further research.
  • Skogberg, Mikko (Helsingin yliopisto, 2020)
    Static floating chamber (FC) measurements of CH₄ and CO₂ fluxes from northern boreal river Kitinen were analyzed for this thesis. Measurements were carried out in summer 2018. Spatiotemporal variability was measured in the fluxes by comparing three chamber measuring locations: the opposite river banks and the middle of the river. Mean CO₂ flux estimate was 0.83±0.54 μmol CO₂ m⁻² s⁻¹ (mean ± SD, n = 73), consistent with other estimates for similar systems, with a corresponding k₆₀₀ CO₂ gas transfer velocity estimate of 17±9 cm h⁻¹ . Nonlinear modelling of CO₂ flux was found useful for analyzing floating chamber data from a river. The mean CH₄ flux was 0.0084±0.0047 μmol CH₄ m⁻² s⁻¹ , slightly lower than the median for different river systems in literature. The flux estimates were compared with eddy covariance measurements (EC). FC measurements are expected to give larger results, but additionally chambers are known to overestimate fluxes in flowing water. The comparison yielded chamber fluxes 3.3 and 2.9 times the EC median values for CO₂ and CH₄ respectively. Fluxes were similar between the three locations, and they peaked in late July for both gases in all loca- tions. Some differences over the river cross-section were observed. Discharge was significantly correlated to fluxes in the middle of the river, which could be explained by inhomogeneous flow. On two measuring days in early August, the mid-river CO₂ fluxes were three times those observed near the banks. The difference was also measured in methane. No clear cause was determined, but measuring spatial variation in surface water gas concentrations and flow could clarify the causes of similar observations in further studies.
  • Karvonen, Lassi (Helsingin yliopisto, 2021)
    As water flow encounters an object on the sea floor, its hydrodynamics change. Accelerated currents and vortices develop around the object with changing intensity as a function of distance from its proximity. This leads to erosion and aggradation of sediment, known as scour. Studies focusing on formation processes of scour often involve locating visible scour sites by sonar scanning the geomorphology of the seafloor. However, the effects of scour on macroinfauna and small-scale sediment characteristics are not visible in sonar images. In this Master’s thesis, scour at a shipwreck of a timber-built historic sailing ship, the Joskär shipwreck, was first identified by scanning the study area with side-scan sonar, and by measuring water depth contours around the shipwreck by scuba diving. Sediment samples were then taken inside the area assumed to be under the most pressure from scour. Samples from three separate distances on two transects drawn outwards from the hull of the shipwreck were collected and analysed for sediment grain size, organic content, and species assemblages of macroinfauna. In addition, macrofauna were analysed for individual lengths, number of individuals, diversity index, and functional groups. All samples were collected with a core tube sampler operated by a scuba diver. The methods used in this Master’s thesis widen the concept of scour past the sole physical processes observable with sonar to a more holistic level that considers the quality of biological, geological, and chemical characteristics of the benthic environment. The results of the present Master’s thesis show that the quality of the sediment near Joskär shipwreck varies within a relatively small scale. Organic content of the sediment was the most potent descriptor of scour at the study site, exhibiting a consistent decreasing trend as distance to the shipwreck increased on both sampled transects. Sediment grain size became finer as distance to the shipwreck increased. However, compared to grain size, based on visual observations of the sediment samples, shell debris content of the sediment could possibly act as a better measure of presence of scour. The variability of characteristics of macroinfaunal communities as a function of distance from Joskär shipwreck was not a viable tool to describe the presence of scour, as no consistent trends of the variables were observed. As no control site was included in the study design, the characteristics of the benthic environment inside the scour around Joskär shipwreck could not be compared to the seafloor unaffected by scour. Further research could reveal possible variation between these distinct habitats, and that way produce valuable indicators of scour. The hypothesis in the present thesis was that macroinfaunal assemblages and sediment characteristics would exhibit variation between the sampling sites as a function of distance from the shipwreck. The observed trends of sediment characteristics validated a part of the hypothesis, showcasing the utility of sediment characteristics in describing scour at Joskär shipwreck. However, a part of the hypothesis was rejected, as no consistent trends of macroinfaunal features were present.
  • Vikfors, Sofia (Helsingin yliopisto, 2020)
    Microplastics (MPs) are widespread environmental pollutants that have been detected in virtually all environmental compartments. Despite this, research has mainly focused on the impacts of microplastic on shorelines and at sea. The effects of MPs on terrestrial ecosystems has been sparsely investigated, and there are only a few studies on direct effects on terrestrial plants. Although plastic polymers are considered inert and non-hazardous, toxic additives are often added to the polymers during manufacture which may leach out into the environment, displaying ecotoxic effects. In this work, the effects of microplastic particles and microplastic leachate on the germination and growth of Lolium multiflorum (Italian ryegrass) was investigated. High density polyethylene (HDPE), which is one of the plastic polymers with the largest annual production, was chosen as the plastic material for investigation. New MPs, artificially aged MPs, MPs from the Lahti region, and MPs from Port Elizabet, South Africa was used in parallel to compare the effects of ageing and regional environmental factors on the ecotoxicity of MPs. The total germination percentage, mean germination rate, synchronization index, germination index, and time to 50% germination was investigated, as well as the root lengths, shoot lengths, root/shoot ratio, and fresh weights of the seedlings. The results showed that exposure to new and Lahti MPs and leachates severely inhibited the extent and speed of the germination of L. multiflorum, whereas all categories of MPs and leachates inhibited the growth to some extent. Most severe inhibition in germination and growth was seen for the new MP and new leachate, followed by Lahti MP and Lahti leachate. The root growth, shoot growth, and plant biomass were also severely reduced for these exposure media. For the aged and Port Elizabeth material, there were slight but significant (p < 0.05) inhibition in root lengths and fresh weights, but no significant inhibition in the germination parameters. These findings indicate that ageing severely reduces the ecotoxic effects of MPs, and that regional environmental factors affect the ecotoxicity of MPs. Microplastics from Port Elizabeth were significantly less toxic to L. multiflorum than MPs from the Lahti region, possibly due to the warmer climate in South Africa. Another explanation could be that the plastic material collected in Port Elizabeth wast older than the one from Lahti. There was little to no difference in germination and growth between seeds exposed to MPs or leachates of the same origin, indicating that it is the substances leaching out of the MPs that are responsible for their ecotoxicity.
  • Karimaa, Anna-Elina (Helsingin yliopisto, 2021)
    Pollinator abundance and diversity are declining at an alarming rate around the world, which poses a threat to ecosystem stability and human wellbeing. There are signs that growing pollination deficits are limiting agricultural yields in Finland and globally. More information is urgently needed on how changes in pollinator communities affect crop yields and how adequate pollination services could be achieved across a range of crops and locations. This study explores the effects of pollinator abundance and diversity on caraway (Carum carvi L.) pollination and yield. Caraway is partly wind-pollinated, but insect pollination has been shown to increase its yield. Flower visits of pollinating insects were monitored on 30 caraway fields in southern Finland in summer 2019. Yield samples were collected from open-pollinated plants and from control plants excluded from pollinators. Pollinator exclusion reduced caraway fruit set by 13.2% and seed yield by 39.6%. Fruit set, 100-seed weight and seed yield increased with increasing flower visitation. Pollinator species richness and Shannon index had no significant effect on the yield components, but evenness of the pollinator community had a negative effect on seed yield and the numbers of umbels and umbellets in the caraway plants. The most abundant pollinators visiting caraway were syrphid flies, non-syrphid Diptera and honeybees. Visits by syrphid flies and honeybees increased seed yield, while visits by non-syrphid Diptera, solitary bees and Lepidoptera had no significant effect on the yield components. Flower visits by beetles reduced 100-seed weight. The results show that syrphid flies provide an important pollinator service for caraway cultivation. It would be beneficial to study which syrphid fly species are the most effective pollinators for caraway and how to manage fields and farmland landscapes to increase their numbers. Relying only on managed honeybees to enhance caraway pollination may not be advisable due to their potential negative effects on wild pollinators. While increased pollinator diversity did not improve caraway pollination or yield in this one-season study, it may be important for the stability of pollinator services in long term.
  • Syrjälä, Sami (Helsingin yliopisto, 2021)
    Electronic waste is the fastest growing type of waste stream in the world, and this development results from the rapidly accelerating digitalization. Electronic devices become obsolete on an accelerating speed, as there are constantly more powerful devices coming to the market. The most significant environmental impacts of this development are greenhouse gas emissions and natural resource consumption. Circular economy has been proposed as a solution to these environmental challenges, and the goal of this approach is to preserve the value of the materials in the circulation as efficiently as possible. One way of implementing the principles of circular economy is the product-as-a-service-based business model. This research examines the differences between the product-as-a-service-based model and ownership-based model in terms of the environmental impacts that are related to the laptop and tablet procurements. The results of this thesis will be utilized in implementing the actions of the City of Helsinki’s Roadmap for Circular and Sharing Economy. This research was conducted as streamlined life cycle assessment, in which the systematic literature review was used for tracking the environmental impacts of the products’ life cycle stages and components. In addition, expert interviews were carried out in order to collect information about the reuse and recycling practices of the supplier companies that follow these previously mentioned business models. Finally, based on the results of the systematic literature review and the interviews, the company specific differences were assessed in terms of the greenhouse gas emissions and material waste that result from the procurements. The City of Helsinki’s annual procurement volumes were used in this assessment. Based on the results of this research, production and use are the most significant life cycle stages in terms of the devices’ greenhouse gas emissions. Printed circuit boards/printed wiring boards, integrated circuits, displays, and casings are the components with the most significant impact. The results suggest that increasing the lifespan of the devices provides opportunities for significantly lowering impacts in both impact categories, if the devices are efficiently recycled after this.