Browsing by study line "Ympäristömuutos"

Climate change is expected to cause salinity change in the Baltic Sea and therefore may affect organisms living in the Baltic such as plankton. The microbial loop is an important part of the plankton food web. It consists of heterotrophic bacteria, nanoflagellates and ciliates and is connected with the classic plankton food chain through interactions with primary producers and mesozooplankton. Therefore, salinity affects the functioning of the microbial food web not only directly, but also through salinity induced changes on primary producers and mesozooplankton. In this master’s thesis I studied the effects of salinity change on microbial loop components bacteria, nanoflagellates and ciliates in an outdoor mesocosm experiment containing four salinity treatments with salinities of 3.5, 5.5, 7.5 and 9.5, three replicas each. The experiment took place offshore at the Tvärminne Zoological Station. Bacteria were sampled from the mesocosms every other day and nanoflagellates and ciliates every 6th day. Bacteria were analysed with the flow cytometer, nanoflagellates with epifluorescent microscopy and ciliates using an inverted microscope. The effects of salinity on microbial loop components were statistically tested using linear mixed effects models. Results of the experiment show that salinity had an indirect effect on microbial loop components through changes in mesozooplankton composition. There were significant differences between high and low salinity treatments in bacteria abundance and composition, the interaction strength between HNFs and bacteria and in the mean cell size of ciliate communities. These were mainly caused by differences in mesozooplankton community structure between salinity treatments, which had cascading effects on the strength of top-down and bottom-up control on the trophic levels of the microbial loop, leading to changes in bacteria abundances and composition. Based on the results of this thesis, more studies are needed to detect the effects that changes in the composition and functioning of the microbial loop might have on the ecosystem. Further research should also focus on the significance of the structure and diversity of the communities within the microbial loop as well as the functional roles of different species in the microbial food web.

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.

In teleost fish, various egg traits play a crucial role in the development, growth, and survival of the offspring and thus affect maternal reproductive success. Atlantic salmon (Salmo salar) is a species where age at maturity, an important life-history trait influencing reproductive success, is under environmental and genetic control. In this study, I assessed how genetics of the vgll3 genotype and the dietary energy content affect egg traits and female maturation rate. The fish used in this study were lab-bred, three-year- old female Atlantic salmon with different vgll3 genotypes fed on one of two diets differing in energy content. The eggs traits included in the study were egg size, lipid, and protein content. Female maturation rate was not affected by the energy level of the diet or the vgll3 genotype. Egg size expressed as egg dry weight differed between females in the two feed treatments. These differences may be attributed to the increased lipid content of the eggs due to the higher fat content of the maternal diet. Females receiving high energy feed had a significantly higher egg lipid content compared to the low energy feed treatment. Females homozygous for the vgll3 allele associated with early maturity had a significantly lower egg lipid content in comparison to the females homozygous for the vgll3 late maturity allele indicating a potential reproductive fitness cost associated with early maturity. No effect of diet or vgll3 was found in egg protein content. This study provides the first evidence of vgll3 not only affecting Atlantic salmon age at maturity, as found in previous studies, but also egg lipids through maternal provisioning of nutrients.

Microplastics are widely studied subject and have raised concern towards water security worldwide but the vector effect of microplastic has not yet fully understood. In this study the ability of microplastic to attach hydrophobic organic compounds is tested with a nonsteroidal anti-inflammatory drug diclofenac. The ability to attach hydrophobic organic compounds has been proved by microplastics but not with diclofenac. Diclofenac is also causing water security threats nearby wastewater treatment plants because it is biologically active and can cause stress to the aquatic organisms even in small quantities. The aim of this study is to see if microplastic has vector effect for the diclofenac. If microplastic retains diclofenac on its surface area it would decrease the stress factor effect of diclofenac towards the investigated macroalgae Aegagropila linnaei. The possible change of oxidative stress levels in A. linnaei is measured by peroxidase enzyme activity. The aim is to see if the enzyme activity raises or decreases when A. linnaei is exposed to microplastic with and without diclofenac. If the peroxidase enzyme activity decreases in macroalgae while exposing A. linnaei to both microplastic and diclofenac it would strengthen the vector effect hypothesis. As a result, the peroxidase enzyme activity seems to have a decreasing trend when the diclofenac concentrations increase. Diclofenac affected to peroxidase enzyme activity but microplastic does not show any signs of binding of diclofenac in this study, and therefore microplastic cannot act as a vector for diclofenac.

Luontosuhde on noussut tärkeäksi tutkimuskohteeksi muun muassa ympäristövastuullisen käyttäytymisen ja ihmis-ten hyvinvoinnin tutkimuksessa. Ihmisen ja luonnon suhteeseen liittyvä käsitteistö on kuitenkin vielä hyvin haja-naista, ja itse termi ”luontosuhde” voi viitata useampiin eri asioihin. Tämän työn tärkeimpänä tavoitteena on muo-dostaa yhtenäinen, kokonaisvaltaiseen tarkasteluun ohjaava käsitteellinen kehys luontosuhdetutkimuksen käyttöön ja toisaalta työkaluksi ympäristökasvatukseen. Työssä tarkastellaan tieteidenvälisesti sitä, miten luontosuhde käsitetään luontosuhdetutkimuksessa. Työssä etsitään Galtungin-Kuitusen tiedekäsityksen mukaisesti vastauksia kysymyksiin “Miten asioiden pitäisi [luontosuhdetutki-muksessa] olla?”, “Miten asiat ovat nyt?” ja “Miten asioita tulisi kehittää?” Näiden kolmen kysymyksen mukaan muotoiltiin kolme tutkimustehtävää, joita ratkotaan kokonaisvaltaisen lähestymistavan, hermeneuttisen kehän ja ab-duktiivisen päättelyn tuella. Vastauksena kysymykseen ”miten asioiden pitäisi olla?” muodostetaan käsitteellis-teoreettisesti kokonaisvaltaisen luontosuhdekäsityksen kehys, jolla pyritään tavoittamaan luontosuhteen monet eri puolet ja ilmenemistavat. Kehys koostuu kolmesta tasosta, joilla luontosuhdetta voidaan tarkastella. Lähtökohtana ja kehyksen ensimmäisenä tasona on näkemys luontosuhteesta ihmisen suhteena luonnon kokonaisuuteen, jonka osa hän systeemeineen itsekin on. Kehyksen toisella tasolla tarkastellaan käsityksiä ihmisen ja todellisuuden inhimillisen ulottuvuuden (esim. kaupun-git, tietokoneet, ajatusrakennelmat) kuulumisesta luontoon sekä ihmisen oman ekologisen ulottuvuuden, sisäisen luontomme, roolia osana luontosuhdetta. Kolmannella tasolla luontosuhde jäsennetään neljään eri ulottuvuuteen: ekologinen, tajunnallinen, toiminnallinen ja sosiokulttuurinen. Kehyksen avulla analysoidaan systemoidun kirjallisuuskatsauksen keinoin luontosuhdetutkimusten käsityksiä luon-tosuhteesta (vastauksena kysymykseen ”miten asiat ovat?”). Aineistoksi rajattiin 28 luontosuhdetutkimusta rapor-toivaa artikkelia. Tutkimuksista tunnistettiin neljä erilaista luontosuhdekäsityksen tyyppiä. Kokonaisuudessaan luon-tosuhdetutkimuksissa painottui luontosuhteen tajunnallisen ulottuvuuden sekä ihmisen ja muun luonnon suhteen tut-kiminen. Ihmisen omaa ekologista ulottuvuutta käsiteltiin hyvin harvassa tutkimuksessa. Todellisuuden inhimillinen ulottuvuus taas asetettiin läpi aineiston luonnon ulkopuolelle, ja useissa tutkimuksissa se kuvattiin ihmisen luonnosta eriyttävänä tekijänä. Systemoituun kirjallisuuskatsaukseen sisältyi teoriaohjaava sisällönanalyysi, jossa selvitettiin luontosuhdekäsitysten lisäksi luontosuhdetutkimusten kehityskohtia vastauksena kysymykseen “miten asioita tulisi kehittää?” Luontosuh-detutkimuksen käyttöön ehdotetaan kolmea, työssä muodostetun kokonaisvaltaisen luontosuhdekäsityksen mukaista välinettä, joista yksi soveltuu erityisen hyvin myös ympäristökasvatuksen välineeksi. Työn tulosten perusteella luon-tosuhdetutkimuksessa tulisi nostaa selvemmin esiin erityisesti luontosuhteen ilmeneminen myös todellisuuden inhi-millisen ulottuvuuden kautta sekä ihmisen oman ekologisen ulottuvuuden rooli luontosuhteen kokemisessa.