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Browsing by study line "Ympäristömuutos"

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  • Maamela, Katja (2021)
    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.
  • Horten, Hannah (2021)
    Methane (CH4) is a powerful greenhouse gas that has been increasing in total atmospheric concentration since the late 1980s. While more of this gas is being produced through anthropogenic sources, a significant part is still produced by microbial methanogenesis. This process, in combination with atmospheric CH4, provides methane oxidizing bacteria, methanotrophs, with consumable CH4. In this way, methanotrophs are an important part of the CH4 cycle. Most models estimating changes to CH4 concentrations as a result of increasing anthropogenic byproducts often fail to consider the importance of these bacteria as a sink. Methanotrophs have been long studied, but more still needs to be discovered about their functionality in varying ecosystem types. These microbes are cosmopolitan, found in diverse environments across the globe. In this study, soil samples collected from a boreal forest in Pallas, FI were used to measure how well soil properties can be used to approximate potential CH4 oxidation rate. The abundance of methanotrophs was analyzed in soils ranging from upland to peatland using qPCR targeting the methanotrophic bacteria specific pmoA alpha-subunit of the methane monooxygenase gene. Soil samples were also analyzed for microbial biomass, percent carbon, and percent nitrogen. Sample pH and bulk density were also measured. Significant correlations were observed for bulk density and soil layer type (pearsons r = 0.659, p-value = 0.027), pH and percent carbon (pearsons r = -0.582, p-value = 0.014), pH and bulk density (pearsons r = 0.778, p-value = 0.002), and low affinity potential CH4 oxidation rate and microbial biomass in upland and peat-forest ecosystem types (pearsons r = -0.569, p-value = 0.043). Methanotroph abundance was significantly correlated with potential oxidation rates at low and high affinity conditions when analyzed across all sampling locations (pearsons r = 0.854 p-value = 1.27e-05; pearsons r = 0.602, p-value = 0.011). Methanotroph abundance and potential CH4 oxidation under both low and high affinity conditions were not found to be significantly correlated in upland and peat-forest soils alone when peatland samples were omitted. Soil properties show a moderate accuracy to predict high affinity potential oxidation uptake in upland and peat-forest soils when trained using all sample data. The soil properties used in this analysis do not show any ability to predict potential CH4 oxidation under low affinity conditions. All model findings are exploratory and further testing and development would be necessary to strengthen the findings.
  • Kovakoski, Elina (2020)
    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.
  • Värre, Ulla (2018)
    Arvoja pidetään eräinä perimmäisistä yksilöiden ja yhteisöjen toimintaa ohjaavista tekijöistä. Ne esimerkiksi kuvaavat toivottuja lopputuloksia ja menettelytapoja. Tiettyjen ympäristömuutosten mieltäminen ympäristöongelmiksi on myös sidoksissa arvoihin. Politiikassa arvot ohjaavat tavoitteiden asettamista ja keinojen valitsemista tavoitteiden saavuttamiseksi. Tässä tieteidenvälisessä työssä tarkastellaan suomalaista ympäristöpolitiikkaa arvojen valossa. Sosiaalipsykologisen arvoteorian ja ympäristötieteen pohjalta muodostettu viitekehys ohjasi arvo-puheen tarkastelua viiden suomalaisen eduskuntapuolueen ympäristöpoliittisissa ohjelmissa tai niitä vastaavissa asiakirjoissa. Mukana olivat Kansallisen Kokoomuksen, Kristillisdemokraattien, Suomen Keskustan, Suomen Sosialidemokraattisen puolueen ja Vihreän Liiton ohjelmat. Työssä selvitettiin, millaiset arvot ympäristöpolitiikassa vaikuttavat, ja keitä arvojen mukainen toiminta niissä koskee – millainen on ympäristöpolitiikan moraalinen universumi. Analyysi toteutettiin teorialähtöisen laadullisen sisällönanalyysin keinoin: ympäristöpoliittisista ohjelmista etsittiin arvojen ja moraalisen universumin ilmauksia, joiden pohjalta analysoitiin arvopuheen laatua sekä yhtäläisyyksiä ja eroja puolueiden välillä. Ympäristöpoliittinen puhe oli ohjelmissa moniarvoista. Puolueiden ohjelmat olivat keskenään varsin samankaltaisia. Ympäristöpolitiikan tavoitteissa tavallisimpia olivat universalistiset luontoarvot; tärkeänä pidettiin esimerkiksi monimuotoisuuden säilyttämistä. Seuraavaksi tärkeimpiä olivat edellisille vastakkaiset resursseihin liittyvät valta-arvot; ympäristöpolitiikalla pyrittiin resurssien hyödyntämiseen ja talouskasvuun. Turvallisuusarvot olivat myös tärkeitä. Ympäristöpolitiikan keinoissa taas painottuivat suomalaisille tyypilliset työarvot, kuten yhteistyö, määrätietoisuus ja aktiivisuus, sekä koulutusarvot. Lisäksi niissäkin keskityttiin valta-arvoihin. Normeihin liittyviä yhdenmukaisuusarvoja edusti esimerkiksi sääntely. Ohjelmien moraalinen universumi oli laaja: se ulottui kaikilla puolueilla koko ihmiskuntaan. Neljässä viidestä ohjelmasta tuotiin lisäksi esiin ympäristökeskustelussa tavallinen tulevien sukupolvien edusta huolehtiminen. Muut lajit kuuluivat moraaliseen universumiin vain kolmessa ohjelmassa. Poliittisessa keskustelussa käytetty arvopuhe voi osaltaan muovata yhteiskunnan arvoja. Universalististen luontoarvojen korostuminen voi ohjata ympäristöystävällisyyteen myös yksilöiden tasolla. Sitä, miten toisilleen vastakkaisiin universalismi- ja valta-arvoihin vetoaminen vaikuttaa, on kuitenkin vaikea arvioida. Laaja moraalinen universumi on lupaava pohja kompleksisten kestävyys-kysymysten ratkaisemiseen.
  • Salminen, Pihla (2018)
    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.
  • Larsson, Aron (2021)
    The science of fish stock assessment is one that is very resource and labor intensive, with stock assessment models historically being based on data that causes a model to overestimate the strength of a population, sometimes with drastic consequences. The need of cost-effective assessment models and approaches increases, which is why I looked into using Bayesian modeling and networks as an approach not often used in fisheries science. I wanted to determine if it could be used to predict both recruitment and spawning stock biomass of four fish species in the north Atlantic, cod, haddock, pollock and capelin, based on no other evidence other than the recruitment or biomass data of the other species and if these results could be used to lower the uncertanties of fish stock models. I used data available on the RAM legacy database to produce four different models with the statistical software R, based on four different Bayes algorithms found in the R-package bnlearn, two based on continuous data and two based on discrete data. What I found was that there is much potential in the Bayesian approach to stock prediction and forecasting, as our prediction error percentage ranged between 1 and 40 percent. The best predictions were made when the species used as evidence had a high correlation coefficient with the target species, which was the case with cod and haddock biomass, which had a unusually high correlation of 0.96. As such, this approach could be used to make preliminary models of interactions between a high amount of species in a specific area, where there is data abundantly available and these models could be used to lower the uncertanties of the stock assessments. However, more research into the applicability for this approach to other species and areas needs to be conducted.
  • Heinonen, Reija (2020)
    Mining of sulfide minerals produces acidic effluents rich in soluble metals and sulfate. The effluents pose a risk to the environment and must therefore be treated prior to their release. Conventionally, effluents are neutralized, and remaining metals are precipitated as hydroxides by means of alkaline minerals or industrial chemicals. The process leads to a formation of large amounts of disposable sludge containing valuable metals. Efforts are needed for more sustainable and resource efficient water treatment in the spirit of circular economy. Nanofibrillated cellulose (NFC) adsorbents are a promising and sustainable alternative to conventional treatments as cellulose is the most abundant natural polymer. In addition, NFC can be prepared from industrial byproducts and its surface properties can easily be modified to adsorb pollutants with different chemical properties. Understanding the adsorption mechanisms is essential for the rational development and use of NFC in water treatment and environmental protection in the future. Based on previous studies, anionic NFC retains metal cations and sulfate anions simultaneously from aqueous solutions. However, the adsorption mechanisms in conditions comparable to e.g. authentic mining water with high metal salt concentrations are poorly understood. In this Master’s Thesis work, adsorption experiments with pure metal salt solutions of increasing metal concentrations (0-800 mM) were carried out to investigate the adsorption mechanisms of metal cations and anions. Based on previous studies five cations with different chemical properties were chosen: Na⁺, Mg²⁺, Mn²⁺, Al³⁺ ja Fe³⁺. The adsorption was examined in both metal chloride and sulfate solutions to also elucidate the co-adsorption of counter ions and their possible effects on metal adsorption on NFC. The Freundlich adsorption isotherm model was utilized to analyze the adsorption of metals. In addition, removal percentages were calculated for both metal cations and their counter anions. NFC was observed to retain all metal cations equally regardless of their different properties and pH-values of the metal salt solutions. The removal percentage of both cations and anions ranged mainly between 14–20 % and the removal capacity of NFC decreased only slightly with increasing initial concentrations. No remarkable differences were observed in the adsorption isotherms of different metals and the adsorption was almost linear in the whole concentration range. Despite the relatively low removal percentages, the amounts of metals adsorbed by NFC (mmol/g dry weight) were tenfold compared to those previously obtained in many studies. According to the results, NFC adsorbed cations non-specifically with weak interactions and the dominating adsorption mechanism resembles physical rather than chemical adsorption. Upon the adsorption of cations, an equal amount of negative charge was co-adsorbed and hence the adsorption of anions was deemed electrostatic in nature.
  • Juurinen, Valtteri (2022)
    Opinnäytetyössä tutkittiin olosuhteiden muutosten vaikutusta torjunta-ainepitosuuksiin pilot-mittakaavan sedimenttipylväissä ja suodatinpylväissä. Pilot-mittakaavan pylväissä verrattiin ilmastuksen ja veden virtauksen muutosten vaikutusta pitoisuuksiin. Suodatinpylväissä tarkasteltavina tekijöinä oli orgaanisen aineen ja nollaraudan vaikutus torjunta-ainepitoisuuksiin. Tutkittavina torjunta-aineina olivat atratsiini, simatsiini, heksatsinoni ja diklobeniili, sekä hajoamistuotteet DIA, DEA, DEDIA ja BAM. Kyseisiä torjunta-aineita esiintyy pohjavesissä useissa eri Euroopan maissa mukaan lukien Suomi, vaikka niiden käyttö on lopetettu ja kielletty EU:n alueella useita vuosia sitten. Pylväistä analysoidut ulostulovedet valmisteltiin kaasukromatografia-massaspektrometria (GC-MS) mittausta varten kiinteäfaasiuutolla. Suodatinpylväiden torjunta-aineiden puhdistuskapasiteetti vaihteli testikertojen välillä ja yhdisteet käyttäytyivät eri tavalla suhteessa toisiinsa. Ensimmäisen kuukauden jälkeen talousveden raja-arvo 0,10 µg/l ylittyi heksatsinonin osalta. Toisen kuukauden jälkeen heksatsinonin pitoisuus ylitti jälleen talousveden raja-arvon, niin kuin myös BAM:n. Sitten viimeisellä testikerralla kohonneita yli 0,1 µg/l pitoisuuksia oli atratsiinilla ja heksatsinonilla. BAM:n ja heksatsinonin kulkeutuminen oli odotettavissa yhdisteiden ominaisuuksien perusteella ja niiden hajoaminen on hidasta verrattuna muihin yhdisteisiin. Puolestaan atratsiinin kohonneet pitoisuudet voidaan selittää maaperän kiintoaineksen liikkumisella suodatinpylväästä torjunta-aineiden kanssa. Pelkän hiekan vaikutus suodatinpylväissä aliarvioitiin, mikä vaikutti erityisesti BAM:n ja heksatsinonin pitoisuuksiin.
  • Hanström, Neea (2022)
    Heterobasidion genus fungi are the most significant pathogens in Finland causing root rot. These fungi infect Norway spruce (Picea abies), causing wood deficit in the forest industry. Leucoanthosyanidin reductase enzyme encoding gene, PaLAR3, has been linked in to the resistance of Norway spruce against H.parviporum induced root rot infections. The alleles in this locus can be AA, AB or BB, and the enzyme production and (+)-catechin concentrations have been proven to be higher in inoculation experiments in individuals with B allele present in their PaLAR3 locus. Climate change is predicted to increase disturbances in not only on the hydrological cycles, but also on the weather conditions. The drought is predicted to increase in the Northern hemisphere, increasing the risk of pathogens to spread into new areas. Forest breeding programs aim to make the forests more profitable and productive in the future as well. By studying the genetics of Norway spruce, it is possible to add more resilient individuals into the breeding program, to tackle the climate challenges the future might hold. In this Master’s thesis the spreading of the root rot infection under drought stress was studied. The PaLAR3 alleles were determined, and the area of necrosis caused by the fungal infection was compared against the alleles, watering treatments and the fungal strain used in the inoculations. Regarding the results the alleles in an individual’s PaLAR3 locus did not have any effect on the area of the necrosis. There were no statistically significant differences between the watering treatments. The only statistically significant result was that the different fungal strains’ (Hpa1 and Hpa2) infectiveness varied between different watering treatments. This is probably due to the different routes of pathogenesis. Hpa2 strain seems to be more infective in normal watering conditions. However, considering these results the PaLAR3 gene should not be added into the forest breeding program as itself. In the future, the research should focus more on gene interactions, since also other genes (e.g., PaLAC5) have been linked in the resistance against root rot infections in Norway spruce. By studying these genes together, the solutions for the deteriorating situation of the spreading of the fungal diseases could be discovered.
  • Tuominen, Adele (2020)
    Tekstiiliteollisuudessa käytetään merkittäviä määriä kemikaaleja, joista osa on ympäristölle ja terveydelle haitallisia. Tekstiiliteollisuuskehityksen kasvaessa ja kulutuskäytäntöjen kiihtyessä pois heitettävän tekstiilin määrä lisääntyy. Samalla haitalliset kemikaalit vapautuvat saastuttamaan ihmistä ja ympäristöä. Tämä käy ilmi aiemmasta tutkimuksesta, vaikka poistotekstiilien ympärillä tehty tutkimus on muutoin vähäistä. Tämä tutkimus tehdään yritysyhteistyössä Lounais-Suomen Jätehuolto Oy:n kanssa määrittämään poistotekstiilien lajittelutyön yhteydessä ilmeneviä terveysvaikutuksia ja sovellettavia testimenetelmiä yrityksen tarpeisiin. Tutkielman tavoitteena oli ensisijaisesti selvittää kemikaalien, pölyn ja homeen terveysvaikutukset ja ne testimenetelmät, joita tulisi terveysvaikutusten vähentämiseksi tehdä. Muiden tutkimuskysymysten osalta tarkoituksena oli selvittää poistotekstiilien sisältämät merkittävimmät haitalliset kemikaalit ja niiden enimmäisraja-arvot. Näitä tutkittiin tutkimuksen teoreettisessa viitekehyksessä. Tutkimuksessa käytettiin laadullista tutkimussuuntausta ja sen menetelmiä. Aineiston keruumenetelmänä oli asiantuntijahaastattelu, jossa tietoja kerättiin puolistrukturoidun kysymyksenasettelun kautta neljältä asiantuntijataholta: Turun ammattikorkeakoululta, Terveyden- ja hyvinvoinninlaitokselta, Työterveyslaitokselta ja Aalto-yliopistolta. Haastattelut toteutettiin puhelinhaastatteluina. Aineistoa analysoitiin temaattisen sisällönanalyysin avulla, jossa aineisto luokiteltiin tutkimuksen kannalta merkittävimpiin teemoihin. Saatuja tuloksia verrattiin olemassa olevaan tutkimuskirjallisuuteen. Hengitystievälitteinen altistuminen yksistään pölylle nähtiin merkittävimmäksi terveysriskiksi laitosolosuhteissa. Kemikaalien, pölyn ja homeen aiheuttamien terveysvaikutusten vähentämiseksi soveltuvimpina testimenetelminä nähtiin erilaisten keräävien menetelmien käyttö ja biomonitorointi. On selvää, että poistotekstiilit sisältävät ihmisen terveydelle ja ympäristölle haitallisia kemikaaleja, pölyä ja homeita. Testimenetelmiä hyödyntämällä voidaan terveysriskejä paikantaa ja niiden osuutta työperäisessä altistumisessa vähentää. Tutkimustulosten tieteellisen luotettavuuden lisäämiseksi on suositeltavaa, että laitoksella otetaan käyttöön kokeelliset testausmenetelmät.
  • Pulli, Launo (2020)
    In many Fennoscandian lakes, diatoms account for majority of phytoplankton biomass during the spring and autumn maximum. Autumnal blooms of filament-forming diatoms are known to cause fishing net fouling in several boreal lakes. Observations of such net sliming diatom blooms in the northern part of Lake Vesijärvi have increased during 2010’s. This thesis was done in collaboration with Lake Vesijärvi Foundation. The goal was to determine the starting time of the autumnal diatom bloom of 2018 and reveal the species that causes net sliming. Additionally, differences in water quality and phytoplankton composition between Enonselkä and Kajaanselkä basins were examined. Fishing net sliming was studied with netting experiments. Their results were complemented with water quality sampling and observing water column mixing conditions. Local fishermen reported net sliming to begin at week 40 (starting 1.10.2018) in Kajaanselkä basin during autumnal turnover. Results of netting experiments and water quality sampling revealed simultaneous increase in diatom abundance in the area, although no visible sliming occurred during sampling. Based on fishers’ reports and sampling results, fishing net sliming was caused by filament-forming diatom Aulacoseira islandica, that increased in abundance as water temperature reached ca. 11 °C. In Enonselkä, no similar net sliming was observed, and phytoplankton was dominated by cyanobacteria Planktothrix agardhii. Both basins of the lake are affected by eutrophication, but Enonselkä basin more so than Kajaanselkä. Although no clear explanation for differing phytoplankton composition between the two basins was discovered, it’s possible that Aulacoseira islandica receives competitive edge over cyanobacteria in mildly eutrophic waters of Kajaanselkä basin. The fact that Planktothrix agardhii seems to thrive in higher nutrient concentrations might explain its domination over diatoms in phytoplankton community of Enonselkä basin. Future research on net sliming would ideally be conducted as a combination of sliming accounting done by local fishermen and spatially and temporally more comprehensive netting experiments. Furthermore, studying the effects of wind and currents to diatom distribution in lakes could provide useful information for sampling setup.
  • Kuuri-Riutta, Olivia (2021)
    Global warming is changing the ecohydrology and carbon fluxes of northern peatlands. If the soil moisture level remains high enough, peatland carbon sequestration may increase under longer and warming growing seasons, enhancing the cooling climate impact of peatlands. However, in case the evaporation overcomes precipitation, peatlands will dry. This leads to increased carbon dioxide emissions and the weakening of the cooling climate effect of peatlands. In addition, peatland methane fluxes are regulated by temperature and moisture conditions. What remains unknown, is which changes will be the most prominent and to which direction the climate impact of peatlands will develop in the future. The purpose of this thesis is to gain a better understanding of the peatland climate responses by investigating the recent vegetation development of a subarctic aapa mire. In August 2020, four surface peat cores were collected from the margin of Lompolojänkkä fen in Finnish Lapland. Recent changes in plant communities and carbon accumulation rates were investigated. Pb-210 dating method was applied to establish the chronology. A shift from a Cyperaceae-dominated community into a Sphagnum-dominated community in the beginning of the 1960s was detected. The shift indicates drying habitat conditions. Recent drying has been reported from several other northern peatlands. On the other hand, a similar expansion of Sphagna has been interpreted to be caused not only by hydrological changes but also directly by increasing temperatures, which cannot be ruled out in Lompolojänkkä either. Carbon accumulation in Lompolojänkkä seems to have increased following the change in the vegetation. However, the inferred increase might largely reflect an incomplete level of decomposing characteristic to surface peat. In contrast to the peatland margins, no drying signals or vegetation changes were observed in the central parts of Lompolojänkkä. This variation within a single peatland highlights the heterogeneous nature of peatland climate responses and carbon dynamics.
  • Pursiainen, Annie (2020)
    Introduction: High anthropogenic pressure exercised on the Baltic Sea causes a decline in valuable reproduction areas of coastal fish, such as the northern pike (Esox lucius L.). Hence, the conservation and restoration of the reproduction areas of pike are increasingly of importance. The Kvarken Archipelago, located in the Gulf of Bothnia, presents valuable reproduction habitats for fish. The pre-flads, flads, glo-flads and glo-lakes provide warm and sheltered areas that are preferred by spring-spawning fish, such as pike. However, the precise environmental factors influencing pike reproduction in the region have not yet been identified. In this study, different environmental factors influencing pike reproduction in the Kvarken Archipelago were assessed. Furthermore, as technology advances, there is a need to evaluate the use of new techniques alongside the generally time consuming and expensive traditional research methods applied for surveying the pike reproductive areas. Henceforth, the present study assessed the suitability of the high-resolution aerial photography for identifying potential reproduction areas of northern pike. Methods: The data of pike fry density, the vegetation, the abiotic and biotic environmental factors, as well as the aerial images of the 45 sampling sites were collected by Natural Resources Institute Finland and Metsähallitus Parks and Wildlife Finland as part of the Kvarken Flada -project. Pike fry were sampled with a flat dipnet amongst vegetation along a 100 m sampling line during spring. Concurrently, the vegetation, the occurrence of sticklebacks (Gasterosteidae) and the abiotic factors affecting water quality, including salinity, pH, oxygen content and turbidity were determined. The temperature was recorded with temperature loggers from early spring until late summer. The temperature sum for June showed the greatest effect on pike fry densities and was thus used in the analyses. The archipelago zones, which are based on previously modelled temperature sums, were defined for the sampling sites in the geographic information system (QGIS). Additionally, factors describing the morphology, the vegetation and bottom substrate coverage of the sampling sites were utilized in the analyses. The presence of pike fry was analysed with binary logistic regression. The pike fry densities were studied using non-parametric analyses due to the high number of zero observations in the data. The aerial images were taken in late summer of 2017 and 2018, when the vegetation was fully developed. The vegetation types, i.e. reed, fallen reed, wetland grasses, submerged vegetation and filamentous algae, identified in the images were compared to the vegetation data gathered during field survey in QGIS. The performance of the aerial images was assessed by calculating the accuracy, sensitivity and specificity for the different vegetation classes, first for the whole dataset and then for the sampling points with pike fry observations. Results and conclusions: This study determines two key factors defining suitable reproduction areas of pike, the temperature sum for June and the morphology of the sampling site. The results indicate that pike prefer warm and sheltered areas with suitable vegetation, such as reed and wetland grasses. In particular, glo-lakes provide favorable conditions for pike and the temperature sum for June was significantly higher in the glo-lakes compared to the pre-flads. The temperatures of the glo-lakes were constant throughout the archipelago, providing suitable conditions for pike reproduction also in the outermost archipelago. In all of the glo-lakes pike fry were observed and generally the highest pike fry densities were found in glo-lakes. However, the year class strength of pike can be affected by the possibility of the juvenile pike to emigrate from the enclosed glo-lakes back to the sea. Salinity reflects the connectivity of the site to the surrounding sea and had a significant negative effect on pike fry density. Additionally, the presence of sticklebacks affected negatively the presence of pike fry, which might be traced back to the different use of the archipelago zones and site morphologies of these species. Increasing pH negatively influenced the pike fry density. However, pike fry were observed also in the highest pH conditions and therefore pH alone is not sufficient to explain the presence and density of pike fry. Due to the small sample size of the dataset, it can be assumed that not all of the factors influencing pike reproduction were identified and thus the use of a larger dataset is recommendable in future studies. This study provides new methodological information on reproduction area surveying of pike with high-resolution aerial photography. The different vegetation classes were successfully identified from the aerial images. The seasonal differences were noticeable in the results, as in the aerial photographs taken in late summer, the vegetation was fully developed compared to the field study in early spring. Nevertheless, aerial photography proved to be an effective method for identifying reproduction areas of pike based on the vegetation. Furthermore, reproduction areas in need of restoration could be assessed with aerial photography.
  • Rajala, Salla (2022)
    Tiivistelmä * Referat * Abstract Brownification is a serious environmental problem, which means a substantial increase in water color. Suggested reasons for brownification are soil recovery from acidification, land-use change, especially ditching, climate change. Brownification changes the light conditions in the lakes, increases thermal stratification, and sedimentation. Despite the considerable effects of brownification on lake ecosystem, currently in the EU Water Framework Directive, there is no sufficient biological indicator for lake browning. Biological indicators of the Water Framework Directive are mainly targeted to eutrophication, and thus are not sufficient for measuring the effects of brownification. Macrophyte chlorophyll a:b ratio has been shown to decrease with decreasing light conditions, thus making it a potential indicator for browning. The seasonal variation of macrophyte chlorophyll content is not well studied. This master’s thesis aims to find out, how the chlorophyll content of yellow water lily (Nuphar lutea) changes during the growing season in lakes with variable water quality. N. lutea was chosen as a study species, as it is very common in different lakes in Finland. It is important to study the seasonal variation of the macrophyte chlorophyll content, because if the chlorophyll content reacts rapidly for example changes in the weather, it might be too sensitive to be used as a long-term indicator for lake browning. It is also needed to study, if the seasonal variation is different in lakes with variable water quality, so that in the future, the possible sampling can be timed right in different lakes. The study lakes were clear water lakes, humic and eutrophic lake, and their water quality and the chlorophyll content of N. lutea were examined with two weeks intervals from June to September. The concentration of chlorophyll a and chlorophyll b were measured from the floating leaf and from the petiole at 10 cm intervals. Based on these, the total chlorophyll concentration (CHL a+b) and CHL a:b ratio was calculated. In addition to macrophyte samples, water samples were taken from each lake from both epilimnion and hypolimnion. From the water samples, dissolved organic carbon, water color, iron concentration and specific ultraviolet absorbance at 254 nm were measured. In addition, water temperature, light intensity, oxygen concentration and water turbidity were measured at each sampling time. The results of this thesis showed, that the CHL a:b ratio, and total CHL concentration (a+b) were significantly lower in the humic than in the clear water lake. In the eutrophic lake, CHL a:b ratio and CHL a+b concentration was higher than in the humic lake but lower than in the clear water lake. In each lake, the CHL a:b ratio increased during the growing season, together with the increasing water clarity. The change in the CHL a:b ratio was detected best in the 10-30 cm petiole depth. In the floating leaf, CHL a:b ratio and CHL a+b concentration varied a lot, meaning that the floating leaf is not a sufficient indicator for brownification. The change in CHL a:b ratio took approximately 5 to 7 weeks, and the seasonal variation was similar in each lake. Based on the results of this thesis, the CHL a:b ratio of the N. lutea petiole seems to be a very promising long-term indicator for lake browning. In the future, it would be, however, important to study, how the carbon sequestration changes as a result of brownification, if the macrophyte chlorophyll concentration decreases, since this might have considerable effects on lake carbon sequestration. Also, the eutrophic study lake of this thesis had a water color over 100 mg Pt l-1, so it would be important to study, what is the macrophyte chlorophyll content in clear, but eutrophic lakes.
  • Manninen, Juulia (2022)
    Immune-mediated diseases, such as various allergies and asthma, are increasing rapidly in an urbanized world where biodiversity is steadily declining. Decreased biodiversity and homogenous microbiota have been associated with weaker immune defence. Studies show that contact with the natural environment enriches the human microbiota, promotes immune response, and protects against allergies and inflammatory diseases. For this reason, in order to prevent immune-mediated diseases, solutions have been sought from nature-based approaches in which the immune system encounters environmental microbial stimuli in a natural way. The aim of this master's thesis was to study how different nature-based materials (sod and forest floor) affect the skin microbiota of kindergarten-age children and to examine how different factors such as varying weather conditions and different sampling times affect the results. The results supported the hygiene hypothesis and previous research according to which increasing biodiversity can have a positive effect on human skin microbial communities. A positive effect on children's skin was achieved with sod alone, which is important information in the development of suitable biodiverse materials for urban planning. The results also supported the surmise that different weather conditions and sampling methods can significantly affect the results.
  • Atti, Sanna (2021)
    Underwater light climate in mountain lakes is controlled by dissolved organic carbon concentrations and by lake ice regimes. Both are affected by local, regional and global variables linked to anthropogenic disturbances such as climate change and atmospheric pollution. Aim of this work was to investigate changes in underwater light climate over the past ~200 years in two oligotrophic mountain lakes and how it reflects on diatom (Bacillariophyceae) guild distribution. For these aims, diatom communities and ecological guilds were analyzed from sediment core and contemporary habitat samples along a depth gradient. In addition, sediment inferred chlorophyll a (CHLa) and lake water total organic carbon (TOC) were analyzed to detect development of primary production and lake water carbon content. Results showed that acidification of the lakes together with climate induced changes have been important drivers of the ecology of the lakes. Lake water TOC showed a decline and subsequent increase in line with the acidification and subsequent recovery of the lakes, likely affecting underwater light climate in the lakes. However, this did not reflect unambiguously into changes in diatom functionality. Warming has likely contributed to diversification of the diatom community over the study period while no distinct increases were observed in whole lake primary production. Overall, if the present study could not distinguish the exact role of underwater light in driving changes in diatom communities and functional traits, the result show that human pressures have left distinct imprints in the development of biotic communities in these remote mountain lakes.
  • Laiho, Helene (2022)
    Mercury (Hg) is a heavy metal acknowledged as a worldwide contaminant that accumulates in organisms and biomagnifies in food webs. The organic methylmercury (MeHg) species is harmful to animals, including humans, and mainly derived from the diet. The dietary Hg consumed by fish is mostly removed through the intestine, but some of the MeHg bioaccumulates, especially in the white muscle tissue of fish. Perch (Perca fluviatilis) and roach (Rutilus rutilus) are commonly found fish species in Finland. Perch has additional im-portance as it is the national fish of Finland, a popular food fish, as well as a monitoring species used to evaluate the chemical status of lakes. Seasonal variation of Hg in muscle tissue of fish is supposedly caused by starvation in winter, which condenses Hg in the muscle, and growth dilution in summer, which refers to fast somatic growth during the growing season, which dilutes Hg in the muscle. Similar to winter, spawning has also been found to condense Hg in muscle tissue of fish due to high energy investment into gonad development. Seasonal variation of Hg and variables driving seasonal changes have been shown to differ between fish species. Seasonal variation has been studied mainly during the open-water season. However, less is known about how winter conditions under ice affect Hg levels in fish. In this MSc thesis, I asked (Q1) How total mercury (THg) content in the muscle tissue of perch and roach change annually? (Q2) How THg bioaccumulation in the muscle tissue of perch and roach change annually? (Q3) What are the factors explaining annual variation in THg content in the muscle tissue of perch and roach? The practical application of results was to discuss if annual variation should be considered in monitoring programs and human health questions. The materials used in this study were collected from Lake Pääjärvi monthly from March 2020 to March 2021. Fish were collected using gillnet series. Length, weight, sex, sexual maturity, stomach fullness, Fulton’s condition factor (K), and muscle THg were determined from each fish. The annual length-corrected THg content variation was tested using analysis of variance. The annual THg bioaccumulation variation in the relationship between muscle and fish length was tested using simple linear regression analysis, and the seasonal variation in THg bioaccumulation was tested with LOESS regression analysis. Variables affecting seasonal variation were tested with stepwise multiple linear regression analysis. THg content of perch was the highest in winter and spring and the lowest in fall, while roach showed no significant seasonal variation. THg bioaccumulation of both species was highest in winter, spring, and early summer and lowest in fall. Perch displayed more substantial seasonal variation than roach. Biological and environmental variables that explained the THg content of perch were length, ice thickness, gonadosomatic index (GSI), light, and condition factor. Variables that explained the THg content of roach were length, sex, and total phosphorus (Tot-P). This study confirmed that starvation in winter, growth dilution in summer, and spawning in spring/early summer are vital factors driving seasonal variation. Due to evident seasonal variation, monitoring month should be pre-set in current monitoring programs.
  • Mattila, Bernd-Niklas (2020)
    Cladocerans play a key role in the aquatic ecosystem. They are abundant in lakes and are an essential part in the carbon and energy transfer of the food webs. These species are, however, prone to various environmental changes. Estimates have shown that dissolved organic carbon (DOC) concentrations in northern lakes are likely to increase in the future. This increase of DOC in lakes has multiple impacts ranging from nutrient levels to shading impacts reducing primary productions. Investigating changes in cladocerans along a DOC gradient could help us understand how these species might develop in the future in our changing climate. In this Master’s Thesis, I studied how the cladoceran body length and community structure varied between 9 lakes with dissolved organic carbon (DOC) concentration ranging from 2.4-33.5 mg l-1. For the analyses, these lakes where divided into two groups with a threshold of 12 mg l-1 or into groups of three based on their DOC concentrations. Then, the results were compared with cladoceran length data from an earlier study. Additionally, the changes in phytoplankton abundances and communities as well as the relation between DOC concentration and other environmental variables were analysed. The results showed an increase in the cladoceran body length above the DOC threshold. Moreover, the changes in body length varied between the studied genera. Both Ceriodaphnia sp. and Diaphanosoma sp. body length decreased in groups with higher DOC concentrations while Bosmina sp. were larger at high DOC concentrations. DOC concentration did not have any significant effect on the community structure of zooplankton. The studied lakes varied from their environmental condition making comparisons and general statements challenging. The results indicated that DOC concentration regulates the planktonic communities, but it is solely an imprecise predictor for changes in zooplankton communities. However, cladoceran densities seemed to benefit from increased DOC concentrations as nutrient levels also increased. Changes in cladoceran body lengths were challenging to interpret, because there are multiple factors that can have an impact both alone and combined with others.
  • Torvinen, Ida (2022)
    More than half of the global population lives in urban areas. Urban sprawl and densification have affected urban ecosystems and the services they provide. Urban vegetation is one of the most important providers of ecosystem services. Previous studies have shown that plant functional type and age of parks/trees affect soil properties in urban environments. However, knowledge on the effects of plant roots on ecosystem services is limited. In this thesis I focused on exploring the contribution of root biomass to soil carbon and nitrogen accumulation under evergreen and deciduous trees in urban greenspaces. In addition, I explored how soil properties differ based on tree type and age of the park/tree, and how sampling distance from the tree affects root biomass and soil properties. Soil samples were taken at five distances: 1) under the canopy (midway between the trunk and the canopy edge), 2) at the canopy edge, and 3)–5) 1 m apart, starting from the canopy edge. This transect of five distances was replicated three times per tree (30 trees in total). Trees belonging to two functional types were sampled, evergreen (mostly Norway spruce, Picea abies (L.) H. Karst.) and deciduous (Linden, Tilia x europaea L.) trees. Sampling was done in young (ca. 15 years) and old (>70 years) urban parks in Lahti and Helsinki. The results show higher root biomass under young trees than old trees, and spruces had higher root biomass compared to lindens. Root biomass was positively correlated with soil organic matter, soil carbon and soil nitrogen. Sampling distance from the tree affected both root biomass and soil properties in young and old parks. Plant functional type affected soil organic matter, soil carbon, C/N ratio and acidity, but not soil nitrogen. Irrespective of tree type, soil properties varied less in old parks than in young parks between the sampling distances. Soils under old spruces had higher total carbon content compared to young spruces, whereas for lindens, tree age affected soil carbon less on. Total nitrogen content was higher in old parks than in young parks for both tree types. My study provides new information about how park tree roots affect urban park soil carbon and nitrogen accumulation. There are no previous studies on how far this root effect extends, and my study fills this knowledge gap. My results show that tree roots are an important factor in urban park carbon stocks. I also showed that age of the park/tree has an evident effect on urban soil properties. In the light of my research findings, it seems that a significant portion of ecosystem services provided by urban vegetation is produced underground.
  • Mäkelä, Iida (2021)
    Microbial diversity can be found everywhere around us. The diversity is however declining globally and the diversity loss is most visible in highly urbanized areas. The lack of microbial biodiversity has been linked to increased risk of certain im-mune mediated diseases most prevalent within urban population. Understanding how diversity differs between urban and rural areas can help us to figure out mechanisms behind biodiversity loss and higher frequency of immune-mediated dis-eases and develop prevention methods for the latter. The aim of the thesis is to study how bacterial communities differ between urban and rural areas using indicator species as proxy. The aim is also to find out if the results support the biodiversity hypothesis. The results of the thesis found out significant differences in diversity indexes between bacterial communities in urban and rural areas, which supports the biodiversity hypothesis. The study also found differences in Proteobacteria diversity index-es, which have been linked to some immune mediated diseases in previous studies.