The role of environmental factors in methane fluxes in north boreal catchment area

Kasvillisuuden ja kasvien toiminnallisten ryhmien tarkastelu on olennainen osa metaanivoiden mallinnusta ja siihen liittyvien prosessien arviointia, koska kasvillisuus ilmentää paikallisia metanogeneesiin ja metaanin hapetukseen vaikuttavia abioottisia ympäristöoloja, sekä itsessään vaikuttaa metaanivoihin joko suoraan tuottamalla metaania tai epäsuorasti kemiallisten ja fysikaalisten ominaisuuksiensa kautta metanogeenien toimintaan. Tutkimuksessani tarkastellaan erilaisten kasvillisuustyyppien metaanivoita kasvukauden aikana Muonion Pallaksella pohjoisboreaalisella valuma-alueella. Tutkimus keskittyy määrittelemään toiminnallisten kasviryhmien, biomassan ja yhteyttävän lehtipinta-alan sekä erilaisten abioottisten ympäristötekijöiden rooleja eri kasvillisuustyyppien metaanivoissa. Metaanivoita mitattiin kammiomittausmenetelmällä 23 pisteestä kesäkuun alusta elokuun puoliväliin kahden viikon välein. Samoista pisteistä kerättiin kasvillisuuteen ja muihin ympäristötekijöihin liittyvää aineistoa. Aineisto jaoteltiin kasvillisuustyyppeihin ordinaatioanalyysin avulla, minkä jälkeen metaanivoiden ja ympäristötekijöiden suhdetta näissä tyypeissä mallinnettiin lineaarisen sekamuuttujamallin (LMER) ja yleistetyn additiivisen mallin (GAM) avulla. Karkeassa jaotteluanalyysissä kasvillisuustyyppejä määritettiin neljä, jotka olivat kuivimmasta kosteimpaan kangas, korpi, räme ja neva. Märimmällä kasvillisuustyypillä havaittiin korkeimmat metaaniemissiot (ka 5959 µg/m²/h) ja suurin voiden vaihtelu (s 5285 µg/m²/h). Suomaiset kasvillisuustyypit toimivat metaanin lähteinä ja vaikutus voimistui kohti kasvukauden kliimaksia. Kuivin kasvillisuustyyppi toimi nettona metaanin nieluna, vaihtelu oli pientä (s 117 µg/m²/h) ja vuot hyvin vähäisiä (ka -107 µg/m²/h) edellisiin verrattuna. Abioottisten tekijöiden rooli metaanivoiden määrittäjänä oli suurin kuivemmissa kasvillisuustyypeissä. Toiminnallisia ryhmiä korostuneempi metaanivoiden bioottinen säätelijä oli kasvillisuuden kokonaisbiomassa. Abioottisten tekijöiden suhteellinen rooli pieneni ja toiminnallisten kasviryhmien rooli kasvoi märemmissä kasvillisuustyypeissä. Toiminnallisista ryhmistä sara- ja heinäkasvit olivat etenkin märemmissä kasvillisuustyypeissä yhteydessä korkeampiin metaaniemissioihin. Metsäsammalet ja erilaiset varvut olivat yhteydessä mataliin päästöihin tai metaanin sidontaan. Muiden toiminnallisten ryhmien vaikutus metaanivoihin vaihteli enemmän eikä niistä voitu tehdä yhtenäisiä johtopäätöksiä. Tutkimuksen perusteella mikään ympäristömuuttuja ei yksin selitä metaanivoita kovin hyvin, vaan metaanitase on usean tekijän yhteinen summa sekä koko aineistoa että sen osia tarkasteltaessa. Kunkin toiminnallisen ryhmän rooli metaanivoiden muodostumisessa oli hyvin riippuvainen ympäröivästä laajemmasta kasvillisuustyypistä ja lajistosta. Tutkimusta erilaisten ympäristötekijöiden ja kasvillisuustyyppien yhteisvaikutuksesta metaanivoihin on jatkettava ja tarkennettava, jotta voidaan tuottaa riittävän tarkkoja arvioita laajojen alueiden metaanitaseista ja saavuttaa riittävä ymmärrys ympäristön- ja ilmastonmuutoksen mekanismeista.Environmental factors are important tools in constructing methane flux models and estimations. Among the abiotic factors, plants and their functional groups have been noted to have significant effect on methane fluxes for three reasons. First, the vegetation community compositions express their abiotic environmental factors that affect not only the plants, but also local methanogen and methanotroph communities. Second, the vegetation itself might produce methane emissions and have a direct effect on methane balance. Third, the plant functional groups and species have differences in their chemical and physical properties that support different methanogen communities and therefore have an indirect impact on methane fluxes. In this study, methane fluxes of different plant communities were observed during one growing season in northern boreal catchment area in Muonio. Study focuses to determine the link between methane fluxes and abiotic and biotic environmental factors in different vegetation types. Closed chamber technique was used to measure methane and carbon dioxide fluxes from 23 plots every two weeks in period of June-August. Environmental data, such as moisture, temperature species composition etc. were collected from the plots. Vegetation types for each plot were determined via ordination analysis. Linear mixed-effects regression model and generalized additive model were applied and compared to observe the relationships of methane and environmental factors in different vegetation types. Dataset was divided into four vegetation types in clustering analysis: wet fen, pine bog, spruce swamp and forest. The greatest amount (average 5959 µg/m²/h) and biggest range (standard deviation 5285 µg/m²/h) of methane emissions were observed on wettest fen-like study sites. Peatland types in general acted as net methane sources. The driest, forest-like vegetation type acted as a net methane sink. The amount (average -107 µg/m²/h) and range (standard deviation 117 µg/m²/h) of methane fluxes were very moderate in comparison to peatland types. These effects intensified towards the climax of growing season. The most significant environmental factors were mostly abiotic on driest study sites and the whole plant biomass was more significant biotic methane flux regulating factor than plant functional groups. On wetter study sites, the role of abiotic factors decreased, and plant functional group increased. Graminoids were linked to bigger methane emissions especially on wetter study sites. Forest mosses and different shrub types seemed to have a link with lower methane emissions or methane absorption. The effect of other plant functional groups on methane fluxes varied more, and their role remains unclear. None of the environmental factors could estimate the methane flux alone, and the methane budget seems to be a sum of multiple variables in each vegetation type. The role of plant functional groups varied in different vegetation types and was dependent on surrounding vegetation. More research is needed to get better tools to estimate methane balance and to understand the underlying mechanisms in climate and environmental change

Sytokiniinioksidaasigeenin yliekspression vaikutus lituruohon juuren jälsisolukon sekundääriseen kasvuun ja Dof-geeniperheen ekspression karakterisointi

Opinnäytetyön tarkoituksena oli karakterisoida Dof-mutanttilinjojen geeniekspressiota, sekä selvittää estradiolilla indusoitavan sytokiniinioksidaasigeenin yliekspression vaikutusta kasvin fenotyyppiin ja löytää saatujen tietojen avulla lupaavat linjat jatkotutkimuksia varten. Sytokiniinioksidaasigeenin yliekspressiolinjojen CKX30 ja CKX32 analysoiminen perustuu T-DNA-insertion avulla tehtävään mutaatioon, jossa estradioli-indusointi saa aikaan sytokiniinia hajottavan proteiinin liikatuotannon. Sytokiniini on tärkeä osatekijä juurten sekundäärisessä kasvussa. Mutaation vaikutuksia lituruohon fenotyyppiin arvioitiin tarkkailemalla RFP-ekspression voimakkuutta ja sijaintia juuressa, sekä vertailemalla estradioli-indusoitujen mutanttilinjojen juurten sekundääristä kasvua DMSO-kontrollimaljalla kasvaneiden saman mutanttilinjan edustajien, sekä villityypin (Columbia) linjojen kehitykseen. Dof1-, Dof2- ja Dof3-mutanttilinjat tuotettiin laboratoriossa kasvattamalla transgeeniset bakteerikannat, jotka transformoitiin villityypin kasveihin. T-DNA-insertiovektorin transformaatiossa käytettiin floral dip–menetelmää. Geenin ekspressioalueita pyrittiin karakterisoimaan RFP- ja GUS-merkkigeenien avulla. Keskeisinä tuloksina homotsygooteista CKX-linjoista löytyi 4 tilastollisesti merkitsevää linjaa, joissa esiintyy mahdollinen sekundääriseen kasvuun vaikuttava fenotyyppi. Suurin ero villityypin ja ohuimman mutanttilinjan (CKX32 9-5) välillä oli –269 μm, ja estradioli- ja DMSO-maljoilla kasvatettujen saman mutanttilinjan edustajien välillä oli -220 μm. Saatujen tietojen avulla voidaan karsia useita tutkittavia mutanttilinjoja pienestä otoksesta huolimatta. Dof1- ja Dof2-linjojen GUS-ekspressio sijoittui parenkyymisolukkoon koko juuren pituudelta, kun Dof3-linjassa ekspressio näkyi kaikkialla solukossa, mutta vain vanhimmissa juurten osissa.The aim of this thesis was to characterise the location of Dof gene expression in the roots of Arabidopsis thaliana mutant lines, and analyse how over-expression of estradiol induced cytokinin oxidase gene effects to root phenotype. In cytokinin oxidase over-expression lines CKX30 and CKX32 a T-DNA-insertion causes a gene mutation that leads to overproduction of cytokinin disruptive protein when exposed to estradiol. Cytokinin is an important operator in the secondary growth of the root. The conclusions were made by observing the location and intensiveness of RFP-expression and comparing the secondary growth of induced mutant lines to non-induced identical mutant lines and wild type plants. The thickness of the root were measured from cross sections taken 0.5 cm below hypocotyl. Dof1, Dof2 and Dof3 lines were produced in laboratory by growing transgenic bacterial strains containing T-DNA-insertion vector and transforming them to wild type plants using floral dip method. The location of gene expression could be visualized by using RFP and GUS marker genes. As the mainline results were found 4 statistically significant mutant lines, which possibly had phenotype modifications having an impact to secondary growth of the root. The big-gest difference between the most tenuous estradiol induced plants compared to DMSO and wild type controls were shown in line CKX32 9-5. In this line the width of the estradiol induced roots were –269 μm in comparison to DMSO controls and -220 μm in comparison to wild type. The purpose of this study was to help narrow down the amount of cambium mutant gene plant lines, and help for further research. GUS expression in Dof1 and Dof2 lines were located in parenchyma cells. In Dof3 line, GUS expression appeared only in the developmentally older parts of the root, but didn’t seem to be specific to any cell type

Detecting peatland vegetation patterns with multi-temporal field spectroscopy

doi: 10.1080/15481603.2022.2152303Peatlands are one of the most significant terrestrial carbon pools, and the processes behind the carbon cycle in peatlands are strongly associated with different vegetation patterns. Handheld spectroradiometer data has been widely applied in ecological research, but there is a lack of studies on peatlands assessing how the temporal and spectral resolution affect the detectability of vegetation patterns. We collected field spectroscopy and vegetation inventory data at two northern boreal peatlands, Lompolojankka and Halssiaapa, between late May and August 2019. We conducted multivariate random forest regressions to examine the appropriate periods, benefits of multi-temporal data, and optimal spectral bandwidth and sampling interval for detecting plant communities and the two-dimensional (2D) %-cover, above-ground biomass (AGB) and leaf area index (LAI) of seven plant functional types (PFTs). In the best cross-site regression models for detecting plant community clusters (PCCs), R-2 was 42.6-48.0% (root mean square error (RMSE) 0.153-0.193), and for PFT 2D %-cover 53.9-69.8% (RMSE 8.2-17.6%), AGB 43.1-61.5% (RMSE 86.2-165.5 g/m(2)) and LAI 46.3-51.3% (RMSE 0.220-0.464 m(2)/m(2)). The multi-temporal data of the whole season increased R-2 by 13.7-24.6%-points and 10.2-33.0%-points for the PCC and PFT regressions, respectively. There was no single optimal temporal window for vegetation pattern detection for the two sites; in Lompolojankka the early growing season between late May and mid-June had the highest regression performance, while in Halssiaapa, the optimal period was during the peak season, from July to early August. In general, the spectral sampling interval between 1 to 10 nm yielded the best regression performance for most of the vegetation characteristics in Lompolojankka, whereas the optimal range extended to 20 nm in Halssiaapa. Our findings underscore the importance of fieldwork timing and the use of multi-temporal and hyperspectral data in detecting vegetation in spatially heterogeneous landscapes.Peer reviewe

Detecting peatland vegetation patterns with multi-temporal field spectroscopy

Peatlands are one of the most significant terrestrial carbon pools, and the processes behind the carbon cycle in peatlands are strongly associated with different vegetation patterns. Handheld spectroradiometer data has been widely applied in ecological research, but there is a lack of studies on peatlands assessing how the temporal and spectral resolution affect the detectability of vegetation patterns. We collected field spectroscopy and vegetation inventory data at two northern boreal peatlands, Lompolojänkkä and Halssiaapa, between late May and August 2019. We conducted multivariate random forest regressions to examine the appropriate periods, benefits of multi-temporal data, and optimal spectral bandwidth and sampling interval for detecting plant communities and the two-dimensional (2D) %-cover, above-ground biomass (AGB) and leaf area index (LAI) of seven plant functional types (PFTs). In the best cross-site regression models for detecting plant community clusters (PCCs), R2 was 42.6–48.0% (root mean square error (RMSE) 0.153–0.193), and for PFT 2D %-cover 53.9–69.8% (RMSE 8.2–17.6%), AGB 43.1–61.5% (RMSE 86.2–165.5 g/m2) and LAI 46.3–51.3% (RMSE 0.220–0.464 m2/m2). The multi-temporal data of the whole season increased R2 by 13.7–24.6%-points and 10.2–33.0%-points for the PCC and PFT regressions, respectively. There was no single optimal temporal window for vegetation pattern detection for the two sites; in Lompolojänkkä the early growing season between late May and mid-June had the highest regression performance, while in Halssiaapa, the optimal period was during the peak season, from July to early August. In general, the spectral sampling interval between 1 to 10 nm yielded the best regression performance for most of the vegetation characteristics in Lompolojänkkä, whereas the optimal range extended to 20 nm in Halssiaapa. Our findings underscore the importance of fieldwork timing and the use of multi-temporal and hyperspectral data in detecting vegetation in spatially heterogeneous landscapes

Clonal dissemination of successful emerging clone mecA-MRSA t304/ST6 among humans and hedgehogs in the Helsinki metropolitan area in Finland

Methicillin-resistant Staphylococcus aureus (MRSA) carrying mecC gene (mecC-MRSA) is frequently reported among European hedgehogs (Europeaus erineaus) due to co-evolutionary adaptation to dermatophyte infection in European hedgehogs. The occurrence of MRSA in European hedgehogs in Finland is unknown. Consequently, we investigated the occurrence of MRSA in wild hedgehogs from urban Helsinki metropolitan area in 2020–2021 and applied whole genome sequencing (WGS) to further characterize the studied isolates and compared them with human clinical MRSA isolates. Altogether 115 dead hedgehogs were screened for MRSA using selective cultivation methods. Presumptive MRSA isolates were tested for antimicrobial susceptibility and confirmed MRSA isolates were further characterized by spa-typing and WGS. Hedgehog derived MRSA isolates were compared with clinical human MRSA isolates using core genome multilocus sequence typing (cgMLST). In total MRSA was recovered from 11 out of 115 (10%) hedgehogs. Among these four different spa types (t304; n = 4, t8835; n = 4, t5133; n = 2 and t622; n = 1) and three different sequence types (STs) (ST6; n = 6, ST7663; n = 4 and ST2840; n = 1) were identified. From the studied MRSA isolates seven harboured the mecA gene (mecA-MRSA) and four were identified as mecC-MRSA. All mecA-MRSA isolates carried immune evasion cluster genes, and one isolate was positive for Panton-Valentine leukocidin. cgMLST comparison revealed close genetic relatedness among three hedgehog and two human mecA-MRSA isolates all belonging to t304/ST6. Our results suggest a clonal dissemination of a successful MRSA clone among humans and hedgehogs. Further studies are warranted to investigate the sources and dissemination of such clone in urban environments. We observed a relatively low occurrence of mecC-MRSA in Finnish hedgehogs.Methicillin-resistant Staphylococcus aureus (MRSA) carrying mecC gene (mecC-MRSA) is frequently reported among European hedgehogs (Europeaus erineaus) due to co-evolutionary adaptation to dermatophyte infection in European hedgehogs. The occurrence of MRSA in European hedgehogs in Finland is unknown. Consequently, we investigated the occurrence of MRSA in wild hedgehogs from urban Helsinki metropolitan area in 2020–2021 and applied whole genome sequencing (WGS) to further characterize the studied isolates and compared them with human clinical MRSA isolates. Altogether 115 dead hedgehogs were screened for MRSA using selective cultivation methods. Presumptive MRSA isolates were tested for antimicrobial susceptibility and confirmed MRSA isolates were further characterized by spa-typing and WGS. Hedgehog derived MRSA isolates were compared with clinical human MRSA isolates using core genome multilocus sequence typing (cgMLST). In total MRSA was recovered from 11 out of 115 (10%) hedgehogs. Among these four different spa types (t304; n = 4, t8835; n = 4, t5133; n = 2 and t622; n = 1) and three different sequence types (STs) (ST6; n = 6, ST7663; n = 4 and ST2840; n = 1) were identified. From the studied MRSA isolates seven harboured the mecA gene (mecA-MRSA) and four were identified as mecC-MRSA. All mecA-MRSA isolates carried immune evasion cluster genes, and one isolate was positive for Panton-Valentine leukocidin. cgMLST comparison revealed close genetic relatedness among three hedgehog and two human mecA-MRSA isolates all belonging to t304/ST6. Our results suggest a clonal dissemination of a successful MRSA clone among humans and hedgehogs. Further studies are warranted to investigate the sources and dissemination of such clone in urban environments. We observed a relatively low occurrence of mecC-MRSA in Finnish hedgehogs.Peer reviewe

New national and regional biological records for Finland 11. Contributions to Bryophyta and Marchantiophyta 10

Ten species of mosses (Bryophyta: Entosthodon obtusus, Entosthodon ulvinenii, Eurhynchiastrum diversifolium, Hedwigia emodica, Hedwigia mollis, Hygrohypnum styriacum, Plagiothecium rossicum, Polytrichum perigoniale, Tortella alpicola and Ulota intermedia) are presented as new for Finland. Cephalozia lacinulata, previously considered to be regionally extinct from Finland, is reported to being found again. New records in biogeographical provinces for 67 species of mosses and 34 species of liverworts are listed. Finally, 6 occurrences in provinces are removed due to misidentifications or missing specimens

Water flow controls the spatial variability of methane emissions in a northern valley fen ecosystem

Northern peatlands are projected to be crucial in future atmospheric methane (CH4) budgets and have a positive feedback on global warming. Fens receive nutrients from catchments via inflowing water and are more sensitive than bogs to variations in their ecohydrology. Yet, due to a lack of data detailing the impacts of moving water on microhabitats and CH4 fluxes in fens, large uncertainties remain with respect to predicting CH4 emissions from these sites under climate changes. We measured CH4 fluxes with manual chambers over three growing seasons (2017-2019) at a northern boreal fen. To address the spatial variation at the site where a stream flows through the long and narrow valley fen, we established sample plots at varying distances from the stream. To link the variations in CH4 emissions to environmental controls, we quantified water levels, peat temperature, dissolved oxygen concentration, vegetation composition, and leaf area index in combination with flux measurements during the growing season in 2019. We found that due to the flowing water, there was a higher water level, cooler peat temperatures, and more oxygen in the peat close to the stream, which also had the highest total leaf area and gross primary production (GPP) values but the lowest CH4 emissions. CH4 emissions were highest at an intermediate distance from the stream where the oxygen concentration in the surface peat was low but GPP was still high. Further from the stream, the conditions were drier and produced low CH4 emissions. Our results emphasize the key role of ecohydrology in CH4 dynamics in fens and, for the first time, show how a stream controls CH4 emissions in a flow-through fen. As valley fens are common peatland ecosystems from the Arctic to the temperate zones, future projections of global CH4 budgets need to take flowing water features into account.Peer reviewe

Clonal dissemination of successful emerging clone mecA-MRSA t304/ST6 among humans and hedgehogs in the Helsinki metropolitan area in Finland

Methicillin-resistant Staphylococcus aureus (MRSA) carrying mecC gene (mecC-MRSA) is frequently reported among European hedgehogs (Europeaus erineaus) due to co-evolutionary adaptation to dermatophyte infection in European hedgehogs. The occurrence of MRSA in European hedgehogs in Finland is unknown. Consequently, we investigated the occurrence of MRSA in wild hedgehogs from urban Helsinki metropolitan area in 2020–2021 and applied whole genome sequencing (WGS) to further characterize the studied isolates and compared them with human clinical MRSA isolates. Altogether 115 dead hedgehogs were screened for MRSA using selective cultivation methods. Presumptive MRSA isolates were tested for antimicrobial susceptibility and confirmed MRSA isolates were further characterized by spa-typing and WGS. Hedgehog derived MRSA isolates were compared with clinical human MRSA isolates using core genome multilocus sequence typing (cgMLST). In total MRSA was recovered from 11 out of 115 (10%) hedgehogs. Among these four different spa types (t304; n = 4, t8835; n = 4, t5133; n = 2 and t622; n = 1) and three different sequence types (STs) (ST6; n = 6, ST7663; n = 4 and ST2840; n = 1) were identified. From the studied MRSA isolates seven harboured the mecA gene (mecA-MRSA) and four were identified as mecC-MRSA. All mecA-MRSA isolates carried immune evasion cluster genes, and one isolate was positive for Panton-Valentine leukocidin. cgMLST comparison revealed close genetic relatedness among three hedgehog and two human mecA-MRSA isolates all belonging to t304/ST6. Our results suggest a clonal dissemination of a successful MRSA clone among humans and hedgehogs. Further studies are warranted to investigate the sources and dissemination of such clone in urban environments. We observed a relatively low occurrence of mecC-MRSA in Finnish hedgehogs

New national and regional biological records for Finland 11 : Contributions to Bryophyta and Marchantiophyta 10

Ten species of mosses (Bryophyta: Entosthodon obtusus, Entosthodon ulvinenii, Eurhynchiastrum diversifolium, Hedwigia emodica, Hedwigia mollis, Hygrohypnum styriacum, Plagiothecium rossicum, Polytrichum perigoniale, Tortella alpicola and Ulota intermedia) are presented as new for Finland. Cephalozia lacinulata, previously considered to be regionally extinct from Finland, is reported to being found again. New records in biogeographical provinces for 67 species of mosses and 34 species of liverworts are listed. Finally, 6 occurrences in provinces are removed due to misidentifications or missing specimens.peerReviewe