71 research outputs found

    Undrained peatland areas disturbed by surrounding drainage : A large scale GIS analysis in Finland with a special focus on aapa mires

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    Half of the Finnish peatland area is drained for forestry. The remaining undrained peatlands are not all pristine, because surrounding drainage may disturb their hydrology. This concerns especially aapa mires, which are dependent on hydrological connections to their upper catchments. We investigated the amount and sizes of Finnish undrained peatlands, the drainage state of their margins, and the naturalness of aapa mires in large (> 50 ha) undrained peatland areas, using a GIS analysis based on digital map data, aerial images and an elevation model. The results show that a majority (66.7 % of count, 84.7 % of area) of undrained peatland areas have at least partly drained margins. Drainage activities commonly disturb minerotrophic water discharge to aapa mires. In the middle boreal zone, on average 41.6 % (median 42.8 %) of the catchment area of aapa mires is such that hydrological connection with the mire is disturbed by intervening drainage. In the southern boreal zone, the figure is 25.1 % (median 16.1 %), and in the southern part of the northern boreal zone 24.2 % (median 9.9 %). Possible implications of the disturbances include tree encroachment, hummock formation and fen–bog transition, which is likely to cause a loss of biodiversity but could potentially increase peat growth and carbon sequestration

    PRELI is a mitochondrial regulator of human primary T-helper cell apoptosis, STAT6, and Th2-cell differentiation

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    The identification of novel factors regulating human T helper (Th)–cell differentiation into functionally distinct Th1 and Th2 subsets is important for understanding the mechanisms behind human autoimmune and allergic diseases. We have identified a protein of relevant evolutionary and lymphoid interest (PRELI), a novel protein that induces oxidative stress and a mitochondrial apoptosis pathway in human primary Th cells. We also demonstrated that PRELI inhibits Th2-cell development and down-regulates signal transducer and activator of transcription 6 (STAT6), a key transcription factor driving Th2 differentiation. Our data suggest that calpain, an oxidative stress–induced cysteine protease, is involved in the PRELI-induced down-regulation of STAT6. Moreover, we observed that a strong T-cell receptor (TCR) stimulus induces expression of PRELI and inhibits Th2 development. Our results suggest that PRELI is involved in a mechanism wherein the strength of the TCR stimulus influences the polarization of Th cells. This study identifies PRELI as a novel factor influencing the human primary Th-cell death and differentiation

    Inarijärven tilan kehittyminen vuosina 1960–2009

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    Inarijärvestä on olemassa kohtuullisen hyvin tutkimus- ja seurantatietoa usean vuosikymmenen ajalta, mikä antaa hyvät mahdollisuudet järven tilaa ja sen kehittymistä kuvaavien mittareiden kehittämiseen ja hyödyntämiseen. Työssä pyrittiin löytämään tutkimus- ja seuranta-aineistoon perustuvia mittareita, jotka kuvaavat monipuolisesti Inarijärven tilaa ja käyttöä, etenkin järven yleisiä hydrologisia ja meteorologisia olosuhteita ja niiden kehittymistä (ilmastonmuutos), järveen tulevaa kuormitusta ja veden laatua, virkistyskäyttöä, rantavyöhykkeen eliöyhteisöjen tilaa, kalakantoja ja kalastusta sekä säännöstelykäytäntöä ja säännöstelyn vaikutuksia. Tavoitteena oli kuvata myös eri muuttujien välisiä vuorovaikutuksia. 2000-luvulla toteutetulla Inarijärven vesiluonnon tilan kannalta aikaisempaa paremmalla säännöstelykäytännöllä on parannettu virkistyskäytön olosuhteita kesällä ja osittain vähennetty säännöstelyn aiheuttamia haittoja rantavyöhykkeen eliöstöön. Vesistön tilan ja käytön kannalta eniten myönteisiä muutoksia on tapahtunut kalakannoissa. Punalihaisten petokalojen saaliit, yksikkösaaliit ja saaliskalojen koko ovat suurentuneet 2000-luvulla hyvän muikkukannan ja tuloksellisten istutusten ansiosta. Inarijärven hydrologisissa mittareissa on havaittavissa merkkejä ilmaston lämpenemisestä. Julkaisu tarjoaa kattavan yhteenvedon Inarijärven tilasta ja sen kehittymisestä viime vuosikymmeninä. Raportin tuloksia voidaan hyödyntää mm. säännöstelykäytännön ja kalaston hoidon kehittämisessä sekä matkailussa, opetuksessa ja yleisessä viestinnässä. Tarkastelu tukee myös vesienhoitotyötä, koska se auttaa ymmärtämään biologisten laatutekijöiden tilaan vaikuttavia tekijöitä ja selittämään syitä järven ekologisen tilan kehityssuunnille. Työssä kehitettyä lähestymistapaa ja mittareita voidaan soveltuvin osin hyödyntää myös muissa vesistöissä

    The effects of peatland restoration on water-table depth, elemental concentrations, and vegetation: 10 years of changes. Restor. Ecol

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    Abstract We studied the effects of restoration on water-table depth (WTD), element concentrations of peat and vegetation composition of peatlands drained for forestry in southern Finland. The restoration aimed to return the trajectory of vegetation succession toward that of undisturbed systems through the blockage of ditches and the removal of trees. Permanent plots established on a bog and a fen were sampled 1 year before, and 1, 2, 3, and 10 years after the restoration. The restoration resulted in a long-term rise of the water-table in both peatlands. Ten years after restoration, the mineral element concentrations (Ca, K, Mg, Mn, and P) of peat corresponded to those reported from comparable pristine peatlands. In particular, the increase of K and Mn concentrations at both sites suggests the recovery of ecosystem functionality in terms of nutrient cycling between peat and plants. The restoration resulted in the succession of plant communities toward the targeted peatland vegetation of wetter condition at both sites. This was evident from the decreased abundance of species benefiting from drainage and the corresponding increase of peatland species. However, many species typical of pristine peatlands were missing 10 years after restoration. We conclude that the restoration led to a reversal of the effects of drainage in vegetation and studied habitat conditions. However, due to the slow recovery of peatland ecosystems and the possibility that certain failures in the restoration measures may become apparent only after extended time periods, long-term monitoring is needed to determine whether the goals of restoration will be met

    An artificial intelligence approach to remotely assess pale lichen biomass

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    Although generally given little attention in vegetation studies, ground-dwelling (terricolous) lichens are major contributors to overall carbon and nitrogen cycling, albedo, biodiversity and biomass in many high-latitude ecosystems. Changes in biomass of mat-forming pale lichens have the potential to affect vegetation, fauna, climate and human activities including reindeer husbandry. Lichens have a complex spectral signature and terricolous lichens have limited growth height, often growing in mixtures with taller vegetation. This has, so far, prevented the development of remote sensing techniques to accurately assess lichen biomass, which would be a powerful tool in ecosystem and ecological research and rangeland management. We present a Landsat based remote sensing model developed using deep neural networks, trained with 8914 field records of lichen volume collected for > 20 years. In contrast to earlier proposed machine learning and regression methods for lichens, our model exploited the ability of neural networks to handle mixed spatial resolution input. We trained candidate models using input of 1 x 1 (30 x 30 m) and 3 x 3 Landsat pixels based on 7 reflective bands and 3 indices, combined with a 10 m spatial resolution digital elevation model. We normalised elevation data locally for each plot to remove the region-specific variation, while maintaining informative local variation in topography. The final model predicted lichen volume in an evaluation set (n = 159) reaching an R2 of 0.57. NDVI and elevation were the most important predictors, followed by the green band. Even with moderate tree cover density, the model was efficient, offering a considerable improvement compared to earlier methods based on specific reflectance. The model was in principle trained on data from Scandinavia, but when applied to sites in North America and Russia, the predictions of the model corresponded well with our visual interpretations of lichen abundance. We also accurately quantified a recent historic (35 years) change in lichen abundance in northern Norway. This new method enables further spatial and temporal studies of variation and changes in lichen biomass related to multiple research questions as well as rangeland management and economic and cultural ecosystem services. Combined with information on changes in drivers such as climate, land use and management, and air pollution, our model can be used to provide accurate estimates of ecosystem changes and to improve vegetation-climate models by including pale lichens.Peer reviewe

    New national and regional biological records for Finland 7. Contributions to Bryophyta and Marchantiophyta

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    Three species of mosses (Bryophyta: Philonotis yezoana, Protobryum bryoides, Rhynchostegium murale) and one of liverworts (Marchantiophyta: Moerckia flotoviana) are presented new for Finland. Timmia megapolitana, previously thought to be regionally extinct, is reported to being found again. New records in biogeographical provinces for 82 species of mosses and 34 species of liverworts are listed. Finally, 8 occurrences in provinces are removed due to misidentifications or missing specimens

    New national and regional biological records for Finland 7. Contributions to Bryophyta and Marchantiophyta

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    Three species of mosses (Bryophyta: Philonotis yezoana, Protobryum bryoides, Rhynchostegiummurale) and one of liverworts (Marchantiophyta: Moerckia flotoviana) are presented new for Finland.Timmia megapolitana, previously thought to be regionally extinct, is reported to being foundagain. New records in biogeographical provinces for 82 species of mosses and 34 species of liverwortsare listed. Finally, 8 occurrences in provinces are removed due to misidentifications ormissing specimens.</p

    Biologian kenttäopetus yliopistoissa: yhteistyöllä uuteen nousuun

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    Kenttäkurssit ovat keskeinen osa biologian ja lähitieteiden opetusta yliopistoissa. Luonnossa tapahtuva opetus kehittää sekä ymmärrystä tieteenalan teoreettisista perusteista että ammatillisia käytännön taitoja. Kenttäkursseilla omat havainnot muodostuvat oppimisen perustaksi muiden oppimistapojen rinnalla. Vaikka kenttäopetuksen tarpeellisuudesta ollaan yksimielisiä, kenttäkursseja uhkaavat yliopistojen rahoituksen väheneminen ja tutkimusasemaverkoston karsiminen. Tässä kirjoituksessa pohdimme, kuinka uhkista huolimatta kenttäopetuksen määrää, laatua ja kustannustehokkuutta voidaan lisätä yliopistojen ja niiden tutkimusasemien välisellä yhteistyöllä.</p
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