Since the start of the industrialisation, the deposition of nitrogen and sulphur and the atmospheric concentrations of greenhouse gases have increased. The main objectives of this study were to find how these changes in climate and deposition can change the vegetation of mire ecosystems and the growth of Sphagnumspecies. Two main approaches were applied: re-investigated of two mires previously investigated 40-50 years ago and experiment manipulations. The plant species diversity had decreased on one of the two re-investigated mires (Skattlösbergs Stormosse; central Sweden), but the total number of species was unchanged on the other (Åkhultmyren; southern Sweden). On Skattlösbergs Stormosse, an acidification was found in the high pH areas, coinciding with reduction in rich fen species. At Åkhultmyren, there was a similar reduction in pH, but the changes in the plant composition also indicated increased nutrient levels and a drier mire surface. Therwere large changes in species composition on Åkhultmyren. For instance Scheuchzeria palustris had disappeared from the investigated area. Further, the cover of Scots pine (Pinusylvestris) had increased, which can be explained by a changed ground-water table regime. Monitoring of pines growing on a bog over a ten-year period showed that pines growing higher above the ground-war table had higher survival than lower-growing pines. Experimental addition of nitrogen during 3-4 years reduced Sphagnum growth in bogs and poor fens repressenting a wide range of ambient nitrogen deposition. A changed interspecific competitive relation was found between S. lindbergand S. balticum when increasing nitrogen influx, but the competitive relations between two hummock-growing species pairs did not change in a three-year nitrogen fertilization study. Sulphur additiodid not affect the production or length increment in S. balticum. An increased temperature reduced Sphagnum growth, but there were no indications of altered competitive relationshipbetween hummock and hollow inhabiting Sphagnum species in a four-year experiment.

Arctic soils store half of the global soil organic carbon (OC) pool and twice as much C as is currently present in the atmosphere. A considerable part of these carbon pools are stored in permafrost. Amplified climate warming in the Arctic will thaw permafrost and remobilize some of these substantial carbon stocks into the active carbon cycle, potentially causing positive feedback to global warming. Despite the global importance of this mechanism, our understanding of the fate of these thawing organic carbon (OC) pools is still poor, particularly regarding its degradation potential. This makes good estimates on greenhouse gas emissions versus coastal reburial impossible. This doctoral thesis aims to improve our understanding on the fate of high-latitude terrestrial OC during fluvial and coastal transport. In two study regions, the Bothnian Bay and the East Siberian Sea, we apply a wide range of bulk, molecular and isotopic geochemical analyses to reveal information on sources, age, degradation and transport routes. Our results show that both study regions receive and store large amounts of terrestrial OC, largely derived from peatlands (paper I, II and IV). This terrestrial matter undergoes extensive degradation in both the water column and surface sediments (paper I, III and IV). Surface sediments in the East Siberian Sea show a offshore-decreasing input of riverine OC and a considerable and constant input of OC from coastal erosion. The strong imprint of rapidly settling coastal OC far out on the shelf may be explained by a strong benthic boundary layer transport in combination with offshore ice-transport and selective preservation of erosion OC compared to riverine OC (paper IV). Molecular radiocarbon data allowed us to distinguish between two (sub-)Arctic soil OC pools that show a remarkably different susceptibility to degradation upon arrival in the coastal system; a young and easily degradable pool originating in surface peatlands, and an old and recalcitrant pool originating in deep mineral soils and coastal mineral Pleistocene deposits (paper III and IV). Our first estimates suggest that, in the Bothnian Bay coastal system, mineral soil OC is at least 20 times less susceptible to degradation than peatland OC (paper III). Hence, a considerable part of the thaw-released mineral OC pool may simply be relocated to coastal sediments instead of being emitted to the atmosphere. / At the time of the doctoral defense, the following paper was unpublished and had a status as follows: Paper 3: Accepted. Paper 4: Manuscript.

Baigiamajame darbe tiriama pramonės įmonių tarša pasyviosios lichenoindikacijos, pasyvaus kaupimo ir biotestavimo metodais. Darbo objektas - tyrimo metu vertintos įmonių teritorijose ant medžių aptinkamos epifitinių kerpių rūšys, taip pat vertinama teršalų sklaida pagal sėjamosios pipirnės (Lepidium sativum L.) augimą ant kiminų (sugėrusių įmonių išmetamus oro teršalus) terpės. Darbo tikslas – įvertinti oro kokybę pramonės įmonių teritorijose pagal ten aptinkamas epifitinių kerpių rūšis ir sėjamosios pipirnės (Lepidium sativum L.) augimą bei gautus rezultatus palyginti su pasyviųjų kaupiklių rezultatais. Darbo metodai – tyrimai buvo atliekami 2013-2014 metais didžiausias teršalų koncentracijas Šakių rajone išleidžiančių įmonių: UAB „Idavang“ ir UAB „Kriūkų baldai“ teritorijose. Tyrimo vietose 100 m, 200 m ir 500 m atstumais nuo taršos šaltinių buvo vertinamos ant medžių aptiktos epifitinių kerpių rūšys, kiekvienos rūšies padengimas procentais ir poleotolerantiškumo indeksas, taip pat vertintas biotestinio organizmo sėjamosios pipirnės (Lepidium sativum L.) augimas kiminų (augusių taršos šaltinių zonose) terpėje bei azoto dioksido koncentracijos iš pasyviųjų kaupiklių. Darbo rezultatai. Tyrimo objektų teritorija pasižymi nedidele kerpių gausa. Iš viso identifikuota 17 skirtingų kerpių rūšių abiejų tyrimo objektų teritorijose: 5 krūmiškosios, 8 lapiškosios ir 4 žiauberiškosios. Tiek UAB „Idavang“, tiek UAB „Kriūkų baldai“ teritorijose tolstant nuo taršos šaltinio... [toliau žr. visą tekstą] / In this thesis industrial company's pollution is investigated using passive Lichen Indication method, passive accumulation and biotesting methods. Object of research: Two species of plants were selected: garden cress (Lepidium sativum L.) and epiphytic lichen. During the evaluation we examined epiphytic lichen found on trees surrounding the territories of industrial companies and evaluated pollution dispersion by the growth of garden crass (Lepidium sativum L.) on sphagnum (which have absorbed the air pollutants produced by the companies) seedbed. Aim of the research: The aim of this research is to evaluate the air quality in the territories of industrial companies by the types of epiphytic lichen found in the perimeter and the spread of garden cress (Lepidium sativum L.) on sphagnum (which have absorbed the air pollutants produced by the companies) seedbed. Methods. The evaluation took place in year 2013-2014 in the territories of the most polluting companies in Šakiai district: UAB “Indavang” and UAB “Kriūkių baldai”. At distances of 100, 200 and 500 meters from the pollution source different types of epiphytic lichen were examined, as well as their coverage in percents and polio tolerance index. Both biotest organism's garden crass (Lepidium sativum L.) growth in sphagnum seedbed (growing in the pollution source territory) and nitrogen dioxide concentration from passive accumulators were evaluated. Results. Territories evaluated in this research have a small... [to full text]

Dans un contexte de réchauffement climatique, la fonction puits de carbone des tourbières à sphaignes est susceptible d’être altérée en raison d’une modification des interactions sphaignes-microorganismes, responsables de l’accumulation de carbone. L’objectif de cette thèse a été (1) d’identifier les interactions chimiques entre les polyphénols des sphaignes et les communautés microbiennes des sphaignes et (2) d’évaluer l’impact du réchauffement climatique sur ces relations.Un dispositif expérimental (Open Top Chambers) simulant in situ une hausse modérée des températures (+ 1°C) a été installé sur la tourbière de Frasne (25). La hausse des températures a provoqué une modification du réseau alimentaire microbien avec l’augmentation de la biomasse des bactéries et une baisse importante (-70%) de la biomasse des prédateurs (amibes à thèque). Le réchauffement climatique a également induit une baisse de la production de polyphénols, diminuant ainsi leur effet inhibiteur sur les microorganismes. En parallèle à cette baisse, une hausse des activités enzymatiques phénoloxydases a également été enregistrée. Le réchauffement a ainsi modifié les relations polyphénols – phénoloxydases, deux éléments essentiels du cycle du carbone des tourbières.Les différents changements induits par le réchauffement climatique (polyphénols, phénoloxydases, réseau trophique microbien) ont aussi conduit à une modification des relations « sphaignes-microorganismes » via une accélération potentielle du recyclage des nutriments, ce qui pourrait influencer sur le long terme le fonctionnement de l’écosystème tourbière. / Carbon stocks of Sphagnum-peatlands are likely to be altered by climate warming due to important changes in “Sphagnum-microorganisms” relationships which are responsible for carbon sequestration. The objectives of the thesis are (1) to identify the chemical interactions between Sphagnum-polyphenols and Sphagnum associated microbial communities and (2) to understand the impact of warming on these relationships.An experimental design using Open-Top-Chambers (OTC) was used to simulate an increase of air temperatures (+1°C) on a peatland situated in Jura Mountains (Frasne, 25). Temperature increase induced a modification of the microbial food web with an increase of the biomass of bacteria and a strong decrease of the biomass of top-predators (-70%), i.e. testate amoebae. Warming also induced a decrease of Sphagnum-polyphenols, diminishing their inhibitory effect on microbial communities. In parallel, an increase of phenoloxidase enzymatic activities was recorded in OTC. Climate warming thus modified polyphenol-phenoloxidase interplay, two crucial components of carbon cycle in peatlands. Warming effects on the different components – i.e. polyphenols, phenoloxidases, microbial food web – induced a modification of Sphagnum-microbial communities interplay, favoring carbon and nutrient recycling, which could alter peatland functioning in long-term.

Les tourbières ont stocké un tiers du carbone organique des sols mondiaux (C) malgré une superficie ne représentant que 3% de la surface terrestre. Cependant, en réponse aux changements globaux, les tourbières boréales et tempérées, majoritairement dominées par des sphaignes, peuvent être envahies par des plantes vasculaires susceptibles de modifier la dynamique du C dans ces écosystèmes. Cette thèse vise à étudier comment la présence des plantes vasculaires affecte le cycle du C des tourbières à sphaignes. Ces travaux ont porté principalement sur une plante envahissante de nombreuses tourbières, Molinia caerulea, via une étude en mésocosmes. Les expérimentations montrent que les plantes vasculaires sont à la fois favorables à la croissance des sphaignes et à la décomposition des litières. In fine, les résultats montrent que la présence de Molinia caerulea augmente la capacité de stockage du C dans les mésocosmes de sphaignes (30 to 220 gC stock m⁻² an⁻1), probablement liée à la forte productivité racinaire de cette plante. Cependant, cela semble s’opérer au détriment du C déjà stocké dans la tourbe avec une stimulation des microorganismes à travers la production d’exsudats racinaires. Ces derniers semblent également, d’une part promouvoir la consommation du C organique dissous et les émissions de CO₂ et de CH₄ observées en présence de Molinia caerulea, et d’autre part être responsables de la modification de la sensibilité à la température des exports de C via des changements des communautés microbiennes. L’impact de Molinia caerulea sur les microorganismes va aussi altérer ceux impliqués dans le cycle du N et entrainer une diminution des émissions de N₂O. / Peatlands have stored a third of the soil organic Carbon (C) in only 3% of the land area. However, in response to global change, boreal and temperate peatlands may shift from Sphagnum to vascular plant-dominated peatlands that may alter their C-sink function. This thesis aims at providing a better understanding of the vascular plants interactions in a Sphagnum dominated peatland and their implications on the C cycle. This work mainly focus on the invasion of a graminoid plant, Molinia caerulea, through a mesocosm experiment. Results from experiments show that vascular plants are both able to promote the growth of Sphagnum mosses as well as the decomposition of their litter. Molinia caerulea occurrence appears to increase the C sink capacity of Sphagnum peat mesocosms passing of 30 to 220 gC stock m⁻² y⁻1. This capacity of Molinia caerulea to store C is probably due to it high roots productivity. However, it also seems to stimulate the decomposition of ‘old’ C, stored as peat, by stimulating microorganisms activity through roots exudates. These latter also promote the dissolved organic C consumption and CO₂ and CH₄ emissions observed with Molinia caerulea occurrence, as well as the temperature sensitivity of C exports by altering the microbial communities. Molinia caerulea impacts on microorganisms also affect N cycle conducting to a decrease of N₂O emissions in these ecosystems.

Avec les craintes actuelles sur la péjoration du climat, l'enjeu pour des tourbières<br />abandonnées après exploitation est d'y permettre la réinstallation d'une production végétale<br />susceptible d'y réassurer la pérennité de la séquestration du carbone à long terme. Dans cette<br />perspective, les objectifs de cette étude étaient d'identifier des indicateurs de la reprise des<br />processus d'accumulation de la matière organique (MO) dans des tourbières anciennement<br />exploitées, actuellement à des stades de régénération spontanée différents. Dans le but d'identifier<br />l'origine de la MO et d'appréhender les modalités de sa dégradation, une combinaison d'approches<br />micromorphologiques, géochimiques globales et moléculaires a été appliquée à des échantillons de<br />tourbe brute et de fractions fines (< 200μm), ainsi qu'à des végétaux-sources typiques. La MO<br />accumulée dans les niveaux superficiels montre une composition très contrastée (forts C/N,<br />prédominance des tissus hérités bien préservés, fortes teneurs en sucres...) par rapport à celle,<br />beaucoup plus humifiée, des compartiments sous-jacents. Ceci a permis de délimiter précisément la<br />tourbe régénérée de la tourbe du catotelm. Contrairement aux stades de régénération précoces (5-10<br />ans), la composition de la MO des stades plus avancés (30-40 ans) est comparable à celle de la zone<br />non exploitée (MO homogène, dominance des marqueurs de sphaignes, forts C/N). Une analyse en<br />composante principale (ACP) a permis de proposer des trajectoires de régénération distinctes pour<br />chacun des sites d'étude, en fonction de leur végétation et de leur mode d'exploitation.<br />Globalement, la bonne préservation des polysaccharides dans la tourbe, clairement mise en lumière<br />dans cette étude, en fait de bons indicateurs de régénération.

Central to the issue of harvest feasibility on the outer BC coast (CWHvh) is the question of whether sites, once harvested, can be regenerated, and whether the time period for replacement and subsequent growth is economically and environmentally acceptable. Since low productivity sites have not been harvested in the past, there is a lack of data to answer this question. We tried to provide an answer by assessing regeneration following natural disturbances. Small scale gap disturbances are the norm within old-growth stands. If regeneration is not a problem in gaps, then we have some evidence that regeneration should not be a problem upon implementation of our management practices. The objectives of this study were: (1) to develop baseline information on the mechanisms and the patterns of regeneration across a sequence of forest types; (2) to assess regeneration success with respect to productivity; and (3) to estimate future growth and productivity.

In the general section of this thesis are shortly characterized fossil fuel, peat bogs and peat, process of their origin, their types and importance. Another important part of this work is the extraction of peat, its trend, subsequent restoration and environmental problem of the peat extraction. The main part is the characteristic of the area Borkovická blata, mapping out mining process in the area and the present condition. Furthermore, there is shortly characterized the company Rašelina, a. s., which extracted in Borkovická blata peat for a long time and is still engaged in the extraction and processing of peat.

Les amibes à thèque, également appelés thécamoebiens, sont des micro-organismes unicellulaires, qui construisent une enveloppe rigide, appelée thèque (Adl et al., 2012). Ces thèques ont des tailles, formes et natures très variées (Ogden & Hedley, 1980). Les récentes études sur la composition des thèques ont conduit à émettre l’hypothèse que les amibes xénosomiques (constituées de particules exogènes), peuvent constituer des bio-indicateurs pertinents de la diversité particulaire de l’environnement minéral, organique et biologique dans lequel elles évoluent.L’objectif principal des recherches menées au cours de cette thèse vise donc à caractériser la composition des thèques d’amibes xénosomiques et à en évaluer leur utilisation potentielle en tant que bio-indicateurs des dépôts de particules d'origine atmosphérique. Pour cela, des thèques d’amibes ont été analysées in situ en conditions naturelles et après dépôts artificiels de particules minérales allochtones.Ces travaux permettent de dégager plusieurs conclusions majeures :(1) La taille des particules minérales intégrées dans la thèque xénosomique de Bullinularia indica est similaire à celle des particules minérales transportées dans l'atmosphère; (2) les particules minérales intégrées dans les thèques sont des silicates stables dans les conditions physico-chimiques régnant dans les tourbières, les bryophytes et les sols étudiés; (3) certains minéraux comme la phlogopite, même lorsqu’ils sont présents en de fortes concentrations, ne sont jamais intégrés par les amibes; (4) la combinaison des observations portant sur la taille, la forme et la nature des particules utilisées par des amibes xénosomiques permet de poser les bases de l'utilisation des amibes à thèques pour la bio-indication de la diversité particulaire atmosphérique récente ou ancienne. / Theca-like amoebae, also called thecaamoebius, are unicellular microorganisms, which construct a rigid envelope called theca (Adl et al., 2012). These themes have very varied sizes, shapes and natures (Ogden & Hedley, 1980). Recent studies on the composition of the themes have led to the hypothesis that xenosomal amoebae (constituted by exogenous particles) can constitute relevant bio-indicators of the particulate diversity of the mineral, organic and biological environment in which they evolve . The main objective of the research carried out during this thesis is therefore to characterize the composition of the xenosomal amoebae and to evaluate their potential use as bioindicators of deposits of atmospheric particles. For this purpose, amoeba theae were analyzed in situ under natural conditions and after artificial deposits of allochtonous mineral particles. Several major conclusions can be drawn from this work: (1) The size of the mineral particles integrated in the xenosomal theca of Bullinularia indica Is similar to that of mineral particles transported into the atmosphere; (2) the mineral particles integrated into the thecs are stable silicates under the physico-chemical conditions prevailing in the peatlands, bryophytes and soils studied; (3) some minerals such as phlogopite, even when present in high concentrations, are never integrated by amoebae; (4) the combination of observations on the size, shape and nature of the particles used by xenosomic amoebae forms the basis for the use of tea amoeba for bioindication of recent or former atmospheric particulate diversity .

La presente investigación busca analizar los principales factores internos y externos que intervienen en el desarrollo de la exportación del musgo específicamente Sphagnum con destino a EE.UU. En tal sentido, la investigación considera como objetivo principal analizar los factores internos y externos que influyeron en las exportaciones de dicho producto en el periodo de los años 2015-2019. Por lo cual, se realizó el manejo de la información primaria considerando como base principal los antecedentes epistemológicos en bases de datos destacadas, bases de datos bibliométricas y bancos de datos (todas consideradas fuentes confiables y reconocidas); además, la búsqueda de bases teóricas que respaldan el tema de investigación; también, la detección de la realidad problemática evidenciando el problema principal y los problemas específicos; además, la investigación plantea argumentos que justifican el presente estudio, analizado la documentación e información del sector e inquiriendo en la base teórica que sustente el tema de investigación. Para la presente investigación, se consideró un enfoque cualitativo, logrando la obtención de datos a través de 15 entrevistas a directivos y colaboradores del MINAGRI, PROMPERÚ, MINCETUR, especialistas en internacionalización del sector agrícola y presidentes de las empresas exportadoras de musgo Sphagnum. Finalmente, se utilizó el software Atlas. Ti y la técnica de triangulación de datos, contrastando los antecedentes y de la información obtenida en el marco teórico y el resultado de las entrevistas para poder obtener una discusión, en base a la que se realizó las conclusiones y recomendaciones correspondientes. Finalmente, los principales factores que intervienen en el desarrollo de la exportación del musgo Sphagnum con destino a EE.UU en el periodo de 2015-2019 fueron: proceso de secado, comercio justo, uso de tecnología y normatividad. En base a ellos, los resultados del estudio, servirá para contribuir a futuras investigaciones que aborden el tema de investigación, ya sea desde la misma u otra perspectiva. / This research seeks to analyze the main internal and external factors that intervene in the development of the export of Sphagnum moss specifically to the US In this sense, the main objective of the investigation is to analyze the internal and external factors that influenced the exports of said product in the period of the years 2015-2019. Therefore, the management of primary information was carried out considering as the main basis the epistemological antecedents in prominent databases, bibliometric databases and data banks (all considered reliable and recognized sources); in addition, the search for theoretical bases that support the research topic; also, the detection of the problematic reality showing the main problem and the specific problems; In addition, the research raises arguments that justify the present study, analyzing the documentation and information of the sector and inquiring into the theoretical basis that supports the research topic. For the present investigation, a qualitative approach was considered, obtaining data through 15 interviews with managers and collaborators of MINAGRI, PROMPERÚ, MINCETUR, SERFOR, specialists in internationalization of the agricultural sector and presidents of the exporting companies of Sphagnum moss. Finally, the Atlas.ti software and the data triangulation technique were used, contrasting the antecedents and the information obtained in the theoretical framework and the results of the interviews in order to obtain a discussion, based on which the conclusions were made. and corresponding recommendations. Finally, the main factors that intervene in the development of the export of sphagnum moss to the US in the period 2015-2019 were: drying process, fair trade, use of technology and regulations. Based on them, the results of the study will serve to contribute to future research that addresses the research topic, either from the same or another perspective. / Tesis