L’exploitation minière de l’uranium et les processus de traitement du minerai sont à l’origine d’un marquage potentiel de l’environnement par les descendants des chaînes de désintégration U-Th et des éléments traces métalliques (ETM) associés. Ces contaminants s’accumulent ensuite préférentiellement dans des zones de sédimentation continentales (étangs ou lacs) ou des zones humides (tourbières, berges de rivière) situées à l’aval hydraulique des mines. Les zones humides en particulier sont des milieux sensibles aux changements globaux et à la pression anthropique, situés en général en tête de bassin versant. Cela pose donc un risque en cas relargage des contaminants depuis ces milieux. L’objectif de cette étude est de mettre en place une méthodologie aisément reproductible, y compris aux sites miniers orphelins, et permettant l’identification et la caractérisation des contaminations et la compréhension des mécanismes d’accumulation et des risques de relargage. Cette étude a été réalisée dans l’environnement de l’ancienne mine de Bertholène (Aveyron, 12, France). Les zones d’accumulations préférentielles ont été identifiées par spectrométrie gamma in situ mobile et fixe. Des échantillons de sols, sédiments, végétaux, eaux et tourbes ont été prélevés autour du site, afin (a) de caractériser l’activité des différents descendants des chaînes de l’U et du Th et les contaminations en ETM associées à différentes échelles d’observation, (b) de comprendre les mécanismes d’accumulation et de relargage potentiel et (c) de tracer les sources des contaminants. Les résultats obtenus montrent que l’essentiel de la contamination est localisée dans une zone inondable de l’environnement proximal aval de la mine. Les activités en uranium élevées (U-238 > 20000 Bq.kg-1) et le fort enrichissement des radionucléides du début de chaîne par rapport à la fin de chaîne de l’U-238 traduisent un apport préférentiel d’U-238 et de Th-230, par rapport au Ra-226, lors d’inondations. Les contaminations en ETM associées sont relativement faibles, excepté en Mn, en Ba et en S. Les accumulations en radionucléides et en ETM sont expliquées à la fois par les caractéristiques géochimiques du minerai d’uranium et par les processus de traitement du minerai et des eaux d’exhaure. Les lessivages chimiques réalisés révèlent que les fractions acido-solubles et oxydes amorphes des sols constituent des pièges prépondérants des contaminants et que des variations du pH ou du potentiel d’oxydoréduction pourraient générer des relargages important d’uranium et de radium dans l’environnement. Finalement les déséquilibres radiologiques et les isotopes du plomb sont des traceurs fiables de la contamination associée à l’exploitation d’une mine d’uranium. / Uranium mining and uranium ore processing increase the environmental activity of U and Th decay products and trace elements, in particular in case of releases to the adjacent rivers. Contaminants accumulate then preferentially in sedimentation areas (such as ponds or lakes) or in wetlands (peatlands, marshes or riverbanks) located downstream to the mine. Wetlands – generally located at the head of watershed – are particularly sensitive to environmental changes and anthropogenic pressure. This poses a risk of release of contaminants from these accumulation areas. The objective of the present study is to propose an easily reproducible methodology – in particular for the orphan mining sites – to identify and characterize accumulation areas. This study also aims to improve our understanding of the mechanisms of accumulation and release, in these areas. This study was performed around the former mining site of Bertholène (France). Standing and mobile in situ gamma spectrometry is used to accurately locate the accumulation areas. Soils, sediments, vegetation, water and peat are also sampled upstream and downstream of the mine, in order to (a) characterize the activities and the disequilibria of the U-Th decay chains and the associated trace elements according to the scale of observation, (b) understand the mechanisms of accumulation and release and (c) identify the potential sources using geochemical proxies and isotopic analyses. The results obtained show that radionuclides are mainly accumulated in a flooding area located downstream the mine. Strong U-238 activities (> 20000 Bq.kg-1) and strong Ra-226/U-238 and Th-230/Ra-226 activity ratios are recorded, involving preferential inputs of U-238 and Th-230 during flooding events. Trace element contamination is low, except for Mn, Ba and S. Such contaminations are potentially explained by the geochemical composition of the uranium ore and by the past and current processes of ore and water mine. Sequential extractions highlight the importance of the acido-soluble and the amorphous oxides in the trapping of contaminants. Thus, pH or Eh potential changes could induce major releases of uranium to the environment. The large differences in Pb isotope composition between natural soils and uranium ores, as well the activity ratios of the U-238 and decay chain products, make these indicators helpful to identify the soils and the sediments impacted by uranium mining.

Les poussières atmosphériques naturelles jouent un rôle complexe dans le système climatique global étant à la fois un facteur affectant le climat et variant en fonction de ce dernier. Notre compréhension des différentes interactions entre les poussières atmosphériques et le climat est limitée par l’importante variabilité spatiale et temporelle des celles-ci. À l’aide de tourbières ombrotrophes, la variabilité spatiale et temporelle des dépôts de poussières atmosphériques holocènes au Québec boréal fut caractérisée en lien avec les fluctuations climatiques. Les flux de poussières atmosphériques furent reconstruits à l’aide des concentrations en terres rares. Les isotopes du Nd et Pb en combinaison avec les terres rares ont été utilisés afin de déterminer la source des particules déposées dans les tourbières. Afin d’évaluer les liens entre les flux de poussières et la variabilité climatique, les changements temporels dans les flux de poussières et l’isotopie du Nd furent comparés à la taille des particules déposée et des reconstitutions écohydrologiques basées sur l’analyse des macrorestes végétaux et des thécamoebiens. Dans les deux premiers volets de l’étude, les flux de poussières atmosphériques furent reconstruits dans deux tourbières de la Côte-Nord alors que les particules déposées dans celles-ci furent caractérisées à l’aide des concentrations des terres rares (REE), des isotopes du néodyme et du plomb ainsi que la granulométrie. Les deux profils présentent des valeurs de Nd similaires, ce qui s’explique soit par une source commune des poussières atmosphériques ou encore des sources distinctes, mais possédant des valeurs de Nd similaires dans les deux régions. Les deux sites étudiés montrent des tendances différentes dans les flux de poussières. La tourbière IDH montre peu de variations dans les flux de poussières, ce qui s’explique en partie par l’emplacement du site d’étude, qui prévient les apports de poussières atmosphérique. La tourbière Baie quant à elle, montre deux périodes de flux de poussières plus élevés soit 1700-1000 et 650-100 cal a BP correspondant avec des périodes de refroidissement du climat documentées. Les REE, le Nd et les tailles de particules suggèrent qu’au cours des 2000 dernières années, la tourbières de Baie a reçu une proportion accrue de poussières atmosphériques provenant de sources locales. Ces deux périodes ont été identifiées comme des épisodes d’instabilité climatique en réponse à une instabilité hydroclimatique régionale et une plus grande variabilité des températures (principalement contrôlée par l’activité solaire). Un changement du régime des vents dans la région a aussi probablement influencé ces les variations observées. Dans le troisième chapitre, les mêmes analyses furent réalisées sur des carottes de tourbe d’une tourbières de la Baie James, La Grande 2 (LG2). Des apports accrus de poussières furent observés lors de différentes période : 4000 à 3000, 2600 à 2000, 1600 à 1000, 800 à 650 cal a BP et de 1960 à 1990AD. Au moins trois sources distinctes constituent les apports de poussières dans le temps: les sédiments marins à la base de la tourbières, la moraine de Sakami, deux sources locales, ainsi qu’une source probablement plus régionale dont l’origine est non-identifiée. La période allant de 7000 à 4100 cal a BP montre des valeurs près des sources locales (Nd : -36 à -29). Une augmentation graduelle des valeurs de Nd à partir de 4100 cal a BP suggère une diminution des apports locaux de poussière à la faveur d’une source non identifiée. La majorité des périodes d’apports accrus de poussières identifiées correspondent à des périodes documentées comme étant froides et sèches probablement lié à des intrusions de masses d’air arctiques. La présence de certains de ces pics de poussières lors de minimums solaires suggère que la variabilité solaire joue aussi un rôle dans la variabilité climatique de la région. / Mineral dust plays an important role in the global climate system having effects on the radiation budget and the chemical composition of the atmosphere. Our understanding of the exact role of dust in the Earth’s climate system is still poorly constrained mostly due to a lack of data reflecting the high spatial and temporal variability of dust. Using peat bogs, spatial and temporal variability of Holocene dust deposition in boreal Quebec was investigated in relation to climate fluctuations. Dust fluxes were reconstructed using rare earth elements (REE) concentrations in bulk peat, while Nd and Pb isotopes in combination with REE were used to identify the source of dust particles deposited into these bogs. In order to evaluate the relationship between dust fluxes and climate variability, temporal changes in dust flux, and Nd isotopes were compared to dust grain size and ecohydrological reconstructions derived from testate amoebae and plant macrofossils. In two peat bogs from the North Shore region of the St. Lawrence Estuary (Baie bog) and Gulf (IDH bog), atmospheric dust fluxes were reconstructed using REE concentration while the geochemical composition of deposited dust was characterized using Nd and Pb isotopes combined with REE and grain size. Both peat bogs present similar Nd values, which suggests either a common source or sources with similar signatures in both regions. In terms of dust flux, the two study sites display distinct tendencies. IDH bog show few variations in dust flux, which can be explained by its geographical setting, where a tree fringe and higher altitude likely partially prevent dust from reaching the peat bog. Two dust events were recorded in the Baie bog from 1750 to 1000 cal BP and 600 to 100 cal BP and correspond to documented cold periods. These two periods have been found to occur at the same time as periods of high variability in the macrofossil record (i.e. successive layers dominated by Sphagnum or Ericaceae). REE elements, Nd and grain-size distribution suggest that, over the last 2000 years, the Baie bog received more local dust. The two periods were identified as periods of increased local storminess in response to regional hydroclimatic instability and temperature variations mainly controlled by solar activity. These episodes of climatic instability could also have been caused by changes in the wind regime. The same set of analyses were performed in a third peatland located in the James Bay region, the La Grande 2 bog (LG2). Increases in dust flux were reconstructed from 4000-3000, 2600-2000, 1600-1000, 800-650 cal BP and from 1960-1990AD. The Nd values show a large variability from -37 to -12, identifying a least three sources: local marine sediment, the Sakami moraine and another unidentified source likely from a more regional origin. Between 7000 and 4100 cal BP, Nd values resemble those localsources (-36 to -29). A gradual increase in Nd signature is observed from 4100 to 1500 cal BP suggesting a decreasing influence of local sources in favor of a yet unidentified source. The occurrence of increased dust deposition during cold periods in two of the three studied bogs suggests that dust fluxes can be used as an indicator of cold and dry climatic conditions in boreal Quebec. In northeastern Canada, these cold and dry conditions are usually the results of the intrusion of Arctic air masses. The exact mechanism controlling these incursion is yet unknown, but the similar timing of solar minima and dust peaks suggest that solar irradiance may also have played a role. The fact that both Baie and LG2 sites display similar tendencies during the last 2000 years reveals that both regions were likely controlled by the same climatic processes.

This study aimed to understand the interactions between humic substances extracted from peat and metallic species, of the National Park of Itabaiana - SE, seeking a further application in the remediation of soil, surface water contaminated by agricultural activities. We collected samples of soil, fertilizer and peat and characterized by the organic matter content, elemental analysis, pH and concentrations of metals, and for peat analysis was performed in the infrared spectroscopic and complexation capacity of humic substances peat with potentially toxic metals (Ni, Pb, Cu and Mn). In surface water samples were analyzed for major physico-chemical parameters and metal concentrations. Soil samples (2.62%) and poultry manure (13.77%) analyzed showed low levels of organic matter, the goat manure (72.72%) and the mixture of castor bean and goat manure (75.56%) showed high levels of organic matter. The concentrations of the metals Ni, Cr and Cd in samples of soil, fertilizers, except for the castor-oil sample, surface water Pb, Ni, Cd, Al, Cu and Mn exceeded the limits provided by law. The peat samples collected at depth higher (40 to 60 cm) had organic matter content and C / N ratio higher indicating that the organic matter is more decomposed and humified. The infrared spectra in the region of humic substances showed absorption bands more intense than those of peat. The metals Fe, K and Na showed higher concentrations at depth 0-20 cm, while others (Cd, Pb and Mo) were below the limit of quantification, the Ni remained constant at all depths (0-20, 20-40 , 40 - 60 cm). The values of complexing capacity of humic substances of peat for metal species in this study was 1.06, 1.53, 1.84, 2.06 mmol g-1 SH; for Pb, Cu, Ni and Mn respectively indicating a optimal interaction of humic substances extracted from peat of the National Park of Itabaiana-SE. / Este trabalho teve como objetivo compreender as interações entre substâncias húmicas extraídas de turfas e espécies metálicas, do Parque Nacional Serra de Itabaiana SE, visando uma posterior aplicação na remediação de solos, águas superficiais contaminadas com metais potencialmente tóxicos pelas atividades agrícolas na região do açude Macela, Itabaiana - SE. Foram coletadas amostras de solo, fertilizantes e turfa e caracterizadas por meio do teor de matéria orgânica, análise elementar, pH e concentrações de metais, sendo que, para a turfa foi feita análise espectroscópica na região do infravermelho e a capacidade de complexação das substâncias húmicas de turfa com metais potencialmente tóxicos (Ni, Pb, Cu e Mn). Foram coletadas amostras de águas superficiais e analisados os principais parâmetros físico-químicos e as concentrações de metais. As amostras de solo (2,62 %) e esterco de aves (13,77 %), analisadas apresentaram baixos teores de matéria orgânica, as de esterco caprino (72,72 %) e as da mistura torta de mamona e esterco caprino (75,56 %) apresentaram altos teores de matéria orgânica. As concentrações dos metais Ni, Cr e Cd nas amostras de solo, fertilizantes, exceto na amostra torta de mamona, nas amostras de águas superficiais Pb, Ni, Cd, Al, Cu e Mn excederam os limites apresentados pelas legislações. As amostras de turfa coletadas em profundidade mais elevada (40 - 60 cm) apresentaram teor de matéria orgânica e a razão C/N mais elevada indicando que a matéria orgânica está mais decomposta e humificada. Os espectros na região do infravermelho das substâncias húmicas apresentaram bandas de absorção mais intensas do que as de turfa. Os metais Fe, K e Na apresentaram concentrações superiores na profundidade 0 - 20 cm, enquanto outros (Cd, Mo e Pb) ficaram abaixo do limite de quantificação, o Ni manteve-se constante em todas as profundidades (0 20; 20 40; 40 - 60 cm). Os valores da capacidade de complexação das substâncias húmicas de turfa por espécies metálicas neste trabalho foi 1,06; 1,53; 1,84; 2,06 mmol g-1 SH; para o Pb, Cu, Ni e Mn respectivamente indicando uma ótima interação das substâncias húmicas extraídas de turfa do Parque Nacional Serra de Itabaiana-SE.

Les tourbières ont accumulé des quantités importantes de matière organique (tourbe) depuis le début de l’Holocène. La tourbe séquestre des quantités de carbone (C), d’azote (N) et de phosphore (P) substantielles à l’échelle globale. Cependant, très peu d’études ont estimé les stocks de ces nutriments à l’échelle régionale. De plus, les estimations actuelles sont souvent obtenues sans considérer la variabilité des profondeurs de tourbe et les variables biophysiques et physiques qui dictent la capacité de stockage en nutriments. Ce mémoire vise à estimer les stocks en C, N et P des tourbières d’une région du sud du Québec en modélisant les variations de profondeurs de tourbe et en identifiant quelles variables biophysiques et physiques expliquent la capacité de stockage en nutriments des différents types de tourbières. Le sondage manuel des sites d’études a révélé des différences significatives de profondeurs de tourbe entre les types de tourbières. La profondeur moyenne de tourbe obtenue pour les tourbières ombrotrophes était de 4,4 m alors que celles des tourbières minérotrophes et forestières étaient respectivement de 2,3 et 2,0 m. Les profondeurs ont été modélisées par interpolation spatiale pour chaque bassin d’accumulation de tourbe. La relation entre la superficie des tourbières et les stocks en C était significativement différente entre les tourbières ombrotrophes et les tourbières minérotrophes et forestières. Aucune variable étudiée ne permettait de discriminer les stocks en N et P selon le type de tourbière. Les stocks en C, N et P de la tourbe ont été extrapolés pour la région en utilisant la superficie des tourbières et estimés à 5,65 Tg C, 230,5 Gg N et 21,8 Gg P. Mes travaux ont démontré que l’hétérogénéité du bassin d’accumulation et les caractéristiques de surface influencent les stocks en C, N et P contenus dans la tourbe. / Peatlands have accumulated important amounts of organic matter since the beginning of the Holocene. This organic matter accumulation is described as peat, that globally stores large amounts of carbon (C), nitrogen (N), and phosphorus (P). Regional estimations of C and nutrients stocks have seldom been quantified. Moreover, peat depth variability and biophysical and physical variables are often not included in actual peat C, N, and P pool size estimations. The goal of this thesis is to provide an estimation of peat C, N, and P pool sizes for a regional county of southern Quebec by modeling peat depth variations and by using biophysical and physical variables to discriminated peat C, N, and P storage among peatland types. Manual peat depth probing showed significant differences in peat depth among peatland types. Mean peat depth of bogs was 4.4 m, while fens and forested peatlands mean peat depths were of 2.3 and 2.0 m, respectively. Modeling of peat accumulation basin by spatial interpolation took these peat depth variations into account, among peatland types. The relationship between peatland area and peat C stocks was statistically different between bogs and fens, and bogs and forested peatlands. Peat N and P content among peatland types were not discriminated by the biophysical and physical variables considered in this study. Peat C, N, and P stocks were extrapolated within the study region using peatland area and estimated at 5.65 Tg C, 230.5 Gg N et 21.8 Gg P. This study has shown that peat accumulation basin heterogeneity and peatland geometric shape influenced peat C, N, and P stocks at the regional scale.

Peatlands are considered to be valuable ecosystems on the Planet and play an important role in many processes globally likewise and in the landscape. They are important for maintaining a global biodiversity, play an important role in landscape hydrology and can be a source of drinking water. They can help minimize floods and contribute to climate change mitigation. The peat bogs are one of the largest terrestrial carbon reservoirs. They have been storing carbon for centuries. Many of peat functions are affected due to human activities. It can result into release of greenhouse gases into atmosphere and the excretion of organic carbon into watercourses. The subject of the thesis is understanding of the mechanisms of water binding in peat and exploring possible dependencies within the depth profile of the peatlands using thermal analytical methods, more preciously using thermogravimetry (TG) and differential scanning calorimetry (DSC). The stability of water molecule bridge (WaMB) was investigated. It was found out that the minimum temperature required for WaMB abatement decrease and the whole structure becomes less stable with increasing peat layer depth. Water release processes were evaluated with the meaning of the TGA measurements. A decreasing trend in the degradation of thermolabile substances and an increasing trend in thermostable substances within the peat profile were observed.

Im Fokus der Untersuchungen steht das hydrologische Einzugsgebiet der oberen Wilzsch im Westerzgebirge. Veränderte Stoffausträge des bewaldeten und zum Teil vermoorten hydrologischen Einzugsgebietes führen zu erhöhten Stoffkonzentrationen im Hauptzufluss der Trinkwassertalsperre Weiterswiese (Carlsfeld). Seitens der Trinkwasseraufbereitung stellen insbesondere die gestiegenen Gehalte an gelösten organischen Kohlenstoffen (DOC) Mehraufwendungen dar. Im Zuge der Wiedervernässung der Moorflächen kommt es zu relevanten bodenchemischen Veränderungen, die im Abfluss messbar sind. Eine räumliche Betrachtung der Teileinzugsgebiete des hydrologischen Einzugsgebietes der oberen Wilzsch ermöglicht, das Abflussgebiet in verschiedene Herkunftsräume zu gliedern. Dieser raumbezogene Ansatz leistet einen wesentlichen Beitrag in der Herkunftsanalytik von Wässern, deren Fließwege durch Standorte unterschiedlicher Nutzung geprägt sind. Die Arbeit bedient sich hydrochemischen Analysen sowie multitraceranalytischen Verfahren. Die Analyse der stabilen Umweltisotope ²H und 18O am Wasser, 13C am DIC und DOC, 34S und 18O am Sulfat sowie 15N und 18O am Nitrat hilft bei der Identifizierung von Stoffquellen und Transformationsprozessen. Die Arbeit verfolgt das Ziel, den Beitrag der verschiedenen Stoffsysteme am gesamten Stoffaustrag des Vorfluters aufzuzeigen sowie die atmosphärische Grundlast an den Messstandorten nachzuweisen. Dazu wurden von Mai 2009 bis August 2010 fünf Beprobungskampagnen angelegt. Das Messdesign erstreckte sich auf 19 Standorte in ausgewählten Teileinzugsgebieten, die maßgeblichen Einfluss auf die Vorflut haben. Parallel dazu erfolgte die Untersuchung des Niederschlags an der Station Talsperre Weiterswiese. Erfasst wurden die Inhalte von Wässern verschiedener Moorgebiete, Moorwasserpegel unterschiedlich degradierter Moorbereiche, Gräben und Bodendrainagen im Fichtenforst, der Vorfluter Wilzsch und Kranizsch und des Grundwassers im Fichtenforst. Es kann festgehalten werden, dass je nach Lage bzw. Entfernung der Ursprungsgebiete der Anteil des DOC - Exports unterschiedlich stark ist. So sind die DOC - Austräge saisonal sehr verschieden. Im Ergebnis ist der hydrochemische Beitrag - im Besonderen DOC - der unterschiedlichen Stoffsysteme des hydrologischen Einzugsgebietes letztlich am finalen Pegel der Wilzsch messbar. Die vom Basisabfluss gesteuerten silikatischen Standorte im Fichtenforst leisten einen wesentlichen Anteil zum hydrochemischen Milieu der Vorfluter. Die im Untersuchungsgebiet eingeleiteten Renaturierungsmaßnahmen beeinflussen die Trinkwasserqualität in der Talsperre Carlsfeld nicht. Eine Abgrenzung der atmosphärischen Grundlast ist ebenfalls möglich, atmogen eingetragene Stoffe können an den Standorten ausgewiesen werden.

Die Hochmoore des Erzgebirges sind auf Grund ihrer jahrhunderte langen Nutzung und der ökosystemaren Wandelprozesse der vergangenen 10 - 15 Jahre unterschiedlich stark degradiert. Gleichzeitig sind sie durch den Austrag vergleichsweise hoher Austräge von DOC (Dissoloved Organic Carbon) gekennzeichnet. Um den Zusammenhang zwischen dem Zustand der Hochmoore, als Ergebnis in erster Linie der unterschiedlich nutzungsbedingten Degradation und den Stoffausträgen speziell den DOC-Austrägen zu erfassen, wurden mittels landschaftsökologischer Methoden Hochmoortestflächen verschiedener Zustände vergleichend untersucht. Die Ergebnisse lieferten erste Hinweise, dass in Flächen mit natürlicher Regeneration oder anthropogener Wiedervernässung vergleichsweise hohe DOC-Konzentrationen und – Austräge zu beobachten waren. Demgegenüber standen stärker degradierte Flächen mit zum Teil aktueller forstlicher Nutzung (geräumte Entwässerungsgräben), die durch geringere DOC-Konzentrationen und – Austräge charakterisiert waren. Da die gefundenen Zusammenhänge nicht endgültig belegt werden konnten, besteht insbesondere Forschungsbedarf hinsichtlich landschaftshaushaltlicher Untersuchungen unterschiedlich degradierter Hochmoore im Erzgebirge. / Natural peat bogs are known as a sinks especially for carbon because of theire special matter and water balance. The use of peat bogs requiers their drainage, but consequently the peat will decompose unreversible and peatlands turn to a source esspecially for carbon. The peat bogs in the “Erzgebirge Mountains” were used over several centuries. Thats why the peatlands existing nowadays have different states dependent on the duratian of their use. Beside the use peatlands were mostly negativly effected by processes of ecological change in the “Erzgebirge Maountains” in the last 10 to 15 years. As one result of ecological change the increased output of DOC (Dissolved Organic Carbon) into surface waters can be seen. The main source for DOC are peatlands. By the way it seems to exist a connection between the output of DOC and other dissolved substances and the state of the peatlands especially of their ditches. To research this hypothesis four test areas of different state were chosen. Their state and the output of DOC and other dissolved substances were investigated with methods from landscape ecology from 2001-2003. It was the first time, that peatlands in the “Erzgebirge Mountains” were investigated in such a way. The badest state had the test area where the ditches were cleaned in 2000/ 2001 (“Weiße Mulde”, Western “Erzgebirge Mountains”). This test area showed the lowest but constant DOC-concentrations and DOC-output during the investigation period. The test areas “Carlsfeld” and “Löffelsbach” (Western “Erzgebirge Mountains”) had the best state. The state of “Carlsfeld” is related to the narueal closed ditches, which cause the processes of self regeneration. Due to such processes the DOCconcentrations were distinctly higher but very variable in dependence on weather and runoff. The same was supposed to DOC-output. The same valuation got the test area “Löffelsbach”, because of rewetting by technical closed ditches in 2001. During the investigation period the highest DOC-concentrations of all test areas were measured there. Similar to “Carlsfeld” DOC-concentrations and –output were highly variable in dependence on weather and runoff. The state of the test area “Salzflüßchen” (Eastern “Erzgebirge Mountains”) is also related to processes of self regeneration but was valuated bader than “Carlsfeld”, because the effect of former drainage was stronger in this area. In 2005 the rewetting of the test area is planed by “Naturpark Erzgebirge/ Vogtland”. In the consequence the DOC-concentrations and –output will increase similar to “Löffelsbach”. The results of the investigations indicate that a connection exists between state of peatlands and output of dissolved substances esspecially DOC. The results are supported by national and international literature. It will be clear, that more research is necessary especially on the field of comparative investigations of peatlands with different states in the “Erzgebirge Mountains”.

This study concerns in a three peatland sites: the epilitorals of Pilská reservoir and Hořejší Padrťský fishpond in Příbram region and Kamenný fishpond in Pilsen. These peat-bobg were affected by negative conseqences of human activities. The aim of this study is to find out what kind these changes was and what extent they were. The changes in vegetation were observed from two points of view. The GIS analyses of aerial photographs represent the macroscale view. Repeating of old phytosociological relevées was the microscale view. To understand the cause of vegetation changes, the species-environment analyses were used. Four transects were made for this purpose and a water table level, pH and conductivity were mesured monthly along these transects. One-shot measurements of N and P water concentration and a peat depth were also carried out. Measured data from transects were uses in multivariate vegetation analyses and also in one- way analysis, aimed to an expansion plant species. All three sites of concern came through strong changes in past. In all of them the area of biotops of great conservation importance decreased and some endangered plant species have been lost there. The changes in Pilská reservoir epilitoral were mostly anthropogenic, whereas the mires of Hořejší Padrťský fishpond and Kamenný...

Background: Wetlands store significant amounts of carbon through plant respiration and anaerobic peat formation, however, there is little knowledge on which factors affect the carbon storage distribution within wetlands. Aims: To determine how much carbon and nitrogen wetlands can store over time and whether there are patterns of high and low carbon and nitrogen storage within wetlands. Methods: Peat samples of a defined volume, cut out from three constructed wetlands were dried, weighed and analysed for their carbon and nitrogen content. To determine whether there are any patterns in carbon and nitrogen storage distribution or differences between sampling points, their values as well as their ratios were statistically analysed using ANOVA and Kruskal-Wallis. Results: On average 48.94 t C ha-1is stored at the constructed wetland facility which equates 3.06 t C ha-1 storage per year. There is no patterns in carbon storage within wetlands, however, the C:N mass ratio is lower at the inlet suggesting that high N concentrations in inflowing water increases N content. Conclusions: The carbon storage found is significantly lower than storage at natural inland and coastal wetlands, however, similar to anthropogenically affected wetlands. Standardisation across studies through using same sampling depths, vegetation cover measurement and climate classification may help to uncover patterns in carbon storage in the future. Focus should be placed on protecting wetlands rather than restoring them as the latter often fails to restore full functionality. This is especially important for cold climate wetlands which store significantly more carbon through slower plant respiration and subsequently slower re-uptake of carbon.

No description available.