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Forest plantations in the UK are often established on seasonally waterlogged peaty gley soils which often require site preparation (drainage and mounding) to lower the water table and prepare planting positions. Substantial changes in the physical environment of peaty gley soils can accompany site preparation including fluctuations in soil temperature and soil moisture. These and other changes can all affect soil properties and decomposition processes and well as the dynamics of CO2, CH4 and N2O. A field experiment was established at Harwood Forest (NE England) to investigate the effects of three site management practices (drainage, mounding and fertilisation) frequently used for afforestation and replanting on peaty gley soils in the UK on soil properties and various of C and N, environmental variables (soil temperature, water content and water table height) and emissions of CO2, CH4 and N2O. The relationship between GHG emissions and environmental variables was also examined. The experiment was laid out in a factorial split-plot design. Drainage decreased C and N concentration in the 10 cm soil layer. The soil bulk density in the 0 to 20 cm soil layer was increased by mounding. Drainage and fertilisation increased soil CO2 efflux, whereas mounding did not affect soil CO2 efflux. All three practices affected soil CH4 fluxes with drainage reducing the fluxes and mounding and fertilisation increasing the fluxes. Nitrous oxide emissions were significantly affected by mounding and fertilisation, with mounding decreasing emissions and fertilisation increasing emissions. Soil temperature was the main environmental factor controlling soil respiration in this site. Over the two years study drainage and fertilisation increased the total greenhouse budget by 13.1% and 97.9%, while mounding caused a reduction of−17.6%. Drainage plus mounding reduced the total greenhouse budget by 6.9%, while drainage plus mounding plus fertilisation increased the total greenhouse budget by 101.8%. There is a potential for up-scaling GHG emissions from newly drained peaty gley for inclusion in the UK Land Use Land-Use Change and Forestry (LULUCF) Greenhouse Gas Inventory. However up-scaling and evaluation of the net emissions requires high quality data from different sites newly drained for afforestation. More studies are needed if net fluxes from newly drained sites are to the included in the LULUCF Greenhouse Gas Inventory.

Over the last millennium peatlands have accumulated significant carbon stores. Drainage for agricultural use has been widespread and has altered the functioning of these mires: shifting them towards carbon release. Recently, in recognition of the range of ecosystem services derived from these landscapes peatland restoration projects have been initiated. Carbon storage is often cited amongst the aims of these projects, especially since the inclusion of rewetting wetlands in the Kyoto Protocol. However, little is known about the effects of ditch blocking on CO2 fluxes, particularly in Molinia caerulea dominated peatlands, a species common on degraded peatlands which tolerates a range of water table depths. This thesis aims firstly to quantify CO2 fluxes from a drained Molinia caerulea dominated blanket bog and to improve understanding of the temporal and spatial controls on these fluxes and secondly, to quantify the immediate effects of ditch blocking. Closed chamber measurements of net ecosystem exchange and partitioned below-ground respiration from control-restored paired sites were collected over the growing seasons immediately pre- (2012) and post-restoration (2013/2014). These flux data were coupled with remotely sensed data quantifying vegetation phenology and structure with a fine resolution (daily/cm) over large extents (annual/catchment). Although temporal variation in water table depth was not related to CO2 fluxes, the seasonal average related to vegetation composition suggesting raising water tables may promote a change in vegetation composition within these species-poor ecosystems. The distribution of water table depths, vegetation composition and CO2 fluxes did not vary with proximity to drainage ditches despite their prominence. An empirical model suggests in a drained state these peatlands are CO2 sources, indicating carbon previously accumulated is gradually being lost. Data suggest restoration does not always significantly affect water tables and consequently CO2 fluxes in the short-term. Where shallower water tables were maintained during dry conditions photosynthesis decreased and heterotrophic respiration increased: enhancing carbon release. Research undertaken during atypical weather has been unable to determine if restoration will be able to raise water tables sufficiently to protect the existing peat store and promote the vegetation change required to reinstate CO2 sequestration in the longer-term.

This work deal with a brief characterization of three materials, namely oxyhumolite and sapropelite from Sokolov basin that are compared with peat from Františkovy Lázně. The sampling localities are briefly geographically and geologically described including the genesis of the deposits. All materials are specifically characterized by analysis. The materials are compared based on the results of the analysis. Greater attentinon is paid to the comparison of sulfur content, humic acides and warmth retention. A part of the work is devoted to description of peloids and their influence on the human organism. The history of using peloids is briefly discussed. The possibility of using oxyhumolite and sapropelite for production of natural cosmetics or for balneological use is examined as a replacement for native and especially for regenerated peat.

Assessment the effect of revitalizing measures of chosen peat bogs in the upper Vydra River basin on their water regime Abstract: Despite a number of research projects, the influence of peat bogs on the hydrological regime remains a largely unexplored topic. In the past, several peat bogs in the Šumava National Park were exposed to a very strong anthropogenic pressure. Subsequently, revitalizing measures were applied to mitigate the impact of human interventions, to stop the degradation of these precious habitats, and to reform the disturbed peat bog water regime. This thesis is focused especially on fluctuations of water table level and on the hydrological regime in the catchments of Rokytka and Cikánský Brooks. Thesis further develops the topic solved in author's bachelor thesis called "Peat bog revitalizing measures and their effect on runoff dynamics in the Otava River headstream area." It contains experimental research of the influence of drainage canals and revitalizing measures on water table fluctuation. It also aims to identify the extent to which meteorological factors contribute to changes in groundwater level and to assess the present state of revitalization measures and their influence on the runoff regime. Key words: peat bogs, revitalizing measures, Šumava Mountains, water regime

A traditional species concept of diatoms is based on morphological characters of their siliceous boxes. A multidisciplinary approach to defining species of diatoms has revealed the hidden diversity within the traditionally defined species. But the newly recognized species are morphological variable and indistinguishable by the naked eye. Recent studies showed that different morphotypes show different ecological preferences. This master thesis focuses on the morphology of natural populations of the diatom species complex Frustulia rhomboides which contains both the traditional and the cryptic species, and it engages how the morphology reflects the effects of environmental conditions. Landmark methods of geometric morphometrics were used in order to analyze the morphological variability of diatom frustules of this species complex within various peat bog habitats in the Czech Republic. Selected environmental parameters were measured and the species composition of diatom communities present in the samples was investigated. These data were used to analyze the relationship between the environmental conditions and the cell shape variability within the complex. The analysis revealed the main trends of morphological variability related to different environmental conditions. Two morphotypes characteristic...

Orientador: Julio Cesar Rocha / Banca: Ladislau Martin-Neto / Banca: Nivaldo Baccan / Banca: Mário Miyazawa / Banca: Nilso Barelli / Resumo: Este trabalho aborda novos desenvolvimentos relacionados à pesquisa científica de substâncias húmicas (SH) extraídas de amostras de solos/turfas . Assim, na primeira etapa descreve-se o desenvolvimento de um procedimento em fluxo contínuo para extração de substâncias húmicas e fracionamento destas em ácidos húmicos e fúlvicos. O procedimento em fluxo proposto apresenta vantagens em relação ao procedimento tradicionalmente utilizado (batelada) devido ao aumento do rendimento e diminuição do tempo de extração. Além disso, facilita o trabalho dispendiosos no manuseio, transferência e ajuste de pH das frações. Numa segunda parte do trabalho, descreve-se a preparação de um novo suporte para imobilização da enzima invertase utilizando-se substâncias húmicas. O suporte preparado pela ativação da aminopropil sílica com SH (APTS-SiO2-HS) mostrou ser um método viável e interessante para a imobilização da invertase. Os resultados referentes a quantidade e atividade da invertase imobilizada no APTS-SiO2-HS foi comparado com um suporte tradicional (aminopropil sílica ativada com glutaraldeído, APTS-SiO2-GA). A quantidade de invertase imobilizada no APTS-SiO2-HS foi 15200 U g-1 enquanto que no APTS-SiO2-GA foi 13400 U g-1. As atividades enzimáticas experimentais foram 3700 e 3270 U g-1, para os sistemas APTS-SiO2-HS e APTS-SiO2-GA, respectivamente. A terceira etapa do trabalho trata da caracterização de espécies...(Resumo completo, clicar acesso eletrônico abaixo) / Abstract: This work presents new developments about the scientific research of humic substances (HS) extracted from soils/peat samples. So, the first part describes the development of continuous flow procedure for extraction and fractionation of humic substances in humic and fulvic acids. The proposed flow procedure presents advantages in relation to the traditional used procedure (bath) due to the increasing of the yields and decrease of extraction time. Besides, discharge the research work in the handling and transference and pH adjust of the fractions. The second part, describes the preparation of a new support for immobilization of invertase enzyme using humic substances. The prepared support by aminopropil silica activation with HS (APTS-SiO2-HS) showed be a good method for invertase immobilization. The results about the quantity and activity of the invertase immobilized in the APTS-SiO2-HS it was compared with a traditional support (aminopropil silica activated with glutaraldeyde, APTS-SiO2-GA). The quantify of immobilized invertase in the APTS-SiO2-HS it was 15200 U g-1, while in the APTS-SiO2-GA it was 13400 U g-1. The experimental enzymatic activities were 3700 and 3270 U g-1, for the systems APTS-SiO2-HS and APTS-SiO2-GA, respectively...(Complete abstract, click electronic access below) / Doutor

L’utilisation de la minéralogie magnétique en tant que marqueur des changements environnementaux dans les tourbières a été envisagé dès 1986 (Richardson, 1986) mais n’a pas été réellement prise au sérieux jusque très récemment (Hutchinson and Armitage, 2009; Mighall et al., 2009). Notre étude se proposait d’abord de déterminer quelles techniques sont les plus adaptées à des mesures sur tourbe (acquisition progressive d’ARI et ARA associées à leurs désaimantations AF) et comment les mettre en place afin de garantir la qualité des mesures malgré les nombreuses contraintes : faiblesse du signal, évolution temporelle de la minéralogie, caractère meuble et instable des dépôts. Le protocole d’étude de la minéralogie magnétique a ensuite été appliqué à trois carottes prélevées dans le marais de la Trézence (Charente-Maritime, France) en parallèle d’analyses géochimiques à même de retracer l’histoire environnementale du site (analyse élémentaire, isotopes du plomb, rapport C/N,datations radiocarbones). A la confrontation des résultats, il apparaît qu’une partie des variations de minéralogie magnétique correspond aux indications environnementales apportées par les paramètres géochimiques. Les autres variations mises en exergues peuvent être interprétées en termes d’indicateurs de processus pédologiques non observable avec les paramètres géochimiques étudiés. / Despite a first study dating from 1986 (Richardson, 1986), magnetic mineralogy in peat was not considered and used as a potential palaeoenvironmental proxy until very recently. The first aim of our study was to determine what technics can be used on peat (SIRM, SARM and their demagnetization) and how, to overcome the specific problems arising from the use of peat : very low magnetic signal, evolution of the signal through time, etc. The relevant magnetic procedure was then applied to three peat cores frome La Trézence peat bog(Charente-Maritime, France) along with geochemical analyses giving informations on the environmental evolution throught time. After comparison of all the results, part of the magnetic mineralogy variations fits with environmental evolution. The other part can be concidered as a proxy of pedologic processes that studied geochemical parameters do not show.

Peat soils are known to be a significant emitter of atmospheric greenhouse gasses. However, the spatial and temporal variability in production and release of greenhouse gases (such as methane) in peat soils remains uncertain, particularly for low-latitude peatlands like the Florida Everglades, as the majority of studies on gas dynamics in peatlands focus on northern peatlands. The purpose of the work outlined here is focused on understanding the spatial and temporal variability in biogenic gas dynamics (i.e. production and release of methane and carbon dioxide) by implementing various experiments in the Florida Everglades at different scales of measurement, using noninvasive hydrogeophysical methods. Non-invasive methods include ground-penetrating radar (GPR), gas traps, time-lapse cameras, and hydrostatic pressure head measurements, that were constrained with direct measurements on soil cores like porosity, and gas composition using gas chromatography. By utilizing the measurements of in-situ gas volumes, we are able to estimate gas production using a mass balance approach, explore spatial and temporal variabilities of gas dynamics, and better constrain gas ebullition models. A better understanding of the spatial and temporal variability in gas production and release in peat soils from the Everglades has implications regarding the role of subtropical wetlands in the global carbon cycle, and can help providing better production and flux estimates to help global climate researchers improve their predictions and models for climate change. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2018. / FAU Electronic Theses and Dissertations Collection

Humic substances (HS), the complex mixture of organic molecules produced by microbial and abiotic degradation of plant and animals residues, are the major components of organic matter in soil and natural waters. As such, they are vital to the integrity of soil, play important roles in nutrient biogeochemical cycling and determine the mobility and fate of both nutrients and contaminants. How HS enact their varied roles, however, is largely unknown due to the lack of comprehension of their molecular make-up. What is known is that they contain aromatic (e.g. phenols, condensed aromatics) and aliphatic (e.g. carbohydrates, lipids) molecules with prevailing carboxyl and hydroxyl functionalities. As for other complex chromatographically inseparable mixtures, high-resolution analytical techniques such as Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (FT-ICR MS) as well as Nuclear Magnetic Resonance (NMR) spectroscopy have been applied to study HS composition at the molecular level. While FT-ICR MS can provide molecular formulae, it is only NMR that can unveil structures. Until now, however, very few unambiguous structures of individual molecules have emerged from standard NMR experiments. This is because purposely designed multidimensional NMR experiments are required to achieve ‘spectroscopic separation’ where chromatography fails. In this work, ‘spectroscopic separation’ was accomplished with the aid of chemical modification in the form of 13C methylation of COOH and OH groups. 13C containing tags allow the observation of signals only from molecules carrying these tags. In combination with purposelydesigned isotope-filtered NMR experiments, these tags act as spies reporting on their surrounding structure. This is achieved by utilising scalar and dipolar couplings to transfer the polarisation between protons and carbons of the 13CH3O groups and nuclei of the parent molecules. The necessary spectral resolution is attained using 3D/4D NMR experiments. This approach provides access to an array of correlated chemical shifts of HS molecules and represents a paradigm shift in the use of tags in investigations of complex mixtures: instead of focusing only on the tags, they are used to obtain structural information from the molecules they are attached to. The compounds at the centre of this investigation are the phenols of HS. These molecules are thought to be important in many of the key processes in organic matter rich soils, particularly peat. For example, their accumulation is thought to impair the activity of extracellular enzymes essential for the degradation of peat HS. Understanding the nature and source of phenols would provide a more fundamental framework for rationalising their role in peat, as well as other carbon rich soils. The developed methodology was initially tested on model mixtures containing 3 or 9 phenolic compounds before applying it to a operational fraction of HS, fulvic acid, extracted from a Scottish raised peat bog. For this fulvic acid, over 30 major phenolic molecules/moieties were identified, many of which can be directly traced to the flora prevalent in the vicinity of the sampling site. For the first time in 150 years of HS research, a novel analytical methodology has yielded unambiguous structural information, providing the first steps towards understanding the various roles of HS in natural systems.