Decay and accumulation of blanket peat in the Northern Pennine region of England are considered, both in quantitative and qualitative terms. Productivity on the surface of these peat bogs is not unusually high, suggesting that a low decay rate may be responsible for the accumulation of the peat. Considerable study has formerly been made of the aerobic decay processes, at the expense of the parallel anaerobic processes, which have largely hitherto been considered negligible. Yet a current mathematical model of peat accumulation suggests that it is likely to be the anaerobic decay rate which determines the total depth of peat which may accumulate. Further, such models intimate that a very small absolute change in the anaerobic decay rate will have an unexpectedly large effect on the potential steady state depth of peat. The present study concentrates on obtaining measurements of anaerobic decay rates, and on identifying the possible limiting environmental factors of the decay. The design of a sampler to collect gas samples in situ from blanket peat is described. The components of particular interest in the samples are CH4 and C02. Gas concentrations down eight peat profiles at two sites are monitored over two seasons. Simultaneous surface flux measurements above pool, lawn and hummock microhabitats are also made. Water level, temperature, pH, redox potential, depth of the sulphide zone and total sulphide concentration are recorded on each field visit. The results from the gas sample analyses are discussed in relation to the environmental factors and in relation to our present understanding of peat decay rates and their consequences on peat accumulation. The anaerobic decay rate is calculated, and is confirmed to be several orders of magnitude less than that in the overlying aerobic peat. It is shown that the methane is not fossil, but is continually being produced at all depths. Rates of gas production are calculated. Annual methane and carbon dioxide losses from entire peat bogs are calculated to contribute a significant amount to carbon cycling, on a site-specific and global scale.

Thesis (doctoral)--Hochschule zu Stockholm, 1921. / Includes bibliographical references (p. 165-171).

Thesis (M.A.)--University of Wisconsin, 1936. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves [48]-51).

Thesis (Ph.D.)--University of Waikato, 2006. / Includes bibliographical references (p. [75]-85) Also available via the World Wide Web.

The Sphagnum bogs of the Tofino-Ucluelet area of the western coast of Vancouver Island were studied from vegetational, edaphic, and historical aspects. An integrated approach to these three aspects was attempted in order to give in a relatively limited time as complete a picture as possible of the bog ecosystem. The bog vegetation was studied on 110 sample plots using analytical and synthetic methods of the Zurich-Montpellier school of phytosociology. Ten different vegetation types were described and characterized, nine belonging to the bog ecosystem and one to the surrounding scrub forest. The nine bog vegetation types consist of five distinct associations and one association composed of five variants. The vegetation types studied are summarized below, in order of increasing floristic complexity. Low moor bog associations: 1. Caricetura pluriflorae (Carex plurlflora association) 2. Scirpeto-Sphagnetum mendoclnl (Sclrpus caespitosus - Sphagnum mendocinum association) 3. Oxycocceto-Sphagnetum papillosi (Oxycoccus quadripetalus - Sphagnum papillosum association) High moor bog association: 4. Ledeto-Sphagnetum caplllacei (Ledum groenlandicum - Sphagnum capillaceum association) Peripheral bog associations: (Bog-forest transition) 5. Pineto-Sphagnetum capillacei (Pinus contorta - Sphagnum capillaceum association) a. Pineto-Sphagnetum capillacei sphagnosum papillosi (Pinus contorta hummock variant) b. Pineto-Sphagnetum capillacei myricosum galis (Myrica gale variant) c. Pineto-Sphagnetum capillacei chamaecyparosum nootkatensis (Chamaecyparis nootkatensis variant) Secondary succession variants established after fire: d. Pineto-Sphagnetum capillacei vacciniosum vitis-idaeae (Vaccinium vltis-idaea variant) e. Pineto-Sphagnetum capillacei vacciniosum parvifolii (Vaccinium parvifollum variant) Scrub forest association surrounding bogs: 6. Pineto-Chamaecypareto-Sphagnetum recurvi (Pinus contorta - Chamaecyparis nootkatensis - Sphagnum fecurvum association) (Bog forest) Edaphic considerations were limited to the analysis of soils from representative sample plots of each association and variant. Soils were analyzed for available cations, including Ca⁺⁺, Mg⁺⁺, Na⁺, K⁺, adsorbed phosphate, total nitrogen, cation exchange capacity, percent base saturation pH, and soil moisture. The results of the soil analyses were wherever possible correlated with trends in the development of plant associations. Climatic factors were regarded as constant over so limited an area as the one under study. Historical considerations included a pollen analysis from a representative core in the center of the major study bog, and a radiocarbon dating to determine the age of a representative bog. The results of the pollen analysis appeared to confirm previous ideas that the bog did not develop from a lake, but rather it developed from a wet seepage forest habitat. The radiocarbon dating indicated the age of the bog at only 390± 90 years B.P., thus explaining partially the apparent very juvenile phase of the bogs of the area. The general hypothesis is suggested that the distribution of the bog plant associations is primarily dependent upon a complex of environmental factors that are dependent upon topography. / Science, Faculty of / Botany, Department of / Graduate

Continuous eddy covariance measurements were conducted for a 125 day period, throughout the 2007 growing season, in a northern Alberta peatland. Significant diurnal and seasonal variation in methane fluxes were observed. Diurnal variation in methane flux was suggested to be due to variation in soil temperature and methane convective flow through vegetation to the atmosphere. Seasonal variation in methane flux was associated with a variety of factors, most notably seasonal variation in the capacity for methane emission at 10 ºC (R10). The R10 values varied as a function of soil temperature and were an important control of seasonal variation in methane flux. Also, a greenhouse gas budget was calculated comparing net methane emission and net CO2 sequestration. This analysis indicated that the peatland was acting as a net sink of radiative forcing agents for the 2007 growing season. / xiii, 100 leaves ; 29 cm. --

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...

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.

A hydrological and biogeochemical study was undertaken at the Mer Bleue bog, Ottawa, Ontario, Canada from May 22, 1998 to May 21, 1999. Basin runoff was generated by groundwater discharge at the peatland margin, and groundwater discharge was controlled by hydraulic gradients and horizontal hydraulic conductivities (Kh). Flux of dissolved organic carbon (DOC) measured at the basin outflow was 8.3 g C m-2 yr-1 and compared to within 23% of DOC flux estimated using a Dupuit approximation of seepage during the ice-free season. Annual DOC flux was 11% of the annual carbon sink. / Flownet analysis showed that seasonal patterns of groundwater flow were controlled by boundary condition changes that resulted from precipitation and evapotranspiration events. A pattern of recharge was most common over the hydrological year, but a discharge pattern was observed during a 40 day groundwater flow reversal. Evaluation of the peatland recharge-discharge function using in situ sodium concentrations and a diffusion model revealed that the peatland is a long-term recharge system. It is hypothesized that peatland biogeochemical function is controlled by long-term recharge despite annual occurrence of groundwater flow reversals.