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<p>Validerat; 20111223 (anonymous)</p>

No

Yes / Understanding the chronology of Norse settlement is crucial for deciphering the archaeology of many sites across the North Atlantic region and developing a timeline of human-environment interactions. There is ambiguity in the chronology of settlements in areas such as the Northern Isles of Scotland, arising from the lack of published sites that have been scientifically dated, the presence of plateaus in the radiocarbon calibration curve, and the use of inappropriate samples for dating. This novel study uses four absolute dating techniques (AMS radiocarbon, tephrochronology, spheroidal carbonaceous particles and archaeomagnetism) to date a Norse house (the “Upper House”), Underhoull, Unst, Shetland Isles and to interpret the chronology of settlement and peat which envelops the site. Dates were produced from hearths, activity surfaces within the structure, and peat accumulations adjacent to and above the structure. Stratigraphic evidence was used to assess sequences of dates within a Bayesian framework, constraining the chronology for the site as well as providing modelled estimates for key events in its life, namely the use, modification and abandonment of the settlement. The majority of the absolute dating methods produced consistent and coherent datasets. The overall results show that occupation at the site was not a short, single phase, as suggested initially from the excavated remains, but instead a settlement that continued throughout the Norse period. The occupants of the site built the longhouse in a location adjacent to an active peatland, and continued to live there despite the encroachment of peat onto its margins. We estimate that the Underhoull longhouse was constructed in the period cal. AD 805–1050 (95% probability), and probably in cal. AD 880–1000 (68% probability). Activity within the house ceased in the period cal. AD 1230–1495 (95% probability), and most probably in cal. AD 1260–1380 (68% probability). The Upper House at Underhoull provides important context to the expansion and abandonment of Norse settlement across the wider North Atlantic region.

O presente estudo traz para discussão as ações educativas destinadas aos trabalhadores, no âmbito do licenciamento ambiental das atividades de perfuração e exploração de petróleo e gás offshore - à luz dos referenciais teórico metodológicos de uma Educação Ambiental (EA) crítica. Muito embora as pesquisas em EA no Brasil tenham alcançado um elevado grau de maturidade, produzindo reflexões profícuas e embasando a elaboração tanto de diretrizes quanto instruções normativas; ainda hoje, importantes eixos de atuação e públicos de interesse específicos - a exemplo de trabalhadores alocados em unidades de perfuração, produção e embarcações de apoio - carecem de uma reflexão aprofundada que questione tanto o substrato epistemológico empregado quanto o tipo de práxis educativa que vem sendo construída. Neste sentido o estudo analisa o Projeto de Educação Ambiental dos Trabalhadores (PEAT) elaborado por duas grandes empresas de consultoria, sediadas no Rio de Janeiro, com o objetivo de avaliar em que medida seus projetos pedagógicos incorporam os princípios da EA instituídos pela Política Nacional de Educação Ambiental. Ademais são observados os pontos críticos (contradições) para a operacionalização do Projeto e o embate entre discursos antagônicos, que buscam a hegemonia material e simbólica do campo da EA, tomando por base a análise de discurso a partir de entrevistas realizadas com os principais atores envolvidos na elaboração do PEAT: empreendedor-consultoria-órgão ambiental. Como resultado observamos: (i) uma deficiência (por parte das consultorias) em incorporar os fundamentos teóricos da EA ao PEAT submetido para aprovação do órgão ambiental licenciador; (ii) uma inadequação das concepções metodológicas do PEAT, com consequentes advertências por parte do órgão ambiental e (iii) o engendramento de uma situação de incoerência na qual o órgão ambiental licenciador aprova um documento escrito (PEAT submetido) e desaprova as práticas educativas por este desencadeadas. / This study starts the discussion of educational actions designed for workers, under the environmental licensing process of exploration and production of oil and gas from the perspective of the theoretical methodological references of critical Environmental Education (EE). Even though research in EE in Brazilhas reached an elevated degree of maturity, producing fruitful reflections and providing basis for the elaboration of guidelines as well as normative instructions; even today, important areas of action and target publics of specific interests as is exemplified by workers allocated in drilling and production units and supply vessels lack a deeper reflection that questions not only the epistemological basis used but also the kind of educational praxis that is being constructed. In this way, this study analyses the Environmental Education Project for Workers (PEAT) elaborated by two large consulting companies, based in Rio de Janeiro, so as to evaluate in what way their pedagogical projects incorporate the principles of EE put forth by the National Environmental Education Policy. Critical points (contradictions) for the operationalization of the Project are also observed as well as the shock between conflicting discourses that look for material and symbolic hegemony in the EE field, by analyzing the discourse from interviews carried out with the main actors involved in the elaboration of the PEAT: the company consulting company environmental agency. As a result, we see: (i) a deficiency (on the part of the consulting companies) in incorporating the theoretical foundations of EE into the PEAT submitted for approval by the environmental agency responsible for the licensing process; (ii) inadequate methodological conceptions of the PEAT, with subsequent warnings from the environmental agency and (iii) the creation of a situation of incoherencies in which the environmental agency approves a written document (the submitted PEAT) and disapproves of the educational practices that this document propagates.

O presente estudo traz para discussão as ações educativas destinadas aos trabalhadores, no âmbito do licenciamento ambiental das atividades de perfuração e exploração de petróleo e gás offshore - à luz dos referenciais teórico metodológicos de uma Educação Ambiental (EA) crítica. Muito embora as pesquisas em EA no Brasil tenham alcançado um elevado grau de maturidade, produzindo reflexões profícuas e embasando a elaboração tanto de diretrizes quanto instruções normativas; ainda hoje, importantes eixos de atuação e públicos de interesse específicos - a exemplo de trabalhadores alocados em unidades de perfuração, produção e embarcações de apoio - carecem de uma reflexão aprofundada que questione tanto o substrato epistemológico empregado quanto o tipo de práxis educativa que vem sendo construída. Neste sentido o estudo analisa o Projeto de Educação Ambiental dos Trabalhadores (PEAT) elaborado por duas grandes empresas de consultoria, sediadas no Rio de Janeiro, com o objetivo de avaliar em que medida seus projetos pedagógicos incorporam os princípios da EA instituídos pela Política Nacional de Educação Ambiental. Ademais são observados os pontos críticos (contradições) para a operacionalização do Projeto e o embate entre discursos antagônicos, que buscam a hegemonia material e simbólica do campo da EA, tomando por base a análise de discurso a partir de entrevistas realizadas com os principais atores envolvidos na elaboração do PEAT: empreendedor-consultoria-órgão ambiental. Como resultado observamos: (i) uma deficiência (por parte das consultorias) em incorporar os fundamentos teóricos da EA ao PEAT submetido para aprovação do órgão ambiental licenciador; (ii) uma inadequação das concepções metodológicas do PEAT, com consequentes advertências por parte do órgão ambiental e (iii) o engendramento de uma situação de incoerência na qual o órgão ambiental licenciador aprova um documento escrito (PEAT submetido) e desaprova as práticas educativas por este desencadeadas. / This study starts the discussion of educational actions designed for workers, under the environmental licensing process of exploration and production of oil and gas from the perspective of the theoretical methodological references of critical Environmental Education (EE). Even though research in EE in Brazilhas reached an elevated degree of maturity, producing fruitful reflections and providing basis for the elaboration of guidelines as well as normative instructions; even today, important areas of action and target publics of specific interests as is exemplified by workers allocated in drilling and production units and supply vessels lack a deeper reflection that questions not only the epistemological basis used but also the kind of educational praxis that is being constructed. In this way, this study analyses the Environmental Education Project for Workers (PEAT) elaborated by two large consulting companies, based in Rio de Janeiro, so as to evaluate in what way their pedagogical projects incorporate the principles of EE put forth by the National Environmental Education Policy. Critical points (contradictions) for the operationalization of the Project are also observed as well as the shock between conflicting discourses that look for material and symbolic hegemony in the EE field, by analyzing the discourse from interviews carried out with the main actors involved in the elaboration of the PEAT: the company consulting company environmental agency. As a result, we see: (i) a deficiency (on the part of the consulting companies) in incorporating the theoretical foundations of EE into the PEAT submitted for approval by the environmental agency responsible for the licensing process; (ii) inadequate methodological conceptions of the PEAT, with subsequent warnings from the environmental agency and (iii) the creation of a situation of incoherencies in which the environmental agency approves a written document (the submitted PEAT) and disapproves of the educational practices that this document propagates.

Abstract Peat starts to decompose more rapidly after drainage, due to exposure to oxygen. While methane (CH4) emissions tend to decrease after drainage, carbon dioxide (CO2) and nitrous oxide (N2O) emissions from drained peatlands are considerable, especially the if the area is used for cultivation. Drainage and subsequent land management change the physical characteristics and thus hydrology and thermal conductivity of the soil, which affects greenhouse gas production. This thesis examined CH4 and N2O emissions and respiration from a peatland complex in Northern Finland, including a cultivated peatland, a forested peatland, a peat extraction site and a pristine mire. Chambers were used during the snow-free period and the snow gradient method during winter. Peat physical properties at the sites were also measured. The DRAINMOD model was used to assess measured peat hydraulic conductivity compared with the values needed to fit observed groundwater depth fluctuations. Effects of mineral soil content, drainage conditions and temperature on thermal conductivity of peat were examined and well-known equations for thermal conductivity of organic soils were tested. Respiration was highest in the cultivated study site, and this site and the peat extraction site were major sources of N2O. The pristine site was a large source of CH4 during the growing season. During winter, the peat extraction site and the cultivated site emitted CH4. The results suggested that raising mean groundwater level from 60 cm to 40 cm could potentially mitigate the greenhouse gas emissions at the cultivated site. Soil hydraulic conductivity at the drained sites was found to be better predicted by land use type than by soil physical parameters. Hydraulic conductivity values needed for DRAINMOD were at least one order of magnitude higher than those observed in field measurements. This demonstrates the potential role of land use and macropore flow in controlling hydrological processes in peat soils. The samples with the highest mineral soil content and bulk density had the highest thermal conductivity, especially at above-zero temperatures. The best equation for predicting thermal conductivity for unfrozen and frozen mineral soil-enriched peat soils was the Brovka-Rovdan equation, but the deVries equation performed fairly well for unfrozen soils. Soil water content and vegetation cover strongly influenced soil thermal regime. / Tiivistelmä Turve alkaa hajota nopeammin ojituksen jälkeen happipitoisuuden lisääntyessä maassa. Metaanin (CH4) päästöt ovat yleensä vähäisiä ojituksen jälkeen, kun taas hiilidioksidin (CO2) ja typpioksiduulin (N2O) päästöt erityisesti viljellyiltä turvemailta voivat olla merkittäviä. Ojitus ja sen jälkeinen maankäyttö vaikuttavat maan fysikaalisiin ominaisuuksiin ja siten alueen hydrologiaan ja maan lämmönjohtavuuteen, mikä vaikuttaa kasvihuonekaasujen muodostumiseen. Tässä tutkimuksessa mittasimme CH4- ja N2O-päästöjä ja respiraatiota (talvella lumigradientti-menetelmällä ja kasvukauden aikana kammiomenetelmällä) turvemaa-alueella Pohjois-Suomessa. Koealue sisälsi turvepellon, turvemetsän, turvetuotantoalueen ja luonnontilaisen suon. Mittasimme alueilla myös maan fysikaalisia ominaisuuksia. DRAINMOD-mallia käytettiin saatujen hydraulisen johtavuuden mittausarvojen mallinnukseen sopivuuden tarkasteluun. Maan mineraaliaineksen osuuden, ojituksen ja lämpötilan vaikutusta turpeen lämmönjohtavuuteen tutkittiin ja testattiin eräiden tunnettujen lämmönjohtavuusmallien toimivuutta. Respiraatio oli suurinta turvepellolla ja turvetuotantoalue ja pelto olivat merkittäviä N2O-lähteitä. Suo oli sulan maan aikana merkittävä CH4-lähde. Talvella turvetuotantoalue ja pelto olivat CH4-lähteitä. Tutkimus viittasi siihen, että pohjavedenpinnan nostaminen turvepellolla 60 cm tasosta 40 cm tasoon voisi vähentää kasvihuonekaasupäästöjä. Maankäyttö ennusti hydraulista johtavuutta paremmin kuin fysikaaliset parametrit. DRAINMOD-malliin tarvittiin vähintään kertaluokkaa suurempia arvoja kuin kentällä mitatut. Tutkimus viittasi maankäytön ja macrohuokosten mahdollisesti merkittävään vaikutukseen turvemaa-alueiden hydrologiassa. Lämmönjohtavuus oli korkein näytteissä, joissa mineraalimaan osuus ja kiintotiheys olivat korkeita, erityisesti sulissa näytteissä. Brovka &#38; Rovdan- malli oli paras näiden näytteiden kuvaamiseen mutta myös de Vries-malli toimi kohtalaisen hyvin sulille näytteille. Lämmönjohtavuus oli vähemmän merkittävä maan lämpötilojen kannalta kuin maan vesipitoisuus ja kasvillisuuspeite.

This work aims to clarify and describe the necessary conditions of the peat soil horizon formation. The following three types of locations were compared. Drained locations that were revitalized afterwards. Locations which were drained and never revitalized. And lastly undrained localities where the original peat horizons are still presented. It has been proven that the grounwater level differs in drained and undrained areas. However, there was no significant differrence between revitalized and non-revitalized areas in drained types of locations. The results confirmed that Sphagnum spp., which is the most important species in peat formation, dominates the plant community where the groundwater level is higher than 25 cm. If the grounwater level is lower than 25 cm below the surface, Sphagnum spp. disappears very quickly and degrades peat soil horizons. The work also proved the groundwater level directly affects plant comunities that more or less promote carbon accumulation in the soil but water level and anaerobic conditions have no direct affect on soil carbon accumulation and only affect the vegetation composition of the peat soil horizon.

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. --

The present status of the environment, including environmental problems such as heavy metal accumulation in aquatic and terrestrial ecosystems, is in part the consequence of long-term changes. Cores from peatlands and other natural archives provide us with the potential to study aspects of the atmospheric cycling of elements, such as metal pollutants, on timescales much longer than the decade or two available to us with atmospheric deposition monitoring programs. The past decade especially has seen a rapid increase in interest in the biogeochemical record preserved in peat, particularly as it relates to environmental changes (e.g. climate and pollution). Importantly, recent studies have shown that carbon dynamics, i.e., organic matter decomposition, may influence the record of atmospherically derived elements such as halogens and mercury. Other studies have shown that under certain conditions some downward movement of atmospherically deposited elements may also occur, which adds complexity to establishing reliable chronologies as well as inherent problems of estimating accurate accumulation rates of peat and past metal deposition. Thus, we still lack a complete understanding of the basic biogeochemical processes and their effects on trace element distributions. While many studies have validated the general temporal patterns of peat records, there has been a limited critical examination of accumulation records in quantitative terms. To be certain that we extract not only a qualitative record from peat, it is important that we establish a quantitative link between the archive and the few to several decades of data that are available from contemporary monitoring and research. The main objective of this doctoral thesis was to focus on improving the link between the long-term paleorecord and the contemporary monitoring data available from biomonitoring and direct deposition observations. The main research questions have therefore been: Are peat archives an absolute or relative record? And how are geochemical signals, including dating, incorporated in the peat archive? What temporal resolution is realistic to interpret by using peat cores?