Search results for "Peat"
showing 10 items of 1026 documents
Stages in the compaction of peat; examples from the Stephanian and Permian of the Massif Central, France
1987
Thick coal seams in the intramontane basins of the Massif Central allow a detailed study of peat/coal compaction. Three stages of compaction can be detected. Stage 1—occurred during the deposition of the peat. Coal beds which thicken and dip away from penecontemporaneous sandstones suggest rapid compaction. Stage 2—compaction of peat related to overburden pressure in some cases resulted in the formation of lakes over peat beds. The thickness of the lacustrine deposits may give an indication of the amount of compaction that took place. One possibility is that the early compaction was related to the progradation of siliciclastics over the peat. Stage 3—occurred after the organic sediment achi…
Drained organic soils under agriculture — The more degraded the soil the higher the specific basal respiration
2019
Abstract Drained peatlands are hotspots of carbon dioxide (CO2) emissions from agricultural soils. As a consequence of both drainage-induced mineralisation and anthropogenic mixing with mineral soils, large areas of former peatlands under agricultural use underwent a secondary transformation of the peat (e.g. formation of aggregates). These soils show contents of soil organic carbon (SOC) at the boundary between mineral and organic soils. However, the carbon (C) dynamics of such soils have rarely been studied so far. The aim of the present study was to evaluate the vulnerability of soil organic matter (SOM) to decomposition over the whole range of peat-derived soils under agriculture includ…
Peat stratigraphy and changes in peat formation during the Holocene in Latvia
2015
Mires represented by raised bogs, fens, and transitional mires cover approximately 10 % of Latvia. They started to form towards the end of the last glacial period and the beginning of the Holocene under varying geological and palaeoecological conditions. The aim of the study was to evaluate how the results of peat palaeobotanical investigation can reveal changes in the conditions of peat formation and allow a subdivision to be made of the Holocene according to the scheme suggested by the INTIMATE group (Walker et al. 2012). Records from 21 mires have been evaluated to find evidence of changes in mire vegetation and peat formation, and to discover whether these records define boundaries allo…
Fen peat in environmentally friendly technologies
2018
Abstract Using peat as an energy source is currently incompatible with Environmental Policy Strategy of Latvia and 2030 Climate and Energy Package of European Union. The European Commission is looking at cost-efficient ways to make European economy more climate-friendly and less energy consuming. Although, fen peat alongside raised bog peat is categorized as fossil fuel, it is not traditionally used as fuel or growth substrate or for any other significant purposes in reasonable amounts. Large areas of fens are neglected where fen peat is slowly mineralizing and emitting greenhouse gases, such as carbon dioxide and methane, that are ones of the main triggers for the Climate Change. Thus, to …
Peat florulas in the Madonie Regional Park (Sicily)
2009
The floristic exploration of the eastern slopes of the Madonie Mountains in Sicily, carried out between 1975 and 1980, resulted in the discovery of several hydromorphic environments characterized by a thick peaty horizon. Locally named “margiu” or “triemula”, depending on the lower or higher depth, they host plant communities characterized by some species of Juncus and Carex together with acidophilous bryophytes including some species of Sphagnum. Their ecology as well as their flora and vegetation have been studied (Petronici et al. 1978). In some localities fossil pollens have also been examined (Bertolani Marchetti et al. 1984). Floristic analyses pointed out some phytogeographical patte…
Holocēna veģetācijas izmaiņu liecības organogēnajos nogulumos Ziemeļvidzemē
2013
„Holocēna organogēnie nogulumi un to uzkrāšanās apstākļu izmaiņas purvos Ziemeļvidzemē”. Disertācijā analizēti piecu Ziemeļvidzemes purvu nogulumu pētījumu rezultāti, kas iegūti, izmantojot lauka un laboratorijas pētījumu metodes - augu makroskopisko atlieku, sporu un putekšņu, citu mikroskopisko atlieku, kūdras sadalīšanās pakāpes un botāniskā sastāva, nogulumu karsēšanas zudumu analīzi, kā arī nosakot nogul umu absolūto vecumu ar 14 C un AMS 14 C metodēm. Pētītajos ezeru un purvu nogulumos Ziemeļvidzemē atpazītas liecības pa r būtiskām nogulumu uzkrāšanās apstākļu izmaiņām visā holocēna laikā, kas ietekmējušas nogulumu sastāvu un raksturu, tai skaitā noskaidrot a aukstā 8200 notikuma un M…
Statistical upscaling of ecosystem CO2 fluxes across the terrestrial tundra and boreal domain: Regional patterns and uncertainties
2021
The regional variability in tundra and boreal carbon dioxide (CO2) fluxes can be high, complicating efforts to quantify sink-source patterns across the entire region. Statistical models are increasingly used to predict (i.e., upscale) CO2 fluxes across large spatial domains, but the reliability of different modeling techniques, each with different specifications and assumptions, has not been assessed in detail. Here, we compile eddy covariance and chamber measurements of annual and growing season CO2 fluxes of gross primary productivity (GPP), ecosystem respiration (ER), and net ecosystem exchange (NEE) during 1990–2015 from 148 terrestrial high-latitude (i.e., tundra and boreal) sites to a…
Hetkinen! Ei kai se vain ollut Minuuttivalssi? : pianistien nuottikuvasta tekemät nopeat päätelmät
2016
Tässä maisterintutkielmassa selvitettiin, millaisia havaintoja eksperttitason pianistit pystyvät tekemään 500 ms:n aikana nuottikuvasta. Aineiston keruuta varten suunniteltiin nuotinlukukoe, jossa koehenkilöille esitettiin yhteensä yhdeksän kolmen rivin mittaista katkelmaa kolmelta eri tyylikaudelta (barokki, klassismi ja romantiikka) peräisin olevista pianoteoksista. Jokaisen näytteen jälkeen koehenkilöt saivat kuvailla omin sanoin tekemiään havaintoja. Lisäksi he esittivät arvion kunkin teoksen edustamasta tyylikaudesta. Kokeeseen osallistui 25 eksperttitason pianistia, joista 4 henkilöä oli suorittanut musiikin ylemmän korkea-koulututkinnon, 11 alemman korkeakoulututkinnon, 8 opiskeli pa…
Changes in pore water quality after peatland restoration: Assessment of a large¿scale, replicated Before-After-Control-Impact study in Finland
2017
Drainage is known to affect peatland natural hydrology and water quality, but peatland restoration is considered to ameliorate peatland degradation. Using a replicated BACIPS (Before-After-Control-Impact Paired Series) design, we investigated 24 peatlands, all drained for forestry and subsequently restored, and 19 pristine control boreal peatlands with high temporal and spatial resolution data on hydroclimate and pore water quality. In drained conditions, total nitrogen (Ntot), total phosphorus (Ptot), and dissolved organic carbon (DOC) in pore water were several-fold higher than observed at pristine control sites, highlighting the impacts of long-term drainage on pore water quality. In gen…
Where do food likes and dislikes come from?
2020
Where do food likes and dislikes come from ? In other words, what are the factors that could explain why someone likes or dislikes a given food ? Most of the hedonic reactions to sensory stimulations brought by foods and, as a result reactions to foods carrying these sensory properties are learned through different learning mechanisms. The efficiency of these learning mechanisms mat depend on individual characteristics, in particular on the sensitivity to different sensory properties. Not all learnings are related to experiments with the food itself; many leamings depend on interactions within the family or social environment. Finally, cognitive determinants play also a role and, in particu…