4 research outputs found

    On the Importance of Pollen Morphology in Classification of Chenopodiaceae in Mongolia

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    The pollen morphology of 18 species from 12 genera of Chenopodiaceae native to Mongolia was studied. Plants were collected during field courses and research projects on useful plants and are deposited in the Herbarium of the Mongolian State University of Education. Chemical preparation was carried out in the Palynological Laboratories at the School of Natural Sciences of the Mongolian State University of Education and the Department of Palynology and Climate Dynamics of the University of Göttingen in Germany. The results show, that all investigated species are distinguishable in terms of pollen morphology bases on their pollen grain sizes, exine thickness and number of pores

    On the Importance of Pollen Morphology in Classification of Chenopodiaceae in Mongolia

    Get PDF
    The pollen morphology of 18 species from 12 genera of Chenopodiaceae native to Mongolia was studied. Plants were collected during field courses and research projects on useful plants and are deposited in the Herbarium of the Mongolian State University of Education. Chemical preparation was carried out in the Palynological Laboratories at the School of Natural Sciences of the Mongolian State University of Education and the Department of Palynology and Climate Dynamics of the University of Göttingen in Germany. The results show, that all investigated species are distinguishable in terms of pollen morphology bases on their pollen grain sizes, exine thickness and number of pores

    Prediction of Holocene Mercury Accumulation Trends by Combining Palynological and Geochemical Records of Lake Sediments (Black Forest, Germany)

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    Forest vegetation plays a key role in the cycling of mercury (Hg) and organic matter (OM) in terrestrial ecosystems. Litterfall has been indicated as the major transport vector of atmospheric Hg to forest soils, which is eventually transported and stored in the sediments of forest lakes. Hence, it is important to understand how changes in forest vegetation affect Hg in soil and its biogeochemical cycling in lake systems. We investigated the pollen records and the geochemical compositions of sediments from two lakes (Schurmsee and Glaswaldsee) in the Black Forest (Germany) to evaluate whether long-term shifts in forest vegetation induced by climate or land use influenced Hg accumulation in the lakes. We were particularly interested to determine whether coniferous forests were associated with a larger export of Hg to aquatic systems than deciduous forests. Principal components analysis followed by principal component regression enabled us to describe the evolution of the weight of the latent processes determining the accumulation of Hg over time. Our results emphasize that the in-lake uptake of Hg during warm climate periods, soil erosion after deforestation and emissions from mining and other human activities triggered changes in Hg accumulation during the Holocene stronger than the changes caused by forest vegetation alone

    Intensification of agriculture in southwestern Germany between the Bronze Age and Medieval period, based on archaeobotanical data from Baden-WĂĽrttemberg

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    A system of farming with an alternation of land use between being cultivated or left fallow as grassland (Feldgraswirtschaft) developed in southwestern Germany since the Bronze Age. It involved fallow periods, where the arable land is left without crops in order to let it recover its fertility for several years while becoming grassland. This led to regeneration of the topsoil humus, which could later be mobilized by cultivation. With later farming systems, the supply of nutrients needed for crops could also be provided by manuring, which allowed shorter fallow periods but required the production of manure. Such cultivation systems with short or even without fallow phases and with intensive manuring are known from the medieval period as one, two or three field systems of agriculture and their development was an important step towards the intensification of farming. The current study considers on-site plant macrofossil data from archaeological sites as well as the off-site pollen data from cores in Baden-WĂĽrttemberg in order to recognize the main changes towards agricultural intensification through time from the Bronze Age up to medieval times. The various landscape types included in the study area also reveal their different agricultural histories of intensification. In lowlands with good soils, the intensification can be recognized earlier and more strongly than in uplands or other marginal areas. The main shift towards intensification took place in the Roman period, which is also confirmed by written sources of the time that mention manuring as well as a kind of two field system and alternation between grassland and arable land.publishedVersio
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