49 research outputs found

    Pollen reveals the diet and environment of an extinct Pleistocene giant deer from the Netherlands

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    Pollen analysis of five teeth (two premolars, three molars) from a single maxilla of a giant deer (Megaloceros giganteus) found in Pleistocene deposits in The Netherlands reflects the diet and the landscape of the specimen that lived in eastern Doggerland. Apiaceae (among which Anthriscus sylvestris, Heracleum and Hydrocotyle), Asteraceae (among which Anthemis-type, Senecio-type and Cichorioideae), Filipendula, Poaceae and Symphytum were among the ingested plants. The landscape had dense, species-rich tall-herb vegetation and an open tree layer of Alnus and Betula, whereas thermophilous tree taxa were absent. Climate was probably cool-temperate, semi-dry, sub-continental. A radiocarbon date of the maxilla is beyond the 14C detection limit. We conclude that our giant deer most likely lived during the early Eemian or during an early Weichselian interstadial.</p

    Testate amoebae in pollen slides

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    Among the non-pollen micro-fossils commonly encountered in Quaternary sediment samples prepared for pollen analysis are many shells of testate amoebae. Testate amoebae are eukaryotic micro-organisms which are increasingly used in ecological and palaeoecological studies, particularly as indicators of hydrological change in Sphagnum-dominated peatlands. In this study we address the extent to which testate amoebae are used in palynological research, the key challenges to more widespread use, and the extent to which ecological information is retained in the testate amoeba assemblages of standard palynological slides. To achieve this we review the literature on the use of testate amoebae in palynology, compare testate amoeba records produced by palynological and water-based preparation methods and carry out simulations using previously-derived datasets. Our results show that testate amoebae are widely encountered in Quaternary palynological studies, primarily in peatlands, but the information which they can provide is undermined by limited taxonomic knowledge. Many taxa are destroyed in pollen preparations, but for taxa that are retained patterns of abundance parallel those determined using water-based preparation methods. Although the loss of sensitive taxa limits the ecological information contained in testate amoeba assemblages the information preserved is likely to be useful in a multiproxy approach to palaeoenvironmental reconstruction. To help improve taxonomic awareness and encourage the use of testate amoebae in palynology we present a basic introduction to testate amoeba taxonomy and a guide to the taxonomic literature

    Original plant diversity and ecosystems of a small, remote oceanic island (Corvo, Azores): Implications for biodiversity conservation

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    Remote islands harbour many endemic species and unique ecosystems. They are also some of the world's most human-impacted systems. It is essential to understand how island species and ecosystems behaved prior to major anthropogenic disruption as a basis for their conservation. This research aims to reconstruct the original, pre-colonial biodiversity of a remote oceanic island to understand the scale of past extinctions, vegetation changes and biodiversity knowledge gaps. We studied fossil remains from the North Atlantic island of Corvo (Azores), including pollen, charcoal, plant macrofossils, diatoms and geochemistry of wetland sediments from the central crater of the island, Caldeirão. A comprehensive list of current vascular plant species was compiled, along with a translation table comparing fossilized pollen to plant species and a framework for identifying extinctions and misclassifications. Pollen and macrofossils provide evidence for eight local extinctions from the island's flora and show that four species listed as ‘introduced’ are native. Up to 23% of the pollen taxa represent extinct/misclassified species. Corvo's past environment was dynamic, shifting from glacial-era open vegetation to various Holocene forest communities, then almost completely deforested by fires, erosion and grazing following Portuguese colonisation. Historical human impacts explain high ecological turnover, several unrecorded extinctions and the present-day abundance of vegetation types like Sphagnum blanket mire. We use Corvo as a case study on how fossil inventories can address the Wallacean and Hookerian biodiversity knowledge gaps on remote islands. Accurate baselines allow stakeholders to make informed conservation decisions using limited financial and human resources, particularly on islands where profound anthropogenic disruption occurred before comprehensive ecological research

    Veranderingen in de epifytenflora van Rijnmond sinds 1972

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