64 research outputs found

    Faciès, biostratigraphie et paléogéographie du Jurassique portugais

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    The facies distribution along the Jurassic stages in an already well established stratigraphic frame is defined for the three portuguese basins: North of Tagus, Santiago de Cacém and Algarve. The deposits are organized in two sedimentary cycles. The first one from the Liassic to Calovian shows, in the Tagus Basin, a transgression from NW which did not surpass the Meseta present limits. The iniatilly brackish deposits only changed to marine by the end of Lotharingian. The sedimentation, mainly marly during the Liassic became more calcareous since the Aalenian. During the Dogger the basin differentiated into platform deposits towards East and South and open sea zone towards West. This zone underwent a progressive reduction and, during the Callovian, two small basins were individualized: Cabo Mondego basin in the North and Serra de El-Rei-Montejunto in the South. It is from the latter that the second sedimentary cycle (Middle Oxfordian-Portlandian) developed with open sea deposits along the Sintra–Torres Vedras axis surrounded by platform and litoral brackish formations. During the first sedimentary cycle only litoral platform deposits are known in Santiago de Cacém and Algarve basins. During the second sedimentary cycle temporary sea open deposits are known in Santiago de Cacém and Central Algarve

    Stratigraphie du Dogger et crise lusitanienne dans la Serra de Candeeiros

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    New elements about the stratigraphy of the Serra de Candeeiros Dogger and Lower «Lusitanian» are presented. The Lower Aalenian was recognized for the first time. Bathonian (more than 50 metres thick) is dated on brachiopods and foraminifera. It corresponds to a series of massive micritic, biodetritical, coral-reef, chaetetid, bryozoa and oolitic-limestones. Callovian (120 m) begins by whitish or yellowish limestones with ammonites and brachiopods of the Gracilis zone. It is followed by regressive limestone sequences ending with thick oncolitic layers. The «Lusitanian» base is formed by greyish lagoon brackish limestones; it lies unconformably on the Dogger, with or without angular and/or cartographic unconformity. This radical facies change is related to tectonic deformation of several blocks between the Nazaré and Tagus faults during Oxfordian times

    Simulation of winter wheat yield and its variability in different climates of Europe: A comparison of eight crop growth models

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    We compared the performance of eight widely used, easily accessible and well-documented crop growth simulation models (APES, CROPSYST, DAISY, DSSAT, FASSET, HERMES, STICS and WOFOST) for winter wheat (Triticum aestivum L.) during 49 growing seasons at eight sites in northwestern, Central and southeastern Europe. The aim was to examine how different process-based crop models perform at the field scale when provided with a limited set of information for model calibration and simulation, reflecting the typical use of models for large-scale applications, and to present the uncertainties related to this type of model application. Data used in the simulations consisted of daily weather statistics, information on soil properties, information on crop phenology for each cultivar, and basic crop and soil management information. Our results showed that none of the models perfectly reproduced recorded observations at all sites and in all years, and none could unequivocally be labelled robust and accurate in terms of yield prediction across different environments and crop cultivars with only minimum calibration. The best performance regarding yield estimation was for DAISY and DSSAT, for which the RMSE values were lowest (1428 and 1603 kg ha−1) and the index of agreement (0.71 and 0.74) highest. CROPSYST systematically underestimated yields (MBE – 1186 kg ha−1), whereas HERMES, STICS and WOFOST clearly overestimated them (MBE 1174, 1272 and 1213 kg ha−1, respectively). APES, DAISY, HERMES, STICS and WOFOST furnished high total above-ground biomass estimates, whereas CROPSYST, DSSAT and FASSET provided low total above-ground estimates. Consequently, DSSAT and FASSET produced very high harvest index values, followed by HERMES and WOFOST. APES and DAISY, on the other hand, returned low harvest index values. In spite of phenological observations being provided, the calibration results for wheat phenology, i.e. estimated dates of anthesis and maturity, were surprisingly variable, with the largest RMSE for anthesis being generated by APES (20.2 days) and for maturity by HERMES (12.6). The wide range of grain yield estimates provided by the models for all sites and years reflects substantial uncertainties in model estimates achieved with only minimum calibration. Mean predictions from the eight models, on the other hand, were in good agreement with measured data. This applies to both results across all sites and seasons as well as to prediction of observed yield variability at single sites – a very important finding that supports the use of multi-model estimates rather than reliance on single model

    An ensemble of projections of wheat adaptation to climate change in europe analyzed with impact response surfaces

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    IRS2 TEAM:Alfredo Rodríguez(1), Ignacio J. Lorite(3), Fulu Tao(4), Nina Pirttioja(5), Stefan Fronzek(5), Taru Palosuo(4), Timothy R. Carter(5), Marco Bindi(2), Jukka G Höhn(4), Kurt Christian Kersebaum(6), Miroslav Trnka(7,8),Holger Hoffmann(9), Piotr Baranowski(10), Samuel Buis(11), Davide Cammarano(12), Yi Chen(13,4), Paola Deligios(14), Petr Hlavinka(7,8), Frantisek Jurecka(7,8), Jaromir Krzyszczak(10), Marcos Lana(6), Julien Minet(15), Manuel Montesino(16), Claas Nendel(6), John Porter(16), Jaime Recio(1), Françoise Ruget(11), Alberto Sanz(1), Zacharias Steinmetz(17,18), Pierre Stratonovitch(19), Iwan Supit(20), Domenico Ventrella(21), Allard de Wit(20) and Reimund P. Rötter(4).An ensemble of projections of wheat adaptation to climate change in europe analyzed with impact response surfaces . International Crop Modelling Symposiu

    Can prepared anticipatory postural adjustments be updated by proprioception ?

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    Effect of gravity-like torque on goal-directed arm movements in microgravity

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