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Author Hjelkrem, A.-G.R.; Höglind, M.; van Oijen, M.; Schellberg, J.; Gaiser, T.; Ewert, F. url  doi
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  Title Sensitivity analysis and Bayesian calibration for testing robustness of the BASGRA model in different environments Type Journal Article
  Year 2017 Publication Ecological Modelling Abbreviated Journal Ecol. Model.  
  Volume 359 Issue Pages 80-91  
  Keywords Metropolis-hasting; Morris method; Reducing complexity; Robustness  
  Abstract Highlights • The parameters to be fixed were consistent across sites. • Model calibration must be performed separately for each specific case. • Possible to reduce model parameters from 66 to 45. • Strong model reductions must be avoided. • The error term for the training data were characterised by timing (phase shift). Abstract Proper parameterisation and quantification of model uncertainty are two essential tasks in improvement and assessment of model performance. Bayesian calibration is a method that combines both tasks by quantifying probability distributions for model parameters and outputs. However, the method is rarely applied to complex models because of its high computational demand when used with high-dimensional parameter spaces. We therefore combined Bayesian calibration with sensitivity analysis, using the screening method by Morris (1991), in order to reduce model complexity by fixing parameters to which model output was only weakly sensitive to a nominal value. Further, the robustness of the model with respect to reduction in the number of free parameters were examined according to model discrepancy and output uncertainty. The process-based grassland model BASGRA was examined in the present study on two sites in Norway and in Germany, for two grass species (Phleum pratense and Arrhenatherum elatius). According to this study, a reduction of free model parameters from 66 to 45 was possible. The sensitivity analysis showed that the parameters to be fixed were consistent across sites (which differed in climate and soil conditions), while model calibration had to be performed separately for each combination of site and species. The output uncertainty decreased slightly, but still covered the field observations of aboveground biomass. Considering the training data, the mean square error for both the 66 and the 45 parameter model was dominated by errors in timing (phase shift), whereas no general pattern was found in errors when using the validation data. Stronger model reduction should be avoided, as the error term increased and output uncertainty was underestimated.  
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  ISSN 0304-3800 ISBN Medium  
  Area Expedition Conference  
  Notes (down) CropM, LiveM, ft_macsur Approved no  
  Call Number MA @ admin @ Serial 5010  
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Author Kopacz, M.; Twardy, S. openurl 
  Title Spatial modeling as a tool supporting the management of catchment area of retention reservoir Type Journal Article
  Year 2014 Publication Polish Journal of Environmental Studies Abbreviated Journal Pol. J. Environ. Stud.  
  Volume 23 Issue 3a Pages 53-57  
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  Notes (down) CropM, LiveM Approved no  
  Call Number MA @ admin @ Serial 4628  
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Author Kopacz, M.; Twardy, S. openurl 
  Title A spatial analysis of biogenic load differentiation of an agricultural origin in the Carpathian basin Type Journal Article
  Year 2012 Publication Polish Journal of Environmental Studies Abbreviated Journal Pol. J. Environ. Stud.  
  Volume 21 Issue 5a Pages 196-200  
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  Notes (down) CropM, LiveM Approved no  
  Call Number MA @ admin @ Serial 4587  
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Author Curnel, Y. url  openurl
  Title Satellite remote sensing priorities for better assimilation in crop growth models: winter wheat LAI and grassland mowing dates case studies Type Book Whole
  Year 2015 Publication Abbreviated Journal  
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  Corporate Author Thesis Ph.D. thesis  
  Publisher Université Catholique de Louvain Place of Publication Louvain Editor  
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  Series Editor Series Title Abbreviated Series Title PhD  
  Series Volume PhD Series Issue Edition  
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  Notes (down) CropM, LiveM Approved no  
  Call Number MA @ admin @ Serial 5157  
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Author Sánchez, B.; Rasmussen, A.; Porter, J.R. doi  openurl
  Title Temperatures and the growth and development of maize and rice: a review Type Journal Article
  Year 2014 Publication Global Change Biology Abbreviated Journal Glob. Chang. Biol.  
  Volume 20 Issue 2 Pages 408-417  
  Keywords Climate Change; Oryza/*growth & development; Temperature; Zea mays/*growth & development; cardinal temperatures; climatic change impacts; development; growth; lethal temperatures; maize; rice  
  Abstract Because of global land surface warming, extreme temperature events are expected to occur more often and more intensely, affecting the growth and development of the major cereal crops in several ways, thus affecting the production component of food security. In this study, we have identified rice and maize crop responses to temperature in different, but consistent, phenological phases and development stages. A literature review and data compilation of around 140 scientific articles have determined the key temperature thresholds and response to extreme temperature effects for rice and maize, complementing an earlier study on wheat. Lethal temperatures and cardinal temperatures, together with error estimates, have been identified for phenological phases and development stages. Following the methodology of previous work, we have collected and statistically analysed temperature thresholds of the three crops for the key physiological processes such as leaf initiation, shoot growth and root growth and for the most susceptible phenological phases such as sowing to emergence, anthesis and grain filling. Our summary shows that cardinal temperatures are conservative between studies and are seemingly well defined in all three crops. Anthesis and ripening are the most sensitive temperature stages in rice as well as in wheat and maize. We call for further experimental studies of the effects of transgressing threshold temperatures so such responses can be included into crop impact and adaptation models.  
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  ISSN 1354-1013 ISBN Medium Article  
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  Notes (down) CropM, ftnotmacsur, IPCC-AR5 Approved no  
  Call Number MA @ admin @ Serial 4693  
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