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Kersebaum, K. C., Boote, K. J., Jorgenson, J. S., Nendel, C., Bindi, M., Frühauf, C., et al. (2015). Analysis and classification of data sets for calibration and validation of agro-ecosystem models. Env. Model. Softw., 72, 402–417.
Abstract: Experimental field data are used at different levels of complexity to calibrate, validate and improve agroecosystem models to enhance their reliability for regional impact assessment. A methodological framework and software are presented to evaluate and classify data sets into four classes regarding their suitability for different modelling purposes. Weighting of inputs and variables for testing was set from the aspect of crop modelling. The software allows users to adjust weights according to their specific requirements. Background information is given for the variables with respect to their relevance for modelling and possible uncertainties. Examples are given for data sets of the different classes. The framework helps to assemble high quality data bases, to select data from data bases according to modellers requirements and gives guidelines to experimentalists for experimental design and decide on the most effective measurements to improve the usefulness of their data for modelling, statistical analysis and data assimilation. (C) 2015 Elsevier Ltd. All rights reserved.
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Nosalewicz, A. (2015). The effect of combination of drought and heat stresses on plant transpiration and photosynthesis (Vol. 5).
Abstract: Expected increasing intensity and frequency of droughts with climate changes is often accompanied by increased air temperature resulting in decreased stability of crop yields. Owing to the complex nonlinear interactions between a plant and its environment, it is difficult to evaluate the effect of multi-stress on plant functioning.The main aim of presented research was to analyse spring wheat response to combination of two abiotic stresses: drought and heat.The growth chamber experiment with controlled environment was conducted on spring wheat growing in cylindrical soil columns. Four treatments were compared: control with optimum soil moisture and air temperature (C), heat wave (HW) – as C but with temperature elevated up to 34°C for four days at flowering, drought (D) with soil water content decreasing from initially optimum level to water deficit (pF> 3.4) at flowering, drought and heat wave (DHW) – the combination of two stresses .The results indicated different course of leaf transpiration and photosynthesis rates in analysed treatments in response to soil water content. HW treatment during period of increased temperature were characterised by significantly increased average transpiration as compared to all other treatments. However photosynthesis rate in this treatment were slightly lower than in control plants. Comparison of D and DHW treatments shows similarities in the trends of transpiration increase with increasing soil moisture with some offset to lower soil moisture in DHW resulting from higher evapotranspiration. Photosynthesis rate showed relatively large variation characterised by steeper increase with increasing soil water content in D as compared to DHW. No Label
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Sandars, D. (2015). Understanding Europe’s future ability to feed itself within an uncertain climate change and socio economic scenario space (Vol. 5).
Abstract: Europe’s ability to feed its population depends on the balance of agricultural productivity (yields and land suitability) and demand which are affected by future climate and socio-economic change (arising from changing food demand; prices; technology change etc). Land use under 2050 climate change and socio-economic scenarios can be rapidly and systematically quantified with a modelling system that has been developed from meta-models of optimal cropping and crop and forest yields derived from the outputs of the previously developed complex models (Audsley et al; 2015). Profitability of each possible land use is modelled for every soil in every grid across the EU. Land use in a grid is then allocated based on profit thresholds set for intensive agriculture extensive agriculture, managed forest and finally unmanaged forest or unmanaged land. The European demand for food as a function of population, imports, food preferences and bioenergy, is a production constraint, as is irrigation water available. The model iterates until demand is satisfied (or cannot be met at any price). Results are presented as contour plots of key variables. For example, given a 40% increase in population from the baseline socio-economic scenario, adapting by increasing crop yields by 40% will leave a 38% probability that the 2050 future climate will be such that we cannot feed ourselves – considering “all” the possible climate scenarios. No Label
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Rivington, M., & Wallach, D. (2015). Quantified Evidence of Error Propagation (Vol. 6).
Abstract: Error propagation within models is an issue that requires a structured approach involving the testing of individual equations and evaluation of the consequences of error creation from imperfect equation and model structure on estimates of interest made by a model. This report briefly covers some of the key issues in error propagation and sets out several concepts, across a range of complexity, that may be used to organise an investigation into error propagation. No Label
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Meyer, P. (2015). Epigenetic variation and environmental change. J. Experim. Bot., 66(12), 3541–3548.
Abstract: Environmental conditions can change the activity of plant genes via epigenetic effects that alter the competence of genetic information to be expressed. This may provide a powerful strategy for plants to adapt to environmental change. However, as epigenetic changes do not modify DNA sequences and are therefore reversible, only those epi-mutations that are transmitted through the germline can be expected to contribute to a long-term adaptive response. The major challenge for the investigation of epigenetic adaptation theories is therefore to identify genomic loci that undergo epigenetic changes in response to environmental conditions, which alter their expression in a heritable way and which improve the plant’s ability to adapt to the inducing conditions. This review focuses on the role of DNA methylation as a prominent epigenetic mark that controls chromatin conformation, and on its potential in mediating expression changes in response to environmental signals.
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