The COVID-19 pandemic offers an historic precedent to review and challenge the values of social, economic, environmental, and cultural belief systems. The concept of the “New Normal” and the experience of the global pandemic provide points of transition in thinking about our relationship to our planet and to each other. These include the fragility of contemporary economics, dependency on industrialized urban infrastructures, and reliance on top-down governance, vulnerability to climate disasters, dislocation from the natural world, societal inequalities, and the loss of cultural memory. The paper considers the potential role of systems thinking in attempting to manage societies’ responses to the pandemic. To provide the methodological context in which some systems thinking can be applied to alleviate the pandemic, we conduct a focused literature review of systemic frameworks, and using examples from Brazil and England, the paper questions the validity of existing disaster management systems and proposes an integrated critical systems approach. Reflecting on these experiences, questions of systems criticality are further developed and considered in relation to critical recovery from disasters and as integral critical systems (ICS) to interrogate the intention of systems. Finally, the paper reflects upon the value of systems and the values embedded in systems that may or may not promote equitable well-being in recovery from disasters such as COVID-19.
Knowledge of the soil hydraulic functions is required for various hydrological studies and for the simulation of water and solute fluxes in unsaturated soils. Sand/kaolin boxes are frequently used to determine these properties in the low-tension range. For higher tensions the pressure plate extractor is mainly applied. The extended evaporation method allows a more efficient determination of the water-retention curve in an adequate range. Besides this method enables to quantify simultaneously the unsaturated hydraulic-conductivity function. The objective of this study was to compare the water-retention curves obtained from the standard methods (STM) with those determined with the extended evaporation method (EEM). A set of 90 natural soil samples of different texture and origin was analyzed, and the agreement between the methods was statistically evaluated. The average water-content deviation (AWCD) of all samples was 1.83 vol.%, and the root mean square error (RMSE) 2.08 vol.%. The deviation of soil water-storage capacity in the pore-size classes 0-6, 6-30, 30-500, 500-1500 kPa varied between minimum -0.17 and 0.25 vol.% and maximum -2.89 and 2.36 vol.%, and confirmed the good comparability among the adopted methods. Systematic deviations between the methods were not found.
Maize is one of the world's most important cereals, cultivated in a wide range of environments. Besides the importance of maize and the gains in yield from selection schemes, commercial breeding drastically reduced the number of cultivars of this crop. Current common sense states that hybrids, when compared to open-pollinated cultivars, are a better adaptation strategy to cope with the impacts of climate change. However, the performance and resilience of cultivars with different levels of improvement are still not explored in this context. Four cultivars-a commercial hybrid, one commercially improved open-pollinated, one improved openpollinated derived from participatory breeding, and one from a farmer's selection-were tested using the CERES-Maize crop model. Field experiments conducted in Brazil were used for calibration and evaluation. Synthetic scenarios of climate change resulted from the application of the incremental method on historical series of observations (30 years), with temperature increments ranging from +0.5 up to +3.0°C and precipitation changes from −30 up to +30%. Planting dates consisted in nine dates (August 1-December 1, each 15 days).Results demonstrate that the model could mimic the phenology and yield of two improved open-pollinated cultivars (MPA01 and Fortuna) and the hybrid (AS1548). One openpollinated cultivar could not be validated due to its high phenotypic variability. Yield response surfaces showed distinct impacts among cultivars, with improved open-pollinated cultivar MPA01 having a higher yield stability when compared to the hybrid. Early planting dates produced lower yields with higher risk of crop failure for all cultivars. Late planting dates produced higher yields with higher failure risk. Considering risk and yield, the best planting window for all cultivars and scenarios is between September and October. Our results demonstrate, for the first time, that improved open-pollinated cultivars are equivalent or more resilient than hybrids to yield changes under different scenarios of abiotic stresses.
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