| 1. |
- Rodríguez, A., et al.
(författare)
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Implications of crop model ensemble size and composition for estimates of adaptation effects and agreement of recommendations
- 2019
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Ingår i: Agricultural and Forest Meteorology. - : Elsevier BV. - 0168-1923 .- 1873-2240. ; 264, s. 351-362
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Tidskriftsartikel (refereegranskat)abstract
- Climate change is expected to severely affect cropping systems and food production in many parts of the world unless local adaptation can ameliorate these impacts. Ensembles of crop simulation models can be useful tools for assessing if proposed adaptation options are capable of achieving target yields, whilst also quantifying the share of uncertainty in the simulated crop impact resulting from the crop models themselves. Although some studies have analysed the influence of ensemble size on model outcomes, the effect of ensemble composition has not yet been properly appraised. Moreover, results and derived recommendations typically rely on averaged ensemble simulation results without accounting sufficiently for the spread of model outcomes. Therefore, we developed an Ensemble Outcome Agreement (EOA) index, which analyses the effect of changes in composition and size of a multi-model ensemble (MME) to evaluate the level of agreement between MME outcomes with respect to a given hypothesis (e.g. that adaptation measures result in positive crop responses). We analysed the recommendations of a previous study performed with an ensemble of 17 crop models and testing 54 adaptation options for rainfed winter wheat (Triticum aestivum L.) at Lleida (NE Spain) under perturbed conditions of temperature, precipitation and atmospheric CO2 concentration. Our results confirmed that most adaptations recommended in the previous study have a positive effect. However, we also showed that some options did not remain recommendable in specific conditions if different ensembles were considered. Using EOA, we were able to identify the adaptation options for which there is high confidence in their effectiveness at enhancing yields, even under severe climate perturbations. These include substituting spring wheat for winter wheat combined with earlier sowing dates and standard or longer duration cultivars, or introducing supplementary irrigation, the latter increasing EOA values in all cases. There is low confidence in recovering yields to baseline levels, although this target could be attained for some adaptation options under moderate climate perturbations. Recommendations derived from such robust results may provide crucial information for stakeholders seeking to implement adaptation measures.
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| 2. |
- Ruiz-Ramos, Miguel, et al.
(författare)
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Adaptation response surfaces for managing wheat under perturbed climate and CO2 in a Mediterranean environment
- 2018
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Ingår i: Agricultural Systems. - : Elsevier BV. - 0308-521X. ; 159, s. 260-274
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Tidskriftsartikel (refereegranskat)abstract
- Adaptation of crops to climate change has to be addressed locally due to the variability of soil, climate and the specific socio-economic settings influencing farm management decisions. Adaptation of rainfed cropping systems in the Mediterranean is especially challenging due to the projected decline in precipitation in the coming decades, which will increase the risk of droughts. Methods that can help explore uncertainties in climate projections and crop modelling, such as impact response surfaces (IRSs) and ensemble modelling, can then be valuable for identifying effective adaptations. Here, an ensemble of 17 crop models was used to simulate a total of 54 adaptation options for rainfed winter wheat (Triticum aestivum) at Lleida (NE Spain). To support the ensemble building, an ex post quality check of model simulations based on several criteria was performed. Those criteria were based on the "According to Our Current Knowledge" (AOCK) concept, which has been formalized here. Adaptations were based on changes in cultivars and management regarding phenology, vernalization, sowing date and irrigation. The effects of adaptation options under changed precipitation (P), temperature (T), [CO2] and soil type were analysed by constructing response surfaces, which we termed, in accordance with their specific purpose, adaptation response surfaces (ARSs). These were created to assess the effect of adaptations through a range of plausible P, T and [CO2] perturbations. The results indicated that impacts of altered climate were predominantly negative. No single adaptation was capable of overcoming the detrimental effect of the complex interactions imposed by the P, T and [CO2] perturbations except for supplementary irrigation (sI), which reduced the potential impacts under most of the perturbations. Yet, a combination of adaptations for dealing with climate change demonstrated that effective adaptation is possible at Lleida. Combinations based on a cultivar without vernalization requirements showed good and wide adaptation potential. Few combined adaptation options performed well under rainfed conditions. However, a single sI was sufficient to develop a high adaptation potential, including options mainly based on spring wheat, current cycle duration and early sowing date. Depending on local environment (e.g. soil type), many of these adaptations can maintain current yield levels under moderate changes in T and P, and some also under strong changes. We conclude that ARSs can offer a useful tool for supporting planning of field level adaptation under conditions of high uncertainty.
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| 3. |
- Mechiche-alami, Altaaf, et al.
(författare)
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Agricultural land acquisitions unlikely to address the food security needs of African countries
- 2021
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Ingår i: World Development. - : Elsevier BV. - 0305-750X. ; 141
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Tidskriftsartikel (refereegranskat)abstract
- In recent years, Large Scale Land Acquisitions (LSLA), direct land tenure changes have been gaining momentum in developing countries. In this study, we evaluate the potential extent to which agricultural land deals in Africa are able to address the host countries’ food security needs, a commonly cited motivation for their establishment. First, we develop a framework to evaluate the priority food security needs of 38 African countries in 2000 based on indicators of food availability, accessibility, stability, and utilization. Second, we estimate whether the crops from land deals would be sold on export or local food markets based on the origin of investments (domestic, foreign or mixed), type of investors (eg. agribusiness, finance, or government) and the intended crops (eg. food, cash crop, or biofuel). This enables us to estimate how likely the investment is to improve in-country food security, versus serving other purposes (e.g., speculation, enclosure of natural resources). Third, we account for the characteristics of the locations where the deals happen (population density, land cover and distance to markets) in order to estimate the level of conflict and deforestation that they could exacerbate. We find that LSLA are only likely to address the identified food security needs of 7 countries. LSLA are also at risk of increasing land pressures and conflicts or deforestation on 83% of the acquired area, including in countries where they could meet food security needs. We also find that the more productive lands are most often allocated to flex crops, while food crops are produced on more marginal lands. We thus argue that even when their purpose is agricultural production, most LSLA are not likely to improve food security; rather, they often serve the financial interests of transnational companies and local elites with the support of host governments. Finally, we recommend agricultural investments to be elaborated in consultation with local communities and marginalized groups to sustainably support their socio-ecological systems.
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| 4. |
- Mechiche-alami, Altaaf, et al.
(författare)
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Transnational land acquisitions beyond the food and financial crises
- 2019
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Ingår i: Environmental Research Letters. - : IOP Publishing. - 1748-9326. ; 14:8
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Tidskriftsartikel (refereegranskat)abstract
- Large-scale land acquisitions (LSLA) in resource-rich countries came to global attention after the food and financial crises of 2008. Previous research has assessed the magnitude of these land investments in terms of land areas acquired. In this study, we analyze the trends in the evolution of LSLA by framing the latter as virtual land trade network with land transactions occurring between 2000 and 2015, in order to shed light on the development and evolution of this system. Based on an index we introduce to represent both the number of countries and size of deals, we discover three main phases of trade activity: a steady increase from 2000 until 2007 (Phase 1) followed by a peak coinciding with the food and financial crises between 2008 and 2010 (Phase 2) and concluded by a decline from 2011 to 2015 (Phase 3). We identify 73 countries that remained active in land trading during all three phases and form a core of land traders much larger than previously thought. Using network analysis methods, we group countries with similar trade patterns into categories of competitive, preferential, diversified, and occasional importers or exporters. Finally, in exploring the changes in investors and their interests in land throughout the phases, we attribute the evolution of LSLA to the different stages in the globalization and financialization of different industries. By showing that land investments seem fully integrated as investment strategies across industries we argue for the urgency of better regulation of LSLA so that they also benefit local populations without damaging the environment regardless of their primary purpose.
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