scholarly journals Concurrent Drought and Temperature Stress in Rice—A Possible Result of the Predicted Climate Change: Effects on Yield Attributes, Eating Characteristics, and Health Promoting Compounds

Author(s):  
Alphonsine Mukamuhirwa ◽  
Helena Persson Hovmalm ◽  
Hans Bolinsson ◽  
Rodomiro Ortiz ◽  
Obedi Nyamangyoku ◽  
...  

Despite the likely increasing co-occurrence of drought and heat stress, not least in equatorial regions, due to climate change, little is known about the combinational effect of these stresses on rice productivity and quality. This study evaluated the impact of simultaneous drought and temperature stress on growth, grain yield, and quality characteristics of seven rice cultivars from Rwanda, grown in climate chambers. Two temperature ranges—23/26 °C night/day and 27/30 °C night/day—together with single or repeated drought treatments, were applied during various plant developmental stages. Plant development and yield were highly influenced by drought, while genotype impacted the quality characteristics. The combination of a high temperature with drought at the seedling and tillering stages resulted in zero panicles for all evaluated cultivars. The cultivar ‘Intsindagirabigega’ was most tolerant to drought, while ‘Zong geng’ was the most sensitive. A “stress memory” was recorded for ‘Mpembuke’ and ‘Ndamirabahinzi’, and these cultivars also had a high content of bioactive compounds, while ’Jyambere’ showed a high total protein content. Thus, climate change may severely impact rice production. The exploitation of genetic diversity to breed novel rice cultivars that combine drought and heat stress tolerance with high nutritional values is a must to maintain food security.

2020 ◽  
Vol 13 (1) ◽  
pp. 27
Author(s):  
Hatem Mahmoud ◽  
Ayman Ragab

The density of building blocks and insufficient greenery in cities tend to contribute dramatically not only to increased heat stress in the built environment but also to higher energy demand for cooling. Urban planners should, therefore, be conscious of their responsibility to reduce energy usage of buildings along with improving outdoor thermal efficiency. This study examines the impact of numerous proposed urban geometry cases on the thermal efficiency of outer spaces as well as the energy consumption of adjacent buildings under various climate change scenarios as representative concentration pathways (RCP) 4.5 and 8.5 climate projections for New Aswan city in 2035. The investigation was performed at one of the most underutilized outdoor spaces on the new campus of Aswan University in New Aswan city. The potential reduction of heat stress was investigated so as to improve the thermal comfort of the investigated outdoor spaces, as well as energy savings based on the proposed strategies. Accordingly, the most appropriate scenario to be adopted to cope with the inevitable climate change was identified. The proposed scenarios were divided into four categories of parameters. In the first category, shelters partially (25–50% and 75%) covering the streets were used. The second category proposed dividing the space parallel or perpendicular to the existing buildings. The third category was a hybrid scenario of the first and second categories. In the fourth category, a green cover of grass was added. A coupling evaluation was applied utilizing ENVI-met v4.2 and Design-Builder v4.5 to measure and improve the thermal efficiency of the outdoor space and reduce the cooling energy. The results demonstrated that it is better to cover outdoor spaces with 50% of the overall area than transform outdoor spaces into canyons.


2017 ◽  
Vol 68 (12) ◽  
pp. 1158 ◽  
Author(s):  
J. Chang-Fung-Martel ◽  
M. T. Harrison ◽  
R. Rawnsley ◽  
A. P. Smith ◽  
H. Meinke

Extreme climatic events such as heat waves, extreme rainfall and prolonged dry periods are a significant challenge to the productivity and profitability of dairy systems. Despite projections of more frequent extreme events, increasing temperatures and reduced precipitation, studies on the impact of these extreme climatic events on pasture-based dairy systems remain uncommon. The Intergovernmental Panel on Climate Change has estimated Australia to be one of the most negatively impacted regions with additional studies estimating Australian production losses of around 16% in the agricultural sector and 9–19% between the present and 2050 in the south-eastern dairy regions of Australia due to climate change. Here we review the literature on the impact of climate change on pasture-based dairy systems with particular focus on extreme climatic events. We provide an insight into current methods for assessing and quantifying heat stress highlighting the impacts on pastures and animals including the associated potential productivity losses and conclude by outlining potential adaptation strategies for improving the resilience of the whole-farm systems to climate change. Adapting milking routines, calving systems and the introduction of heat stress tolerant dairy cow breeds are some proposed strategies. Changes in pasture production would also include alternative pasture species better adapted to climate extremes such as heat waves and prolonged periods of water deficit. In order to develop effective adaptation strategies we also need to focus on issues such as water availability, animal health and associated energy costs.


2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Beatriz Fátima Alves de Oliveira ◽  
Marcus J. Bottino ◽  
Paulo Nobre ◽  
Carlos A. Nobre

AbstractLand use change and deforestation can influence local temperature and climate. Here we use a coupled ocean-atmosphere model to assess the impact of savannization of the Amazon Basin on the wet-bulb globe temperature heat stress index under two climate change scenarios (RCP4.5 and RCP8.5). We find that heat stress exposure due to deforestation was comparable to the effect of climate change under RCP8.5. Our findings suggest that heat stress index could exceed the human adaptation limit by 2100 under the combined effects of Amazon savannization and climate change. Moreover, we find that risk of heat stress exposure was highest in Northern Brazil and among the most socially vulnerable. We suggest that by 2100, savannization of the Amazon will lead to more than 11 million people will be exposed heat stress that poses an extreme risk to human health under a high emission scenario.


2016 ◽  
Vol 25 ◽  
pp. 1-12 ◽  
Author(s):  
Fredrik Lindberg ◽  
Sofia Thorsson ◽  
David Rayner ◽  
Kevin Lau

Author(s):  
Cicero H. O. Lallo ◽  
Sebrena Smalling ◽  
Audley Facey ◽  
Martin Hughes

Many Caribbean small ruminant management systems are forage-based, relying on rain to sustain pastures for feed. Animal performance is thus heavily dependent on forage availability. The nutritive value of pasture was highest during the intermediate season and lowest during the dry season, leading to under nutrition, and declined flock performance in the dry season. Climate change will therefore seriously hamper pasture availability and nutritive value. Hair sheep on pasture, without shade or water, experienced increased respiration rate, they were under chronic heat stress. However, where adequate shade and water were provided, heat stress was reduced. The current system of small ruminant production is prone to the negative impacts of climate change events due to its effect on nutrition, growth and reproduction. Immediate actions are needed to prepare farmers to respond by mitigation methods, to maintain and enhance animal productivity if the envisaged protein security goals set for this sector are to be realized.


GigaScience ◽  
2019 ◽  
Vol 8 (5) ◽  
Author(s):  
Lovely Mae F Lawas ◽  
Xia Li ◽  
Alexander Erban ◽  
Joachim Kopka ◽  
S V Krishna Jagadish ◽  
...  

2019 ◽  
Vol 39 (6) ◽  
pp. 3013-3030 ◽  
Author(s):  
Sarah Chapman ◽  
Marcus Thatcher ◽  
Alvaro Salazar ◽  
James E.M. Watson ◽  
Clive A. McAlpine

Plants ◽  
2019 ◽  
Vol 8 (11) ◽  
pp. 518 ◽  
Author(s):  
Nelimor ◽  
Badu-Apraku ◽  
Tetteh ◽  
N’guetta

Climate change is expected to aggravate the effects of drought, heat and combined drought and heat stresses. An important step in developing ‘climate smart’ maize varieties is to identify germplasm with good levels of tolerance to the abiotic stresses. The primary objective of this study was to identify landraces with combined high yield potential and desirable secondary traits under drought, heat and combined drought and heat stresses. Thirty-three landraces from Burkina Faso (6), Ghana (6) and Togo (21), and three drought-tolerant populations/varieties from the Maize Improvement Program at the International Institute of Tropical Agriculture were evaluated under three conditions, namely managed drought stress, heat stress and combined drought and heat stress, with optimal growing conditions as control, for two years. The phenotypic and genetic correlations between grain yield of the different treatments were very weak, suggesting the presence of independent genetic control of yield to these stresses. However, grain yield under heat and combined drought and heat stresses were highly and positively correlated, indicating that heat-tolerant genotypes would most likely tolerate combined drought and stress. Yield reduction averaged 46% under managed drought stress, 55% under heat stress, and 66% under combined drought and heat stress, which reflected hypo-additive effect of drought and heat stress on grain yield of the maize accessions. Accession GH-3505 was highly tolerant to drought, while GH-4859 and TZm-1353 were tolerant to the three stresses. These landrace accessions can be invaluable sources of genes/alleles for breeding for adaptation of maize to climate change.


2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Hanna Leona Lokys ◽  
Jürgen Junk ◽  
Andreas Krein

Projected climate change will cause increasing air temperatures affecting human thermal comfort. In the highly populated areas of Western-Central Europe a large population will be exposed to these changes. In particular Luxembourg—with its dense population and the large cross-border commuter flows—is vulnerable to changing thermal stress. Based on climate change projections we assessed the impact of climate change on human thermal comfort over the next century using two common human-biometeorological indices, the Physiological Equivalent Temperature and the Universal Thermal Climate Index. To account for uncertainties, we used a multimodel ensemble of 12 transient simulations (1971–2098) with a spatial resolution of 25 km. In addition, the regional differences were analysed by a single regional climate model run with a spatial resolution of 1.3 km. For the future, trends in air temperature, vapour pressure, and both human-biometeorological indices could be determined. Cold stress levels will decrease significantly in the near future up to 2050, while the increase in heat stress turns statistically significant in the far future up to 2100. This results in a temporarily reduced overall thermal stress level but further increasing air temperatures will shift the thermal comfort towards heat stress.


2014 ◽  
Vol 65 (12) ◽  
pp. 1267 ◽  
Author(s):  
Wenxiang Wu ◽  
Qian Fang ◽  
Quansheng Ge ◽  
Mengzi Zhou ◽  
Yumei Lin

Global temperatures are rising, and concerns about the response of agricultural production to climate change are increasing. Adaptation is a key factor that will shape the severity of impacts of future climate change on food production. Based on actual meteorological, soil and agricultural management data at site scale, the CERES-Rice model, combined with the Regional Climate Model (RCM)-PRECIS, was used to simulate both the effects of climate change on rice yields and the efficacy of adaptive options in Northeast China. The impact simulation showed that rice yield changes ranged from +0.1% to –44.9% (A2 scenario) and from –0.3% to –40.1% (B2 scenario) without considering CO2 fertilisation effects. When considering CO2 fertilisation effects, rice yield reductions induced by temperature increases were decreased at all sites. The CO2 fertilisation effects may partly offset the negative impacts of climate change on rice yields. Adaptive option results revealed that the adverse impacts of climate change on rice yields could be mitigated by advancing the planting dates, transplanting mid–late-maturing rice cultivars to replace early-maturing ones, and breeding new rice cultivars with high thermal requirements. Our findings provide insight into the possible impacts of climate change on rice production, and we suggest which adaptive strategies could be used to cope with future climate change, thus providing evidence-based suggestions for government policy on adaptive strategies.


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