scholarly journals Parenting in a warming world: thermoregulatory responses to heat stress in an endangered seabird

2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Timothée R Cook ◽  
Rowan Martin ◽  
Jennifer Roberts ◽  
Henry Häkkinen ◽  
Philna Botha ◽  
...  
Keyword(s):  
Heat Stress ◽  
Water Conservation ◽  
Heat Waves ◽  
Conservation Status ◽  
Extreme Weather Events ◽  
Evaporative Heat Loss ◽  
Trade Off ◽  
Thermoregulatory Responses ◽  
High Solar Radiation ◽  
Warming World

Abstract The frequency of extreme weather events, including heat waves, is increasing with climate change. The thermoregulatory demands resulting from hotter weather can have catastrophic impacts on animals, leading to mass mortalities. Although less dramatic, animals also experience physiological costs below, but approaching, critical temperature thresholds. These costs may be particularly constraining during reproduction, when parents must balance thermoregulation against breeding activities. Such challenges should be acute among seabirds, which often nest in locations exposed to high solar radiation and predation risk. The globally endangered bank cormorant Phalacrocorax neglectus breeds in southern Africa in the winter, giving little scope for poleward or phenological shifts in the face of increasing temperatures. Physiological studies of endangered species sensitive to human disturbance, like the bank cormorant, are challenging, because individuals cannot be captured for experimental research. Using a novel, non-invasive, videographic approach, we investigated the thermoregulatory responses of this seabird across a range of environmental temperatures at three nesting colonies. The time birds spent gular fluttering, a behaviour enhancing evaporative heat loss, increased with temperature. Crouching or standing birds spent considerably less time gular fluttering than birds sitting on nests (ca 30% less at 22°C), showing that postural adjustments mediate exposure to heat stress and enhance water conservation. Crouching or standing, however, increases the vulnerability of eggs and chicks to suboptimal temperatures and/or expose nest contents to predation, suggesting that parents may trade-off thermoregulatory demands against offspring survival. We modelled thermoregulatory responses under future climate scenarios and found that nest-bound bank cormorants will gular flutter almost continuously for several hours a day by 2100. The associated increase in water loss may lead to dehydration, forcing birds to prioritize survival over breeding, a trade-off that would ultimately deteriorate the conservation status of this species.

Water Supply Rates for Recirculating Evaporative Cooling Systems

2018 ◽  
Vol 34 (3) ◽  
pp. 581-590 ◽  
Author(s):  
Joseph L. Purswell ◽  
John E. Linhoss ◽  
Carson M. Edge ◽  
Jeremiah D. Davis ◽  
Jesse C. Campbell
Keyword(s):  
Heat Stress ◽  
Water Supply ◽  
Water Conservation ◽  
Evaporative Cooling ◽  
Extreme Weather Events ◽  
Water Supply Systems ◽  
Animal Housing ◽  
Housing Design ◽  
Housing Systems ◽  
Poultry Facilities

Abstract. Evaporative cooling (EC) is an important tool to reduce heat stress in animal housing systems. Expansion of ventilation capacity in tunnel ventilated poultry facilities has resulted in increased water demand for EC systems. As water resources become more limited and costly, proper planning and design of water supply systems is critical to ensure demand is met during periods of heat stress which increase EC use and bird water consumption. Few estimates of EC water use in animal housing applications are available in the literature and available estimates are geographically limited or rely on extreme weather events. The goal of this analysis was to provide guidance for EC water supply design to accommodate estimates of peak demand, rather than average consumption rates. Keywords: Ventilation, Broiler house, Water conservation, Housing design.

scholarly journals Transcriptomic and Physiological Response of Durum Wheat Grain to Short-Term Heat Stress during Early Grain Filling

2021 ◽  
Author(s):  
Anita Arenas-M ◽  
Francisca M. Castillo ◽  
Diego Godoy ◽  
Javier Canales ◽  
Daniel F. Calderini
Keyword(s):  
Heat Stress ◽  
Durum Wheat ◽  
Grain Quality ◽  
Heat Waves ◽  
Grain Filling ◽  
Grain Weight ◽  
Extreme Weather Events ◽  
Climate Extreme ◽  
Short Term ◽  
Wheat Grains

In a changing climate, extreme weather events such as heat waves will be more frequent and could affect grain weight and the quality of crops such as wheat, one of the most significant crops in terms of global food security. In this work, we characterized the response of Triticum turgidum spp. durum wheat to a short-term heat-stress (HS) treatment at transcriptomic and physiological levels during early grain filling in glasshouse experiments. We found a significant reduction in grain weight and size from HS treatment. Grain quality was also affected, showing a decrease in starch content in addition to increments in grain protein levels. Moreover, an RNA-seq analysis of durum wheat grains allowed us to identify 1590 differentially expressed genes related to photosynthesis, response to heat, and carbohydrate metabolic process. A gene regulatory network analysis of HS-responsive genes uncovered novel transcription factors (TFs) controlling the expression of genes involved in abiotic stress response and grain quality, such as a member of the DOF family predicted to regulate glycogen and starch biosynthetic processes in response to HS in grains. In summary, our results provide new insights into the extensive transcriptome reprogramming that occurs during short-term HS in durum wheat grains.

scholarly journals The Effect of Water Stress Combined with a Heatwave on Reproduction and Yield of Roma-VF Tomatoes

Proceedings ◽  
2019 ◽  
Vol 36 (1) ◽  
pp. 12
Author(s):  
Amuji
Keyword(s):  
Heat Stress ◽  
Water Stress ◽  
Heat Waves ◽  
Recovery Period ◽  
Field Capacity ◽  
Climatic Conditions ◽  
Extreme Weather Events ◽  
Control Treatment ◽  
Yield Response ◽  
High Plasticity

Tomato (Solanum lycopersicum) is one of the most consumed fruits, supplying humanity with both economic and nutritional benefits. However, its production is affected significantly by climatic conditions especially extreme weather events, such as heat waves, flooding and drought. The objective of this study was to evaluate the additively combined effects of heat and water stresses on the reproductive traits and yield of Roma-VF tomato variety. Pollen morphology, number of developed flowers, fruits and aerial biomass were monitored. At five weeks after sowing, the tomato plants were subjected to day/night temperatures of 28/20 °C as a control treatment and 35/23 °C as the heat stress treatment. The water stress was imposed by reducing the water received by plants in each 10-L plastic pot to 70% soil field capacity (moderate stress) and 40% (severe stress). The stress lasted for eight weeks, which was followed by five weeks of recovery period. Our results showed that plants under additively combined heat stress with either moderate or severe water stress produced flowers with no single pollens during the treatment period. We also found that Roma-VF tomato has a high plasticity in response to this particular heat stress for vegetative growth when well irrigated, but when heat and water stresses were additively combined the plants became highly susceptible. This is also the first report of yield response of Roma-VF tomatoes to the additively combined effect of heat and water stressors.

scholarly journals Urban Heat Islands and Thermal Comfort: A Case Study of Zorrotzaurre Island in Bilbao

2021 ◽  
Vol 13 (11) ◽  
pp. 6106
Author(s):  
Irantzu Alvarez ◽  
Laura Quesada-Ganuza ◽  
Estibaliz Briz ◽  
Leire Garmendia
Keyword(s):  
Thermal Comfort ◽  
Heat Waves ◽  
Urban Environments ◽  
Urban Heat Islands ◽  
Extreme Weather Events ◽  
Climate Index ◽  
Physiological Equivalent Temperature ◽  
Heat Islands ◽  
The North ◽  
The Impact

This study assesses the impact of a heat wave on the thermal comfort of an unconstructed area: the North Zone of the Island of Zorrotzaurre (Bilbao, Spain). In this study, the impact of urban planning as proposed in the master plan on thermal comfort is modeled using the ENVI-met program. Likewise, the question of whether the urbanistic proposals are designed to create more resilient urban environments is analyzed in the face of increasingly frequent extreme weather events, especially heat waves. The study is centered on the analysis of temperature variables (air temperature and average radiant temperature) as well as wind speed and relative humidity. This was completed with the parameters of thermal comfort, the physiological equivalent temperature (PET) and the Universal Temperature Climate Index (UTCI) for the hours of the maximum and minimum daily temperatures. The results demonstrated the viability of analyzing thermal comfort through simulations with the ENVI-met program in order to analyze the behavior of urban spaces in various climate scenarios.

scholarly journals Bacillus subtilis-Based Probiotic Improves Skeletal Health and Immunity in Broiler Chickens Exposed to Heat Stress

Animals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1494
Author(s):  
Sha Jiang ◽  
Fei-Fei Yan ◽  
Jia-Ying Hu ◽  
Ahmed Mohammed ◽  
Heng-Wei Cheng
Keyword(s):  
Bacillus Subtilis ◽  
Heat Stress ◽  
Broiler Chickens ◽  
Heat Waves ◽  
Stress Sensitivity ◽  
Current Data ◽  
Negative Effects ◽  
Skeletal Health ◽  
Welfare Issue ◽  
And Performance

The elevation of ambient temperature beyond the thermoneutral zone leads to heat stress, which is a growing health and welfare issue for homeothermic animals aiming to maintain relatively constant reproducibility and survivability. Particularly, global warming over the past decades has resulted in more hot days with more intense, frequent, and long-lasting heat waves, resulting in a global surge in animals suffering from heat stress. Heat stress causes pathophysiological changes in animals, increasing stress sensitivity and immunosuppression, consequently leading to increased intestinal permeability (leaky gut) and related neuroinflammation. Probiotics, as well as prebiotics and synbiotics, have been used to prevent or reduce stress-induced negative effects on physiological and behavioral homeostasis in humans and various animals. The current data indicate dietary supplementation with a Bacillus subtilis-based probiotic has similar functions in poultry. This review highlights the recent findings on the effects of the probiotic Bacillus subtilis on skeletal health of broiler chickens exposed to heat stress. It provides insights to aid in the development of practical strategies for improving health and performance in poultry.

A review of intervention methods used to reduce flying-fox mortalities in heat stress events

2021 ◽  
Vol 43 (2) ◽  
pp. 137
Author(s):  
Matthew Mo ◽  
Mike Roache
Keyword(s):  
Climate Change ◽  
Systematic Review ◽  
Heat Stress ◽  
Evidence Based ◽  
Evaporative Heat Loss ◽  
Temperature And Humidity ◽  
Intervention Trials ◽  
Individual Scale ◽  
The Relationship ◽  
Flying Fox

Heat stress events in Australian flying-fox camps have resulted in significant numbers of flying-fox deaths. The frequency and intensity of such events have increased in recent decades, attributed to anthropogenic climate change. Evidence-based interventions are required to address this growing threat. Responders currently use different combinations of a range of intervention methods. We undertook a systematic review of heat stress interventions, which we classified as either ‘camp-scale’ or ‘individual-scale’. Camp-scale interventions included manual and automated misting of roost vegetation, whereas individual-scale interventions included spraying individual animals or removing them for intensive cooling and rehydration procedures. Our study showed that to date, evaluation of the efficacy of heat stress interventions has been largely anecdotal rather than empirical. This highlights the need for dedicated rigorous studies to evaluate the effectiveness of all the intervention methods described here. It will be especially important to understand the relationship between camp temperature and humidity levels and their influence on flying-foxes’ ability to regulate their body temperature, because high relative humidity reduces the ability of mammals to cool themselves using evaporative heat loss. The development of biophysiological measures such as temperature and humidity indices for different flying-fox species would enable meaningful interpretations of intervention trials under controlled conditions.

scholarly journals Impacts of compound extreme weather events on ozone in the present and future

2018 ◽  
Author(s):  
Junxi Zhang ◽  
Yang Gao ◽  
Kun Luo ◽  
L. Ruby Leung ◽  
Yang Zhang ◽  
...  
Keyword(s):  
Extreme Events ◽  
Heat Waves ◽  
Extreme Weather ◽  
Extreme Weather Events ◽  
Low Wind Speed ◽  
Weather Events ◽  
The Us ◽  
The Future ◽  
Compound Events ◽  
Ozone Episodes

Abstract. The Weather Research and Forecasting model with Chemistry (WRF/Chem) was used to study the effect of extreme weather events on ozone in US for historical (2001–2010) and future (2046–2055) periods under RCP8.5 scenario. During extreme weather events, including heat waves, atmospheric stagnation, and their compound events, ozone concentration is much higher compared to non-extreme events period. A striking enhancement of effect during compound events is revealed when heat wave and stagnation occur simultaneously and both high temperature and low wind speed promote the production of high ozone concentrations. In regions with high emissions, compound extreme events can shift the high-end tails of the probability density functions (PDFs) of ozone to even higher values to generate extreme ozone episodes. In regions with low emissions, extreme events can still increase high ozone frequency but the high-end tails of the PDFs are constrained by the low emissions. Despite large anthropogenic emission reduction projected for the future, compound events increase ozone more than the single events by 10 % to 13 %, comparable to the present, and high ozone episodes are not eliminated. Using the CMIP5 multi-model ensemble, the frequency of compound events is found to increase more dominantly compared to the increased frequency of single events in the future over the US, Europe, and China. High ozone episodes will likely continue in the future due to increases in both frequency and intensity of extreme events, despite reductions in anthropogenic emissions of its precursors. However, the latter could reduce or eliminate extreme ozone episodes, so improving projections of compound events and their impacts on extreme ozone may better constrain future projections of extreme ozone episodes that have detrimental effects on human health.

The impact of extreme climatic events on pasture-based dairy systems: a review

2017 ◽  
Vol 68 (12) ◽  
pp. 1158 ◽  
Author(s):  
J. Chang-Fung-Martel ◽  
M. T. Harrison ◽  
R. Rawnsley ◽  
A. P. Smith ◽  
H. Meinke
Keyword(s):  
Climate Change ◽  
Heat Stress ◽  
Heat Waves ◽  
Animal Health ◽  
Adaptation Strategies ◽  
Pasture Production ◽  
Potential Productivity ◽  
Extreme Climatic Events ◽  
Dairy Systems ◽  
The Impact

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.

scholarly journals Seascape genomics reveals candidate molecular targets of heat stress adaptation in three coral species

2020 ◽  
Author(s):  
Oliver Selmoni ◽  
Gaël Lecellier ◽  
Hélène Magalon ◽  
Laurent Vigliola ◽  
Francesca Benzoni ◽  
...  
Keyword(s):  
Heat Stress ◽  
Molecular Mechanisms ◽  
Coral Species ◽  
New Caledonia ◽  
Heat Waves ◽  
Molecular Targets ◽  
Remote Sensing Data ◽  
Stress Adaptation ◽  
Nucleotide Polymorphisms ◽  
Apoptotic Pathways

AbstractAnomalous heat waves are causing a major decline of hard corals around the world and threatening the persistence of coral reefs. There are, however, reefs that had been exposed to recurrent thermal stress over the years and whose corals appeared tolerant against heat. One of the mechanisms that could explain this phenomenon is local adaptation, but the underlying molecular mechanisms are poorly known.In this work, we applied a seascape genomics approach to study heat stress adaptation in three coral species of New Caledonia (southwestern Pacific) and to uncover molecular actors potentially involved. We used remote sensing data to characterize the environmental trends across the reef system, and sampled corals living at the most contrasted sites. These samples underwent next generation sequencing to reveal single-nucleotide-polymorphisms (SNPs) of which frequencies associated with heat stress gradients. As these SNPs might underpin an adaptive role, we characterized the functional roles of the genes located in their genomic neighborhood.In each of the studied species, we found heat stress associated SNPs notably located in proximity of genes coding for well-established actors of the cellular responses against heat. Among these, we can mention proteins involved in DNA damage-repair, protein folding, oxidative stress homeostasis, inflammatory and apoptotic pathways. In some cases, the same putative molecular targets of heat stress adaptation recurred among species.Together, these results underscore the relevance and the power of the seascape genomics approach for the discovery of adaptive traits that could allow corals to persist across wider thermal ranges.

scholarly journals Affrontare il cambiamento climatico è una ‘missione possibile’

2020 ◽  
Vol 32 (1) ◽  
pp. 154-160
Author(s):  
Roberto Buizza
Keyword(s):  
Climate Change ◽  
Greenhouse Gases ◽  
Heat Waves ◽  
Extreme Weather Events ◽  
Health Issues ◽  
Ice Melting ◽  
Greenhouse Gases Emissions ◽  
The Earth ◽  
Weather Events ◽  
Change Impact

Climate change is real, and we, humans, are responsible for it. Its impact is already evident, both on the Earth system (global warming, sea-level rise, sea-ice melting, more intense and frequent extreme weather events such as heat waves and fires) and on people (famines, health issues, migrations, political tensions and conflicts). We need immediate and concrete mitigation actions aiming to reduce greenhouse gases emissions, and adaptation actions to be able to cope with the increasing changing climate. We have to reach zero-net greenhouse gases emissions as soon as possible, by reducing emissions by at least 5% a year, starting from now. Otherwise the climate change impact will become more and more severe: it will induce more injustice, and it will have a major impact on people health. We have the resources and the technologies to deal with it: we must have the courage to change and transform and deal with it. Addressing climate change is not impossible: to the contrary, it is a ‘possible mission’.

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