Diurnal Temperature Range Research Articles

Distribution Pattern of Species Richness of Endemic Genera in Mountainous Areas of Southwest China and Its Influencing Factors

China’s southwest mountainous region is one of the hotspots of biodiversity in the world. However, the study on the pattern of species richness distribution of endemic plants in this region and its influencing factors is still in the exploration stage. A clear regional spatial distribution pattern of plants and its influencing factors are very important for the protection and management of plant diversity in southwest China. In this study, 511 county-level regions in the southwest mountainous region were taken as examples to establish a plant species resource bank in the southwest mountainous region, and the distribution pattern of the proportion and abundance of endemic plant families and genera was analyzed based on 19 climate and environmental factors and 8 human disturbance factors in the southwest mountainous region. The geographical weighted regression model (GWR) was used to reveal the main factors affecting the spatial distribution of species. The results showed that: (1) A total of 4688 species investigated in the southwest mountain belong to 19 families and 32 genera. (2) The endemic species richness in the southwest mountainous region showed a significant uneven spatial pattern, mainly concentrated in the Heng Duan Mountain area, southwest Sichuan and northern Yunnan area, and the Ruoergai-Hongyuan area of West Sichuan Plateau. (3) The results of the GWR model showed that the diurnal mean temperature range, precipitation seasonality and distance from the main road had significant effects on species richness. The study on the distribution of endemic genera and their influencing factors in the southwest mountainous region has important implications for the exploration of the evolutionary history and species conservation of the mountain flora.

Role of climate change on Oriental spruce (Picea orientalis L.): Modeling and mapping

Global climate change is a process with dramatic consequences for ecosystems, and changes that may occur in the potential distribution of plant communities especially draw attention. This study aimed to reveal the potential distribution modeling and mapping of the Oriental spruce (Picea orientalis L.), distributed in a limited area, using current and future (year 2100) climate scenarios in Turkey. The maximum entropy method for potential distribution and Chelsa V2.1 technical specification IPSL-CM6A-LR scenarios (SSP126-SSP370-SSP585) were preferred to reveal the effect of climate change. Results for the current were in the “excellent” category with training and test data AUC 0.981 and 0.977, respectively. The variables contributing to the model were the precipitation amount of the driest month, mean diurnal air temperature range, annual precipitation amount, and mean annual air temperature. Variables contributing to the current model were analysed using the SSP126, SSP370, and SSP585 scenarios of the year 2100. It was assessed that the potential distribution for 2100 decreases according to SSP126, was fragmented according to SSP370, and decreased according to the SSP585 scenario. As a result, the authors determined that the high potential distribution is reduced 61% when the current mapping of Oriental spruce is compared with the SSP585 mapping.

IMPACTS OF CLIMATE CHANGE ON THERMAL BIOCLIMATIC INDICES OVER IRAQ

This study was aimed to investigate the trends in (11) thermal bioclimatic indicators throughout Iraq's various climates to better understand their spatiotemporal variations in different climates. All bioclimatic indicators have been calculated from daily ERA5 datasets of temperature extracted from 361 grid points covering Iraq. This data set covers global coverage of monthly temperatures from 1980 to 2022, with a spatial resolution of (0.25°x0.25°). Eleven thermal bioclimatic indicators were subjected to the Mann-Kendall (MK) test in order to measure trends in a single direction, without taking into account the influence of natural cycles. The findings showed that the majority of Iraq's thermal bioclimate indicators had changed. implying that rising temperatures have had a significant influence on the country's bioclimate. The annual mean temperature data revealed that Iraq had a considerable increase in Bio1 of (0.28 to 0.48) °C/decade, which is more than the )0.15( °C/decade worldwide average. The rise was found to be significantly greater in Iraq's northern and eastern regions. The analysis suggested that the diurnal temperature range decreased in most regions of Iraq, especially in the southern and northeastern sections. The maximum temperature increased most dramatically in the warmest quarter, whereas the changes in the coldest quarter were less noticeable, showing an increase in climatic extremes in Iraq. The study unequivocally shows that climate change is leading to an increase in the mean temperature, specifically during the warmest months of the year.

Nonlinear impacts of climate change on dengue transmission in mainland China: Underlying mechanisms and future projection

Dengue fever is a climate-sensitive health concern caused by mosquito-borne virus. Both temperature- and precipitation-related factors are important for dengue transmission. Previous studies mainly focused on the effects of individual factors on the spread of dengue. However, given the potential synergistic effects of temperature and precipitation on virus transmission, it is vital to provide a holistic view of their interplay in shaping the transmission patterns. In this study, utilizing a vectorial capacity (VC)-based mathematical model, we investigated the mechanisms by which the daily mean temperature (DMT), diurnal temperature range (DTR) and daily mean precipitation (DMP) jointly influence the dengue spread. We further forecast future dengue patterns in mainland China under different climate scenarios (Shared Socioeconomic Pathways (SSP)) by 2050 and 2080. Results show that these three climate factors trigger complex nonlinear effects on dengue transmission. Interactions between DMT and DTR plays a decisive role in determining the spreading fronts of dengue epidemics, while DMP considerably impacts its transmission intensity. Although future climate changes would facilitate northward expansion of areas at risk of dengue under SSP245 and SSP585, significant contraction would happen under SSP126. These findings illuminate the interacting mechanisms of temperature and precipitation on dengue transmission, call for the comprehensive considerations of DMT, DMP and DTR in formulating effective dengue control policies, and warrant achieving a sustainable future in line with the SSP126 scenario to effectively mitigate dengue transmission risks and ensure a resilient future.

Unravelling the Fractal Complexity of Temperature Datasets across Indian Mainland

Studying atmospheric temperature characteristics is crucial under climate change, as it helps us to understand the changing patterns in temperature that have significant implications for the environment, ecosystems, and human well-being. This study presents the comprehensive analysis of the spatiotemporal variability of scaling behavior of daily temperature series across the whole Indian mainland, using a Multifractal Detrended Fluctuation Analysis (MFDFA). The analysis considered 1° × 1° datasets of maximum temperature (Tmax), minimum temperature (Tmin), mean temperature (Tmean), and diurnal temperature range (DTR) (TDTR = Tmax − Tmin) from 1951 to 2016 to compare their scaling behavior for the first time. Our results indicate that the Tmin series exhibits the highest persistence (with the Hurst exponent ranging from 0.849 to unity, and a mean of 0.971), and all four-temperature series display long-term persistence and multifractal characteristics. The variability of the multifractal characteristics is less significant in North–Central India, while it is highest along the western coast of India. Moreover, the assessment of multifractal characteristics of different temperature series during the pre- and post-1976–1977 period of the Pacific climate shift reveals a notable decrease in multifractal strength and persistence in the post-1976–1977 series across all regions. Moreover, for the detection of climate change and its dominant driver, we propose a new rolling window multifractal (RWM) framework by evaluating the temporal evolution of the spectral exponents and the Hurst exponent. This study successfully captured the regime shifts during the periods of 1976–1977 and 1997–1998. Interestingly, the earlier climatic shift primarily mitigated the persistence of the Tmax series, whereas the latter shift significantly influenced the persistence of the Tmean series in the majority of temperature-homogeneous regions in India.

Estimating species distribution from camera trap by‐catch data, using jaguarundi (Herpailurus yagouaroundi) as an example

AbstractAimPlanning conservation action requires accurate estimates of abundance and distribution of the target species. For many mammals, particularly those inhabiting tropical forests, there are insufficient data to assess their conservation status. We present a framework for predicting species distribution using jaguarundi (Herpailurus yagouaroundi), a poorly known felid for which basic information on abundance and distribution is lacking.LocationMesoamerica and South America.Time PeriodFrom 2003 to 2021.Taxa Herpailurus yagouaroundi. MethodsWe combined camera‐trap data from multiple sites and used an occupancy modelling framework accounting for imperfect detection to identify habitat associations and predict the range‐wide distribution of jaguarundis.ResultsOur model predicted that the probability of jaguarundi occupancy is positively associated with rugged terrain, herbaceous cover, and human night‐time light intensity. Jaguarundi occupancy was predicted to be higher where precipitation was less seasonal, and at intermediate levels of diurnal temperature range. Our camera data also revealed additional detections of jaguarundis beyond the current International Union for Conservation of Nature (IUCN) range distribution, including the Andean foothills of Colombia and Bolivia.Main ConclusionOccupancy was predicted to be low throughout much of Amazonian lowlands, a vast area at the centre of jaguarundi known range. Further work is required to investigate whether this area represents sub‐optimal conditions for the species. Overall, we estimate a crude global jaguarundi population of 35,000 to 230,000 individuals, covering 4,453,406 km2 of Meso‐ and South America at the 0.5 probability level of occupancy. Our current framework allows for an initially detailed, well‐informed species distribution that should be challenged and refined with improved habitat layers and additional records of jaguarundi detection. We encourage similar studies of lesser‐known mammals, pooling existing by‐catch data from the growing bank of camera‐trap surveys around the world.

Meteorological factors associated with the occurrence of the vasovagal reflex during blood donation

Internal factors such as young age, female sex, and first-time blood donation are implicated as risk factors for vasovagal reaction (VVR) associated with blood donation for blood donors. However, the involvement of external factors has not yet been clarified. This study explored the effects of meteorological conditions as external factors on the onset of blood donation-associated VVR. Meteorological conditions were compared between days when blood donation-associated VVR occurred and days when it did not. During the 3-year period from April 1, 2020, 1 092 days during which at least one of the fixed facilities or mobile blood drives was operational were examined for the VVR cases. For meteorological conditions, we used meteorological data published on the website of the Nara Local Meteorological Observatory, located in the northern part of Nara Prefecture. Occurrence and non-occurrence groups included the days when VVR occurred and did not occur among blood donors, respectively. Days of VVR occurrence only in the southern part of the prefecture, which is a mountainous area with different meteorological conditions, were excluded from the occurrence group. A multivariate logistic regression analysis was conducted to identify meteorological variables associated with VVR occurrence. The occurrence and non-occurrence groups included data from 348 and 744 days, respectively. The regression analysis indicated that a large diurnal temperature range, low minimum temperature, and low wind speed were risk factors. The meteorological conditions may play a role in VVR onset.

Responses of phenology to preseason drought and soil temperature for different land cover types on the Mongolian Plateau

Drought and heat caused major disturbance in nature by interfering with plant phenology, and can also alter the vulnerability and resilience of terrestrial ecosystems. Existing research on the Mongolian Plateau has primarily focused on studying the response of the start (SOS) and end (EOS) of the growing season to drought and heat variations. However, there is still a lack of comprehensive understanding regarding the coupled effects of drought and heat on phenology across different land cover types. In this study, we retrieved SOS and EOS based on 34-year (1982–2015) normalized difference vegetation index (NDVI) dataset from Global Inventory Modeling and Mapping Studies (GIMMS). Results showed that grasslands and the Gobi-Desert show rapid advancement in SOS, and forests presented the slowest advancement in SOS, but SOS in croplands were delayed. EOS across four land cover types advanced, with the Gobi-Desert showed the highest rate of advancement and forests the lowest. Using the Palmer Drought Severity Index (PDSI) and soil temperature as the indicators of drought and thermal conditions, the responses of SOS and EOS to these two climate variables were evaluated. The advanced SOS driven by lower drought severity was detected in forests, grasslands, croplands and the Gobi-Desert. The dominant response of EOS to drought severity was positive in croplands, grasslands and forests, except for the Gobi-Desert, where drought severity had negative effects on EOS. Compared with the daily average soil temperature (STmean), the daily maximum soil temperature (STmax, daytime), and the daily minimum soil temperature (STmin, nighttime), the daily diurnal soil temperature range (DSTR, where DSTR = STmax − STmin) between night and day were the most suitable indicators for assessing the response of SOS and EOS to soil temperature. Strong negative correlation between SOS and the preseason DSTR was pronounced in all land cover types on the Mongolian Plateau. However, EOS was negatively correlated with the preseason DSTR only in the Gobi-Desert. Last but not least, normalized sensitivity assessments reveal that the negative impacts of DSTR on SOS and EOS were the main controlling factors on the Mongolian Plateau phenology, followed by the couple negative effects of drought severity and DSTR.

Mapping an endangered living fossil's distribution, threats, and protection coverage

AbstractSpecies Distribution Models have emerged in recent decades as a powerful tool for biodiversity research, as they allow, for example, assessing the status of species in their whole distributions. These models have been particularly helpful in demonstrating that amphibian populations are at high risk, with many declining and others already extinct. Here, we assessed the potential distribution of the helmeted water toad (Calyptocephalella gayi), an endemic Chilean amphibian considered a living fossil and cataloged as vulnerable, which requires significant conservation efforts. We modeled the species' potential distribution using the Maximum Entropy (Maxent) approach and determined the overlap with national protected areas. In addition, we conducted a geospatial risk analysis to estimate the threat level to which this toad is being subjected. The potential distribution of C. gayi ranges from 28°S to 44°S, mainly explained by altitude, mean diurnal temperature range, slope, and distance to water bodies. Protected areas only cover 3.55% of the species' potential geographic distribution, which is of concern, considering that the geospatial risk analysis showed that 60.61% of C. gayi's distribution is subjected to extreme and high risks. We discuss how these results are relevant to focusing and directing efficient protection and conservation efforts for this species shortly.

Global Warming Drives Transitions in Suitable Habitats and Ecological Services of Rare Tinospora Miers Species in China

Tinospora Miers is considered a valuable medicinal herb that is suffering from severe habitat degradation due to climate change and human activities, but the variations in its suitable habitats and ecological service values remain unclear, especially in the context of accelerating global warming. In this study, we employed the MaxEnt model to estimate the suitable habitat changes and ecological service values of three rare Tinospora (T. craveniana, T. yunnanensis, and T. sinensis) species in China under four climate change scenarios (SSP126, SSP245, SSP370, and SSP585) from 2041 to 2100. The results show that the suitable habitats of T. craveniana, T. yunnanensis, and T. sinensis are mainly distributed in Sichuan, Yunnan, and Guangxi, respectively. Under the future climate scenarios, the suitable habitat of T. craveniana and T. sinensis is projected to expand toward the northeast and north, while that of T. yunnanensis will contract toward the northeast. The mean diurnal temperature range is the main environmental factor affecting T. craveniana and T. yunnanensis, while the annual mean temperature is a more important factor affecting T. sinensis. In the SSP245 scenario, T. craveniana and T. yunnanensis are expected to have the highest ecological service values from 2081 to 2100, while they will be relatively consistent in other climate scenarios and chronologies. The case of water protection accounts for the highest proportion of the total ecosystem service values, except for the economic value. This study provides a scientific reference for the diversity conservation of these rare species.

Structure, modulation and impacts of southeastern Africa’s diurnal convection

This study explores the structure, modulation, and impacts of the mean diurnal climate across southeast Africa using high-resolution hourly reanalysis and satellite rainfall. This research was motivated by upward trends in diurnal temperature range and vegetation index over the Drakensberg escarpment. Statistical analysis identified a land-sea rainfall dipole pattern associated with diurnal airflows. Point-to-field regressions (Oct–Mar 2000–2023) found that sea breeze-driven convection is underpinned by ‘col’ airflow between adjacent sub-tropical low-pressure cells (30°S, 20°E/22°S, 37°E) and a weak mid-latitude anticyclone (40°S, 10°E). Diurnal residual and case study analysis demonstrate an ~ 6-m/s sea breeze penetrating ~ 200 km inland during the day, as part of an over-turning zonal circulation. Land > sea rainfall during summer is initiated by temperature gradients ∂T/∂x ~ 5 °C at 29°S, 31°E and convergence in the afternoon ∂U/∂x ~ − 4 × 10−5 s−1. Further inland (29°S, 26°E) a 1007-hPa thermal low and counter-clockwise rotating airflows interact with the incoming sea breeze. Together these contribute to evening rainfall ~ 30 mm over the Drakensberg escarpment. The drivers of diurnal rainfall show little response to global climate variability, and help sustain water resources during multi-year dry spells over southeastern Africa.

Impacts of Climate Change on the Biogeography and Ecological Structure of Zelkova schneideriana Hand.-Mazz. in China.

This study utilized the platform for ensemble forecasting of species distributions, biomod2, to predict and quantitatively analyze the distribution changes of Zelkova schneideriana Hand.-Mazz. under different climate scenarios (SSP1-2.6 and SSP5-8.5) based on climate and land-use data. This study evaluated the geographic range changes in future distribution areas and the results indicated that, under both SSP1-2.6 and SSP5-8.5 scenarios, the distribution area of Zelkova schneideriana would be reduced, showing a trend towards migration to higher latitudes and elevations. Particularly, in the more extreme SSP5-8.5 scenario, the contraction of the distribution area was more pronounced, accompanied by more significant migration characteristics. Furthermore, the ecological structure within the distribution area of Zelkova schneideriana also experienced significant changes, with an increasing degree of fragmentation. The variables of Bio6 (minimum temperature of the coldest month), Bio2 (mean diurnal temperature range), Bio15 (precipitation seasonality), and elevation exhibited important influences on the distribution of Zelkova schneideriana, with temperature being particularly significant. Changes in land use, especially the conversion of cropland, had a significant impact on the species' habitat. These research findings highlight the distributional pressures faced by Zelkova schneideriana in the future, emphasizing the crucial need for targeted conservation measures to protect this species and similar organisms.

Nighttime warming and nitrogen addition effects on the microclimate of a freshwater wetland dominated by Phragmites australis

The critical impacts of microclimate on carbon (C) cycling have been widely reported. However, the potential effects of global change on wetland microclimate remain unclear, primarily because of the absence of field manipulative experiment in inundated wetland. This study was designed to examine the effects of nighttime warming and nitrogen (N) addition on air, water, and sediment temperature and also reveal the controlling factors in a Phragmites australis dominated freshwater wetland on the North China Plain. Nighttime warming increased daily air, water, and sediment temperature by 0.24 °C, 0.27 °C, and 0.36 °C, respectively. The diurnal temperature range of water was decreased by 0.44 °C under nighttime warming, whereas warming had no effect on diurnal temperature range of air and sediment. In addition, N addition caused a reduction of 0.20 °C and 0.14 °C in daily water and sediment temperature by increasing vegetation coverage. There was a significant interaction between nighttime warming and N addition on water temperature. Furthermore, the vapor pressure deficit is the main factor affecting the extent of the warming-induced increases in air temperature. The changes of height and leaf area index of Phragmites australis are responsible for the cooling effects in the N addition plots. This study provides empirical evidence for the positive climate warming – microclimate feedback in freshwater wetland. However, N deposition leads to decreased water and sediment temperature. Our findings highlight the importance of incorporating the differential impacts of nighttime warming and N addition on air, water, and sediment temperature into the predictions of wetland C cycling responses to climate change.

Dynamic Changes in Vegetation Ecological Quality in the Tarim Basin and Its Response to Extreme Climate during 2000–2022

The Tarim Basin is located in an arid inland area; the ecological environment is fragile, and it is extremely sensitive to climate change. For the purpose of studying dynamic changes in the vegetation response of vegetation in the Tarim Basin to extreme climate, this study used the Vegetation Ecological Quality Index (EQI) as a vegetation indicator and calculated 12 extreme climate indices using Rclimdex. Pearson correlation analysis was used to explore the relationship between EQI values and various extreme climate indices at both inter-annual and intra-annual scales. Additionally, geographic detector analysis was employed to examine the single and interactive effects of extreme climate on the EQI for different vegetation types. The following was found: (1) During 2000–2022, the EQI showed an upward trend in the Tarim Basin, and the increase in agricultural vegetation was the fastest. (2) Since 2000, the extreme warm temperature indices have risen, whereas the extreme cold temperature indices have declined. The warming rate of nighttime temperatures exceeds that of daytime, and the extreme precipitation rises intensively. Simultaneously, continuous dry days have also increased. (3) On an inter-annual scale, the EQI is primarily negatively correlated with the most extreme warm temperature indices, while it is positively correlated with extreme cold temperatures and extreme precipitation indices. On an intra-annual scale, there is an obvious regional concentration in the correlation between the EQI and extreme climate indices. The diurnal temperature range (DTR) and cold daytimes (TX10P) have inhibitory and promoting effects on areas with high and low EQI, respectively. The extremum indices, temperature warm indices, and precipitation intensity indices have a promoting effect on areas with a high EQI and an inhibiting effect on areas with a low EQI. The interaction between extreme climate indices has a greater impact on the EQI than the effect of a single extreme climate index, especially with a significant impact on forests and shrubs. This study provides a reference for the early warning of meteorological disasters, ecosystem protection, and sustainable management in the Tarim Basin.

Climate changes altered the citrus fruit quality: A 9-year case study in China

Global climate change has significantly impacted the production of various crops, particularly long-term fruit-bearing plants such as citrus. This study analyzed the fruit quality of 12 citrus orchards (Citrus Sinensis L.Osbeck cv. Bingtang) in a subtropical region in Yunnan, China from 2014 to 2022. The results indicated that high rainfall (>220 mm) and low cumulative temperature (<3150 °C) promoted increases in titratable acidity (>1.8 %) in young fruits. As the fruits further expanded (with a horizontal diameter increasing from 50 to 65 mm), excessive rainfall (300-400 mm), lower cumulative temperature (<2400 °C), and a reduced diurnal temperature range (<10 °C) hindered decreases in titratable acidity. Conversely, low rainfall (<220 mm), high cumulative temperature (>3150 °C), and a high diurnal temperature range (>14 °C) promoted the accumulation of soluble solids in young fruits (9 %) at 120 days after flowering (DAF). Furthermore, low rainfall (<100 mm) favored the accumulation of soluble solids (1.5 %) during fruit expansion (195-225DAF). To quantify the relationship between fruit acidity and climate variables at 120 DAF, we developed a regression model, which was further validated by actual measurements and accurately predicted fruit acidity in 2023. Our findings have the potential to assist citrus growers in optimizing cultivation techniques for the production of high-quality citrus under increasingly variable climatic conditions.

Climate change increases threat to plant diversity in tropical forests of Central America and southern Mexico.

Global biodiversity is negatively affected by anthropogenic climate change. As species distributions shift due to increasing temperatures and precipitation fluctuations, many species face the risk of extinction. In this study, we explore the expected trend for plant species distributions in Central America and southern Mexico under two alternative Representative Concentration Pathways (RCPs) portraying moderate (RCP4.5) and severe (RCP8.5) increases in greenhouse gas emissions, combined with two species dispersal assumptions (limited and unlimited), for the 2061-2080 climate forecast. Using an ensemble approach employing three techniques to generate species distribution models, we classified 1924 plant species from the region's (sub)tropical forests according to IUCN Red List categories. To infer the spatial and taxonomic distribution of species' vulnerability under each scenario, we calculated the proportion of species in a threat category (Vulnerable, Endangered, Critically Endangered) at a pixel resolution of 30 arc seconds and by family. Our results show a high proportion (58-67%) of threatened species among the four experimental scenarios, with the highest proportion under RCP8.5 and limited dispersal. Threatened species were concentrated in montane areas and avoided lowland areas where conditions are likely to be increasingly inhospitable. Annual precipitation and diurnal temperature range were the main drivers of species' relative vulnerability. Our approach identifies strategic montane areas and taxa of conservation concern that merit urgent inclusion in management plans to improve climatic resilience in the Mesoamerican biodiversity hotspot. Such information is necessary to develop policies that prioritize vulnerable elements and mitigate threats to biodiversity under climate change.

The impact of short-term exposure to meteorological factors on the risk of death from hypertension and its major complications: a time series analysis based on Hefei, China.

This study aimed to reveal the short-term impact of meteorological factors on the mortality risk in hypertensive patients, providing a scientific foundation for formulating pertinent prevention and control policies. In this research, meteorological factor data and daily death data of hypertensive patients in Hefei City from 2015 to 2018 were integrated. Time series analysis was performed using distributed lag nonlinear model (DLNM) and generalized additive model (GAM). Furthermore, we conducted stratified analysis based on gender and age. Relative risk (RR) combined with 95% confidence interval (95% CI) was used to represent the mortality risk of single day and cumulative day in hypertensive patients. Single-day lag results indicated that high daily mean temperature (T mean) (75th percentile, 24.9°C) and low diurnal temperature range (DTR) (25th percentile, 4.20°C) levels were identified as risk factors for death in hypertensive patients (maximum effective RR values were 1.144 and 1.122, respectively). Extremely high levels of relative humidity (RH) (95th percentile, 94.29%) reduced the risk of death (RR value was 0.893). The stratified results showed that the elderly and female populations are more susceptible to low DTR levels, whereas extremely high levels of RH have a more significant protective effect on both populations. Overall, we found that exposure to low DTR and high T mean environments increases the risk of death for hypertensive patients, while exposure to extremely high RH environments significantly reduces the risk of death for hypertensive patients. These findings contribute valuable insights for shaping targeted prevention and control strategies.

Interannual variability of diurnal temperature range in CMIP6 projections and the connection with large-scale circulation

Interannual variability of diurnal temperature range in CMIP6 projections and the connection with large-scale circulation

Effect of Ecological Factors on Nutritional Quality of Foxtail Millet (Setaria italica L.)

Foxtail millet (Setaria italica [L.] P. Beauv.) is a climate-change-ready crop, and it is crucial for predicting the impact of ecological factors on grain quality. In this study, multivariate statistical analysis was used to explore the relationship between ecological factors and the key nutritional quality of Jingu 21 from twelve production areas. The results showed that the crude fat and amylopectin content of foxtail millets showed a downward trend from south to north. The nutritional quality was significantly affected by geographical, climatic, and soil factors, and the foxtail millet produced in geographically close areas was extremely similar in nutritional quality. Most nutritional quality indicators of Jingu 21 had a strong correlation with the latitude and climatic factors such as average temperature, diurnal temperature range, and average precipitation, while the content of mineral elements was greatly affected by soil factors. Moreover, higher average precipitation in the jointing, booting–heading, and heading stages, a higher average temperature, and a lower diurnal temperature range in the heading and grain-filling stages are conducive to the establishment of nutritional quality. The findings could facilitate the rational distribution of high-quality foxtail millets under global climate change.

Effects of diurnal temperature range on diarrhea in the subtropical megacity of Dhaka, Bangladesh

IntroductionWhile numerous studies have assessed the association of diarrhea with temperature, few have addressed the relationship between within-day variation of temperature and diarrhea. Materials and methodsWe investigated the association between diurnal temperature range (DTR) and daily counts of hospitalizations for all-cause diarrhea in Dhaka, Bangladesh using time series regression analysis employing distributed lag-linear models. Defining DTRs below 10th, 5th and 1st percentiles as low, very low and extremely low DTR, and DTRs above 90th, 95th and 99th percentiles as high, very high and extremely high DTRs, we additionally analyzed the effects of extreme DTR on diarrhea hospitalization. Effects were assessed for all ages, under-5 children and by gender. ResultsAlthough we did not find any significant effects of overall DTR and large DTRs, we detected significant effects of small DTRs on diarrhea hospitalization in all subgroups. A unit rise in low, very low and extremely low DTR was associated with a 4.9 % (95 % CI: 3.6 – 6.2), 7.1 % (95 % CI: 5.4 – 8.9) and 11.8 % (95 % CI: 8.3 – 15.5) increase in all-cause diarrhea hospitalization in all ages, respectively. A unit increase in low, very low and extremely low DTR was associated with a 4.9 %, 5.1 % and 18.4 % increase in all-cause diarrhea hospitalization in children under 5 years of age, respectively. The impact of extremely low DTR varied by gender (16.2 % in females versus 10.1 % in males). The effect of extremely low DTR was most pronounced in children under 5 years of age. ConclusionLess variation in within-day temperatures is a risk factor for diarrhea hospitalization in Dhaka, Bangladesh. Further research is needed to elucidate the causal pathways and identify the preventive measures necessary to mitigate the impacts of lowering DTRs on diarrhea.