scholarly journals Thermal sensitivity and seasonal change in the gut microbiome of a desert ant, Cephalotes rohweri

2021 ◽  
Author(s):  
Marshall S McMunn ◽  
Asher I Hudson ◽  
Ash Zemenick ◽  
Monika Egerer ◽  
Stacy M Philpott ◽  
...  
Keyword(s):  
Climate Change ◽  
Elevated Temperatures ◽  
Variable Temperature ◽  
Thermal Sensitivity ◽  
Thermal Exposure ◽  
Seasonal Temperature ◽  
Microbiome Composition ◽  
Desert Ant ◽  
Temperature Regimes ◽  
Response To Temperature

Microorganisms within ectotherms must withstand the variable body temperatures of their hosts. Shifts in host body temperature resulting from climate change have the potential to shape ectotherm microbiome composition. Microbiome compositional changes occurring in response to temperature in nature have not been frequently examined, restricting our ability to predict microbe-mediated ectotherm responses to climate change. In a set of field-based observations, we characterized gut bacterial communities and thermal exposure across a population of desert arboreal ants (Cephalotes rohweri). In a paired growth chamber experiment, we exposed ant colonies to variable temperature regimes differing by 5 C for three months. We found that the abundance and composition of ant-associated bacteria were sensitive to elevated temperatures in both field and laboratory experiments. We observed a subset of taxa that responded similarly to temperature in the experimental and observational study, suggesting a role of seasonal temperature and local temperature differences amongst nests in shaping microbiomes within the ant population. Bacterial mutualists in the genus Cephalotococcus (Opitutales: Opitutaceae) were especially sensitive to change in temperature - decreasing in abundance in naturally warm summer nests and warm growth chambers. We also report the discovery of a member of the Candidate Phlya Radiation (Phylum: Gracilibacteria), a suspected epibiont, found in low abundance within the guts of this ant species.

scholarly journals Proteomic Signatures of Corals from Thermodynamic Reefs

2020 ◽  
Vol 8 (8) ◽  
pp. 1171
Author(s):  
Anderson B. Mayfield
Keyword(s):  
Molecular Mechanisms ◽  
Elevated Temperatures ◽  
Variable Temperature ◽  
Deep South ◽  
Lipid Trafficking ◽  
Reef Corals ◽  
Temperature Conditions ◽  
Temperature Regimes ◽  
Unique Nature ◽  
Seriatopora Hystrix

Unlike most parts of the world, coral reefs of Taiwan’s deep south have generally been spared from climate change-induced degradation. This has been linked to the oceanographically unique nature of Nanwan Bay, where intense upwelling occurs. Specifically, large-amplitude internal waves cause shifts in temperature of 6–9 °C over the course of several hours, and the resident corals not only thrive under such conditions, but they have also been shown to withstand multi-month laboratory incubations at experimentally elevated temperatures. To gain insight into the sub-cellular basis of acclimation to upwelling, proteins isolated from reef corals (Seriatopora hystrix) featured in laboratory-based reciprocal transplant studies in which corals from upwelling and non-upwelling control reefs (<20 km away) were exposed to stable or variable temperature regimes were analyzed via label-based proteomics (iTRAQ). Corals exposed to their “native” temperature conditions for seven days (1) demonstrated highest growth rates and (2) were most distinct from one another with respect to their protein signatures. The latter observation was driven by the fact that two Symbiodiniaceae lipid trafficking proteins, sec1a and sec34, were marginally up-regulated in corals exposed to their native temperature conditions. Alongside the marked degree of proteomic “site fidelity” documented, this dataset sheds light on the molecular mechanisms underlying acclimatization to thermodynamically extreme conditions in situ.

scholarly journals Oat development in response to temperature

2022 ◽  
Vol 52 (1) ◽  
Author(s):  
Carla Andréa Delatorre ◽  
Vanessa de Freitas Duarte ◽  
Andriele Wairich ◽  
Guilherme Paim Fraga ◽  
Márcio Pacheco Ribeiro ◽  
...  
Keyword(s):  
Elevated Temperatures ◽  
Development Stage ◽  
Reproductive Stage ◽  
Degree Days ◽  
Temperature Regimes ◽  
Thermal Sum ◽  
Maximum Temperatures ◽  
The Moment ◽  
Response To Temperature ◽  
Inductive Photoperiod

ABSTRACT: Temperature affects plant development therefore phyllochron has been used as a predictor for developmental events to define the time for agricultural managing practices. This study aims to evaluate changes in phyllochron and thermal sum required for flowering by oat genotypes developed at different decades at three temperature regimes; the effect of high temperature on phytomere development; and identify the development stage at the moment of meristem transition to reproductive stage. Three environments were obtained by sowing in the fall, in the spring, and under constant temperature (17oC), always at inductive photoperiod. Despite changes in nominal values small differences were found among genotypes’ phyllochron. Adding specific optimal and maximum temperatures into the growing degree days’ calculation demonstrated phyllochron stability among environments. Plant cycle length and thermal sum correlated with the number of developed phytomeres. UFRGS 078030-2 plants flowered earlier, had a small number of phytomeres, and greater tolerance to elevated temperatures than the other genotypes. More recent genotypes transit to reproductive stage at an earlier Haun stage than older ones.

scholarly journals Effect of Temperature on Sowing Dates of Wheat under Arid and Semi-Arid Climatic Regions and Impact Quantification of Climate Change through Mechanistic Modeling with Evidence from Field

Atmosphere ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 927
Author(s):  
Jamshad Hussain ◽  
Tasneem Khaliq ◽  
Muhammad Habib ur Rahman ◽  
Asmat Ullah ◽  
Ishfaq Ahmed ◽  
...  
Keyword(s):  
Climate Change ◽  
Grain Yield ◽  
Arid Region ◽  
Field Experiments ◽  
Climatic Conditions ◽  
Seasonal Temperature ◽  
Sowing Dates ◽  
Rcp 8.5 ◽  
Semi Arid Region ◽  
Semi Arid

Rising temperature from climate change is the most threatening factor worldwide for crop production. Sustainable wheat production is a challenge due to climate change and variability, which is ultimately a serious threat to food security in Pakistan. A series of field experiments were conducted during seasons 2013–2014 and 2014–2015 in the semi-arid (Faisalabad) and arid (Layyah) regions of Punjab-Pakistan. Three spring wheat genotypes were evaluated under eleven sowing dates from 16 October to 16 March, with an interval of 14–16 days in the two regions. Data for the model calibration and evaluation were collected from field experiments following the standard procedures and protocols. The grain yield under future climate scenarios was simulated by using a well-calibrated CERES-wheat model included in DSSAT v4.7. Future (2051–2100) and baseline (1980–2015) climatic data were simulated using 29 global circulation models (GCMs) under representative concentration pathway (RCP) 8.5. These GCMs were distributed among five quadrants of climatic conditions (Hot/Wet, Hot/Dry, Cool/Dry, Cool/Wet, and Middle) by a stretched distribution approach based on temperature and rainfall change. A maximum of ten GCMs predicted the chances of Middle climatic conditions during the second half of the century (2051–2100). The average temperature during the wheat season in a semi-arid region and arid region would increase by 3.52 °C and 3.84 °C, respectively, under Middle climatic conditions using the RCP 8.5 scenario during the second half-century. The simulated grain yield was reduced by 23.5% in the semi-arid region and 35.45% in the arid region under Middle climatic conditions (scenario). Mean seasonal temperature (MST) of sowing dates ranged from 16 to 27.3 °C, while the mean temperature from the heading to maturity (MTHM) stage was varying between 12.9 to 30.4 °C. Coefficients of determination (R2) between wheat morphology parameters and temperature were highly significant, with a range of 0.84–0.96. Impacts of temperature on wheat sown on 15 March were found to be as severe as to exterminate the crop before heading. The spikes and spikelets were not formed under a mean seasonal temperature higher than 25.5 °C. In a nutshell, elevated temperature (3–4 °C) till the end-century can reduce grain yield by about 30% in semi-arid and arid regions of Pakistan. These findings are crucial for growers and especially for policymakers to decide on sustainable wheat production for food security in the region.

scholarly journals Forage quality declines with rising temperatures, with implications for livestock production and methane emissions

2017 ◽  
Vol 14 (6) ◽  
pp. 1403-1417 ◽  
Author(s):  
Mark A. Lee ◽  
Aaron P. Davis ◽  
Mizeck G. G. Chagunda ◽  
Pete Manning
Keyword(s):  
Climate Change ◽  
Methane Production ◽  
Nutritive Value ◽  
Elevated Temperatures ◽  
Environmental Changes ◽  
Forage Quality ◽  
Livestock Farming ◽  
Forage Plants ◽  
Model Average ◽  
Enteric Methane

Abstract. Livestock numbers are increasing to supply the growing demand for meat-rich diets. The sustainability of this trend has been questioned, and future environmental changes, such as climate change, may cause some regions to become less suitable for livestock. Livestock and wild herbivores are strongly dependent on the nutritional chemistry of forage plants. Nutrition is positively linked to weight gains, milk production and reproductive success, and nutrition is also a key determinant of enteric methane production. In this meta-analysis, we assessed the effects of growing conditions on forage quality by compiling published measurements of grass nutritive value and combining these data with climatic, edaphic and management information. We found that forage nutritive value was reduced at higher temperatures and increased by nitrogen fertiliser addition, likely driven by a combination of changes to species identity and changes to physiology and phenology. These relationships were combined with multiple published empirical models to estimate forage- and temperature-driven changes to cattle enteric methane production. This suggested a previously undescribed positive climate change feedback, where elevated temperatures reduce grass nutritive value and correspondingly may increase methane production by 0.9 % with a 1 °C temperature rise and 4.5 % with a 5 °C rise (model average), thus creating an additional climate forcing effect. Future methane production increases are expected to be largest in parts of North America, central and eastern Europe and Asia, with the geographical extent of hotspots increasing under a high emissions scenario. These estimates require refinement and a greater knowledge of the abundance, size, feeding regime and location of cattle, and the representation of heat stress should be included in future modelling work. However, our results indicate that the cultivation of more nutritious forage plants and reduced livestock farming in warming regions may reduce this additional source of pastoral greenhouse gas emissions.

Comparisons of Machine Learning Methods of Statistical Downscaling Method: Case Studies of Daily Climate Anomalies in Thailand

2021 ◽  
Author(s):  
Kanawut Chattrairat ◽  
Waranyu Wongseree ◽  
Adisorn Leelasantitham
Keyword(s):  
Climate Change ◽  
Statistical Downscaling ◽  
Performance Criteria ◽  
Maximum Temperature ◽  
Daily Minimum Temperature ◽  
Daily Maximum Temperature ◽  
Support Vector ◽  
Seasonal Temperature ◽  
Statistical Downscaling Method ◽  
Downscaling Method

The climate change which is essential for daily life and especially agriculture has been forecasted by global climate models (GCMs) in the past few years. Statistical downscaling method (SD) has been used to improve the GCMs and enables the projection of local climate. Many pieces of research have studied climate change in case of individually seasonal temperature and precipitation for simulation; however, regional difference has not been included in the calculation. In this research, four fundamental SDs, linear regression (LR), Gaussian process (GP), support vector machine (SVM) and deep learning (DL), are studied for daily maximum temperature (TMAX), daily minimum temperature (TMIN), and precipitation (PRCP) based on the statistical relationship between the larger-scale climate predictors and predictands in Thailand. Additionally, the data sets of climate variables from over 45 weather stations overall in Thailand are used to calculate in this calculation. The statistical analysis of two performance criteria (correlation and root mean square error (RMSE)) shows that the DL provides the best performance for simulation. The TMAX and TMIN were calculated and gave a similar trend for all models. PRCP results found that in the North and South are adequate and poor performance due to high and low precipitation, respectively. We illustrate that DL is one of the suitable models for the climate change problem.

scholarly journals Impact of climate change on sediment yield in the Mekong River basin: a case study of the Nam Ou basin, Lao PDR

2013 ◽  
Vol 17 (1) ◽  
pp. 1-20 ◽  
Author(s):  
B. Shrestha ◽  
M. S. Babel ◽  
S. Maskey ◽  
A. van Griensven ◽  
S. Uhlenbrook ◽  
...  
Keyword(s):  
Climate Change ◽  
Sediment Yield ◽  
General Circulation ◽  
Climate Models ◽  
Greenhouse Gas Emission ◽  
Circulation Model ◽  
Sediment Flux ◽  
Seasonal Temperature ◽  
Impact Of Climate Change ◽  
The Impact

Abstract. This paper evaluates the impact of climate change on sediment yield in the Nam Ou basin located in northern Laos. Future climate (temperature and precipitation) from four general circulation models (GCMs) that are found to perform well in the Mekong region and a regional circulation model (PRECIS) are downscaled using a delta change approach. The Soil and Water Assessment Tool (SWAT) is used to assess future changes in sediment flux attributable to climate change. Results indicate up to 3.0 °C shift in seasonal temperature and 27% (decrease) to 41% (increase) in seasonal precipitation. The largest increase in temperature is observed in the dry season while the largest change in precipitation is observed in the wet season. In general, temperature shows increasing trends but changes in precipitation are not unidirectional and vary depending on the greenhouse gas emission scenarios (GHGES), climate models, prediction period and season. The simulation results show that the changes in annual stream discharges are likely to range from a 17% decrease to 66% increase in the future, which will lead to predicted changes in annual sediment yield ranging from a 27% decrease to about 160% increase. Changes in intra-annual (monthly) discharge as well as sediment yield are even greater (−62 to 105% in discharge and −88 to 243% in sediment yield). A higher discharge and sediment flux are expected during the wet seasons, although the highest relative changes are observed during the dry months. The results indicate high uncertainties in the direction and magnitude of changes of discharge as well as sediment yields due to climate change. As the projected climate change impact on sediment varies remarkably between the different climate models, the uncertainty should be taken into account in both sediment management and climate change adaptation.

scholarly journals The sensitivity of microbial processes in Icelandic soils to increasing temperatures

2009 ◽  
Vol 6 (4) ◽  
pp. 6749-6780 ◽  
Author(s):  
R. Guicharnaud ◽  
O. Arnalds ◽  
G. I. Paton
Keyword(s):  
Microbial Biomass ◽  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Elevated Temperatures ◽  
Microbial Biomass Carbon ◽  
Biomass Carbon ◽  
Labile Carbon ◽  
Soil Microbial ◽  
Arctic Soils ◽  
Temperature Regimes

Abstract. Temperature change is acknowledged to have a significance effect on soil biological processes and the corresponding sequestration of carbon and the cycling of key nutrients. Soils at high latitudes are likely to be particularly impacted by increases in temperature. In this study, the response of a range of soil microbial parameters (respiration, nutrient availability, microbial biomass carbon, arylphosphatase and dehydrogenase activity) to temperature changes was measured in sub-arctic soils collected from across Iceland. Sample sites reflected two soil temperature regimes (cryic and frigid) and two land uses (pasture and arable). The soils were sampled from the field frozen, equilibrated at −20°C and then incubated for two weeks at −10°C, −2°C, +2°C and +10°C. Respiration and enzymatic activity were temperature dependent. Microbial biomass carbon and nitrogen mineralisation did not change with temperature. The main factor controlling soil respiration at −10°C was the concentration of dissolved organic carbon. At −10°C, dissolved organic carbon accounted for 88% of the fraction of labile carbon which was significantly greater than that recorded at +10°C when dissolved organic carbon accounted for as low as 42% of the labile carbon fraction. Heterotrophic microbial activity is governed by both substrate availability and the temperature and this has been described by the Q10 factor. Elevated temperatures in the short term may have little effect on the size of the microbial biomass but will have significant impacts on the release of carbon through respiration. These results demonstrate that gradual changes in temperature across large areas at higher latitudes will have considerable impacts in relation to global soil carbon dynamics.

scholarly journals Effect of elevated temperature on green gram [Vigna radiata (I).Wilczek] performance under temperature gradient tunnel (TGT) environment in Punjab

2021 ◽  
Vol 23 (1) ◽  
pp. 3-13
Author(s):  
HARPREET SINGH ◽  
PRABHJYOT KAUR ◽  
S.K. BAL ◽  
B.U. CHOUDHURY
Keyword(s):  
Elevated Temperature ◽  
Temperature Gradient ◽  
Grain Yield ◽  
Harvest Index ◽  
Elevated Temperatures ◽  
Ambient Condition ◽  
Green Gram ◽  
Seasonal Temperature ◽  
Early Maturity ◽  
Semi Arid

Physiology of green gram is highly sensitive to fluctuations in the thermal environment. Abnormally high temperatures during pod setting to pod development stage induces reduction in pod setting, nonhealthy development and early maturity of grain which results in yield decline. We evaluated the effect of elevated temperatures in a Temperature Gradient Tunnel (TGT) on phenology, physiology and crop performance of green gram cultivars at semi-arid climate of Indian Punjab (Ludhiana). Five green gram cultivars were grown in TGT chambers in a factorial randomized block design with varying level of elevated temperatures (+3.3° C to 5.2° C) for two consecutive kharif seasons (2015-2016). The results reveal that the phenological stages of green gram, were advanced under elevated temperature within the TGT compared to open / ambient condition by 12-13 days. Maximum influence was observed in pod formationand pod maturity stages. With rise in temperatures by 3.3 to 5.2°C in TGT over ambient condition, the plant height increased but the number of branches per plant and the total above ground biomass as well as grain yield decreased consistently. It was found that with 1 oC increase in average seasonal temperature, the grain yield decreased by 75 kg ha-1. On the other hand, the harvest index was in general lower inside TGT chamber implying adverse influence of elevated temperature on biomass production although the partitioning of biomass was more efficient inside the TGT as evident from increase in harvest index. There was strong negative correlation of elevated temperature (inside TGT) with different yield attributes like 1000 seed weight, number of seeds per pod and number of pods per plant. Among the five green gram cultivars, ML-2037 was the most tolerant while cv. SML-1811 was the most susceptible to elevated temperature condition. In general, the grain yield decreased linearly with gradual increase in temperature.Average seasonal temperature of 29-30 oC may be considered as the favourable thermal conditions for the green gram crop in semi-arid conditions of Punjab. However, the future thrust will be to create more temperature gradients in the lower side so that the critical temperature threshold limits for optimum yield of green gram can be ascertained more accurately.

scholarly journals Climate change and landscape-use patterns influence recent past distribution of giant pandas

2020 ◽  
Vol 287 (1929) ◽  
pp. 20200358
Author(s):  
Junfeng Tang ◽  
Ronald R. Swaisgood ◽  
Megan A. Owen ◽  
Xuzhe Zhao ◽  
Wei Wei ◽  
...  
Keyword(s):  
Climate Change ◽  
Large Scale ◽  
Climatic Factors ◽  
Ailuropoda Melanoleuca ◽  
Seasonal Temperature ◽  
Negative Consequences ◽  
Giant Pandas ◽  
Use Patterns ◽  
Changing Climate ◽  
Temperature And Precipitation

Climate change is one of the most pervasive threats to biodiversity globally, yet the influence of climate relative to other drivers of species depletion and range contraction remain difficult to disentangle. Here, we examine climatic and non-climatic correlates of giant panda ( Ailuropoda melanoleuca ) distribution using a large-scale 30 year dataset to evaluate whether a changing climate has already influenced panda distribution. We document several climatic patterns, including increasing temperatures, and alterations to seasonal temperature and precipitation. We found that while climatic factors were the most influential predictors of panda distribution, their importance diminished over time, while landscape variables have become relatively more influential. We conclude that the panda's distribution has been influenced by changing climate, but conservation intervention to manage habitat is working to increasingly offset these negative consequences.

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