Increase In Atmospheric Temperature Research Articles

IMPACT OF TEMPERATURE INCREASE ON POWDERY MILDEW IN MELON

The increase in greenhouse gases (GHG) has caused an increase in atmospheric temperature. It is known that temperature is determinant for the occurrence of plant diseases. In this context, the objective of this study was to evaluate the influence of temperature on powdery mildew in detached leaves of different melon cultivars. Nine melon cultivars were used: Araguaia, Awton, Eldorado, Gladial, Gold, Hibix, Natal, Juazeiro and Sancho. Two experiments were carried out with detached leaves in incubators with control of temperature and photoperiod (12/12h). The first experiment was conducted to determine the optimum temperature (15, 20, 25, 30, 35 and 40 °C) for the development of the disease and, from this temperature, increments of 1.7, 2.6, 3.1 and 5 °C, corresponding to the IPCC scenarios, were evaluated. The leaves were inoculated with a suspension of conidia of Oidium sp., placed on trays and kept in incubators. It was found that air temperature influences both the incubation period and severity of the disease. The optimum range for the development of melon mildew was 20-25 °C, and the increase in air temperature reduces the severity of the disease and, from 30 °C, there is no appearance of symptoms. The incubation period of melon powdery mildew increases at temperatures of 15 °C and above 27.6 °C. Melon cultivars show different responses to temperature increases. However, all cultivars were susceptible to powdery mildew, with high severity at temperatures favorable to the development of the pathogen.

DETERMINATION OF THE DYNAMIC MODULE OF ELASTICITY OF PERMANENTLY FROZEN SOILS DURING DEFROST BY KINEMATIC CHARACTERISTICS OF ELASTIC WAVE

According to the data of monitoring observations of atmospheric air temperature, in the areas of permafrost distribution, the trend of temperature growth is stable. Due to the increase in atmospheric air temperature, the temperature of permafrost soils increases. As a result of changes in the temperature regime, the degradation of permafrost soils occurs. These changes lead to disruption of the operation of buildings and engineering structures. In this situation, geotechnical monitoring plays a special role. Currently, temperature, geodesic and hydrogeological methods are mainly used to solve the problems of geotechnical monitoring. The increase in the number of emergencies associated with thawing of soils indicates that the applied methods of geotechnical monitoring do not give the proper result. In this paper, we consider the possibility of using a temporary type of acoustic control to solve geotechnical monitoring problems. The paper presents a brief analysis of the currently used methods of geotechnical monitoring. The research tasks that need to be solved to assess the possibility of using a temporary type of acoustic control to solve geotechnical monitoring problems are set. Data are given of experimental studies of changes in dynamic modulus model of frozen soils during thawing, defined by equations of the relationship of the kinematic characteristics of elastic waves and elastic properties of soils.

Eco−efficiency limits of product technologies towards achieving science-based targets

Science-based-targets (SBTs) have been introduced to guide companies to reduce their Greenhouse Gas emissions in line with the level of decarbonization required to keep average global atmospheric temperature increase well below 2°C compared to pre-industrial levels. SBTs seeks to decouple economic growth and emissions to achieve the greenhouse gas emission target of zero by 2050. This paper first investigates the eco−efficiency improvement required for various product technologies to achieve SBTs, considering market growth. Afterwards, it investigates the eco−efficiency limits of these product technologies and identifies where system innovation is required to achieve the required emission reduction while providing product functionality.

Reflexiones sobre Calentamiento Global y Turismo. Principales riesgos ambientales y regiones turísticas afectadas

The environmental effects related to global warming jeopardize tourism activity and the economic stability of several countries with a marked dependence on activity. Concepts from Social Theory of Risk and the Climate-Tourism Binomial are used, and an analysis is made of the environmental effects of Global Warming, such as the melting of the eternal snows, the rise in sea level, the changes in marine currents and the extreme weather events (hurricanes, floods, rainfall, drought, heat waves) that affect tourism directly and indirectly. Taking into account the World Tourism Organization (UNWTO) regions, emblematic cases were identified whose selection responds to the role of tourism in the economic development of the place or its wealth in terms of tourist attractions. The results allow to account for the modification of climatic situations that contribute tourism, the greater occurrence of natural disasters, the presence of attractions at risk, the destruction of basic infrastructure, among other issues. Therefore, it is important to plan the tourism activity taking into account the threats and risks arising from an increase in atmospheric temperature.

Towards more intimacy: moderate elevation of temperature drives increases in foraging and mutualistic interactions between Lasius niger and Aphis fabae

1. Climate change will likely affect the association between species interacting at different trophic levels. However, studies focusing on the impact of an elevation of temperature on ant‐hemipteran mutualism remain scarce.2. In the present study we investigated, in laboratory conditions, the foraging behaviour of the ant Lasius niger and its mutualistic interaction with the aphid Aphis fabae under three conditions of temperatures (i.e. 20°C, 23°C, and 26°C), as predicted by climatic scenarios.3. Aphids were more mobile but as likely to release honeydew droplets at higher temperatures. As regards the ants, a moderate 3°C increase of temperature positively impacted their mutualistic interaction with aphids. Such reinforcement was achieved through an increase in the walking speed of ant foragers, in the number of mobilised ants as well as in the total amount of honeydew harvested by the colony.4. A further elevation of temperature to 26°C reduced the benefits gained by the aphid‐tending ants, in terms of lower amount of collected honeydew.5. Based on our results, we hypothesise that, in temperate regions, a moderate increase of ambient atmospheric temperature by 3°C will benefit to the L. niger ‐ A. fabae mutualistic interaction. A more marked elevation of 6°C may represent a threshold thermal value above which a switch of partners or a disruption of the interaction may occur under the temperatures predicted for the end of the century. These results demonstrate the fragility of mutualistic interactions, and more particularly their sensitivity to temperature increases predicted by realistic forecast models.

Elevated temperature and drought stress significantly affect fruit quality and activity of anthocyanin-related enzymes in jujube (Ziziphus jujuba Mill. cv. 'Lingwuchangzao').

The quality attributes of jujube fruit can be directly and indirectly affected by abiotic stresses associated with climate change. Increased temperature and drought are among the most important factors challenging sustainable jujube production in the temperate semi-arid region in northwest China. The main objective of the present study was to understand the effects of elevated air temperature and drought stress on sugar and acid accumulation and coloration of jujube fruits. The content of soluble sugar, organic acid and pigments of traditional jujube "Linwuchangzao" under different atmospheric temperatures and drought stresses were analyzed during three different fruit ripening stages. The elevated temperature (1.5–2.5° C than normal temperature) significantly increased the fruit sugar content, sugar-acid ratio, anthocyanins, flavonoids and carotenoids content. Under the drought stress where the soil moisture was 30% -50% of the field capacity, sugar content, anthocyanin, flavonoid and carotenoid content of the fruit were significantly reduced at the same temperature, but the chlorophyll and organic acid content increased. No significant interaction of Temperature x Drought was observed for all the analyzed quality parameters. The current results showed that the fruit quality of jujube variety "Lingwuchangzao" could be improved when the atmospheric temperature increases by 2° C in this region. However, drought stress had a negative impact on the fruit's sugar-acid ratio and pigment content. The present results also showed that the synthesis and accumulation of anthocyanins in jujube fruit were positively correlated with sugar content and related enzyme activities, especially Phenylalanine Ammonia-lyase (PAL) activity. This study, therefore, provides novel information for understanding the influence of growth environment on the quality properties of jujube fruits. This knowledge will help develop appropriate crop management practices for jujube production in arid and semi-arid areas in northwest China.

Greenhouse Gasses' Effect on Atmospheric Temperature Increase and the Observable Effects on Ecosystems

Greenhouse Gasses' Effect on Atmospheric Temperature Increase and the Observable Effects on Ecosystems

The effect of concurrent elevation in CO2 and temperature on the growth, photosynthesis, and yield of potato crops.

Global climate change accompanied by continuous increases in atmospheric carbon dioxide (CO2) concentration and temperature affects the growth and yield of important crops. The present study investigated the effect of elevated temperature and CO2 concentrations on the growth, yield, and photosynthesis of potato (Solanum tuberosum L. cv. Superior) crops using Korean Soil-Plant-Atmosphere-Research chambers that allow the regulation of temperature and CO2 concentration under daylight conditions. Based on the average temperature from 1991 to 2010 in the Jeonju area, South Korea, potato plants were exposed to four different conditions: ambient weather (400 μmol mol-1, aCaT), elevated temperature (+4°C, aCeT), elevated CO2 concentration (800 μmol mol-1, eCaT), and concurrently elevated CO2 concentration and temperature (eCeT). Under aCeT conditions, the temperature exceeded the optimal growth temperature range towards the late growth phase that decreased stomatal conductance and canopy net photosynthetic rate and subsequently reduced biomass and tuber yield. Stomatal conductance and chlorophyll concentration were lower under eCaT conditions than under aCaT conditions, whereas late-growth phase biomass and tuber yield were greater. Compared to other conditions, eCeT yielded a distinct increase in growth and development and canopy net photosynthetic rate during tuber initiation and bulking. Consequently, biomass and canopy net photosynthesis increased, and tuber yield increased by 20.3%, which could be attributed to the increased tuber size, rather than increased tuber number. Elevated CO2 reduced chlorophyll, magnesium, and phosphorus concentrations; reducing nitrogen concentration (by approximately 39.7%) increased the C:N ratio. The data indicate that future climate conditions will likely change nutrient concentration and quality of crops. The present study shows that while elevated temperature may negatively influence the growth and yield of potato crops, especially towards the late-growth phase, the concurrent and appropriate elevation of CO2 and temperature could promote balanced development of source and sink organs and positively effect potato productivity and quality.

A Pilot‐Scale Demonstration of Mobile Direct Air Capture Using Metal‐Organic Frameworks

AbstractIt is increasingly apparent that negative emissions technologies, such as direct air capture (DAC), are required as part of the technology mix for limiting global atmospheric temperature increase. For all DAC technologies, the requisite energy for regeneration of the separation media strongly influences the overall cost of the process and therefore directly influences their likely implementation. Herein, the results of a pilot‐scale demonstration of a new metal organic framework (MOF) based technology, Airthena, incorporated within a mobile unit for distributed deployment, are reported. Careful preparation of a MOF nanocomposite results in a CO2‐selective sorbent with fine‐tuned kinetic and thermodynamic properties. An optimum regeneration temperature of 80 °C is achieved, along with strong repellence of water vapor during the adsorption process. Taken together, this demonstrator has delivered one of the lowest regeneration energy consumptions, 1.6 kWh kg‐CO2−1 with output purity of 70–80%. This equates to an operational cost of $35–$350 ton‐CO2−1 depending on the source of regeneration energy. Over the duration of the pilot‐scale testing, the demonstrator captures a total of 8 kg of CO2 over 2680 cycles.

Effects of elevated temperature and drought stress on fruit coloration in the jujube variety ‘Lingwuchangzao’ (Ziziphus jujube cv. Lingwuchangzao)

Fruit color of jujube is an important horticultural trait contributing to nutritional components, market value and consumer preference. The objective of this investigation was to gain insight into the influences of elevated atmospheric temperature and drought stress on the coloration of jujube fruits. The fruit skin color, as well as the content of anthocyanins, carotenoids and chlorophyll under different atmospheric temperature and drought stress treatments were analyzed for a traditional jujube cultivar ‘Linwuchangzao’. The elevated temperature (1.5–2.5 ℃) significantly increased the fruit redness and the content of anthocyanins and carotenoids by 21.02 %, 13.20 % and 30.90 %, respectively, in three different stages of fruit ripening. The drought stress, with soil moisture at 30 %–50 % of the field capacity, significantly decreased the fruit redness and the content of anthocyanins and carotenoids but increased the content of chlorophyll under the same temperature. Significant temperature x drought interactions were observed for fruit color and pigments, showing that the positive effect from the elevated temperature was reduced as the drought stress intensified. The present results suggest that under the scenario of a 2 ℃ increase in atmospheric temperature, fruit coloration of jujube cultivar ‘Lingwuchangzao’ can be enhanced. However, drought stress negatively affected fruit coloration and reduced the positive effects resulting from the elevated temperature. This study, therefore, provides novel information for understanding environmental effects on fruit quality attributes of jujube. This knowledge will be useful for developing appropriate crop management practices for jujube production in the arid and semiarid regions in northwest China.

Nondestructive characterization of elastic modulus of APS Ni–5Al/10hBN coating on stainless steel 304 under high temperature

The failure mechanisms of coatings, under high thermo-mechanical loads, can be examined through finite element simulations. However, mechanical properties such as Young’s modulus and Poisson’s ratio are necessary to achieve an accurate model. In this study, nickel–aluminum with hexagonal boron nitride (NiAl/hBN) is deposited on stainless steel 304 substrate using atmospheric plasma spray technique. The effect of the hydrogen content in the plasma-formed gas on the microstructure, hardness, and porosity of the deposited layers is examined. Also, the mechanical properties of the coating are measured at ambient temperatures using non-contact laser ultrasound technique. Results indicated that the flow rate of hydrogen has a major impact on the coating structure and elastic properties. The inhomogeneity in the coating can be minimized by decreasing the hydrogen flow rate. The coating Young’s modulus was increased at room temperature, which slowly decreased while increase in atmospheric temperature. The behavior of Young’s modulus at high temperature causes decrease in flexural strength. In addition, the back calculations are well agreed with experimental results.

NUMERICAL MODEL ON METHANE EMISSIONS FROM AGRICULTURE SECTOR

Atmospheric methane, emitted from agriculture sector such as production of rice paddies and farming of livestock populations, is one of the important factors responsible for increasing the average atmospheric temperature leading to global warming. It is, therefore, crucial to comprehend the dynamics of methane emission and its effect on global warming. In this paper, a nonlinear mathematical model is proposed and analyzed to study the increase of average atmospheric temperature (or average global warming temperature) caused by emission of methane due to various processes involved in the production of rice paddies and farming of livestock populations simultaneously. In the modeling process, six variables are considered, namely, the cumulative biomass density of rice paddies, the cumulative density of livestock populations, the cumulative density of methane formed by various processes involved in the production of rice paddies, the cumulative density of methane formed by various processes involved in the farming of livestock populations, the atmospheric concentration of methane and the average atmospheric temperature. It is assumed that both the cumulative biomass densities of rice paddies and livestock populations follow logistic models with their respective growth rates and carrying capacities. The growth rate of concentration of methane in the atmosphere is assumed to be directly proportional to the cumulative densities of various processes involved in the production of rice paddies as well as in the farming of livestock populations. This growth rate also increases with a constant rate from various natural sources such as wetlands, etc. The growth rate of average global warming temperature is assumed to be proportional to the increased level of methane concentration in the atmosphere from its equilibrium value. It is also assumed that this temperature decreases with a rate proportional to its enhanced level from its equilibrium level caused by various natural factors such as rain fall, snowfall, etc. The proposed model is analyzed using the stability theory of differential equations and numerical simulation. The analysis shows that as the emission of methane from various processes involved in the production of rice paddies and farming of livestock populations increase, the average global warming temperature increases considerably from its equilibrium level. The numerical simulation of the model confirms the analytical results.

Micro- and mesozooplankton successions in an Antarctic coastal environment during a warm year.

The rapid increase in atmospheric temperature detected in the last decades in the Western Antarctic Peninsula was accompanied by a strong glacier retreat and an increase in production of melting water, as well as changes in the sea-ice dynamic. The objective of this study was to analyze the succession of micro- and mesozooplankton during a warm annual cycle (December 2010-December 2011) in an Antarctic coastal environment (Potter Cove). The biomass of zooplankton body size classes was used to predict predator-prey size relationships (i.e., to test bottom-up/top-down control effects) using a Multiple Linear Regression Analysis. The micro- and mesozooplanktonic successions were graphically analyzed to detect the influence of environmental periods (defined by the degree of glacial melting, sea-ice freezing and sea-ice melting) on coupling/uncoupling planktonic biomass curves associated to possible predator-prey size relationship scenarios. At the beginning of the glacial melting, medium and large mesozooplankton (calanoid copepods, Euphausia superba, and Salpa thompsoni) exert a top-down control on Chl-a and microzooplankton. Stratification of the water column benefitted the availability of adequate food-size (Chl-a <20) for large microzooplankton (tintinnids) development observed during fall. High abundance of omnivores mesozooplankton (Oithona similis and furcilia of E. superba) during sea-ice freezing periods would be due to the presence of available heterotrophic food under or within the sea ice. Finally, the increase in microzooplankton abundance in the middle of spring, when sea-ice melting starts, corresponded to small and medium dinoflagellates and ciliates species, which were possibly part of the biota of sea ice. If glacier retreat continues and the duration and thickness of the sea ice layer fluctuates as predicted by climate models, our results predict a future scenario regarding the zooplankton succession in Antarctic coastal environments.

Transformation textures in pure titanium: Texture memory vs surface effect

Surface effect-induced phase transformation heat treatment is performed on cold-rolled commercial pure titanium sheet to change and control the transformation texture. The results show that the type of final transformation texture changes from the texture memory effect type texture of TD-split basal to the surface effect type texture of 〈11−20〉//ND with the increase of heating temperature in helium atmosphere. At a low heating temperature of 920 °C and 1000 °C, the textures in sheets exhibited texture memory effect, while in the high heating temperature of 1100 °C, it showed the effects of both anisotropy in elastic modules of HCP titanium crystals and transformation strain. During the cooling phase, the surface effect can promote the preferred nucleation of α-phase grains on the plate surface, and then grow to the center layer of sheet along the ND direction. In the process of preferential nucleation of surface grains, texture memory effect and surface effect are a competitive process. The result of competition often shows that the small grains with tilted basal orientation (red) and cylindrical orientations (blue-green) are nucleated on the surface together, and the grains with blue-green orientation have the advantage of growth, leading to different grain morphology and microstructure. In addition to heating temperature and protective atmosphere, the degree of recrystallization before phase transformation also significantly affects the type of transformation texture. These differences in transformation texture and microstructure are explained according to the mechanism changes of the factors influencing the variant selection.

Climate change and winter road maintenance

The objective of the article is to analyse the impact of short- and long-term climate variations on the costs of removing snow and ice from the roads in Bergen—the second most populous city in Norway. The analysis applies simple mathematics, Monte Carlo simulations and multivariate regression methodology. The municipality of Bergen manages about 630 km of roads and 100 km of foot and bicycle paths, and the municipal administration spends NOK 37 million (or about USD 4.5 million) annually on removing snow and ice during the winter period. The analysis shows that a 1 °C increase in the mean temperature reduces the winter maintenance costs by NOK 14 million, and it is likely that there will be no need for winter snow-clearing operations if the long-term mean atmospheric temperature increases by approximately 2.5 °C or more relative to the historical mean temperature level. The analysis shows that the variance and trend of the temperature have a strong effect on the likelihood of a snow- and ice-free winter and that a long-term reduction in the variance reduces the likelihood of rare events even though the mean temperature increases. The analysis provides the municipality of Bergen with information about the relationship between climate and winter road maintenance costs, and the statistical models can help to quantify the amount of economic and material resources needed for this purpose. The analysis is a contribution in the field of economic impact analysis of climate change on the transport sector.

Responses of surface SOC to long‐term experimental warming vary between different heath types in the high Arctic tundra

AbstractOver the past few decades the Arctic has warmed up more than the lower latitudes. Soil organic carbon (SOC) in the Arctic is vulnerable to climate change, and carbon dioxide (CO2) produced via SOC decomposition can amplify atmospheric temperature increase. Although SOC composition is relevant to decomposability, studies on its compositional changes with warming are scarce, particularly in the Arctic. Therefore, we investigated the responses of SOC and the bacterial community to climate manipulation under Cassiope and Salix heath vegetation communities in permafrost‐affected soil in Zackenberg, Greenland. After 8–9 years of experimental warming, we evaluated changes in SOC quantity and quality of three density fractions of soil: free light fraction (FLF), occluded light fraction (OLF) and heavy fraction (HF). The SOC content at 0–5‐cm depth was significantly reduced with warming under Cassiope, and it was accompanied by decreased FLF content, attributed to accelerated decomposition of the FLF by warming. However, SOC molecular composition and bacterial community composition were not affected by warming. By contrast, there was no warming effect on SOC under Salix, which could be partially due to smaller temperature increases caused by higher moisture levels associated with larger silt and clay contents, or to different responses of the dominant plant species to temperature. In both soils, more than 55% of SOC was associated with minerals, and its molecular composition indicated microbial decomposition. Our results suggested that long‐term warming in the high Arctic could induce the loss of SOC, particularly in the FLF; however, the response could vary with vegetation type and/or soil properties, that is, soil texture.Highlights We show decreased SOC with long‐term (8‐year) warming of heath soils in the high Arctic Particularly, the free light fraction of SOC in topsoil decreased with warming in a Cassiope heath site Mineral‐associated SOC content was more than 55% and showed signs of microbial processing Effects of warming differed according to soil properties and/or plant community composition

Characterisation of Recent and Future Climatic Trends in the Region of Guelmim (Morocco)

According to the Intergovernmental Panel on Climate Change (IPCC), climate change is manifested by the increase in average surface atmospheric temperatures and a decrease in rainfall. The impacts are multiple, complex and differentiated from one region to another in the world. In the Guelmim region (southern Morocco), climate change is manifested by severe droughts and/or recurrent floods. The objective of this study is to characterize the recent and future climate variability in the Guelmim region based on time series of precipitation, the study period goes from 1985 to 2017, and from 2020 to 2099 using Standardized Precipitation Index (SPI).Results of SPI analysis indicate that the most notable droughts for their varying intensity, duration and frequency occurred during the 1992-94 and 1997-2000 periods. Future analysis indicates the study area will face several extended periods of drought and wet during 2020 to 2099. The results of this study show also the link between North Atlantic Oscillation and winter precipitation in Guelmim, which are associated with the negative phase of NAO. The purpose of the study is to have a good management of crops and water resources in Guelmim region and either to insure a sustainable management of environment.

De Novo Transcriptome Analysis of Durum Wheat Flag Leaves Provides New Insights Into the Regulatory Response to Elevated CO2 and High Temperature.

Global warming is becoming a significant problem for food security, particularly in the Mediterranean basin. The use of molecular techniques to study gene-level responses to environmental changes in non-model organisms is increasing and may help to improve the mechanistic understanding of durum wheat response to elevated CO2 and high temperature. With this purpose, we performed transcriptome RNA sequencing (RNA-Seq) analyses combined with physiological and biochemical studies in the flag leaf of plants grown in field chambers at ear emergence. Enhanced photosynthesis by elevated CO2 was accompanied by an increase in biomass and starch and fructan content, and a decrease in N compounds, as chlorophyll, soluble proteins, and Rubisco content, in association with a decline of nitrate reductase and initial and total Rubisco activities. While high temperature led to a decline of chlorophyll, Rubisco activity, and protein content, the glucose content increased and starch decreased. Furthermore, elevated CO2 induced several genes involved in mitochondrial electron transport, a few genes for photosynthesis and fructan synthesis, and most of the genes involved in secondary metabolism and gibberellin and jasmonate metabolism, whereas those related to light harvesting, N assimilation, and other hormone pathways were repressed. High temperature repressed genes for C, energy, N, lipid, secondary, and hormone metabolisms. Under the combined increases in atmospheric CO2 and temperature, the transcript profile resembled that previously reported for high temperature, although elevated CO2 partly alleviated the downregulation of primary and secondary metabolism genes. The results suggest that there was a reprogramming of primary and secondary metabolism under the future climatic scenario, leading to coordinated regulation of C-N metabolism towards C-rich metabolites at elevated CO2 and a shift away from C-rich secondary metabolites at high temperature. Several candidate genes differentially expressed were identified, including protein kinases, receptor kinases, and transcription factors.

Last-Generation Genome-Environment Associations Reveal the Genetic Basis of Heat Tolerance in Common Bean (Phaseolus vulgaris L.).

Genome–environment associations (GEAs) are a powerful strategy for the study of adaptive traits in wild plant populations, yet they still lack behind in the use of modern statistical methods as the ones suggested for genome-wide association studies (GWASs). In order to bridge this gap, we couple GEA with last-generation GWAS algorithms in common bean to identify novel sources of heat tolerance across naturally heterogeneous ecosystems. Common bean (Phaseolus vulgaris L.) is the most important legume for human consumption, and breeding it for resistance to heat stress is key because annual increases in atmospheric temperature are causing decreases in yield of up to 9% for every 1°C. A total of 78 geo-referenced wild accessions, spanning the two gene pools of common bean, were genotyped by sequencing (GBS), leading to the discovery of 23,373 single-nucleotide polymorphism (SNP) markers. Three indices of heat stress were developed for each accession and inputted in last-generation algorithms (i.e. SUPER, FarmCPU, and BLINK) to identify putative associated loci with the environmental heterogeneity in heat stress. Best-fit models revealed 120 significantly associated alleles distributed in all 11 common bean chromosomes. Flanking candidate genes were identified using 1-kb genomic windows centered in each associated SNP marker. Some of these genes were directly linked to heat-responsive pathways, such as the activation of heat shock proteins (MED23, MED25, HSFB1, HSP40, and HSP20). We also found protein domains related to thermostability in plants such as S1 and Zinc finger A20 and AN1. Other genes were related to biological processes that may correlate with plant tolerance to high temperature, such as time to flowering (MED25, MBD9, and PAP), germination and seedling development (Pkinase_Tyr, Ankyrin-B, and Family Glicosil-hydrolase), cell wall stability (GAE6), and signaling pathway of abiotic stress via abscisic acid (histone-like transcription factors NFYB and phospholipase C) and auxin (Auxin response factor and AUX_IAA). This work offers putative associated loci for marker-assisted and genomic selection for heat tolerance in common bean. It also demonstrates that it is feasible to identify genome-wide environmental associations with modest sample sizes by using a combination of various carefully chosen environmental indices and last-generation GWAS algorithms.

Subtropical freshwater phytoplankton show a greater response to increased temperature than to increased pCO2

Global increases in atmospheric CO2 and temperatures will impact aquatic systems, with freshwater habitats being affected. Some studies suggest that these conditions will promote cyanobacterial dominance. There is a need for a clearer picture of how algal species and strains within species will respond to higher temperatures and CO2, especially in combination. This study examined two chlorophytes (Monoraphidium and Staurastrum), and two strains of the cyanobacterium Raphidiopsis raciborskii (straight S07 and coiled C03), to determine how the combination of higher temperature and CO2 levels will affect their growth and maximum cell concentrations. Continuous cultures were used to compare the steady state cell concentrations at 28 °C and 30 °C, and CO2 partial pressures (pCO2), 400 and 750 ppm for all cultures, and in addition 1000 ppm at 28 °C for R. raciborskii strains. This study showed that, for all species, water temperature had a greater effect than higher pCO2 on cell concentrations. There were clear differences in response between the chlorophyte species, with Monoraphidium preferring 28 °C and Staurastrum preferring 30 °C. There were also differences in response of the R. raciborskii strains to increasing temperature and pCO2, with S07 having a greater increase in cell concentration. Genome analysis of R. raciborskii showed that the straight strain has five additional carbon acquisition genes (β-CA, chpY, cmpB, cmpD and NdhD4), indicative of increased carbon metabolism. These differences in the strains’ response to elevated pCO2 will lead to changes in the species population structure and distribution in the water column. This study shows that it is important to examine the effects of both pCO2 and temperature, and to consider strain variation, to understand how species composition of natural systems may change under future climate conditions.