Warm Conditions Research Articles

Investigating how reproductive traits in rice respond to abiotic stress.

Oryza sativa is one of the most important crops and a food source for billions of people. Anthropic global warming, soil erosion, and unstable environmental conditions affect both its vegetative and reproductive growth, and consequently the final yield of its cultivation. The reproductive phase starts with the transition of apical meristem from vegetative to reproductive, which develops into a panicle, proceeds through the differentiation of the floret, and, after fertilization, the filling of the grain. The physiological events that occur during these stages influence the ability of new seeds to respond to stresses during the future seed germination phase, a key step for successful seedling growth and future plant establishment. This review explores the impacts of different abiotic stresses on the physiological and molecular pathways of the reproductive growth.

Thermal acclimation of tree species in a tropical Andean city: Exploring the role of species origin and thermal niche.

The warmer and drier atmospheric conditions of urban environments challenge plant performance to different extents based on a species' ability to acclimate to the conditions. We evaluated the influence of species origin and thermal niche on the acclimation of leaf traits and shifts in the occupation of the functional trait space of 10 tree species growing in two environmentally contrasting sites in Bogotá, Colombia. We measured six leaf traits per species in both sites and used generalized linear models to evaluate the influence of origin and thermal niche on acclimation of leaf traits and t-tests to analyze shifts in the occupation of the functional trait space. Species origin predicted thermal tolerance and morphological trait acclimation to warmer conditions. Although exotic species decreased thermal tolerance at the warmer site, species from both origins acclimated traits consistently. Shifts in the occupation of the functional trait space varied between origins; warmer conditions reduced the size of the functional trait space of exotics and increased the phenotypic similarity of natives. Thermal tolerance acclimation and changes in functional trait space varied across species. Finally, thermal niche metrics were uncoupled from species origin and failed to explain the acclimation capacity of the studied species. Although species origin influenced acclimation to warmer conditions, the effect of origin was not related to species' thermal niches. Our results provide crucial information for decision-makers involved in designing urban and peri-urban green spaces that can withstand climate change.

Enhanced Extraction of Polyphenols, Physicochemical Properties, and Microbial Control in Vitis vinifera L. Juice Using Ultrasound-Assisted Maceration

Polyphenols are essential bioactive compounds that contribute to the nutritional and sensory properties of grape juice and wine. This study investigates the impact of ultrasound-assisted maceration (UAM) compared to traditional maceration (TM) techniques, under both warm and cold conditions, on the polyphenol content, physicochemical properties, and microbial counts of juice from Vitis vinifera L. Ultrasound-assisted maceration significantly enhanced the extraction of polyphenols, including anthocyanins, flavonols, flavan-3-ols, and stilbenes, within a shorter processing time. The total polyphenol content increased up to 689.3 mg/L under UAM, while TM required extended maceration periods to achieve comparable results. In addition to polyphenol enrichment, UAM resulted in improved physicochemical properties, including higher extract content (% Brix) and increased turbidity (NTU), with minimal impact on pH and acidity levels. Microbial counts in juice remained low under UAM, indicating that this method may also have antimicrobial benefits due to the cavitation effects of ultrasound. Conversely, TM under warm conditions led to a reduction in extract content and nitrogen availability due to fermentation processes initiated during prolonged maceration. The findings highlight that UAM is a highly efficient technique for enhancing the polyphenol profile of grape juice while preserving key physicochemical parameters and microbial decontamination. This study provides valuable insights for the beverage industry, suggesting that UAM can be a sustainable and time-efficient alternative to traditional maceration methods for producing high-quality grape-based beverages.

Reduction in thermal plasticity of life history traits in response to cold selection: an experimental evolution study using Drosophila melanogaster

IntroductionHow selection influences phenotypic plasticity is an important question in evolutionary biology. We report an experimental evolution study that examined how prolonged selection at cold vs. warm temperature impacts the thermal plasticity of traits like reproductive output, body size, and body water content in Drosophila melanogaster.MethodsWe conducted the study on two sets of large, outbred fly populations: one maintained at the standard fly rearing temperature, i.e., 25°C, and another selected at cold temperature, i.e., 17°C, for 3.5 years. Both selection lines were derived from the same ancestral population.Results and discussionWe found that while 25°C selected females lay significantly fewer eggs in cold compared to warm or optimal rearing temperature of 25°C, the 17°C selected females have consistent or canalized fecundity levels across warm and cold conditions. Sustained fecundity levels across cold and warm conditions are potential marks of adaptation to a broader thermal range. While phenotypic plasticity may aid in adaptation to new environments, for traits such as fecundity, consistent levels across environments, that is, low plasticity, may be more adaptive. We also found that male flies from cold vs. warm selection regimes differ in their thermal plasticity. Plasticity of dry weight and body water content was reduced in the cold-selected males, indicating the evolution of canalized levels for these traits too. While canalized fecundity levels across temperatures can potentially help in thermal adaptation, the significance of reduced plasticity of male body size and water content needs to be investigated in the future.

Importance of ecological factors in the regulation of colorado potato beetle populations using the predatory bug Podisus maculiventris

Since the middle of the last century, the practice of using the predatory bug Podisus maculiventris to protect nightshade crops from pests has been known in various regions of the world. In the conditions of the Siberian region, the use of Podisus to regulate the number of Colorado potato beetles has not found wide application to date, which is due to both the availability of the entomophage itself on the market of plant protection products and the need to develop methods and conditions for its use in the production of organic plant products. The paper presents information on the influence of environmental factors on the dynamics of the Colorado potato beetle population, the survival rate and the effectiveness of its entomophage on the colored potato variety Rosemaria. During the years of research, the number of phytophage generations developing during the growing season depended on the temperature factor. In 2023, a high number of the second generation of the Colorado potato beetle was noted, due to the warmer conditions of this growing season, while in 2022, egg-laying and second-generation larvae were single. The influence of local weather conditions on the survival of podisus individuals released into open ground and, as a consequence, on its regulatory activity was noted. Differences in the effectiveness of the entomophage depending on the method of its release were revealed. With uniform dispersal of P. maculiventris nymphs over plants, a decrease in leaf damage by the Colorado potato beetle and an increase in its biological effectiveness were observed compared to the option of releasing podisus at one point. The maximum effectiveness of podisus was noted on the 7th day after its repeated release and was 87.8 and 90.9 % in 2023 and 2022. respectively, in the variant with uniform distribution of the entomophage among plants, while when released at the control point, the biological efficiency was at the level of 63.8 and 64.4 %. The potato yield in the variants using the predatory bug was 1.3-1.5 times higher compared to the control and varied from 124.3±6.6 to 149.9±6.5 c/ha depending on the year of research and the method of release of the entomophage.

Disruption of boreal lake circulation in response to mid-Holocene warmth; evidence from the varved sediments of Lake Nautajärvi, southern Finland.

Future climate projections are expected to have a substantial impact on boreal lake circulation regimes. Understanding lake sensitivity to warmer climates is therefore critical for mitigating potential ecological and societal impacts. The Holocene Thermal Maximum (HTM; ca 7-5ka BP) provides a valuable analogue to investigate lake responses to warmer climates devoid of major anthropogenic influences. Here, we analyse the micro-X-ray core scanning profiles (μ-XRF) of the annually laminated (varved) sediments from Lake Nautajärvi (NAU-23) in southern Finland to elucidate changes in lake circulation and sedimentation patterns. Principal component analysis (PCA) identifies two key components in the geochemical data associated with the nature of the sediments, i.e. detrital vs organic sedimentation (PC1), and hypolimnetic oxidation (PC2). Our findings reveal that during the HTM, the lake became more sensitive to changes in oxygenation and mixing intensity. These changes were triggered by a warmer climate, which increased organic matter and redox sensitive metal solute concentrations in the water column, strengthening lake stratification and weakening dimictic circulation patterns. Superimposed on HTM weakened circulation are distinct phases of increased oxidation and iron-rich varve formation that do not happen when the background conditions are cooler (i.e. the early and late Holocene). This is driven by temporary strengthening of the mixing regime in response to climatic variability and storminess cycles across southern Scandinavia. These findings demonstrate that whilst warmer conditions weaken boreal lake circulation regimes, they can also make them increasingly vulnerable to short term oscillations in prevalent climatic conditions and weather patterns, which could have significant impacts on lake water quality and aquatic ecosystems. These findings underscore the non-stationary nature of lake sensitivity to short-term climatic variability and emphasize the potential for similar shifts to occur under future warming scenarios.

Cold suppresses virus accumulation and alters the host transcriptomic response in the turnip mosaic virus ̶ Arabidopsis halleri system.

Since plant viruses cause lifelong infections, virus-plant interactions are exposed to large temperature fluctuations in evergreen perennials. In such circumstances, virus-plant interactions are expected to change significantly between the warm and cold seasons. However, few studies have investigated the effects of cold temperatures on virus-plant interactions. Here, we show that in a persistent infection system of the turnip mosaic virus (TuMV) -Arabidopsis halleri, cold temperatures lead to slow viral replication/spreading within the host, slow attenuation of host symptoms, and slow cold-specific transcriptomic responses. Many differentially expressed genes (DEGs) were detected between virus-inoculated and mock-inoculated plants under warm and cold conditions; however, the sets of DEGs and response timings were temperature-dependent. Under cold temperatures, the expression of photosynthesis-related genes decreased in the early stages of infection. However, it recovered to the same level as that in uninfected plants in the later stages. In contrast, the transcriptomic changes under warm conditions suggest that viral infections cause auxin-signaling disruption. These responses coincided with the inhibition of host growth. We identified 6 cold- and 38 warm-specific DEGs, that changed their expression in response to TuMV infection under more than half of the conditions for either cold or warm temperatures. Further validation of the putative relationships between transcriptomic and phenotypic responses of the host is required. Our findings on temperature-dependent host responses at both symptomatic and transcriptomic levels help us understand how warm and cold temperatures affect virus-plant interactions in seasonal environments.

Time and climate roles in driving soil carbon distribution and stability in particulate and mineral-associated organic matter pools.

Understanding the accumulation and stability of soil organic matter (SOM) pools as a function of time (i.e., soil age) and climate (i.e., precipitation and temperature) represents a crucial challenge. This study aims at investigating the effect of both climate and time on SOM distribution into particulate and mineral-associated organic matter (POM and MAOM, respectively), using two chronosequences located along a climate gradient. The contribution of POM and MAOM to soil organic carbon (SOC) storage differs between the climo-chronosequences and with depth. The ratio between MAOM and POM pools (MAOM/POM) ranges from 0.9 to 2.0 and from 1.4 to 3.5 in the wetter and cooler and in the drier and warmer chronosequence, respectively. Regardless of the chronosequence, the MAOM/POM ratio increases with depth, highlighting a more important role of the mineral-associated fraction in carbon storage in deeper soils. The concentration of organic carbon in mineral-associated (MAOC) and particulate (POC) pools along the soil profile in the wetter and cooler chronosequence is 2× and 3× higher, respectively, than in soils from the drier and warmer one. In particular, in the wetter and cooler chronosequence, MAOC and POC concentrations decrease with soil age. In the drier and warmer chronosequence, only POC concentration decreases with soil age, whereas MAOC concentration generally increases. The thermal stability of the MAOM fraction increases with soil age and depth only in the drier and warmer climatic conditions, whereas no differences with depth occur in the wetter and cooler chronosequence. Furthermore, the MAOM energy density decreases with soil depth and age in both chronosequences. Independently of the chronosequence, POM represents the most labile pool with higher energy density. In conclusion, time and climate play a different role in SOC distribution between the pools and on their relative stability. Soil age drives MAOM stability in drier and warmer conditions, whereas a wetter and cooler climate determines a higher SOC accumulation in both pools, although these greater carbon stocks are negatively correlated with their stability.

MEDIATOR15 destabilizes DELLA protein to promote gibberellin-mediated plant development.

Mediator, a transcriptional coactivator, regulates plant growth and development by interacting with various transcriptional regulators. MEDIATOR15 (MED15) is a subunit in the Mediator complex potentially involved in developmental control. To uncover molecular functions of Arabidopsis MED15 in development, we searched for its interactors. MED15 was found to interact with DELLA proteins, which negatively regulate gibberellic acid (GA) signaling and positively regulate GA biosynthesis. Mutants and overexpressors of MED15 exhibited multiple GA-related growth phenotypes, which resembled the phenotypes of the DELLA overexpressor and mutant, respectively. Consistent with this observation, DELLA protein levels were inversely correlated with MED15 protein levels, suggesting that MED15 activates GA signaling through DELLA degradation. MED15 was required not only for DELLA-mediated induction of GA-biosynthesis gene expression but also for GA-mediated degradation of DELLA. Therefore, MED15 facilitates DELLA destruction not only by promoting GA biosynthesis but also by accelerating DELLA turnover. Furthermore, MED15-mediated GA signaling was required for timely developmental responses to dark and warm conditions. Our results provide insight into developmental control by Mediator via precise regulation of DELLA stability. These findings are potentially useful for the generation of new crop cultivars with ideal body architecture.

A One-Dimensional Energy Balance Model Parameterization for the Formation of CO2 Ice on the Surfaces of Eccentric Extrasolar Planets.

Eccentric planets may spend a significant portion of their orbits at large distances from their host stars, where low temperatures can cause atmospheric CO2 to condense out onto the surface, similar to the polar ice caps on Mars. The radiative effects on the climates of these planets throughout their orbits would depend on the wavelength-dependent albedo of surface CO2 ice that may accumulate at or near apoastron and vary according to the spectral energy distribution of the host star. To explore these possible effects, we incorporated a CO2 ice-albedo parameterization into a one-dimensional energy balance climate model. With the inclusion of this parameterization, our simulations demonstrated that F-dwarf planets require 29% more orbit-averaged flux to thaw out of global water ice cover compared with simulations that solely use a traditional pure water ice-albedo parameterization. When no eccentricity is assumed, and host stars are varied, F-dwarf planets with higher bond albedos relative to their M-dwarf planet counterparts require 30% more orbit-averaged flux to exit a water snowball state. Additionally, the intense heat experienced at periastron aids eccentric planets in exiting a snowball state with a smaller increase in instellation compared with planets on circular orbits; this enables eccentric planets to exhibit warmer conditions along a broad range of instellation. This study emphasizes the significance of incorporating an albedo parameterization for the formation of CO2 ice into climate models to accurately assess the habitability of eccentric planets, as we show that, even at moderate eccentricities, planets with Earth-like atmospheres can reach surface temperatures cold enough for the condensation of CO2 onto their surfaces, as can planets receiving low amounts of instellation on circular orbits.

Predicting habitat refugia of the medicinal plant Dolomiaea costus under two climate change scenarios

Assessing the impacts of climate change on the distribution of medicinally important and endangered species is critical for conservation planning. This study focuses on Dolomiaea costus (Falc.) Kasana & A.K. Pandey, a critically endangered and highly valuable medicinal plant found in the fragile climate of Pakistan. Using species distribution modelling (MaxEnt), we evaluated the current and future habitat suitability of D. costus under two climate change scenarios (SSP370 and SSP585) for the periods 2041–2070 and 2071–2100. Occurrence data were collected from field surveys and the Global Biodiversity Information Facility (GBIF), while bioclimatic data were sourced from Climatologies at High Resolution for the Earth’s Land Surface Areas (CHELSA). The MaxEnt model achieved a high mean AUC value of 0.967, indicating strong predictive accuracy. Suitable habitats for D. costus span approximately 99,871 Km2 across the western Himalayas, Karakoram, and Hindukush regions. Climate projections revealed that under SSP370, suitable areas decrease from 99,260 Km2 in 2041–2070 to 90,962.5 Km2 in 2071–2100, with high-suitability zones reducing from 13,024.5 Km2 to 11,490.5 Km2. In contrast, the SSP585 scenario showed a modest expansion of suitable habitat from 107,104 Km2 to 111,217.5 Km2, though high-suitability areas declined from 18,208 Km2 to 16,811 Km2. Precipitation-related variables, especially precipitation seasonality, were the most influential drivers of habitat suitability, contributing 64.3% to the model, followed by mean monthly precipitation of the driest quarter (18.8%) and precipitation of the wettest and driest months. Jackknife tests also confirmed their critical importance. These findings underscored the sensitivity of D. costus habitat to the intensity of climate change, particularly under severe warming conditions and highlighted the urgent need for a comprehensive conservation plan. A combination of strategies, including climate-smart conservation, habitat protection, species reintroduction, and cultivation in moderately to highly suitable habitats, is crucial to ensure the long-term survival of D. costus in Pakistan amidst the changing climate.

Will climate warming amplify the effects of a range-expanding marine predator?

The effects of climate warming on the distribution of range-expanding species are well documented, but the interactive effects of climate warming and range-expanding species on recipient communities remain understudied. With climate warming, range-expanding species may threaten local biodiversity due to their relatively stronger competitive or predatory effects on potentially weakened, or less well-adapted recipient communities. Acanthinucella spirata is a predatory marine gastropod that has expanded its distribution north along the California coast since the Pleistocene via a poleward range shift, tracking climatic warming. To assess whether A. spirata has stronger predatory effects on the recipient community in their expanded range and is better suited to a warming climate than a local predatory snail, we used a combination of field and laboratory studies to examine the feeding activity of A. spirata and the predatory whelk (Nucella lamellosa) on shared prey under ambient and elevated conditions. From field surveys, we concluded that A. spirata is a potential competitive threat to N. lamellosa, due to its high local abundance, overlapping habitat, and shared prey on Cape Mendocino. In the laboratory, we observed that A. spirata was a more efficient consumer of prey than N. lamellosa overall and ate significantly more prey than N. lamellosa under warmer conditions. As climate change continues, environmental conditions will become more stressful for all species; however, range-expanding A. spirata populations may be at a competitive advantage relative to N. lamellosa, as they are more abundant and have higher feeding rates at warmer temperatures than the local whelk.

The dominant marine Synechococcus clade II exhibits a non-canonical transcriptional response to cope with thermal stress

Temperature significantly impacts the growth and distribution of marine cyanobacteria, which employ diverse strategies to cope with temperature variations. However, the molecular mechanisms underlying thermal acclimation in cyanobacterial taxa that dominate vast oligotrophic regions of the ocean, such as the Synechococcus clade II, remain unknown. Here, we analysed the physiological and global transcriptional response of an ecologically relevant clade II strain (Synechococcus sp. RS9907) to long-term thermal acclimation at temperatures from 20 to 33 °C. The growth rate in RS9907 increased linearly with temperature up to the warm threshold (33 °C), but genes related with the heat-shock response were upregulated within the range of 28 to 33 °C, indicating significant cellular stress under warm conditions. Carbon fixation and assimilation genes (rcbLS, cbbA, zwf, glgP) showed minimum expression values at 20 °C and 33 °C, but the diel expression patterns of these genes remained unaffected by temperature conditions, being consistently upregulated during day-time. By contrast, some genes involved in photosynthesis (acpA, psbABO, psaABD) were strongly upregulated during night-time under warm conditions, suggesting regulatory imbalances during the diel cycle. Notably, the expression of genes related to the synthesis of osmolytes against salt stress and fatty acid desaturases, which are typically upregulated under cold temperature in other cyanobacteria, was induced in warm acclimated RS9907 cells. These results highlight distinct transcriptional mechanisms of thermal acclimation in members of the Synechococcus clade II compared to other cyanobacterial lineages. This emphasizes the importance of understanding the diverse and intricate ways in which marine cyanobacteria adapt to temperature fluctuations.

Nano-TiO2 impairs the health of crabs Charybdis japonica under warming conditions through waterborne and dietary exposures.

The widespread use of nano titanium dioxide (nano-TiO₂) poses ecological risks to marine ecosystems, especially when combined with ocean warming. However, most previous studies have only examined water-related exposures, leaving a gap in research on the impact of food transfer on organisms. In this work, the harmful impacts of nano-TiO2 on the Japanese swimming crab Charybdis japonica were studied through three scenarios: direct exposure (DE) of the crabs to warming and nano-TiO2, indirect exposure (IE) via consumption of thick-shelled mussels Mytilus coruscus exposed to the same conditions, and combined exposure (CE), where crabs were directly subjected to warming and nano-TiO2 while feeding affected mussels. Moreover, a control group was established, consisting of Japanese swimming crab C. japonica and mussel M. coruscus that were raised under standard temperature (22 °C) and 0 mg L-1 nano-TiO2 concentration conditions. Immune, oxidative, and gene expression parameters were measured in gills and hepatopancreas after 7 exposure days. Furthermore, titanium bioaccumulation, along with the morphometrical and histological analyses, were assessed in gills. Bioaccumulation results (1.69-6.83 μg/g) suggested that foodborne stressors induced higher titanium contents. Additionally, there were deformities in gills morphometry and histology. The multivariate analyses showed that warming and nano-TiO2 combination had a pronounced effect on the overall profile of biological responses in crabs; moreover, the exposure through food alone had the greatest impact on gills immune-oxidative parameters and hepatopancreas gene expressions. The harmful impacts of nano-TiO2 are significant and can manifest through waterborne and dietary exposure pathways, especially when combined with other stressors, warranting further research.

A comparative study of classical and innovative lobbed air diffusers using temperature sensors for thermal environment/comfort in vehicle cabins

Thermal comfort within a vehicle cabin is of utmost importance for both safety and user satisfaction. This study evaluates the impact of two air diffuser geometries—the classical and the innovative lobbed air diffusers—on the thermal environment within a car cabin. Experiments were conducted in an automobile-like enclosure within a climatic chamber, using a Dacia Duster dashboard and ventilation system. The system was manually controlled to vary airflow rates. Wireless temperature sensors were placed at strategic positions and levels (head, chest, knees) to monitor temperature variations over six measurement sessions with different ventilation configurations. Results show that both diffuser types effectively maintain a uniform temperature distribution across seating positions and levels. However, the innovative lobbed air diffusers demonstrated superior performance by maintaining slightly lower or comparable temperature, despite higher inlet air temperature. This suggests enhanced air mixing capability, leading to a more consistent and cooler environment, particularly advantageous during warmer conditions. This study highlights the importance of optimizing thermal comfort in vehicle cabins to improve passenger safety and comfort. Further research on long-term performance and energy efficiency is recommended to fully explore the benefits of innovative air diffusers.

Syntheses, crystal structure, Hirshfeld Surface Analyzes of cocrystals and salt of a flexible imidazole tethered naphthalenediimide with some organic acids.

One salt and three cocrystals of 2,7-bis(3-(1H-imidazol-1-yl)propyl)benzo[lmn][3,8]phenanthroline-1,3,6,8(2H,7H)-tetraone (L) have been synthesized and reported. 3-Nitro benzoic acid (3NBA) forms salt with L and 4-Nitro benzoic acid (4NBA), 4-Hydroxy benzoic acid (4HBA) and 4-Amino benzoic acid (4ABA) forms cocrystals with L. L forms 1:1 salt with 3-NBA and 1:1 cocrystal with 4-NBA, 4-HBA and 4-ABA respectively. All the complexes were formed in a warm solvent condition. The solid-state structures were determined by single crystal X-ray diffraction method. Salt 1, exhibit zig zag tetrameric water cluster in the solid-state structure. Various types of supramolecular interactions such as OH…O, CH…O, π…π, and CH…π were observed in the x-ray structures and all these interactions guide the formation of 3D supramolecular architecture in the solid-state of all the complexes. Besides these, the 2D-fingerprint (2D-FP) and Hirshfeld surface analysis (HSA) computations were served to prove the 2D-network packed crystal lattice interactions.

Enhanced mercury deposition in Arctic Alaskan lake sediments coincides with early Holocene hydroclimate shift.

Substantial amounts of mercury (Hg) are projected to be released into Arctic watersheds as permafrost thaws amid warmer and wetter conditions. This may have far-reaching consequences because the highly toxic methylated form of Hg biomagnifies rapidly in ecosystems. However, understanding how climate change affects Hg dynamics in permafrost regions is limited due to the lack of long-term Arctic Hg records. Using a 27-ka Hg sediment record from Burial Lake, northwestern Alaska, we examine how well-characterized temperature, precipitation, and vegetation shifts affected Hg mobilization in a catchment underlain by permafrost. During the Last Glacial Maximum (29.6-19.6ka), Hg concentrations (63±5μg/kg) and Hg flux (8.6±2.2μgm-2yr-1) remain relatively stable. Abrupt warming trends, starting at 17.6ka, do not coincide with Hg levels. After 15ka, the ecosystem transitions to shrub tundra, Hg concentrations (101.2μg/kg) peak at 14.2ka, while flux (5.3±1.3μgm-2yr-1) declines and stabilizes. At ~11ka, increased precipitation coincides with a 72% rise in Hg concentrations and a 32% increase in Hg flux compared to average Hg levels since 15ka. These results suggest that summer rainfall was the primary driver of Hg mobilization from the catchment, while the vegetation shift influenced lake sediment Hg concentrations. At 1990CE, peak Hg levels represent an 88% increase in Hg concentrations (196.3μg/kg) and a sixfold rise in Hg flux (38.1μgm-2yr-1) above background levels, underscoring the need for further research to understand Hg dynamics driven by anthropogenic Hg emissions and climate change.

Shifts in the Oligotrophic Warm Conditions of the Gulf of Mexico Over MIS‐6 to MIS‐1 Based on Planktonic Foraminifera Assemblages and Mg/Ca Ratios

Shifts in the Oligotrophic Warm Conditions of the Gulf of Mexico Over MIS‐6 to MIS‐1 Based on Planktonic Foraminifera Assemblages and Mg/Ca Ratios

Assessing the Role of Incubation Temperature as a Barrier to Successful Establishment of Coho Salmon (Oncorhynchuskisutch) in a Rapidly Warming Arctic.

Warming associated with climate change is driving poleward shifts in the marine habitat of anadromous Pacific salmon (Oncorhynchus spp.). Yet the spawning locations for salmon to establish self-sustaining populations and the consequences for the ecosystem if they should do so are unclear. Here, we explore the role of temperature-dependent incubation survival and developmental phenology of coho salmon (Oncorhynchus kisutch) as a potential early life history barrier to establishment in an Arctic stream. We exposed embryos to temperatures previously recorded in the substrate of an Arctic groundwater spring-fed spawning environment. Using a common garden experimental design, coho salmon embryos were exposed to treatments that thermally mimicked four spawning dates from August 1 to October 1 (AUG1, SEPT1, SEPT15, and OCT1). Spawning temperatures were 6°C at the warmest (AUG1) and 1.25°C at the coldest (OCT1). We observed low survival rates in SEPT1 (41%) and OCT1 (34%) and near complete mortality in the other treatments. While far below what is considered normal in benign hatchery-like conditions, these rates suggest that temperatures experienced at these spawning dates are survivable. We detected differences in developmental rates across treatments; embryos developed 1.9 times faster in the warmest treatment (AUG1, 120 days) compared to the coldest (OCT1, 231 days). Differences in accumulated thermal units (ATUs) needed for hatching ranged from 392 ATUs in AUG1 to 270 ATUs in OCT1, revealing compensation in developmental requirements. Given these findings, the most thermally suitable spawning dates within our study are between September 15 and October 1, which facilitates hatching and projected nest emergence to occur in spring warming conditions (March-September). Broadly, our findings suggest that spawning sites within thermal tolerances that can support the survival and development of coho salmon exist in the North American Arctic. Whether the habitat is otherwise suitable for transitions through other life stages remains unknown.

Adaptation des cultures au changement climatique : apport possible de l'édition génomique

Climate change means warmer conditions, with more frequent risks of drought, but also a wide variation in conditions, with extreme events, from one year to the next. To adapt crops to this change, we need varieties that combine several types of tolerance, particularly to high temperatures and water stress at different stages of the plant life, as well as resistance to different types of bio-aggressors associated to this change. Using various examples, we show that genome-editing techniques can be a tool to assist conventional plant breeding in obtaining such varieties more quickly. In the discussion, we compare the selection of varieties adapted to different conditions (called multi-adapted varieties), thanks to genome editing, with the mixture of varieties with adaptations to different climatic conditions, and we conclude that the two approaches can be complementary.