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Fruit tree frost, an agricultural meteorological disaster primarily occurring in spring, severely impacts the growth and development of trees and fruit set. Therefore, exploring the temperature change rules of fruit trees during frost events is of considerable importance. This study used a T40 unmanned aerial vehicle (UAV) as the test vehicle based on the air disturbance frost prevention principle. The airflow field change pattern of the UAV was explored using the computational fluid dynamics simulation method, and the reliability of the multi-rotor UAV in frost prevention was verified using field tests. Setting the UAV height at 6.0 m above the ground and the rotor speed at 1000 r min−1, it was found that under the conditions of the inverse temperature phenomenon, the temperatures of different altitude layers will eventually converge to a stable value when the UAV down-rotating airflow is disturbed, which could be completed rapidly within 20 s. The results of the field test also showed that when the fruit trees reached the critical temperature of frost at the flowering stage, UAV intervention could have a substantial effect on the warming of the near-surface layers, whose warming amplitude was in the range of 2.5 °C–3 °C. This study provides a reliable method for mitigating frost, which serves as an important theoretical and guiding basis for improving agricultural frost disasters in China. • A multi-rotor UAV is used to test frost protection performance on fruit trees. • The temperature field characterizations are obtained. • The anti-frost effectiveness of UAV intervention is confirmed. [ABSTRACT FROM AUTHOR]

The paper reports the first results of an experiment in northern Finland during winter 2022–2023 that aimed at studying seismic events caused by seasonal freezing in the so-called critical zone (CZ) of the Earth. These events have attracted public attention recently, as multiple reports about them from local inhabitants in Arctic and sub-Arctic areas appeared on social networks. To make an instrumental study of such events, to reveal the relationship between their occurrence and winter weather conditions, and to evaluate the possible hazard, we installed two high-resolution seismic arrays with co-located soil temperature stations at two sites in Finland, one of them being in the city of Oulu in the sub-Arctic area (65.04° N, 25.61° E) and the other one above the polar circle in the municipality of Sodankylä (67.36° N, 26.63° E). The equipment recorded continuous seismic and soil temperature data during November 2022–April 2023. Based on reports from the inhabitants of Talvikangas (Oulu) about the ground shaking and unusual noises on 6 January 2023 and their observations of new fractures on the roads there, we selected the time interval for the identification of frost quakes that originated during that day from continuous seismic records in Talvikangas and in Sodankylä. During the selected time interval, the extremely rapid air temperature drops of about -1.4 °C h -1 in Talvikangas and -0.88 °C h -1 in Sodankylä were observed. We identified and located two types of seismic events – namely, frost quakes with frequencies of about 10–20 Hz, with waveforms like those of tectonic events, and irregularly shaped frost tremors with frequencies of about 120–180 Hz. The sources of frost quakes in Talvikangas are mainly located on irrigated wetland, while in Sodankylä, about 50 % of registered frost quakes were caused by ice fracturing on the Kitinen River. However, several relatively strong events, with their origin in the wetlands, were also recorded. A significant number of sources of frost tremors are confined to wetland areas cut by irrigation channels and to roads cleaned from snow during winter both in Talvikangas and in Sodankylä. We calculated ground accelerations and ground velocities for the strongest events from both groups and compared them to equivalent properties of other seismic signals, like distant local earthquakes in the area, mining production blasts, and cargo train vibration. Our study shows that high-frequency frost tremors corresponding to surface fracture opening in the uppermost frozen surface layer of a thickness of up to 5 cm can directly damage infrastructure objects like roads and basements of buildings. Surface waves, produced by frost quakes and propagating inside the shallow soil layer, have large enough ground accelerations at epicentral distances of hundreds of metres. Therefore, frost quakes should be considered a phenomenon that can potentially damage infrastructures, and they have to be taken into account in seismic hazard assessments. Our research is the first instrumental study of seismic events originating from wetland areas. These events occur as a result of the interaction between the uppermost layer of the solid Earth's CZ and atmosphere processes that deserves further study. [ABSTRACT FROM AUTHOR]

In this paper, a new direct calculation method of frost ice shape on the blade surface of horizontal axis wind turbine is proposed. Using linear interpolation algorithm, the airfoil ice shape obtained by LEWICE 2D software or ice wind tunnel experiment was fitted with equidistant step length in the first and fourth quadrants and equidistant step length in the second and third quadrants. The key point coordinates of ice shapes on cross-sections along the span-wise were mapped into lagging and flapping surfaces through the mathematical dimension reduction, respectively. The polynomial fitting was used to deal with ice projection points of multiple sections in lagging and flapping surfaces, and then the blade's frost ice shape was obtained. By calculating the sum of squared residuals of the polar diameter at the same polar angle, the errors between experimental and airfoil frost shape fitting methods, experimental and FENSAP, and blade frost shape formation methods and FENSAP were analyzed. The results show that the new method is in good agreement with the ice shape of FENSAP simulation results and experimental results. The residual sum of squares is small. This method makes the analysis of frost ice morphology of wind turbine blades do not need to consider interdisciplinary. The calculation process is simple and reliable. [ABSTRACT FROM AUTHOR]

Background and Aims Geoxyles, a distinctive feature of Afrotropical savannas and grasslands, survive recurrent disturbances by resprouting subshrub branches from large below-ground woody structures. Underground trees are a type of geoxyle that independently evolved within woody genera of at least 40 plant families in Africa. The environmental limits and determinants of underground tree biogeography are poorly understood, with the relative influence of frost and fire debated in particular. We aim to quantify variability in the niche of underground tree species relative to their taller, woody tree/shrub congeners. Methods Using occurrence records of four Afrotropical genera, Parinari (Chrysobalanaceae), Ozoroa (Anacardiaceae), Syzygium (Myrtaceae) and Lannea (Anacardiaceae), and environmental data of nine climate and disturbance variables, the biogeography and niche of underground trees are compared with their open and closed ecosystem congeners. Key Results Along multiple environmental gradients and in a multidimensional environmental space, underground trees inhabit significantly distinct and extreme environments relative to open and closed ecosystem congeners. Niche overlap is low among underground trees and their congeners, and also among underground trees of the four genera. Of the study taxa, Parinari underground trees inhabit hotter, drier and more seasonal environments where herbivory pressure is greatest. Ozoroa underground trees occupy relatively more fire-prone environments, while Syzygium underground trees sustain the highest frost frequency and occur in relatively wetter conditions with seasonal waterlogging. Lannea underground trees are associated with the lowest temperatures, highest precipitation, and varying exposure to disturbance. Conclusions While underground trees exhibit repeated convergent evolution, varied environments shape the ecology and biogeography of this iconic plant functional group. The multiplicity of extreme environments related to fire, frost, herbivory and waterlogging that different underground tree taxa occupy, and the distinctiveness of these environments, should be recognized in the management of African grassy ecosystems. [ABSTRACT FROM AUTHOR]

Spring frost is a perennial and widespread problem across many cool climatic and high-elevation winegrowing regions of the world. Vitis vinifera L. cv. Pinot noir is an early budding cultivar; thus, it is particularly susceptible to late-spring frost damage. In late April 2022, an advective frost event occurred throughout Western Oregon winegrowing regions and subsequently damaged a substantial number of commercial vineyards. Growers often are unsure of how to manage grapevines after a frost event. Limited research has shown little-to-no effect of pruning vs. non-pruning strategies on vine yield and productivity. In addition, pruning a frost-affected vineyard incurs additional labor costs that may offset the cost–benefit balance for the grower. Therefore, in this experiment, the effect of two different post-frost pruning treatments (cane pruning and spur pruning) on vine yield, berry composition, and vine vegetative growth were tested. No effect of post-frost pruning treatments on vine yield, berry composition, and vine vegetative characteristics was observed. Cluster numbers, cluster weights, and berries per cluster only differed between cane- vs. spur-pruned vines. Therefore, leaving frost-affected vines alone and a scaled-back vineyard management practice could be practical for economic reasons. [ABSTRACT FROM AUTHOR]

The frequency of early frosts has increased in recent years, which are injurious to olive growing, causing losses in the yield and quality of virgin olive oil. In this research, it was studied how the management of agronomic factors mitigates frost damage in Arbequina olives, minimizing the loss of phenols and volatiles in virgin olive oil, at different fruit ripening stages. A Box–Behnken design and multivariate analysis were performed, with three levels of irrigation, potassium fertilization, and foliar copper application (15 treatments). Virgin olive oil was extracted from fresh and frozen olives. Light frost caused a significant decrease in the total phenols and secoiridoid compounds in and the antioxidant capacity of the frost-affected oils, which were perceived as more pungent and had the slight defect of "frostbitten olives". According to the Box–Behnken design, an 86% reference evapotranspiration (ET0) or higher with 100 potassium oxide units (UK2O) and a 100% ET0 or higher with 250 UK2O would be required to minimize the effect of light frost on phenols and volatiles. Partial Least Squares Regression–Discriminant Analysis (PLS-DA) differentiated the virgin olive oils according to their ripening stage and fresh and frost conditions. Moreover, PLS-DA positively correlated a 75–100% ET0 and 0 Uk2O with the dialdehydic form of the decarboxymethyl ligstroside aglycone (p-HPEA-EDA), the dialdehydic form of the decarboxymethyl oleuropein aglycone (3,4-DHPEA-EDA), the dialdehydic form of the ligstroside aglycone (p-HPEA-EDA-DLA), and with fruity, pungent, and bitter attributes. Precision agronomic management based on the needs of the crop itself would avoid unnecessary stress on olive trees and oil damage. [ABSTRACT FROM AUTHOR]

Sensitivity analysis of influencing factors on frost resistance is carried out in this paper, and a two-stage neural network model based on grey theory and Back Propagation Neural Networks (BPNNs) is established for the sake of predicting the frost resistance of active-admixture recycled concrete quickly and accurately. Firstly, the influence degree of cement, water, sand, natural aggregate, recycled aggregate, mineral powder, fly ash, fiber and air-entraining agent on the frost resistance of active-admixture recycled-aggregate concrete was analyzed based on the grey system theory, and the primary and secondary relationships of various factors were effectively distinguished. Then, the input layer of the model was determined as cement, water, sand, recycled aggregate and air-entraining agent, and the output layer was the relative dynamic elastic modulus. A total of 120 datasets were collected from the experimental data of another author, and the relative dynamic elastic modulus was predicted using the two-stage BPNN prediction model proposed in this paper and compared with the BPNN prediction results. The results show that the proposed two-stage BPNN model, after removing less-sensitive parameters from the input layer, has better prediction accuracy and shorter run time than the BPNN model. [ABSTRACT FROM AUTHOR]

Given difficulties with modelling radiation fog and the similarity of meteorological conditions linked to dewfall and frost we investigated the formation of dew, frost and fog. For a site in the UK seven years of data were analysed representing high‐resolution atmospheric profiles and dew meter measurements for radiation nights with stable conditions. Classical dewfall occurs by condensation when the surface is below the dew point and cooler than the air above. However, the profiles show that, in the absence of fog, typically dew and frost form with the surface warmer than the immediately overlying air due to lifted temperature minima (LTMs) at about 0.15 m. Observations of aerosol number density and average hydrated radii show that aerosol optical extinction (and hence their radiative effect) is weakly but significantly correlated with the intensity of LTMs. Low wind speed on stable nights allows settling of aerosols which radiatively cool the air near the ground more quickly than the surface cools – thus creating LTMs. In the presence of LTMs typically dew and frost form not by condensation, but by occult deposition of water droplets onto the canopy and ground. Among radiation fog observations, 91% are associated with light near‐surface winds and LTMs. When the rate of removal of suspended water droplets by occult deposition generating dew or frost is too slow, then build‐up of droplets in the air just above the surface leads to the formation of radiation fog. Future modelling should allow for the accumulation of near‐surface aerosols and their radiative effects during stable nights to represent the formation of LTMs. Modelling of typical dew and frost will require representation of occult deposition. Assessing rates of occult deposition compared to rates of generation of suspended water droplets is needed to forecast the onset of radiation fog formed near the ground. [ABSTRACT FROM AUTHOR]

• The presence of frost on the evaporator coil degrades the cooling performance. • K-means image segmentation-based frost detection and thickness estimation is proposed. • Frost thickness was estimated using image analysis with an error of 13.69%. • Results were compared with conventional sensors and existing image processing methods. • The method can serve as a reliable feedback source for efficient defrosting. Frost accumulation is a common problem when moisture in the air condenses and freezes on surfaces like heat exchange tubes of refrigeration units. Frost accumulation negatively impacts heat exchange by disrupting the process, reducing system efficiency, and causing operational issues. Therefore, defrosting is mandatory to maintain the rated performance; however, modern automatic defrosting systems rely on sophisticated sensors for frost quantification. These sensors are susceptible to degraded performance with the passage of time under varying environmental conditions. To this end, we introduce a robust and generic image processing-based solution that relies on building a data-driven regression-based model for frost detection and thickness estimation. We evaluated the effectiveness of the proposed method on a newly collected dataset with encouraging performance in terms of a low error margin of 13.69% when compared to conventional capacitive and photoelectric sensors-based frost thickness estimation with error margins of 15.17% and 17.5%, respectively. Similarly, other image processing-based methods, such as Global thresholding, Adaptive mean, and Adaptive gaussian thresholding for segmentation, were compared with the proposed method. Deviations in the error margins were found to be 19.94%, 28.96%, and 27.85%, respectively. These findings highlight the appropriateness of employing K-means for estimating frost thickness. [ABSTRACT FROM AUTHOR]

The evolutionary dynamics of tree species are influenced by their specific climatic environments, and their ability to persist is determined by adaptive strategies such as broad climate tolerance, phenotypic plasticity or genetic differentiation. Biogeographical predictions indicate that populations located at the edges of their ranges are more likely to experience heightened vulnerability to climatic fluctuations due to approaching tolerance limits. However, if local phenotypic acclimation or genetic adaptation has taken place, trees near the edge of their range could demonstrate comparable sensitivity to freeze and drought as the rest of the sampled population. Nevertheless, there remains uncertainty regarding the extent of developmental and evolutionary adjustments in climate sensitivity across the entire ranges of many tree species.Here, we document the biogeography of tree growth sensitivity to freeze and soil water and vapour pressure deficits during 1950–2018 using an extensive multi‐species tree‐ring dataset of 35,784 trees at 4535 sites covering boreal, temperate conifer and temperate deciduous forests of Canada. We quantify the relationships between tree radial growth increment and seasonal climate variables and explore factors driving the observed patterns of annual growth and climate sensitivity such as species, regional climate and local site conditions, and tree age and size.Freeze and drought had widespread impacts on tree growth that were contingent on the presence of focal species in interaction with tree size. An indirect growth thermal limitation towards cold/wet edges, occurring through the site moisture conditions, was observed in seven widespread species (e.g. Picea glauca, Picea mariana and Larix laricina). Moreover, six species had negative drought impacts more strongly expressed towards their warm/dry edges (e.g. Abies balsamea, Betula papyrifera and Pseudotsuga menziesii). However, widespread Picea, Pinus and Populus species showed no indication of increased sensitivity to soil water conditions at these edges.Synthesis. Our findings support the idea of evolutionary or acclimatization adjustments in the development of populations in response to long‐term climate conditions experienced in their respective locations. This underscores the importance of incorporating phenotypic and genomic data into future analyses of climate change impacts, which would enhance our ability to predict potential ecological shifts. [ABSTRACT FROM AUTHOR]

Engineering usually considers coarse-grained soils as non-frost swelling soils, but serious frost swelling still occurs in coarse-grained canal bases, which is directly related to the recharge conditions and the fine particle content in the soil. Little attention is currently paid to the effect of different fine particle contents on coarse-grained soil frost swelling, especially after the fine particle admixture content exceeds 16%. This paper considers the characteristics of coarse-grained soils in water conservancy projects with fines content between 0% and 50%. The coarse-grained soils with 5%, 15%, 25%, 35%, and 45% fines content were designed for freezing and swelling tests. The evolution of temperature and moisture fields and the amount of freezing and swelling of coarse-grained soils during the freezing process were studied by using servo-type freezing and swelling and thawing tester. The experimental results show that the cooling process of soil samples can be divided into a rapid cooling stage, a slow cooling stage, and a freezing stabilization stage. The cooling rate and the frost heave amount with increasing fines content showed a trend of first increasing and then decreasing. [ABSTRACT FROM AUTHOR]

Based on the conventional observation data and NCEP/NCAR reanalysis data, the circulation situation, influencing systems and causes of the heavy rain during September 20 -21, 2010 in Ulanqab City were analyzed from the evolution process of weather circulation situation and the changes of various physical quantity fields. The results show that there was an obvious frontal zone between 45 -52° N, which brought strong cold air. The transp01t of warm and humid air outside the subtropical high and typhoon was the main water vapor source of the strong precipitation, and the southwest jet at 700 hPa transported abundant water vapor. There was a broad inverted trough to the south of 45° N, with a central value of 1 000. 0 hPa. Ulanqab City was on the top of the inverted trough, stable and less moved, which was conducive to the occurrence of systematic heavy precipitation. The rainstorm was a strong precipitation process caused by the intersection of cold air brought by the southward movement of the upper frontal zone and warm and humid air outside the subtropical high. After the precipitation, the invasion of strong cold air brought frost and cold wave weather to Ulanqab City. [ABSTRACT FROM AUTHOR]

Surfaces capable of delaying the frosting passively and facilitating its removal are highly desirable in fields where ice introduces inefficiencies and risks. Coalescence‐induced condensation droplets jumping (CICDJ), enabled on highly hydrophobic surfaces, is already exploited to slow down the frosting but it is insufficient to completely eliminate the propagation by ice‐bridging. The study shows here how the self‐ejection of single condensation droplets can fully frustrate all the ice bridges, resulting in a frost velocity lower than 0.5 µm s−1 and thus falling below the current limits of passive surfaces. Arrays of truncated microcones, covered by uniformly hydrophobic nanostructures, enable individual condensation droplets to grow and self‐propel toward the top of the microstructures and then to self‐eject once a precise volume is reached. The independency of self‐ejection on the neighbor droplets allows a fine control of the droplets size and distance distributions and thus the ice‐bridging frustration. The truncated microcones with the smallest heads area fraction maximize the percentage of self‐ejecting droplets and minimize the frost velocity. The ice bridges frustration also implies a small frost area coverage, highly desirable in aeronautics and thermal machines. [ABSTRACT FROM AUTHOR]

The occurrence of early spring and late frost damage brought severe challenges to the production of walnuts in China, seriously affecting their growth, development, yield and revenue. In order to clarify the harmful characteristics and influencing mechanisms of late frost on walnuts in China, the influencing factors of the degree of damage caused by late frost on walnuts, as well as the changes in physiological and biochemical indicators and molecular mechanisms in response to low temperature stress were reviewed. It was found that research on physiological changes focused on the three aspects including cell membrane system (relative conductivity), antioxidant system (malondialdehyde, superoxide dismutase, peroxidase and catalase) and osmoregulation substances (soluble sugars, soluble protein and proline), in addition, the expression levels of genes such as JrPAL, JrJAZ, JrGRAS, JrICE1, JrCBF/JrDREB1, JrCOR, JrWRKY, JrDHN, JrGST, and JrPUB were induced by low temperature stress. And prospects were put for future research directions, which provided scientific basis for further exploring the response mechanism of walnuts to late frost damage and adopting effective production measures. [ABSTRACT FROM AUTHOR]

Frosting occurs due to the freezing of condensed water droplets on a supercooled surface. The nucleated frost propagates through interdroplet bridges and covers the entire surface, resulting from the deposition of highly supersaturated vapor surrounding tiny droplets. While inhibition of the formation of frost bridges is not possible, the propagation of frost can be delayed by effectively removing tiny droplets. Passive technologies, such as superhydrophobic surfaces (SHS) and hydrophobic slippery liquid‐infused porous surfaces (SLIPS), rely on static growth and direct contact with densely distributed droplets. However, use of these approaches in delaying frost propagation involves challenges, as the interdroplet distance remains small. Here, we report a new approach of spontaneous droplet movement on hydrophilic SLIPS to delay the formation of interdroplet frost bridges. Surface tension forces generated by the hydrophilic oil meniscus of a large water droplet efficiently pull neighboring droplets with a diameter of less than 20 μm from all directions. This causes a dynamic separation between water droplets and an adjacent frozen droplet. Such a process delays the formation and propagation of interdroplet frost bridges. Consequently, there is significant delay in frosting on hydrophilic SLIPS compared to those on SHS and hydrophobic SLIPS. [ABSTRACT FROM AUTHOR]

Superhydrophobic surfaces with non-wetting characteristics have been considered to be potential candidates for ice/frost prevention. In this study, a transparent superhydrophobic coating was created by using a simple method that employed (3-glycidoxypropyl) trimethoxysilane (KH560) and 1,2-Bis (trimethoxysilyl) ethane (D26) as coupling agents and epoxy resin (E51) as an adhesive. The synergy between KH560 and D26 significantly improves the long-term outdoor durability, anti-icing, and anti-frosting performance of the superhydrophobic coating. The coating also has good acid and alkali resistance, UV resistance, and durability. The obtained SiO2@E51@KH560@D26 can delay the freezing time of water by 1974 s, much longer than bare glass (345 s) and also longer than the coatings with only D26 (932 s) or with only KH560 (1087 s). Moreover, the SiO2@E51@KH560@D26 showed an improved anti-frosting capability compared with the other three samples and better maintained its superhydrophobic properties at low temperatures. Our study proposes a potential method to fabricate a superhydrophobic coating with both anti-icing and anti-frosting properties. [ABSTRACT FROM AUTHOR]

Despite the abundance of rose varieties, it is necessary to create and use new genotypes to improve the appearance of green spaces and meet the demands of society, as well as to ensure their response to environmental variables and climate change. To assess the overall value and flower quality of several Romanian and foreign varieties under the ecological circumstances of Northwest Romania, 14 rose varieties from the shrub and floribunda groups were examined. The study identified notable variations among the cultivars for plant growth, foliage, flowers, and their susceptibility to the three primary fungal diseases (black spot, powdery mildew, and rust) prevalent in the study area. Additionally, the study identified the cultivars with proper resilience to frost during the five-year investigation period, particularly after the cold winters. New varieties obtained at HRS Cluj-Napoca, such as Cristiana, Pasiune mov, Maria-Cristina and Splendid, and international varieties such as Fisherman's Friend, Bonica and Mirato, stood out for their decorative quality and attractive floral elements. Some of these varieties have also been considered potential parents for disease and frost resistance in new hybridization projects. Broad-sense heritability data for the quantitative variables under investigation, as well as multivariate analyses, provided useful information for new rose breeding programs. The comparison of quantitative and qualitative assessments of important decorative traits for the roses, together with proper statistical calculation processes to assure their validity and trustworthiness, enabled the development of hypotheses or working models that can improve rose breeding efficiency.

Precision agriculture (PA), also known as smart farming, has emerged as an innovative solution to address contemporary challenges in agricultural sustainability. A particular sector within PA, precision viticulture (PV), is specifically tailored for vineyards. The advent of the Internet of Things (IoT) has facilitated the acquisition of higher resolution meteorological and soil data obtained through in situ sensing. The integration of machine learning (ML) with IoT-enabled farm machinery stands at the forefront of the forthcoming agricultural revolution. These data allow ML-based forecasting as an alternative to conventional approaches, providing agronomists with predictive tools essential for improved land productivity and crop quality. This study conducts a thorough examination of vineyards with a specific focus on three key aspects of PV: mitigating frost damage, analyzing soil moisture levels, and addressing grapevine diseases. In this context, several ML-based models are proposed in a real-world scenario involving a vineyard located in Southern Italy. The test results affirm the feasibility and efficacy of the ML models, demonstrating their potential to revolutionize vineyard management and contribute to sustainable agricultural practices.

The text introduces a symposium on Samantha Frost's book "Lessons from a Materialist Thinker: Hobbesian Reflections on Ethics and Politics," which has been influential in rethinking Hobbes's work in relation to ethics, politics, and agency. The symposium includes reactions from scholars who highlight Frost's recovery of Hobbes's materialism and anti-Cartesianism, as well as her connections to contemporary ecological and feminist thinking. Frost's response to her critics further explores the implications of Hobbes's materialist metaphysics, challenging traditional interpretations of his work and emphasizing the complexity of causal histories in understanding freedom and agency. [Extracted from the article]

Priming plants with chemical agents has been extensively investigated as a means for improving their tolerance to many biotic and abiotic stresses. Earlier, we showed that priming young avocado (Persea americana Mill cv. 'Hass') trees with sodium hydrosulfide (NaHS), a donor of hydrogen sulfide, improves the response of photosynthesis to simulated frost (cold followed by high light) conditions. In the current study, we performed a transcriptome analysis to gain insight into the molecular response of avocado 'Hass' leaves to frost, with or without NaHS priming. The analysis revealed 2144 (down-regulated) and 2064 (up-regulated) differentially expressed genes (DEGs) common to both non-primed and primed trees. Non-primed trees had 697 (down) and 559 (up) unique DEGs, while primed trees exhibited 1395 (down) and 1385 (up) unique DEGs. We focus on changes in the expression patterns of genes encoding proteins involved in photosynthesis, carbon cycle, protective functions, biosynthesis of isoprenoids and abscisic acid (ABA), as well as ABA-regulated genes. Notably, the differential expression results depict the enhanced response of primed trees to the frost and highlight gene expression changes unique to primed trees. Amongst these are up-regulated genes encoding pathogenesis-related proteins, heat shock proteins, enzymes for ABA metabolism, and ABA-induced transcription factors. Extending the priming experiments to field conditions, which showed a benefit to the physiology of trees following chilling, suggests that it can be a possible means to improve trees' response to cold stress under natural winter conditions. [ABSTRACT FROM AUTHOR]

The subtropical environments, are the regions with the largest area of wheat cultivation in Brazil, however, events, such as frost formation in the period of flowering and grain filling negatively influence the production, due to direct loss in grain formation. Identifying cultivars, which have a higher genetic resistance to frost damage, can provide strategies for maintaining the productive potential in commercial crops in subtropical region in Brazil. The study aimed to evaluate the linear relationships among characters and the agronomic performance of wheat cultivars of different cycles, under the influence of frost stress in a subtropical low altitude region. The experiment was conducted in a subtropical climate triticultural region in the South of Brazil (Santa Maria, RS). A randomized block design with seven cultivars and four repetitions was used, totaling 28 experimental units. The cultivar cycle from the emergence stage to physiological maturity was recorded, as was the recording of the phenological stage on the day of frost formation. The characters evaluated were: plant height, number of fertile tillers, number of spikelets per plant, number of grains per plant, whole grains in the main stem, damaged grains in the main stem, whole grains in the tillers, damaged grains in the tillers, thousand-grain mass, hectoliter weight, grain yield, harvest index, and number of spikes per m². Analysis of variance, test for comparison of means between treatments with significant effect, Pearson linear correlation analysis, and trail analysis were performed. The results show that the cultivars and phenological stages of the plants have different degrees of sensitivity to frost damage, with the early anthesis stage being less sensitive to frost damage than the late milky grain stage. Therefore, the linear relationships indicate that the characters plant height, number of fertile tillers, number of grains per plant, whole grains and hectoliter weight, have positive relationship with grain yield. There is a genetic effect for tolerance to frost damage. The use of cultivars with similar cycle behavior are not indicated, as they increase the risk of frost losses when sowing in only one growing season. [ABSTRACT FROM AUTHOR]

Most trees die as seedlings, with harsh environmental conditions, such as early‐spring frosts and summer heat waves, being important drivers of early mortality. However, it remains unclear whether tolerance to different environmental extremes (e.g. frost vs. heat) trades‐off, or covaries synergistically and how stress tolerances relate to growth rates and life history strategies. Given the likely role of extreme environmental conditions as environmental filters, the ability to tolerate different stressors at the seedling stage could shape the occurrence and composition of present and future forests.We explored the relationships between different leaf‐level stress tolerances, functional traits and geographic distributions across 22 species of temperate European tree seedlings. We measured indicators of tolerance to frost, drought and heat and related these values to growth rates and to important functional traits (e.g. leaf mass per area and stem‐specific density). Finally, we explored the links between measured seedling stress tolerances and climatic niche limits inferred from adult trees' distributions.We found that seedlings of most species were either moderately tolerant to all three stressors, or susceptible to all of them. Moreover, higher stress tolerances were associated with traits describing slower growth and lower competitive ability. However, seedling tolerances to climatic factors were unrelated to the environmental limits of their adult geographic distributions.Synthesis. Our results suggest that temperate tree seedlings might not experience trade‐offs when facing an increase in multiple extreme climate stressors, but may experience trade‐offs related to growth rate and competitive ability in the establishment phase. The lack of correlation between leaf‐level stress tolerances and the environmental limits of adult geographic distributions suggests that predicting species' current or future geographic distributions in Europe will require a more nuanced understanding of how climatic tolerances at juvenile and adult stages influence range limits. A better understanding of the interaction between survival in extreme climate, leaf‐level stress tolerances of seedlings and the factors driving species distributions is needed to understand future forest responses to climate change. [ABSTRACT FROM AUTHOR]

The olive tree is one of the oldest fruit tree cultivars in the ancient world and is the primary source of edible oils and olives. Like many other plants, the olive tree is susceptible to cold stress, one of the most significant environmental stresses that can lead to reduced plant yield or cell death. In this study, the researchers implemented a graphical analysis of the genotype-by-trait (GT) biplot for the first time to identify cold-tolerant olive genotypes. The study was conducted at the Tarom Olive Research Station on 16 olive genotypes with 15 physiological and biochemical traits. According to the GT biplot, the first and second components explained 40% and 20%, and 60% of the total variance, respectively. Concerning the correlation between traits and proline as a criterion, the biplot ranking of different genotypes based on proline content revealed that Zard, Grossane, Abou-satl, Picual, Konservolia, Cornicabra, and Amin cultivars exhibited above-average proline content. Furthermore, Grossane, Cornicabra, Abou-satl, Picual, Zard, and Kaissy cultivars were simultaneously identified as superior based on a pair of proline and stomatal conduction traits. In contrast, the Koroneiki, Meshkat, and Direh cultivars ranked lowest when these two traits were evaluated simultaneously. The hypothetical ideal genotype indicated the genotype with the highest values based on all variables according to the biplot graphic method. Other genotypes were ranked based on their distance from this genotype; the cultivar closest to the hypothetical ideal genotype was Grossane, a cold-tolerant genotype. Next in line were the Abou-satl, Zard, Picual, Konservolia, Cornicabra, and Amin cultivars. This study demonstrates that the graphical method of GT biplot can be used effectively to identify superior genotypes for simultaneously improving several traits. [ABSTRACT FROM AUTHOR]

The northward expansion of peanut cultivation in China is limited by the availability of heat resources, and frost poses a significant challenge to peanut planting in Northeast China. Peanut is the 3rd largest crop in Liaoning province, which is an important exporter of peanuts in China. This paper studied the hazard of frost to peanut cultivation from a disaster-causing perspective, which is of great significance for ensuring the area stability and production safety of oil crops in emerging production areas. Based on the daily minimum temperature data of 56 meteorological stations in Liaoning from 1961 to 2020, the number of spring and autumn frost days were identified, as well as the first and last frost dates during the peanut growing season. The risks of spring frost and autumn frost in peanut cultivation were evaluated and the adaptability of current sowing and harvesting periods in reducing the frost risk in Liaoning was assessed. The results showed that the risk of autumn frost increased from southwest to northeast in Liaoning, while the risk of spring frost increased from south to north. The probability of daily frost occurrence exhibited an "S" shape during autumn and an inverse "S" shape during spring. It took approximately two months for the probability to increase from 0% to 100% and vice versa. The safe growth period for peanuts in Northeast China can be defined as the time between the corresponding date of the sowing lower limit temperature and the date of first frost. Autumn frost has a greater impact on peanut cultivation in Liaoning compared to spring frost. To avoid autumn freezing damage in the highest risk areas such as Fuxin city, the north-central part of Shenyang city and Tieling city, which are the main peanut-producing regions in Liaoning, it is necessary to postpone the harvesting date. While spring freezing damage in most major peanut-producing regions in Liaoning can be avoided by postponing the sowing date, the impact on the harvesting date must also be considered. Frost and wet soil during the autumn harvesting period may pose new challenges. [ABSTRACT FROM AUTHOR]

Quite often, concrete strength parameters must be determined in the shortest possible time. Due to the strong correlation between concrete's mechanical and acoustic properties, ultrasonic devices can be used for this purpose. However, the ultrasonic pulse velocity (UPV) is influenced by a variety of factors, including the curing and exploitation conditions of the concrete, the presence of reinforcement, and other various physical factors. Ignoring these factors may contribute to the misinterpretation of the measurement data when determining the strength of the concrete. Typically, all these factors are analyzed independently. This publication consolidates the findings obtained from our research efforts and field expertise over the past two decades. It outlines the elaborated UPV measurement methodology based on the integration of a four-argument function: the hydration process phase of the hardened cement paste (or concrete aged three days and older), hardening (curing) condition, concrete moisture level, and ambient temperature. To understand the interactions of the key factors, different ultrasonic devices were used to measure the velocities of longitudinal and surface waves in concrete by applying direct and indirect transmission methods when concrete specimens were tested under different moisture and temperature conditions. [ABSTRACT FROM AUTHOR]

Fruits, garden plants, and agricultural crops grown in Poland exhibit wide variations in their sensitivity to frost, particularly in early spring. In the case of frost, generally, the yield and quality are reduced, and sometimes, entire plants can be destroyed. This article characterizes the occurrence of ground frosts (at 5 cm agl) and air frosts (at 200 cm agl) in Poland gathered from 52 meteorological stations affiliated with IMGW-PIB between 1971 and 2020. To assess the real risk of frost to plants, the variability of this phenomenon was analyzed per thermal growing season (defined as air temperature >5 °C), rather than in traditional calendar terms as presented in most studies. In the climatic conditions of Poland, the growing season is characterized by a reported 28 days with ground frost and 13.3 days with air frost, approximately. In spring, the last ground frost disappears, on average, on a country scale, on May 14, and air frost on April 27. In turn, in autumn, the first ground frost is recorded, on average, on 1 October and air frost on 14 October. On the basis of the selected characteristics of frost and the growing season, four areas of potential risk of ground and air frost in the growing season, as well as in spring, were determined with the use of cluster analysis. [ABSTRACT FROM AUTHOR]

Late-spring frost (LSF) is a critical factor influencing the functioning of temperate forest ecosystems. Frost damage in the form of canopy defoliation impedes the ability of trees to effectively photosynthesize, thereby reducing tree productivity. In recent decades, LSF frequency has increased across Europe, likely intensified by the effects of climate change. With increasing warming, many deciduous tree species have shifted towards earlier budburst and leaf development. The earlier start of the growing season not only facilitates forest productivity but also lengthens the period during which trees are most susceptible to LSF. Moreover, recent forest transformation efforts in Europe intended to increase forest resilience to climate change have focused on increasing the share of deciduous species in forests. To assess the ability of forests to remain productive under climate change, dynamic vegetation models (DVMs) have proven to be useful tools. Currently, however, most state-of-the-art DVMs do not model processes related to LSF and the associated impacts. Here, we present a novel LSF module for integration with the dynamic vegetation model Lund–Potsdam–Jena General Ecosystem Simulator (LPJ-GUESS). This new model implementation, termed LPJ-GUESS-FROST, provides the ability to directly attribute simulated impacts on forest productivity dynamics to LSF. We use the example of European beech, one of the dominant deciduous species in central Europe, to demonstrate the functioning of our novel LSF module. Using a network of tree-ring observations from past frost events, we show that LPJ-GUESS-FROST can reproduce productivity reductions caused by LSF. Further, to exemplify the effects of including LSF dynamics in DVMs, we run LPJ-GUESS-FROST for a study region in southern Germany for which high-resolution climate observations are available. Here, we show that modeled LSF plays a substantial role in regulating regional net primary production (NPP) and biomass dynamics, emphasizing the need for LSF to be more widely accounted for in DVMs. [ABSTRACT FROM AUTHOR]

Background: Osteosarcopenia is a common geriatric syndrome with an increasing prevalence with age, leading to secondary diseases and complex consequences such as falls and fractures, as well as higher mortality and frailty rates. There is a great need for prevention and treatment strategies. Methods: In this analysis, we used magnetic resonance imaging (MRI) data from the randomised controlled FrOST trial, which enrolled community-dwelling osteosarcopenic men aged > 72 years randomly allocated to 16 months of twice-weekly high-intensity resistance training (HIRT) or a non-training control group. MR Dixon imaging was used to quantify the effects of HIRT on muscle fat infiltration in the paraspinal muscles, determined as changes in muscle tissue, fat faction and intermuscular adipose tissue (IMAT) in the erector spinae and psoas major muscles. Intention-to-treat analysis with multiple imputation was used to analyse the data set. Results: After 16 months of intervention, 15 men from the HIRT and 16 men from the CG were included in the MRI analysis. In summary, no positive effects on the fat infiltration of the erector spinae and psoas major muscles were observed. Conclusions: The previously reported positive effects on lumbar spine bone mineral density (BMD) suggest that mechanotransduction induces tropic effects on bone, but that fat infiltration of the erector spinae and psoas major muscles are either irreversible or, for some unknown reason, resistant to exercise. Because of the beneficial effects on spinal BMD, HIRT is still recommended in osteosarcopenic older men, but further research is needed to confirm appropriate age-specific training exercises for the paraspinal muscles. The potential of different MRI sequences to quantify degenerative and metabolic changes in various muscle groups must be better characterized. Trial registrations: FrOST was approved by the University Ethics Committee of the Friedrich-Alexander University of Erlangen-Nürnberg (number 67_15b and 4464b) and the Federal Office for Radiation Projection (BfS, number Z 5–2,246,212 – 2017–002). Furthermore, it fully complies with the Declaration of Helsinki and is registered at ClinicalTrials.gov: NCT03453463 (05/03/2018). JAMA 310:2191–2194, 2013. [ABSTRACT FROM AUTHOR]

Observed climate change in northern high latitudes is strongest in winter, but still relatively little is known about the effects of winter climate change on tundra ecosystems. Ongoing changes in winter climate and snow cover will change the intensity, duration and frequency of frost events. Bryophytes form a major component of northern ecosystems but their responses to winter climate changes are largely unknown.Here, we studied how changes in overall winter climate and snow regime affect frost damage in three common bryophyte taxa that differ in desiccation tolerance in a subarctic tundra ecosystem. We used a snow manipulation experiment where bryophyte cores were transplanted from just above the tree line to similar elevation (i.e. current cold climate) and lower elevation (i.e. near‐future warmer climate scenario) in Abisko, Sweden. Here, we measured frost damage in shoots of Ptilidium ciliare, Hylocomium splendens and Sphagnum fuscum with the relative electrolyte leakage (REL) method, during late winter and spring in two consecutive years. We hypothesized that frost damage would be lower in a milder climate (low site) and higher under reduced snow cover and that taxa from moister habitats with assumed low desiccation tolerance would be more sensitive to lower temperature and thinner snow cover than those from drier and more exposed habitats.Contrary to our expectations, frost damage was highest at low elevation, while the effect of snow treatment differed across sites and taxa. At the high site, frost damage was reduced under snow addition in the taxon with the assumed lowest desiccation tolerance, S. fuscum. Surprisingly, frost damage increased with mean temperature in the bryophyte core of the preceding 14 days leading up to REL measurements and decreased with higher frost degree sums, that is, was highest in the milder climate at the low site.Synthesis Our results imply that climate warming in late winter and spring increases frost damage in bryophytes. Given the high abundance of bryophytes in tundra ecosystems, higher frost damage could alter the appearance and functioning of the tundra landscape, although the short and long‐term effects on bryophyte fitness remain to be studied. [ABSTRACT FROM AUTHOR]

From an engineering point of view, it is important to know the factors influencing the frost resistance of rocks with porosity above 2% due to their different frost resistance. The article focused on frost durability research using the thermoporometry method (TMP) and the assessment of water phase transition in the pore spaces of selected rocks. For this purpose, the differential scanning calorimetry method (DSC) was used with the adoption of an original algorithm for eliminating the thermal inertia of the measurement system. The results of the DSC method were supplemented with the results of pore size distribution using the mercury intrusion porosimetry method (MIP) and standard rock frost resistance tests. Based on the research carried out using the thermoporometry method, it was confirmed that the ability of water to freeze in the temperature range from −5 °C to −20 °C was important, as well as the ability of rocks to increase the degree of water saturation during freeze–thaw cycles. Based on calorimetric tests combined with thermoporometry, in the case of non-frost-resistant rocks, a significant (dominant) share of pores with a radius of under 10 nm (amounting to over 0.008 cm3/cm3) was found. Pore connections in the water freezing process do not influence the investigated rocks' frost resistance. [ABSTRACT FROM AUTHOR]

In nature, plants are exposed to a range of climatic conditions. Those negatively impacting plant growth and survival are called abiotic stresses. Although abiotic stresses have been extensively studied separately, little is known about their interactions. Here, we investigate the impact of long-term mild metal exposure on the cold acclimation of Salix viminalis roots using physiological, transcriptomic, and proteomic approaches. We found that, while metal exposure significantly affected plant morphology and physiology, it did not impede cold acclimation. Cold acclimation alone increased glutathione content and glutathione reductase activity. It also resulted in the increase in transcripts and proteins belonging to the heat-shock proteins and related to the energy metabolism. Exposure to metals decreased antioxidant capacity but increased catalase and superoxide dismutase activity. It also resulted in the overexpression of transcripts and proteins related to metal homeostasis, protein folding, and the antioxidant machinery. The simultaneous exposure to both stressors resulted in effects that were not the simple addition of the effects of both stressors taken separately. At the antioxidant level, the response to both stressors was like the response to metals alone. While this should have led to a reduction of frost tolerance, this was not observed. The impact of the simultaneous exposure to metals and cold acclimation on the transcriptome was unique, while at the proteomic level the cold acclimation component seemed to be dominant. Some genes and proteins displayed positive interaction patterns. These genes and proteins were related to the mitigation and reparation of oxidative damage, sugar catabolism, and the production of lignans, trehalose, and raffinose. Interestingly, none of these genes and proteins belonged to the traditional ROS homeostasis system. These results highlight the importance of the under-studied role of lignans and the ROS damage repair and removal system in plants simultaneously exposed to multiple stressors. [ABSTRACT FROM AUTHOR]

Introduction: The cold stress is one of the most important factors for affecting production throughout year, so effectively evaluating frost damage is great significant to the determination of the frost tolerance in lettuce. Methods: We proposed a high-throughput method to estimate lettuce FDI based on remote sensing. Red-Green-Blue (RGB) and multispectral images of open-field lettuce suffered from frost damage were captured by Unmanned Aerial Vehicle platform. Pearson correlation analysiswas employed to select FDIsensitive features from RGB and multispectral images. Then the models were established for different FDI-sensitive features based on sensor types and different groups according to lettuce colors using multiple linear regression, support vector machine and neural network algorithms, respectively. Results and discussion: Digital number of blue and red channels, spectral reflectance at blue, red and near-infrared bands as well as six vegetation indexes (VIs) were found to be significantly related to the FDI of all lettuce groups. The high sensitivity of four modified VIs to frost damage of all lettuce groups was confirmed. The average accuracy of models were improved by 3% to 14% through a combination of multisource features. Color of lettuce had a certain impact on the monitoring of frost damage by FDI prediction models, because the accuracy of models based on green lettuce groupwere generally higher. The MULTISURCE-GREEN-NN model with R² of 0.715 and RMSE of 0.014 had the best performance, providing a high-throughput and efficient technical tool for frost damage investigation which will assist the identification of cold-resistant green lettuce germplasm and related breeding. [ABSTRACT FROM AUTHOR]

Fixing waterpipes using cryogenic technology is a complicated activity because it is difficult to see the transformation of water into ice inside a pipe. To solve this problem, a series of experiments and testing was carried out on three types of waterpipes—75, 100, and 150 mm cast-iron pipes (CIP), respectively—to monitor the external characteristics and the frost growth to accurately predict the completion of ice plug formation inside the pipe before applying the freeze-fixing method. A CCD camera was set up to capture four frosting images per minute and to send one image every 15 s to the computer for processing and for identifying the interface between frost and no frost. The results showed that when the brightness distribution along the pipe axis goes down from the 100% brightest and coldest region near the freezing jacket to 90% and hits the 1/10th mark away from the brightest area, which is the interface, the freezing process is finished, and the ice plug has completely formed and can effectively block water flow to allow safe repairs. In other words, the findings determined that the frost length was more or less equal to the ice plug length. Additional testing was done to increase water pressure up to 35 kg/cm2 for about 10 min on one end of the freezing jacket, which is higher than the regular pressure testing of 10 kg/cm2. When 0 kg/cm2 was recorded on the other end of the freezing jacket, it was concluded that the ice plug was strong enough to resist high pressure. The success of these experiments and testing confirmed that this innovative freezing method was safe, cost-effective, and suitable to be used efficiently in semiconductor factories and modern buildings. [ABSTRACT FROM AUTHOR]

Zygnematophyceae, a class of freshwater green algae, exhibit distinctive seasonal dynamics. The increasing frequency of cold snaps during the growing season might challenge the persistence of some populations. The present study explored the frost hardiness of two Mougeotia species isolated from different elevations and habitats. Additionally, a phylogenetic (rbcL sequence), ultrastructural and physiological characterization was performed. Both species, grown under standard culture conditions and cold acclimated cultures (+4°C), were exposed to freezing temperatures down to −9°C. Furthermore, ultrastructural‐, hydrogen peroxide (H2O2)‐ and photosynthetic pigment analysis were performed on cells exposed to −2°C, with and without induced ice nucleation. The alpine M. disjuncta showed a higher frost hardiness (LT50 = −5.8°C), whereas the lowland M. scalaris was susceptible to ice. However, frost hardiness did not improve after cold acclimation in either species but rather decreased significantly in M. disjuncta (LT50 = −4.7°C). Despite darkness, prolonged sub‐zero temperatures or freezing induced the activation of the xanthophyll (VAZ) cycle in M. scalaris. Our results demonstrate that frost hardiness varies within the genus Mougeotia and that the VAZ cycle can be activated in the dark under subzero temperature‐ and freezing stress but does not necessarily increase frost hardiness. As highly frost hardy cell types are usually formed at the end of the growing season, the ability of young cells to survive ice formation in the upper subzero temperature range represents a crucial survival strategy in populations exposed to late spring frosts. [ABSTRACT FROM AUTHOR]

Sweet cherry producers must deal with different climactic challenges annually, specifically the impact of spring frost and the inherent risk of fruit cracking. This susceptibility arises from the simultaneous occurrence of spring frost during the bloom stage or the sweet cherry cracking at vulnerable maturity stages in sweet cherry trees during persistent rainfall. Given the change in climatic patterns, the implementation of new strategies and innovative approaches becomes imperative to alleviate potential damage from these climatic adversities. This study aims to explore—for the first time—the effectiveness of preharvest putrescine applications during the flowering stage and ripening on-tree to increase tolerance in sweet cherry against adverse climatic events throughout its on-tree development and at the time of harvest. In this context, foliar applications of putrescine at concentrations of 1 and 10 mM were administered to distinct sweet cherry cultivars, namely, 'Prime Giant' and 'Sweetheart'. Over the course of four growing seasons, our investigation focused on evaluating the influence of this natural elicitor on the frost resilience of flower buds during the preharvest period and its impact on reducing fruit cracking in these selected cultivars. In this sense, the overall malondialdehyde content exhibited a reduction in flower buds treated with putrescine, and the fruit set experienced an increase across the majority of evaluated growing seasons. On the other hand, the incidence of sweet cherry cracking in putrescine-treated sweet cherries showed a consistent reduction in all the studied growing seasons. Our results indicate that preharvest treatments with putrescine effectively alleviate the susceptibility of flower buds to spring frost and significantly diminish fruit cracking, thereby enhancing the overall tolerance to abiotic stress. Furthermore, we evaluated different quality parameters at the time of harvest, including fruit firmness, external color, total soluble solids, and total acidity. Generally, the observed changes in these parameters were delayed in putrescine-treated fruit as compared to the control batch or remained unaffected. For this reason, the implementation of preharvest treatments based on putrescine emerges as a valuable strategy for adapting to climate change and mitigating the impact of abiotic stress, potentially increasing sweet cherry production. [ABSTRACT FROM AUTHOR]

Understanding the frost deformation characteristics of rock with varying water contents under freeze–thaw conditions is of great significance to engineering construction activity in cold regions. In this study, sandstone samples with different degrees of water saturation were first prepared and then submitted to cyclic freeze–thaw experiments. Temperature sensors and strain gauges were attached to the samples so as to trace the temperature and strain changes. The changes in the major principal strain and minor principal strain against the temperature were individually explored. It is found that the sandstones exhibit heterogeneous frost deformation behaviors during the freeze–thaw cycle, and the heterogeneity of frost deformation is more considerable in terms of the sandstone with a higher degree of saturation based on the strain ellipse analysis. The coefficient of linear thermal expansion (CLTE), maximum frost heave strain and residual frost heave strain tend to increase exponentially with increasing the degree of saturation. These three parameters, however, are different from one another along the minor and major principal strain directions, which further gives evidence of the heterogeneous frost-heaving features of the sandstone. Finally, the crystallization pressures within a single pore and over the entire sandstone volume were theoretically calculated. It is verified that the resulting stress translated by the crystallization pressure for the 80% or higher saturation degree exceeds the tensile failure threshold, which explains the mechanisms that more considerable frost-heaving damage and heterogeneous behaviors are caused in the sandstone with a saturation degree of 80% or higher. The findings in this study help schedule feasible ways of alleviating the freeze–thaw-induced damage of rock mass in cold regions. Highlights: Integrated strain and temperature measurements of the partially saturated sandstones during the freeze–thaw cycle. Heterogeneous frost deformation was found in the partially saturated sandstones. More considerable heterogeneous frost deformation was generated in the sandstone with a higher degree of saturation. [ABSTRACT FROM AUTHOR]

The main apple-producing areas in northern China are located in the North China plain and the loess Plateau, and the apple blossom frost hazard events have had a severe impact on the income of fruit growers and the economy of the production areas. Future climate change will exacerbate the frequency and intensity of extreme weather and climate events. In this study, based on the climate model data shared by NEX-GDDP, the seven models with the best fitting ability for the minimum temperature during apple blossom were selected using Taylor diagrams, and the annual encounter values of the minimum temperature during apple blossom were calculated and revised using the transfer function correction method of the extreme value distribution, so as to predict the risk of frost disaster and yield reduction of apples in northern China under climate change. Taking the intensity of the apple blossom frost disaster with a 30-year occurring period event across the study area as an example, in the near and distant future under the RCP4.5 scenario, the regions of Henan, Shanxi, northern Shaanxi and, northern Ningxia were the main affected areas, dominated by the minimum temperature of -3 to -2°C, and the highest yield reduction rates were in the northern regions of Henan, Ningxia, Shanxi, and northern Shaanxi provinces, with the yield reduction rate of apples in northern China ranging from 2.47% to 5.22%. Under the RCP8.5 scenario, the frost disaster area with a minimum temperature of -3°C or less expands to the whole of Henan, central Shandong and other places, and the yield reduction rate of apples in northern China is 4.57%-12.39%. In the future, apple cultivation in these areas needs to strengthen the prevention of frost disaster risk. [ABSTRACT FROM AUTHOR]

Spring frosts after budburst are responsible for crop losses and threaten local economies. As global warming brings forward the phenological stages of plants, they are increasingly confronted with long periods of frost. Nowadays, many solutions exist to fight frost, including the wind machines that dot the Quincy vineyard in France. However, their placements often do not consider the spatial variability of spring frost, leading to some zones being insufficiently protected, while others may have overprotection. The temperature within a specific area can vary spatially due to factors such as the meteorological conditions, the topography of the site, and the soil characteristics. Radiative frost can cause the temperature in an area to differ by a few degrees Kelvin, creating colder areas that must be known to protect plants from frost effects. This study, transferable to any other orchard equipped with wind machines, first analyzes the spatial variability of the minimum temperature according to the type of frost. Meteorological variables from a national synoptic weather station, topographic parameters, and local daily minimum temperatures from a network of connected sensors scattered throughout the vineyard are retrieved for the last three spring seasons of 2020, 2021, and 2022. Then, thanks to hierarchical ascendant clusterings, the spatial variability of temperatures is linked to the synoptic situation and the topography of the domain. In a second step, the current implantation of the wind machines is compared with the frost areas previously identified to propose an optimal positioning for the wind machines in the Quincy vineyard. [ABSTRACT FROM AUTHOR]

Background and objectives: The forest ecosystem of Zagros has been attacked by pests and diseases in the last two decades. One of the most significant effects of climate change has been the reduction of frost days, especially in forest ecosystems. Reducing the frequency, intensity, and duration of the frost phenomenon facilitates the wintering of pests and reduces losses and deaths, intensifying their outbreaks. Northern Zagros forests (case study of Azerbaijan). Knowledge of the amount of changes in frost days leads managers and planners of the forest ecosystem toward better solutions to adapt to climate change. Methodology: In this research, the ClimPACT software package was used in the R environment to investigate the changes in glacier indices. The indicators used in this research have been prepared by the World Meteorological Organization (WMO), the Climatology Commission (CCL), and the expert team on climate risk and specific climate indicators (ETCRSCI) to monitor, evaluate, and detect climate change in a place or region. The daily data of minimum temperature, maximum temperature, and precipitation for the statistical period of 1986 to 2019 at Piranshahr station and the statistical period of 1988 to 2019 at Sardasht station were obtained from the National Meteorological Organization. The data was prepared in the required format for entry into the ClimPACT model. The ClimPACT software package was implemented in the R environment, and the climate change-revealing indicators were screened as the output of the model. The cold indicators revealing the occurrence of climate change were separated in the limits of the Piranshahr and Sardasht deterioration monitoring sites in West Azerbaijan province in North Zagros: four cold temperature indicators were selected from among them. For the index of days with frost, severe frost, very severe frost, and icy days, changes in trend line, trend slope error, and significance in the statistical range of p-value = 0.05 were calculated, and changes for all indicators in the R software environment, drawing, and case analysis were conducted. Results: Examining the linear trend slope, slope, and the significance of changes (p-value) in the index of days with frost in oak decay monitoring sites in Piranshahr and Sardasht showed that this index had a significant decreasing trend. This index showed a decrease of 48 days in Piranshahr and 63 days in Sardasht during the studied statistical period. Changes in the trend and significance of the extreme frost days index within the monitoring sites in Piranshahr and Sardasht showed that this index had a significant decreasing trend. This index decreased by 38 days in Piranshahr and 56 days in Sardasht during the studied statistical period. Examining the slope of the trend line, the error of the trend slope, and the significance of the changes in the index of extreme frost days in the range of monitoring sites in Piranshahr showed a significant decreasing trend, while in Sardasht, a significant increasing trend was observed. Changes in the trend and significance of the ice days index in the range of monitoring sites in Piranshahr showed a decreasing and non-significant trend, while in the range of monitoring sites in Sardasht, it showed a decreasing and significant trend. Conclusion: One of the most critical challenges facing Iran's natural environment today is the decline of Zagros oak forests. Various factors have contributed to the deterioration of these ecosystems, but climatic conditions stand out as the most significant. Cold climate indicators in the Piranshahr and Sardasht forests have shown a notable decreasing trend. This decline indicates that the wintering range for many pests and diseases has shrunk, creating favorable conditions for their growth. Considering other factors, this trend is likely to continue due to increasing temperatures in the coming years. Consequently, there will be increased stress related to temperature and humidity, leading to more outbreaks of pests and diseases. Zagros forests, particularly oak trees, play a vital role in maintaining natural resources, storing underground water, and mitigating the effects of climate change. Therefore, it is essential to preserve these valuable resources by leveraging scientific, technical, managerial, and executive approaches. [ABSTRACT FROM AUTHOR]

Precision agriculture (PA), also known as smart farming, has emerged as an innovative solution to address contemporary challenges in agricultural sustainability. A particular sector within PA, precision viticulture (PV), is specifically tailored for vineyards. The advent of the Internet of Things (IoT) has facilitated the acquisition of higher resolution meteorological and soil data obtained through in situ sensing. The integration of machine learning (ML) with IoT-enabled farm machinery stands at the forefront of the forthcoming agricultural revolution. These data allow ML-based forecasting as an alternative to conventional approaches, providing agronomists with predictive tools essential for improved land productivity and crop quality. This study conducts a thorough examination of vineyards with a specific focus on three key aspects of PV: mitigating frost damage, analyzing soil moisture levels, and addressing grapevine diseases. In this context, several ML-based models are proposed in a real-world scenario involving a vineyard located in Southern Italy. The test results affirm the feasibility and efficacy of the ML models, demonstrating their potential to revolutionize vineyard management and contribute to sustainable agricultural practices. [ABSTRACT FROM AUTHOR]

In the present study a scheme for damaging frost occurrence forecast in Bulgaria is presented. It is based on Random Forest technique and uses the regional numerical weather prediction (NWP) model ALADIN output as predictor. Initially, the statistical model is trained with measured data with three-hours frequency at 5 representative meteorological stations in Bulgaria during April and May for the period 1991-2020. Using parameters from the regional NWP model production as predictors gives possibility to forecast frost probability 72 hours ahead. The performance of the scheme is evaluated. Results for 27 synoptic stations during April (2021-2023) show a probability of detection above 0.85 and a false alarm rate below 0.1 independently of the remoteness of the forecast. Most of the considered cases were correctly discriminated by the scheme as "frost" and "non-frost" cases, which would not be the case if only considering the forecasted minimum temperature. Our results show that frost could be forecasted by the presented scheme 3 days before its occurrence, which should be enough to react to minimize damage caused in the agricultural sector. [ABSTRACT FROM AUTHOR]

This study presents an overview of numerical models simulating frost action in cement-based materials. Most of the frost action models are grouped in one of three main groups named poroelastic models, lattice models, and rigid body spring models formed according to the followed mechanical principles providing stress estimation and volume change. Other models are further grouped based on underlying physical or empirical principles and potential applications. It is the intention that the overview of numerical models highlights aspects of frost action that are known to be important in experimental research but considered very sporadically in numerical modeling. This study can help new model builders to choose a modeling approach, and important factors need to be considered for their own work.

Every year, frost causes the loss of many agricultural products. There is numerous equipment to protect plants against frost. Late turning on these equipment causes inefficiency in raising the air temperature, and early turning them on will increases energy consumption and costs. Therefore, accurately forecasting frost is crucial for turning on the equipment on time. In this research, an intelligent radiation frost forecasting and warning system (IFFS) based on the Internet of Things (IoT) technology was designed and constructed. This system comprises a wireless sensor, computing, and intelligent forecasting based on deep learning methods and warning announcements to the farmer by a message. Intelligent forecasting based on forecasting dew point temperature for the next three hours according to the in-situ measurement of temperature and relative humidity of the air. The meteorological data of the studied regain from 2011-2021 were used to train the network. The IFFS Performance was evaluated. Based on the obtained results, the system accuracy in measuring temperature and relative humidity of the air was 99% and 98%, respectively. The F-score of the IFFS obtained 96%, and the system accuracy in the warning announcement obtained 100%. Finally, applying the IFFS for better protection of plants is recommended.

Frosts are one of the atmospheric phenomena with one of the larger negative effects on the agricultural sector in the southern region of Brazil, therefore, an earlier forecast can minimize their impacts. In the present work, artificial neural networks (ANNs) techniques were applied in order to improve the predicting capabilities of frost events in southern Brazil. In the study, two multilayer perceptron (MLP) ANNs were built, one with ADAM optimizer and the other with SGD. The input parameters MLP-ANNs were numerical predictions of the Eta model. The ANNs were trained using four years (2012–2015), while validation and testing were performed using 2016 and 2017, respectively. An episode of frost that occurred on May 21st, 2018, related to an intense cold air mass, was also utilized to evaluate the performance of the ANNs. The best configurations (topologies and hyperparameters) of the ANNs were identified through experiments, using the highest accuracy obtained during the validation period as a metric. The results of the ANNs with ADAM and SGD optimizers were compared with the predictions of the Eta model. For the case study, an additional comparison against the operational frost index (IG) from the National Institute for Space Research (INPE) was also included. The performance of both ANNs (properly configured) with ADAM and SGD optimizers are comparable one to the other. And both are significantly better compared to the Eta model. The ANNs were able to drastically reduce the underestimation trends of frost events caused by the warm bias of the Eta model. The ANNs also indicated more satisfactory performances when compared to the INPE IG. In general, the ANNs were able to identify deficiencies in Eta predictions, and consequently improve their results. In this sense, the use of ANNs to predict frost events can be a very useful tool in an operational environment.

The present study aims to analyze and determine to what extent spring and autumn frosts affect the population size and life cycle of this invasive alien species (IAS). The study area is located in the immediate vicinity of the capital Sofia and covers the Iskar River stream and its tributaries in the gorge between Plana and Lozenska Mountains (Southwestern Bulgaria). The study was carried out in the period 2020-2022. Six permanent sample plots (PSP), each measuring 10 m2, were established in characteristic localities of I. glandulifera populations along the Iskar River and its tributaries (Table 1). Each year, during the spring and autumn frosts, the percentage of dead individuals of I. glandulifera relative to the total number of individuals of this species in the PSP was recorded. During the autumn frosts, the number of alive individuals in the following phenological stages was also recorded: flowering; fruiting; dispersal of fruits and seeds; end of growing season. The results show that frosts in the study area did not significantly affect the population size and life cycle of I. glandulifera. The death of the whole population оccurs only in permanent periods of negative daytime temperatures, however a significant part of the individuals at that time are in a generative stage of development. The temperature conditions in the area favor the invasiveness of I. glandulifera, extending the vegetation period of this species and the possibilities for its reproduction and spread.

Particular frost patterns on natural leaves had prompted Yao et al. [Y. Yao et al., Proc. Natl. Acad. Sci. U.S.A. 117, 6323-6329 (2020)] to investigate the underlying physics. Their work revealed why on corrugated surfaces ice forms on crests and dries out adjacent grooves. In the absence of frost, in contrast, grooves tend to constitute niches on a leaf where microorganisms are less limited by moisture than in other locations. Here, we show that microorganisms able to nucleate ice before it forms on crests can modify the frosting pattern to their advantage. This ability might drive in cold arid environments the association between certain microorganisms and plants. [ABSTRACT FROM AUTHOR]