Search Results (57)

To address the freezing damage to tunnel lining caused by frost heaving of the surrounding rock in water-rich tunnels in cold regions, a numerical thermo-mechanical coupling model for tunnel-surrounding rock that considers the anisotropy of frost heave deformation was established by examining overall frost heaves in a freeze–thaw cycle. Using a COMSOL Multiphysics 6.0 platform and the sequential coupling method, the temperature field evolution of tunnel-surrounding rock, freezing cycle development, and distribution characteristics of the frost heaving force of a tunnel lining under different minimum temperatures, numbers of negative temperature days, frost heave ratios, and anisotropy coefficients of frost heave deformation were systematically simulated. The results revealed that the response of the temperature field of tunnel-surrounding rock to the external temperature varies spatially with time lags, the shallow surface temperatures and the area around the lining fluctuate with the climate, and the temperature of the deep surrounding rock is dominated by the geothermal gradient. The extent of the freezing cycle and the frost heaving force increase significantly when lowering the minimum temperature. The maximum frost heaving force usually occurs in the region of the side wall and the spring line, and tensile stress is prone to be generated at the spring line; the influence of slight fluctuations in the minimum temperature or the short shift in the coldest day on the frost heaving force is limited. A substantial increase in frost heaving force is observed with higher frost heave ratios; for example, an increase from 0.25% to 2.0% results in a 116% rise at the sidewall. Although the increase in the anisotropy coefficient of frost heave deformation does not change the overall distribution pattern of frost heaving force, it can exacerbate the directional concentration of frost heave strain, which can increase the frost heaving force at the periphery of the top arch of the lining. This study revealed the distribution pattern and key influencing factors of the freezing cycle and frost heaving force for tunnels, providing a theoretical basis and data reference for the frost resistance design of tunnels in cold regions. Full article

Late frost damage in spring is a significant limiting factor in peach industry development, with the flowering period being the most vulnerable to late frost. This study aimed to observe the flower organ state and physiological changes of two peach varieties under various temperature treatments and to provide a theoretical basis for selecting frost-resistant varieties. By analyzing the supercooling points of ‘Longyoutao 1’ (Y1) and ‘Longmi 15’ (L15), we simulated late frost at five temperatures, 4 °C, 2 °C, 0 °C, −2 °C, and −4 °C, and observed the flower organ changes at these five temperature stages during the flowering period. The contents of flower hormones (IAA, GA, ABA), membrane lipid peroxidation products (MDA), antioxidant enzymes (POD, SOD, CAT), and osmoregulatory substances (Pro, SS) were analyzed under various low-temperature stress conditions. The results showed no significant difference in flower morphology between Y1 and L15 at 4 °C, 2 °C, and 0 °C. At −2 °C, the anthers of Y1 turned brown and dried, the ovary froze, and water stains appeared on the sepals and the center. At −4 °C, the water stain on the ovary intensified, and the ovule froze. Moreover, by integrating the differences in the contents of IAA, GA, ABA, MDA, POD, SOD, and SS of the two varieties at the critical temperature of 0 °C, L15 showed the strongest ability to resist late frost. This study provides a physiological foundation for researching frost resistance during the flowering period. Full article

Almond cultivation in the Mediterranean basin is driven by Spanish production, which has combined innovation in cultivation techniques with research on varietal improvement, releasing self-compatible and late-flowering varieties that are better suited to areas prone to spring frosts. The growing demand for almonds has also influenced the Italian nut market, pushing growers towards almond cultivation even in areas that historically have no full vocation due to certain climatic constraints, such as cold winters and spring frosts, which are now less severe and less frequent as a result of climate changes, such as along the Latium coastline in Central Italy. In this new regional context, an almond collection orchard was set up in late 2017 in the rural environment of the municipality of Tarquinia (province of Viterbo) to test the local adaptation of commercial almond cultivars. Phenological observations and data acquisition were conducted for three consecutive growing seasons (2022–2024) and referred to eight cultivars introduced in the orchard: namely Genco, Guara, Lauranne Avijour, Penta, Soleta, Supernova, Tuono, and Vialfas. Each accession was monitored for phenological and ecophysiological traits, plant vigor and yield, yield efficiency, and nut and kernel traits. The trial proved that Lauranne, Penta, and Vialfas, due to their late flowering, were able to avoid possible damage from the spring cold recorded in 2023, while Supernova, Penta, and Genco, with an average yield over the three-year period of 2.51 ± 1.53, 2.44 ± 1.07 and 2.69 ± 1.42 kg plant⁻¹, respectively, showed a higher average yield than the other cultivars tested. Full article

Recent meteorological variability in winter and spring complicates predicting and managing frost damage in apples and pears. This study investigated the relationship between frost injury during the flowering stages of apples (‘Hongro’ and ‘Fuji’) and pears (‘Wonwhang’ and ‘Niitaka’) and weather conditions across regions at varying altitudes. Orchards were categorized into coastal, inland, mid-mountainous, and mountainous regions, and flowering stages and frost injury were analyzed. The flowering period of apples, from the onset of blooming to full bloom, averaged approximately 15 days, which was about 3 to 5 times longer than that of pears. Furthermore, the total flowering duration of apples was 1.5 to 2.0 times longer than that of pears. Additionally, flowering exhibited a tendency to be delayed at higher altitudes. However, orchards situated in mid-mountainous regions experienced earlier flowering compared to those in other regions. Among the two apple cultivars, the average frost damage was more severe in central flowers than in lateral flowers and was relatively higher in ‘Fuji’ than in ‘Hongro’. In pears, frost damage was most prevalent in the first to fourth flowers within the inflorescence, with ‘Wonhwang’ exhibiting relatively greater susceptibility than ‘Niitaka’. Across different cultivation regions, severe frost damage was observed in orchards located in mid-mountainous areas for both fruit species and cultivars. The severity of frost damage followed the order mid-mountainous, mountainous, plain, and coastal regions. Minimum temperatures were lowest in mid-mountainous and mountainous regions, while daily temperature differences were largest in mid-mountainous regions. Meteorological analysis (1981 to 2022) revealed consistent trends, with an increase in daily temperature range in recent years. These findings highlight the vulnerability of mid-mountainous orchards due to flowering stages overlapping with coastal and plain regions, exposing them to lower temperatures and larger temperature differences. Further studies on temperature variability are essential to mitigate frost damage risks. Full article

The implementation of real-time dynamic monitoring of disaster formation and severity is essential for the timely adoption of disaster prevention and mitigation measures, which in turn minimizes disaster-related losses and safeguards agricultural production safety. This study establishes a low-temperature disaster (LTD) monitoring system based on machine learning algorithms, which primarily consists of a module for identifying types of disasters and a module for simulating the evolution of LTDs. This study firstly employed the KNN model combined with a piecewise function to determine the daily dynamic minimum critical temperature for low-temperature stress (LTS) experienced by winter wheat in the Huang-Huai-Hai (HHH) region after regreening, with the fitting model’s R², RMSE, MAE, NRMSE, and MBE values being 0.95, 0.79, 0.53, 0.13, and 1.716 × 10⁻¹¹, respectively. This model serves as the foundation for determining the process by which winter wheat is subjected to LTS. Subsequently, using the XGBoost algorithm to analyze the differences between spring frost and cold damage patterns, a model for identifying types of spring LTDs was developed. The validation accuracy of the model reached 86.67%. In the development of the module simulating the evolution of LTDs, the XGBoost algorithm was initially employed to construct the Low-Temperature Disaster Index (LTDI), facilitating the daily identification of LTD occurrences. Subsequently, the Low-Temperature Disaster Process Accumulation Index (LDPI) is utilized to quantify the severity of the disaster. Validation results indicate that 79.81% of the test set samples exhibit a severity level consistent with historical records. An analysis of the environmental stress-mitigation mechanisms of LTDs reveals that cooling induced by cold air passage and ground radiation are the primary stress mechanisms in the formation of LTDs. In contrast, the release of latent heat from water vapor upon cooling and the transfer of sensible heat from soil moisture serve as the principal mitigation mechanisms. In summary, the developed monitoring framework for LTDs, based on environmental patterns of LTD formation, demonstrates strong generalization capabilities in the HHH region, enabling daily dynamic assessments of the evolution and severity of LTDs. Full article

Tea plants Camellia sinensis (L.) O. Kuntze consume substantial quantities of water and nutrients during the flowering period, which can adversely affect the yield and quality of tea plants. Therefore, the effects of thidiazuron, carbaryl, ethephon, and lime sulphur on flower buds and flower abscission in tea plants were investigated. The photosynthetic characteristics and biochemical components, the electrical conductivity of leaves, and the occurrence of insect pests and frost damage in the tea plants were assessed following the exogenous application of these chemicals. The results showed that 0.015, 0.03, and 0.06% thidiazuron, 0.08% ethephon, and 2.0 and 3.0% lime sulphur significantly promoted tea flower buds and flower abscission. Thidiazuron notably increased the concentrations of total amino acids, caffeine, catechin, and soluble sugar in tea leaves while reducing leaf electrical conductivity to some extent. Additionally, it also suppressed the occurrence of Empoasca onukii Matsuda (Hemiptera: Cicadellidae) and Apolygus lucorum Meyer-Dür (Hemiptera: Miridae). Furthermore, thidiazuron enhanced both the length and weight of tea shoots the following early spring. Application of 3.0% lime sulphur enhanced chlorophyll a and b, carotenoid, catechin, and caffeine and decreased the number of Aleurocanthus spiniferus Quaintanca (Hemiptera: Aleyrodidae) on the tea plants. However, no significant differences in frost damage were observed across treatments. Overall, exogenous application of the chemicals, particularly thidiazuron, effectively reduced flower production, altered key biochemical components, controlled tea pests, and ultimately enhanced tea productivity. Full article

Vine damage caused by spring frosts remains one of the main factors threatening grapevine yields in Central European countries, such as Poland. April frosts that followed a very early and warm spring in 2024 caused massive damage to young shoots and primary buds after budburst. This study was conducted on vines of fifty cultivars belonging to Vitis vinifera, interspecific hybrids, and inter-intra- or intra-interspecific hybrids (classified by some sources as V. vinifera), which were obtained via field collection. The aim of this study was to obtain primary results regarding the fertility of secondary, basal, and latent buds. The presence of inflorescences in these buds determines the ability to compensate for yield, i.e., produce a crop after damage to the primary buds. The tested cultivars, which were within the three groups mentioned above, differed significantly in their ability to compensate for yield. The majority of the analyzed V. vinifera cultivars were characterized by lower fertility in their secondary, basal, and latent buds and a reduced ability to compensate for yield after post-budburst freeze damage compared to interspecific hybrids and inter-intra- or intra-interspecific hybrids. Future research, with more comprehensive data collected over a longer period, will provide stronger suggestions for suitable cultivars in regions at risk of spring frost damage. Full article

The accurate and sub-daily identification of agricultural low-temperature disasters (LTDs) facilitates the understanding of their dynamic evolution, the evaluation of the characteristics of disaster events, and informs effective strategies aimed at disaster prevention and mitigation. In order to ensure the timely, precise, and comprehensive capture of disaster processes, we have developed a dynamic evaluation framework for winter wheat spring LTD in the Huang-Huai-Hai (HHH) region, driven by meteorological data. This framework consists of two primary components: a disaster classification module and a dynamic simulation-assessment module. Through disaster mechanisms and comprehensive statistical analysis, we have established the input features and structural framework of the classification module using a decision tree algorithm. The dynamic simulation evaluation module is based on our newly developed index for the cumulative hourly intensity of low-temperature stress (CHI) and its grade indicators. This index integrates the interaction between cold stress (low-temperature intensity, cooling amplitude, and duration) and mitigating conditions (air humidity) during the evolution process of LTD. Based on CHI, we found that as the intensity of low temperatures and the amplitude of cooling rise, along with an extended duration of stress and a reduction in relative humidity, the severity of spring LTDs in winter wheat get worse. The overall validation accuracy of the evaluation framework is 92.6%. High validation accuracy indicates that our newly established framework demonstrates significant efficacy in identifying LTDs and assessing grade. Through the analysis of the characteristics of the disaster process, spring LTDs affecting winter wheat are mainly mild, with frost identified as the primary category of LTD. The duration of freeze injury typically exceeds 24 h, while the duration of frost damage and cold damage is less than 24 h. From 1980 to 2022 in the HHH region, the frequency of spring freeze injury and frost damage on winter wheat showed an overall decreasing trend, with a particularly significant decrease in frost damage occurrences. Conversely, cold damage occurrences are on the rise. In addition, the duration of individual disaster events for the three categories of spring LTDs is decreasing, while both the average intensity and extremity of these events show increasing trends. This study has important practical value for the sub-daily scale evaluation of the spring LTD affecting winter wheat in the HHH region and serves as an effective guide for agricultural disaster prevention and mitigation, as well as for the formulation of planting strategies. Full article

It is crucial for northerly Norway spruce to understand how seasonal warming and site conditions influence the intensity of free growth and what the effects of free growth on stem quality and adaptedness are. We studied the intensity of sylleptic and proleptic free growth in 660 6-to-9-year-old Norway spruce trees planted on normally irrigated and temporary overmoistured sites of variable fertility. We focused on the ability of individual trees to retain a type of free growth over three seasons and examined the associations between free growth, stem quality, and phenology traits. The results show that 23% to 50% of trees exhibited free growth, depending on the season. Mild and warm conditions in August and September tended to promote free growth. Among trees aged 6 to 9 years, 82% to 84% of those without free growth maintained this status over the following two seasons. While sylleptic growth decreased with age, proleptic growth increased. Over the seasons, individual trees were more consistent in maintaining proleptic growth than sylleptic growth. Trees on moist site types exhibited significantly more free growth than those in normally irrigated sites across all seasons. Trees with both sylleptic and proleptic free growth were significantly taller than those without free growth; however, sylleptic trees showed a markedly lower frequency of stem defects compared with those with proleptic growth. Free growth intensity was weakly associated with spring phenology and appeared to disrupt the well-established associations between phenology traits within the annual cycle. We conclude that selecting trees for overall height, particularly those with sylleptic free growth, may well exploit the benefits of free growth without significantly increasing the risk of autumn or winter frost damage. Full article

(1) Background: Spring frost damage is a common phenomenon that occurs in Southern Chile that considerably affects vine productivity and grape quality. (2) Methods: A field trial was conducted in order to study vine phenology and berry physicochemical parameters in Chardonnay, Sauvignon Blanc and Pinot Noir ungrafted and grafted (onto 101-14 Mgt rootstock) grapevines after a spring frost. This event killed the totality of primary bud shoots when the vines reached the phenological stage of unfolded leaves. (3) Results: From budburst, to flowering of secondary bud shoots, ungrafted Sauvignon Blanc grapevines presented an advanced phenology, whereas 101-14 Mgt rootstock tended to advance the maturity of Pinot Noir grapevines from flowering to ripening of berries. At harvest, berries from secondary buds of vines grafted onto 101-14 Mgt rootstock showed higher soluble solids than the ones from ungrafted Chardonnay and Sauvignon Blanc vines. High total phenolic content was found in berries from secondary buds of the grafted vines, compared to the ones from the ungrafted vines. Berry soluble solids variability tended to statistically decrease toward harvest in the studied plant materials, and the maximum coefficient of variation for soluble solids, berry weight, berry firmness and berry size reached 9.5%, 25.9%, 18.6% and 8.9%, respectively. (4) Conclusions: These preliminary results may be interesting for the Southern Chilean viticulturists since it seems that 101-14 Mgt rootstock could affect phenology and grape berry maturity of grapevines established in the Cautín Valley after spring frost damage. Full article

Winter storage of seedlings in freezers reduces the amount of heat sum available for growth in the following growing season compared to seedlings stored outdoors. To test the effects of a reduced growing period on the autumn frost hardiness of the six species most used in Icelandic afforestation, seedlings were stored outdoors or in a freezer during winter. In spring, the seedlings were planted on 24 May, 7 June, 21 June, and 5 July, and the frost hardiness of all treatments was tested on 12 and 26 September. In general, the probability of freezing damage increased with a later planting date, with outdoor-stored seedlings having the lowest probability of damage. The timing of frost events was of great importance; the later the freezing date, the less damage was observed. Growth cessation occurred at different times for each species, and they responded differently to the reduced heat sum. Lodgepole pine and birch accumulated the most frost hardiness in September. Sitka spruce had less autumn frost hardiness than Lutz spruce. Hybrid larch accumulated less frost hardiness than Russian larch and was most sensitive to the reduced heat sum. The results can be used to determine which species should be prioritised in frozen storage with regard to Iceland‘s short growing season. Full article

Among climate-change related effects, drought, heat, and waterlogging are the most important adversely affecting the production of potatoes in Europe. As climate change progresses, agricultural practices must adapt to maintain potato yields. This study is based on a European-wide survey. It presents potato growers’ perception of climate change, its impact, and possible adaptation strategies, focusing on the results from Germany, Switzerland, and Austria. Potato growers strongly agreed that climate change had affected their potato production in the last ten years, as indicated by 98% of German and more than 90% of Swiss and Austrian respondents. Drought caused the most severe impact, and to varying extents damage was caused by heat and the occurrence of pests and pathogens. The most preferred adaptation measure was the planting of adapted varieties. In line with the comparably low access to at least partial irrigation that Austrian potato growers reported, Austria appeared to be the country most affected by drought. Other more pronounced challenges were late spring frost, flash floods, and soil erosion. The study highlights and discusses specific differences between the countries, as well as between conventional and organic potato production based on the Austrian responses. The results underline that to successfully develop effective climate change mitigation strategies, country-specific and local challenges and needs should be considered. Full article

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. Full article

The growth and development of apricot flower organs are severely impacted by spring frosts. To better understand this process, apricot flowers were exposed to temperatures ranging from 0 °C to −8 °C, including a control at 18 °C, in artificial incubators to mimic diverse low-temperature environments. We aimed to examine their physiological reactions to cold stress, with an emphasis on changes in phenotype, membrane stability, osmotic substance levels, and antioxidant enzyme performance. Results reveal that cold stress induces significant browning and cellular damage, with a sharp increase in browning rate and membrane permeability below −5 °C. Soluble sugars and proteins initially rise as osmoprotectants, but their content decreases at lower temperatures. Proline content consistently increases, suggesting a protective role. Antioxidant enzyme activities, including catalase (CAT), peroxidase (POD), superoxide dismutase (SOD), and ascorbate peroxidase (APX), exhibit a complex pattern, with initial increases followed by declines at more severe cold conditions. Correlation and principal component analyses highlight the interplay between these responses, indicating a multifaceted adaptation strategy. The findings contribute to the understanding of apricot cold tolerance and inform breeding efforts for improved crop resilience. Full article

Landslide damage to soil graben slopes in seasonal freezing zones is a crucial concern for highway slope safety, particularly in the northeast region of China where permafrost thawing is significant during the spring. The region has abundant seasonal permafrost and mostly comprises powdery clay soil that is susceptible to landslides due to persistent frost and thaw cycles. The collapse of a slope due to thawing and sliding not only disrupts highway operations but also generates lasting implications for environmental stability, economic resilience, and social well-being. By understanding and addressing the underlying mechanisms causing such events, we can directly contribute to the sustainable development of the region. Based on the Suihua–Beian highway graben slope landslide-management project, this paper establishes a three-dimensional finite element model of a seasonal permafrost slope using COMSOL Multiphysics 6.1 finite element numerical analysis software. Additionally, the PDE mathematical module of the software is redeveloped to perform hydrothermal-coupling calculations of seasonal permafrost slopes. The simulation results yielded the dynamic distribution characteristics of the temperature and seepage field on the slope during the F–T process. The mechanism behind the slope thawing and sliding was also unveiled. The findings provide crucial technical support for the rational analysis of slope stability, prevention of sliding, and effective control measures, establishing a direct linkage to the promotion of sustainable infrastructure development in the context of transportation and roadway engineering. Full article