Monthly Air Temperature Research Articles

Mapping time-series anthropogenic heat flux using the top-down inventory and temporal downscaling in Beijing-Tianjin-Hebei megaregion of China

ABSTRACT Anthropogenic heat could potentially exacerbate heat risk in urban areas. Nighttime light (NTL) data have been widely used in mapping regional-scale anthropogenic heat flux (AHF) due to the close association between NTL and human activities. However, most gridded AHF products are constrained to coarse resolution. This study proposes a novel approach to generate 100 m gridded monthly mean AHF datasets in the Beijing-Tianjin-Hebei megaregion of China from 2012 to 2020. We first estimate the annual mean AHF using the High-Definition Suomi National Polar-orbiting Partnership-Visible Infrared Imaging Radiometer Suite (VIIRS-HD)-based top-down inventory method. We then downscale the annual AHF into monthly products using ancillary data including the monthly NTL and air temperature data. The results indicate that our 100 m gridded annual mean AHF products outperforms the existing datasets by providing more heterogeneous spatial information, apparent temporal variations, and higher accuracy. Furthermore, the spatio-temporal characteristics of our gridded monthly AHF products reflect well the urbanization trends. Our spatiotemporally explicit AHF products can also be utilized to facilitate investigations of the urban thermal environment and urban climate at the fine scale. The method can potentially be applied to larger areas and longer time series due to its simplicity and effectiveness.

Climate Response and Radial Growth Dynamics of Pedunculate Oak (Quercus robur L.) Plus Trees and Their Half-Sib Progeny in Periods of Severe Droughts in the Forest-Steppe Zone of Eastern Europe.

The dendrochronological parameters of 97 pedunculate oak (Quercus robur L.) trees including 20 plus trees (142-year-old on average) and four half-sib families for four of them were analyzed considering also specifically years of the most severe droughts that were identified using average monthly air temperature and precipitation data. The tree-ring width (TRW) was mostly affected by air temperature that had the largest cross-dating indices (CDI), up to 78% maximum. However, the 32-year Brückner-Egeson-Lockyer cycle (a climatic cycle of approximately 30-40 years that correlates with sunspot activity) was more reflected in the TRW dynamics in plus trees than precipitation and air temperature. A high-frequency of abnormal TRW was clearly observed during drought periods and in the following 2-3 years. Tree radial-growth reduction due to drought stress varied significantly between families. The resistance to drought based on TRW was higher in the maternal plus oak trees than in progeny. Drought resulted in reduced growth during the subsequent year(s); hence, the minimum growth occurred after the actual climate event. Autumn-winter precipitation and weather conditions were of the greatest importance at the onset of active vegetation in April and May. The influence of air temperature on oak growth was the largest in March (r = 0.39, p < 0.05). The strongest positive correlation between precipitation and growth (with r up to 0.38) was observed in May 2023. Plus trees had a high adaptive potential due to the stability of radial growth during drought with high resistance (Rt = 1.29) and resilience (Rs = 1.09) indexes. The offspring of families 1 (Rt = 0.89, Rs = 0.89) and 2 (Rt = 1.04, Rs = 0.87) had similar resistance and resilience, but the recovery indices (Rc) for offspring in families 1, 2 and 3 exceeded the recovery values for plus trees. For offspring in families 3 and 4, the index values were lower. The revealed responses of wood growth of plus trees to climatic parameters estimated as resistance (Rt), resilience (Rs) and recovery (Rc) indexes and similar responses in their progeny can be used in breeding pedunculate oak for wood growth productivity and drought resistance.

Xylotrophic Agaricomycetes Monitoring in Some Types of Spruce and Birch Forests (Subzone of the Southern Taiga, Perm Territory, Russia)

We have summarized the results of xylotrophic agaricoid basidiomycetes long-term monitoring in some types of indigenous and derived forests in the southern taiga subzone of Perm Krai. We carried out the research by a stationary method on the test 50×20 m areas, one in each type of forest: spruce forest at the brook, sorrel spruce forest and birch forest. We did the work in three periods: I – 1975–1977, II – 1994–1996, III – 2010–2012. The collection of material was carried out annually: in August 3 times with an interval of 10 days (the species composition, number and air-dry biomass of basidiomes were taken into account), and in September once (only the species composition of fungi was taken into account). To date, we have established that the number of xylotrophic agaricoid fungi in the studied forest types varies from 60 (sorrel spruce forest) to 66 (birch forest). Most of the identified species belong to the Tricholomataceae family (37.7–43.3% of the total number of xylotrophic fungi species in each of the biogeocoenoses). There was an annual accumulation of detectable fungal species, with the largest number of species (67–75%) detected from 2 to 9 times, and 2–3% of them were permanent, occurring annually. There was relative stability of the species composition of higher vascular plants (Jaccard generality coefficient: J = 56–88) over time and more significant changes in the species composition of xylotrophic fungi (J = 36–50). The spruce forests had the most similarity of fungi species composition between the cenoses by periods (J = 44–52), and for the entire observation period, the sorrel spruce forest and birch forest had the maximum Jaccard index between cenoses (J = 56). The yield of xylotrophic agaricoid fungi in the studied cenoses varies by years of observation. The birch forest had the largest number and biomass of basidiomata for all the three periods of the research. A decrease in the number of basidiomes of xylotrophic fungi in the sorrel spruce forest was established with an increase in the average monthly air temperature in August (Spearman correlation coefficient: rs = −0.70). The sorrel spruce forest was the most favorable for the biota of xylotrophic agaricoid basidiomycetes, both in number (Shannon index: H = 1.23) and in biomass (H = 1.20), during all the research, since the biota of xylotrophes of the specified cenosis was more diverse and its components were most aligned.

ПОВТОРЯЕМОСТЬ АДВЕКТИВНО-РАДИАЦИОННЫХ ТУМАНОВ НАД АПШЕРОНСКИМ ПОЛУОСТРОВОМ (АЗЕРБАЙДЖАН)

The article examines the physical and meteorological characteristics of advective-radiation fogs formed on the Apsheron Peninsula and nearby islands, including the dependence of atmospheric elements that influence the formation of fogs on the meteorological visibility range, monthly and long-term fog trends. For this purpose, the initial data of aviation meteorological stations in the water area for 1999...2022 were used. The absence of a large morphometric unit on the Apsheron Peninsula and the archipelago, surroundings by the sea, and air masses affecting the area throughout the year determine its synoptic conditions. With the help of physical-meteorological and mathematical-statistical analyses, it has been established that the bulk of advective-radiation fogs formed in the Apsheron waters are repeated in march...april. With this type of fog, it has been established that the range of meteorological visibility varies depending on wind speed and sky conditions. During the period of advective-radiation fogs, south-eastern winds are most often observed in the water area. Analyzes show that an increase in average monthly and annual air temperatures on the peninsula has recently affected the frequency of advective-radiation fogs. Studying the spatiotemporal distributions of fogs can create conditions for the effective organization of aviation work.

Analysis of long-term dynamics of air temperature fluctuations in the Nura River basin

In recent decades, a different frequency of dry years has been observed in the Nura River basin in Central Kazakhstan. This article examines the trend of changes in temperature fluctuations over a long period using materials from a separate climate element from the Besoba and Karaganda meteorological stations located in the Nura River basin and the Arkalyk meteorological station located outside the basin, to the west of it, but characterized by similar natural conditions. In the course of research over an 81-year time interval from 1939 to 2019, the absolute and relative frequency of average monthly air temperatures in July in the Nura River basin were established. The meteorological stations under consideration are part of the global international network of meteorological data of Kazhydromet and have constant, accurate series of values of meteorological indicators. Based on the use of the method of statistical analysis, an assessment of the spatio-temporal fluctuations of the temperature regime over a long-term period in the Nura River basin was identified. The study expressed the formation of an arid climate associated with an increase in the average monthly air temperature in the basin of the study area.

Temperature Dependence of the Pre-Chromatographic ‘Lawrence’ Method for Bivalves Contaminated with Paralytic Shellfish Poisoning Toxins

Saxitoxins are potent neurotoxins originating the acute human neurological syndrome of paralytic shellfish poisoning (PSP) via bivalve vectors. The official testing method in the European Union, commonly known as the ‘Lawrence method’, involves pre-column oxidation steps. The Portuguese monitoring adopted the hydrogen peroxide oxidation screening approach for bivalves contaminated with Gymnodinium catenatum toxins, which can quantify chromatographically at once 6 out of 10 analogues commonly found in bivalves. Seasonal fluctuation in the fluorescence yield of calibration curves was observed across years in a consistent manner. It correlated with fluctuations in average monthly air temperature in Lisbon, highlighting the importance of recording the room temperature during the oxidation steps as a matter of routine practice. Incubation experiments also showed an increase in fluorescence yield with temperature, more pronounced for the 11-hydroxysulphate analogues (dcGTX2 + 3, C1 + 2, GTX2 + 3) than for the 11-H toxins (dcSTX, GTX5[B1], STX). Temperature can be exploited to increase fluorescence yield, assisting in spectral confirmation, but must not exceed 40–50 °C to avoid toxin decomposition or production of extra oxidation products.

Changes in the air temperature regime across the Dniester River basin at the beginning of the 21st century

The relevance of the chosen topic is based on the goals and objectives of the Water Strategy of Ukraine until 2050 that provides for promotion of studies on the impact of climate change on the water content of Ukrainian rivers. The Dniester River is a transboundary river. It supplies water to Moldova and several regions of Ukraine. Predicting possible changes in the Dniester River's runoff due to global warming will help our society adapt to new climate conditions and take preventive measures. The research of the mountainous part of the watershed is of particular importance, as it is the area of runoff formation. Warming can change contribution of the snow component to the river's feed pattern and affect the total river flow. The object of the study: changes in air temperature due to global warming. The subject of the study: assessment of changes in the temperature regime within the Dniester watershed and impact of such changes on formation of its mountainous part's runoff. The study is aimed at assessing the changes in the air temperature regime within the Dniester River watershed at the beginning of the 21st century and assessing the impact of warming during winter season on formation of mountain rivers' spring floods. The main research methods include the method of difference integral curves and the method of regression analysis. The research materials include average monthly and annual air temperatures at 13 meteorological stations located within the Dniester watershed for the period of 1947-2021. The research indicated that the Dniester watershed is subject to warming. Statistically significant changes in air temperature began in 1988. Fluctuations in average annual air temperatures occur synchronously. Positive statistically significant trends over the entire observation period (1947-2021) were found for average annual air temperatures, average monthly temperatures of both warm and cold periods, and for the winter season. When considering two measurement periods (before 1989 and after), it was found that no statistically significant trends were observed before 1989. They were formed after 1989. It was also discovered that mountainous watersheds of the Ukrainian Carpathians respond to warming by forming negative trends in the fluctuations of average monthly runoff of spring floods.

ИЗМЕНЕНИЯ ТЕМПЕРАТУРЫ ВОЗДУХА В МОСКВЕ В ЭПОХУ ИНСТРУМЕНТАЛЬНЫХ ИЗМЕРЕНИЙ

The total series of monthly and annual mean air temperatures T in Moscow for the entire period of regular instrumental measurements since 1779 has been studied. On average, over the past 243 years, the temperature in Moscow has been increasing by 0.012°C/year. The warming at the end of the Little Ice Age (at the end of the 18th century-the beginning of the 19th century) gave way to a slight cooling in the middle and end of the 19th century and, then, a current new warming since the beginning of the 20th century and its slight deceleration in recent decades. The strong warming in winter and spring is statistically significant, while in summer and early autumn, centennial changes in temperature are insignificant. The distribution functions of T are close to normal in summer and have negative skewness in winter. At the end of the 18th century, extremely low minimum air temperatures reaching -37…-39°С were registered in Moscow. Over 1780-2022, the annual mean air temperature has increased on average by 2.8°С on the Moscow periphery and at least by 1.6°С in the rural zone of the Moscow region. A degree of the Moscow climate continentality has generally been decreasing since the 1780s.

Advanced Forecasting of Drought Zones in Canada Using Deep Learning and CMIP6 Projections

This study addresses the critical issue of drought zoning in Canada using advanced deep learning techniques. Drought, exacerbated by climate change, significantly affects ecosystems, agriculture, and water resources. Canadian Drought Monitor (CDM) data provided by the Canadian government and ERA5-Land daily data were utilized to generate a comprehensive time series of mean monthly precipitation and air temperature for 199 sample locations in Canada from 1979 to 2023. These data were processed in the Google Earth Engine (GEE) environment and used to develop a Convolutional Neural Network (CNN) model to estimate CDM values, thereby filling gaps in historical drought data. The CanESM5 climate model, as assessed in the IPCC Sixth Assessment Report, was employed under four climate change scenarios to predict future drought conditions. Our CNN model forecasts CDM values up to 2100, enabling accurate drought zoning. The results reveal significant trends in temperature changes, indicating areas most vulnerable to future droughts, while precipitation shows a slow increasing trend. Our analysis indicates that under extreme climate scenarios, certain regions may experience a significant increase in the frequency and severity of droughts, necessitating proactive planning and mitigation strategies. These findings are critical for policymakers and stakeholders in designing effective drought management and adaptation programs.

Сравнительная оценка урожайности зерновых культур в зависимости от лимитирующих факторов в условиях почвозащитного земледелия

Abstract. The aim of work – to identify the influence of limiting factors on increasing the yield of grain crops in crop rotations and soil fertility in a sloping landscape. The following methods were used during the study: field, Kosyrev, thermostatic-weight, ionometric, Machigin, Tyurin, quantitative, balance calculations of yield. Scientific novelty. For the first time, the yield of field crops in grain-steam crop rotations was estimated from the influence of meteorological conditions, moisture, mobile forms of nutrients, humus, seedlings and weed infestation in the arid conditions of the Orenburg Trans-Urals. Results. As a result of research (2021–2023), it was revealed that during the growing season (May-August), the average monthly air temperature (18.6 ℃) and the number of dry days (76) adversely affect (55.85 and 67.50 %) the yield (1.00 t/ha) of barley in the lower part of the slope. In the upper and middle parts of the slope, dry days (56.75 and 64.45 %) negatively affect the yield (1.44 and 1.20 t/ha) of barley. Precipitation in the form of rain (116 mm) during the growing season has a beneficial effect (53.05 %) on the yield (1.34 t/ha) of durum wheat in the middle part of the slope. Spring moisture reserves (152.1 mm) in a meter layer of soil have a positive effect (75.15 %) on the yield (1.30 t/ha) of soft wheat in the upper part of the slope. The increase in yield (1.45 t/ha) of durum wheat and (1.44 t/ha) of barley in the upper part of the slope is due to the influence of (72.30 and 56.05 %) phosphorus content (4.7 and 4.1 mg / 100 g) in the arable soil layer by the end of the growing season. In the middle and lower parts of the slope, the yield of soft wheat (1.20 and 1.10 t/ha) depends on the effect (65.50 and 54.01 %) of the residual content (4.7 and 4.4 mg / 100 g) of phosphorus. The use of agrotechnical soil protection techniques increases the yield of grain crops in crop rotations and soil fertility on the slope, especially on the upper part.

Selection varieties of meadow clover with high productive qualities for the conditions of the Volgo-Vyatka region

The results of evaluation of five breeding varieties of meadow clover (Trifolium pratense L.) in terms of fodder and seed productivity are presented. Breeding varietal populations of P-15, GPF-49-3, GPF-86-3 SGPF-159-3, SGPF-159-3 + SGP-117 of the double-cut type were investigated in comparison with the standard Dymkovsky for 3 years of economic use of grass stands (2020-2022) in a competitive varietal trial of 2019 sowing. The studies were conducted on strongly acidic (рНKC1 = 4,47) sod-podzolic soils with high content of exchangeable forms of phosphorus and potassium (192.5 and 217.9 mg/kg), low – humus (2.2%). The weather conditions in the years of research were characterized as moderately warm. The average monthly air temperature for April-August amounted to 13.0-15.6 °C with different precipitation supply: in 2020 – excessive, in 2021 – with a slight deficit, in 2022 – close to normal. During the years of research, high winter hardiness of all the studied varieties (more than 80%) was established. The duration of plant development periods in the varieties at mowed and seed use of grass stands was determined. The economic and biological characteristics of the varieties were given, describing the nature of the changes in plant height and foliage, fodder and seed productivity in comparison with the standard Dymkovsky. Two breeding varieties GPF-49-3 and P-15 have been identified based on the results of this research. The winter hardiness of these varieties was 92.6 and 96.9 %, total dry matter yield for 2 years – 21.90 and 21.56 t/ha (+12.7 and 11.0 % to the standard) and the seed yield on average for 2 years – 1.72 and 2.14 kg/ha (+8.9 and +35.4 % to the standard). These varieties are promising for testing in the Volga-Vyatka region and are suitable for state variety trials.

The link between the normalized difference vegetation index in major crops and meteorological factors

Normalized difference vegetation index (NDVI) is frequently used in monitoring of meteorological events. The goal of this study was to establish the relationship between the spatial NDVI with air temperature and precipitation amounts in major crops cultivated in the steppe zone of Ukraine, namely, winter wheat, winter rapeseed, grain corn, soybeans, and sunflower. The study included the croplands of eight regions: the Crimea, Kherson, Mykolaiv, Odesa, Zaporizhzhia, Dnipropetrovsk, Kirovohrad, and Kharkiv. The yield data were retrieved from the official bodies of the State Statistical Service of Ukraine. The meteorological data on monthly air temperature and rainfall were retrieved from regional hydrometeorological centers. The NDVI values were retrieved from the GIMMS Global Agricultural Monitoring System, which provides Terrain MODIS NDVI 8-Day smoothed time series with 250 m resolution. The study was performed for the 2021-2022 for winter rapeseed and sunflower; 2017 and 2020 for grain corn; 2022 for winter wheat; and 2017 for soybeans. We found almost no or weak correlation between monthly NDVI values of the studied crops and rainfall amounts. A stronger correlation was found for air temperature, with the greatest values of the correlation coefficient of 0.76, 0.72, –0.72 for sunflower, soybeans, and winter wheat, respectively. The linear regression models, developed to predict NDVI based on the air temperature for the mentioned crops, provided good prediction accuracy with the relative error within 10–20%. The best overall fit and accuracy was produced by the model of sunflower’s NDVI. Only winter crops were observed to have a negative correlation with air temperature, suggesting that the cultivated varieties of these crops are heat-intolerant.

INFORMATION MATERIALS FOR ASSESSING THE IMPACT OF CLIMATE FACTORS ON FORMING SOIL WATER REGIME ON DRAINED LANDS

The research results on creating information materials for assessing the impact of modern climatic factors on the formation of soil water regimes on drained lands are presented. By the results of the research, carried out at the "Romen" drainage and irrigation system (Sumy region), it was established that over the past 34 years, the average air temperature during the growing season has varied from 14,2 to 19,4 oC. In general, there is a trend for its slight decrease (almost by 0,2 oC). The highest average monthly air temperatures are recorded in July and August, and the lowest ones - in April. It was specified that the water regime of the active soil layer during the growing season is formed mainly due to moderate (4–14 mm – 44%) and significant (15–49 mm – 40%) precipitation, the total share of which in water reserves is 84%. There is a trend towards an increase in the share of significant precipitation (on average, up to 46–60 % of the total amount during the growing season) in years with high-water growing seasons, and its predominant amount falls in the range of 15–29 mm. There is also an increase in the share of moderate precipitation (up to 49% of the total amount during the growing season) in years with low-water growing seasons. Information materials on the distribution of atmospheric precipitation by year in quantitative and percentage indicators, their recurrence in the growing seasons of 1990–2022 ("Romen" DIS, Sumy region), presented as an interactive visual report with graphic materials (dashboard) have been created. Informational materials in the form of dashboards enable us to monitor changes in climatic conditions, promptly providing up-to-date data when forecasting future trends in changes in the water supply of agricultural territories, in particular, the formation of the soil water regime on drained lands and addressing the challenges related to climate change.

Evolution the Relationship Between Physiologically Equivalent Temperature and Some Meteorological Parameters for Basra City, Iraq

Background: Physiologically equivalent temperatures (PET) is highly efficient in evaluating the thermal component of any given microclimate as a single thermal index. The assist stakeholders in understanding and interpreting existing bioclimatic, allowing them to make any required modifications and become more robust to predicted climate change. Objective: This study assesses the relationship between Physiologically equivalent temperatures (PET) and some Meteorological Parameters. Methods: The data for this study includes observed mean monthly air temperature values, relative humidity, and wind speed for the period (2001-2020). The data was acquired from “Iraqi Meteorological Organization and Seismology (IMOS)” stations for Basra city. The radiation and Human Bioclimatic (RayMan) model were used to simulate bioclimatic indices (SET, UTCI, PET, PMV). Results: The findings revealed that the greatest mean values for PMV (4.3), SET (36.3), PET (45.5), and UTCI (42.1) were seen in July and August. The measurements have a nice thermal sensation of PMV (-0.5 - 1.9), SET (19.2- 29), PET (18.1- 31.8), and UTCI (15.9 - 28.7) is most noticeable in the months of (March, April, and October). The results showed the PET values (cool) and (Slightly cool) between (9- 18.3) for January, February, March, and December. The value of UTCI was between (5.9- 8.5) within classes (Slight cold stress), the values of PMV (-2.6- (-2.1)) within classes (strong cold stress) and (Slight cold stress) and the value of SET was (10.2- 12.4) within classes (Slight cold stress). Conclusions: Correlations between PET and air temperature (0.99), indicating good agreement between PET and air temperature, and relative humidity (0.96). PET and wind speed (R2=0.56). The scattering pattern of PET and other thermal indices shows that all indexes have a significant correlation coefficient, between PET and UTCI (R2=0.99), between PET and SET (R2=0.98), and (R2=0.99) between PET and PMV.

Анализ изменения сезонных явлений хвойных пород Лапландского заповедника и их связь с климатическими факторами.

The temperature regime for 29 years (1994–2022) at the weather station of Monchegorsk City is characterized. The average dates of onset of 9 phenological phases in pine (Pinus sylvestris L.) and spruce (Picea obovata Ledeb.)are given; for the period under consideration, significant trends were found only for several phenological phases of spruce. When comparing the dates of the phenophases "beginning of needle unfolding" for spruce and "beginning of flowering" for pine for the period from 2013 to 2022 with the dates of the period from 1964 to 1972, significant shifts towards earlier onset of these phenophases (by 10 and 8 days, respectively) were found. Correlations with mean monthly air temperatures were determined for nine phenophases for pine and spruce, and a high dependence of the onset of a number of phenological phases on temperatures in May for spruce and June for pine was revealed.

Seasonal phenology and starch allocation patterns in populations of Oxycaryum cubense f. cubense and paraguayense in Mississippi, Louisiana, and Florida

Abstract Phenological studies for Cuban bulrush [Oxycaryum cubense (Poepp. &amp; Kunth) Lye] have been limited to the monocephalous form in Lake Columbus (Mississippi). Accordingly, there is little available information on potential phenological differences among O. cubense forms (monocephalous vs. polycephalous) and populations in other geographic locations in the United States. Therefore, seasonal patterns of biomass and starch allocation in O. cubense were quantified from two populations in Lake Columbus on the Tennessee-Tombigbee Waterway in Mississippi (monocephalous), two populations from Lake Martin in Louisiana (polycephalous), and two populations from Orange Lake in Florida (polycephalous). Monthly samples of O. cubense inflorescence, emergent, and submersed tissue were harvested from two plots per state from October 2021 to September 2022. During monthly data collection, air temperature and photoperiod were recorded. Starch allocation patterns were similar among all sites, with starch storage being less than 1.5% dry weight for all plant tissues. Biomass was greatest in Lake Columbus (monocephalous; 600.7 g dry weight [DW] m−2) followed by Lake Martin (polycephalous; 392.3 g DW m−2) and Orange Lake (polycephalous; 233.85 g DW m−2). Peak inflorescence biomass occurred in the winter for the Lake Martin and Orange Lake populations and in the summer for the Lake Columbus population. Inflorescence biomass in Lake Columbus had a positive relationship (r2 = 0.53) with warmer air temperatures. Emergent and submersed biomass generally had negative relationships with both photoperiod and temperature (r2 = 0.02 to 0.77) in all sites. Peak biomass was also negatively related to temperature and photoperiod. Results from this study indicate that there are differences in biomass allocation between the two growth forms of O. cubense and that growth can occur at temperatures below freezing. Low temperature tolerance may allow this species to expand its range farther north than previously suspected.

A century-long tendency of change in surface air temperature on the territory of Ukraine

A century-long tendency of change in surface air temperature on the territory of Ukraine

ANALYSIS OF CLIMATE CHANGE EFFECT ON EXTREME PRECIPITATION EVENT IN CONSTANTINE ALGERIA

Extreme precipitation events are critical climatic indicators that offer substantial insights into climate change and its variability. This study aims to investigate whether climate change has impacted precipitation frequencies in the Constantine region of Algeria, known for its semi-arid climate with hot-dry summers and cold-wet winters. Temporal variations of monthly air temperature and precipitation were analyzed from 1981 to 2014. Statistical analysis identified a threshold for estimating monthly extreme precipitation during the period from 1981 to 2005 using the Gumbel distribution method. Additionally, a climatic projection of precipitation for return periods of 50 (t = 50) and 100 (t = 100) years was conducted to forecast extreme precipitation values in the future. The results indicate a gradual increase in precipitation levels during the study period, with values generally remaining below extreme thresholds. This suggests no significant escalation in the occurrence of extreme precipitation events. Furthermore, the findings highlight that climate change has had a more pronounced impact on altering air temperature than on influencing extreme precipitation trends.

Morphological, cytological, physiological, and molecular evidence to explain how underground fleshy roots expand in herbaceous peony (Paeonia lactiflora Pall.)

The fleshy roots of herbaceous peonies serve as vital storage organs and are the primary source material for Chinese herbal medicine. Moreover, in certain cultivars, these roots can be propagated by root cuttings. However, the specific mechanisms governing the expansion and development of fleshy roots in herbaceous peonies currently remain unclear. To elucidate patterns of changes during the enlargement and development of herbaceous peony fleshy roots, this study assessed fleshy roots in six growth and development periods (P1–P6). By integrating environmental monitoring data, morphological, cytological, physiological and biochemical, as well as molecular characteristics across these developmental periods were compared. Both precipitation and temperature influenced the development of fleshy roots. The fastest enlargement of fleshy roots occurred under the following growth conditions: daily average precipitation = 5.6 mm; monthly average air temperature = 25.6°C; monthly average soil temperature = 26.3°C. Phloem and xylem, produced by the activity of vascular cambium, are important components of fleshy roots. Secondary xylem thickness consistently increased across the six developmental periods, resulting in the radial expansion of fleshy roots. When average monthly air and soil temperatures were about 26°C, starch accumulated gradually in fleshy roots, and carbohydrates were mostly starch-based. However, when the average monthly air and soil temperatures decreased to about 11.0°C, soluble sugar content increased. Endogenous hormones such as IAA, ZR, GA3, MeJA, and ABA played regulatory roles throughout the development of fleshy roots, and their levels and dynamic equilibrium were correlated with expansion rate. Elevated IAA and ZR content, and stabilized IAA/ABA and MeJA/ABA ratios, favored fleshy root expansion. Trends in the expression of three genes that play key roles in the expansion of fleshy roots (PlEXLB3, PlAUX1 and PlWRKY13) were consistent with morphological and physiological data, but PlHXK1 and PlIPT3 also play important roles. These findings lay a foundation for studying, in greater depth, the regulatory mechanisms governing the enlargement of herbaceous peony fleshy roots, and offer practical advice pertaining to field cultivation and management practices of this ornamental plant.

The Prevalence of Tick-Borne Encephalitis Virus in Wild Rodents Captured in Tick-Borne Encephalitis Foci in Highly Endemic Lithuania.

Wild rodents are considered to be one of the most important TBEV-amplifying reservoir hosts; therefore, they may be suitable for foci detection studies. To investigate the effectiveness of viral RNA detection in wild rodents for suspected TBEV foci confirmation, we trapped small rodents (n = 139) in various locations in Lithuania where TBEV was previously detected in questing ticks. Murine neuroblastoma Neuro-2a cells were inoculated with each rodent sample to maximize the chances of detecting viral RNA in rodent samples. TBEV RNA was detected in 74.8% (CI 95% 66.7-81.1) of the brain and/or internal organ mix suspensions, and the prevalence rate increased significantly following sample cultivation in Neuro-2a cells. Moreover, a strong correlation (r = 0.88; p < 0.05) was found between the average monthly air temperature of rodent trapping and the TBEV RNA prevalence rate in cell culture isolates of rodent suspensions, which were PCR-negative before cultivation in cell culture. This study shows that wild rodents are suitable sentinel animals to confirm TBEV foci. In addition, the study results demonstrate that sample cultivation in cell culture is a highly efficient method for increasing TBEV viral load to detectable quantities.