Continentality Of Climate Research Articles

HABITATION CONDITIONS OF THE CAVE LION IN THE MIDDLE INDIGIRKA RIVER BASIN, NORTH-EAST SIBERIA, DURING THE MIDDLE AND LATE PLENIGLACIAL: RECONSTRUCTION BASED ON PALYNOLOGICAL DATA

Pollen analyses of the sediment from skulls cavities of two cave lions Panthera spelaea from the middle Indigirka River basin, North-East Siberia, were performed to reconstruct the habitat conditions of the animals and to estimate changes in vegetation and climatic conditions in the region. Composition of the pollen and non-pollen palynomorphs indicates that the predators most likely died on the river floodplain or near the shore of the thermokarst lake, where grass/sedge meadows and shrub thickets, providing rich grazing grounds for large herbivores, existed. Palynological data indicate that both in the early Middle Pleniglacial and in the LGM the regional vegetation included forest, shrub tundra, meadow, mire and steppe communities similar to modern cold steppes in central Yakutia. During early Marine Isotope Stage (MIS) 3, the participation of arboreal vegetation was greater than in the Last Glacial Maximum (LGM) due to higher summer temperatures. In MIS 2, the role of open herbaceous cryoxerotic communities was greater, which is associated with a higher continentality of climate and a decrease in winter temperatures. This reconstruction is consistent with the general sequence of landscape and climatic changes in the Arctic and Subarctic regions of Siberia in the Middle and Late Pleniglacial, based on paleobotanical studies of the locations of mammoth fauna and multidisciplinary studies of the Late Pleniglacial sediments from a broader area.

Climate-dependent distribution of Lemna minor, L. turionifera and L. × japonica (Lemnaceae) in temperate Eurasia and high variability of their genome size

In spite of a burst of duckweed biology studies, understanding their diversity is still in progress. We examined 174 reliably-identified (intron length polymorphism in TUBB2) samples of the Lemna minor complex from East Europe and North Asia (41 localities of L. minor, 58 localities of L. turionifera, and 75 localities of their hybrid, L. × japonica) and described clear patterns of their distribution. It is mainly determined by climatic preferences (i.e., the ability to survive unfavorable conditions). Namely, the ranges of L. minor and L. turionifera in the lowlands are separated by the Urals, with populations located west and east of these mountains respectively and coinciding with an eastward increase of climate continentality. However, historical (i.e. European origin of the species) and not ecological factors should explain the absence of L. minor in rather mild climate of the southern Russian Far East. The hybrid has an intermediate ability to tolerate continental climate, and co-occurs with one of its parents. In southern mountains (the Caucasus and Tian-Shan) the three taxa are separated by local climate conditions, determined by the terrain. We revealed high continuous variability of genome sizes within each taxon (two-fold in L. minor and L. turionifera; three-fold in L. × japonica), which is not explained by environmental factors. We propose an approach for distinguishing these three taxa in temperate Eurasia using morphology. We have not documented the invasive spread of L. aequinoctialis, L. minuta and L. turionifera in East Europe.

Climate Continentality in Cisbaikalia in Different Circulation Epochs

Climate Continentality in Cisbaikalia in Different Circulation Epochs

Short-Term Climatic Oscillations in the Central Region of the East-European Plain at the Beginning of the Holocene Based on Palynological Studies of Lacustrine Deposits

The Preboreal (11.75–10.70 ka BP) is still the least paleogeographically studied time interval in the central part of the East European Plain. High-resolution multi-proxy studies of lacustrine sediments at the Seltso site located in the Desna River floodplain (Dnieper River basin) were conducted. Radiocarbon dating, loss-on-ignition determination, sedimentological and palynological studies and identification of Non-Pollen Palynomorphs in lacustrine sediments allow us to reconstruct changes in vegetation caused by rapid warming at the Younger Dryas–Holocene boundary, short-term climatic fluctuations within the Preboreal and subsequent resumption of warming. Initial Preboreal warming reached its maximum at about 11.5 ka BP when a relatively dry continental climate existed. Between 11.4 and 11.2 ka BP, a short-term cooling corresponding to the Preboreal Oscillation in Greenland occurred, as indicated by a significant reduction of woody vegetation and expansion of open plant communities. In the Late Preboreal, approximately 11.2–10.7 ka BP, warming resumed, which was accompanied by a decrease in the climate continentality. Comparison with high-resolution lithological and palynological data from eight reliably dated sections of the central East European Plain indicates that in northwestern and central Europe, the impact of the Preboreal Oscillation cooling on the vegetation and the lake ecosystems’ development was probably somewhat stronger.

Анализ индекса континентальности климата на территории Северо-Востока России

Analysis of climate continentality is a powerful tool for studying and forecasting weath­er. Considering the continentality index enables determining current climate characteristics and predicting potential changes. This study aims to assess climate change in Russia’s North-East by analysing the continentality index as a complex integral indicator of these changes applicable to vast territories. Although there are many methods for assessing climate continentality, there is no uni­versal methodology. It is proposed in this contribution to employ two of the existing tech­niques. The first focuses on the area’s annual temperature amplitude and geographic latitude. The second involves a calculation of the index based on average January and July tempera­tures, the sum of seasonal precipitation and the area’s latitude. An analysis of the index val­ues of the base and calculation periods leads one to conclude that these values do not change significantly towards either weaker or stronger continentality across the study area.

Sedimentation gaps documented in the Eemian (MIS 5e) record in four profiles from the Żabieniec palaeolake (Central Poland)

Palaeobotanical reconstruction of the Eemian Interglacial vegetation and climate, revealed differences resulting from panregional and local factors. Lithostratigraphic analyses documented changes in sediments associated with evolution of three fossil Żabieniec lakes. Special attention was paid to Mid Eemian, for which records of thermophilic taxa were found. During the next phase the eutrophic lake shallowed, and a peatbog was formed. These processes were asynchronous and suggesting three separate lake basins. Sediments recording the longest phase of the interglacial revealed a long pause in sedimentation caused probably by a combination of factors (drop in the water level and increase in climate continentality).

Континентальность климата и теплообеспеченность почв степных склонов в верховьях Индигирки и Колымы

Steppe biotopes on the southern slopes of the Indigirka and Kolyma headwaters, judging by vegetation and invertebrate population, are analogous to South Siberiaвs mountain steppes. At the same time, the area of steppe slopes and the number of steppe plant and animal species decrease from the Indigirka to the Kolyma. Climate continentality decreases in the same direction, which permits to consider it the main factor impacting the distribution of thermophytic steppes in Northeast Asia. Measurements of temperatures in thermophytic steppe soils in the named river basins revealed no soil heat supply differences related to climate continentality. Comparison of the measurement results with long-term observation data on xeromorphic biotopes of southern slopes in the upper reaches of the Kolyma River permitted to extend this conclusion to the soils of all open dry southern slopes in the headwaters of the Kolyma and Indigirka rivers. Thus, the role of climate continentality and summer soil temperature regime in the long-term preservation of "islands" with a large number steppe species of plant and animal surrounded by permafrost mountain-taiga ecosystems in the upper reaches of the Indigirca River is questioned. It is shown that restrictions in the spatial distribution of some steppe invertebrate species are not determined by differences in the summer temperature regime of soil in the headwaters of the Indigirka and Kolyma Rivers, either.

The climate in Poland (central Europe) in the first half of the last millennium, revisited

Abstract. The article presents updated knowledge on climate change in Poland (central Europe) in the first half of the last millennium (1001–1500). This knowledge is required to delimit the existence, duration, and scale of the Medieval Warm Period (MWP, also called the Medieval Climate Anomaly, MCA, here). To this end, it employs all available quantitative climate reconstructions created for Poland in the last 2 decades and four new reconstructions using three dendrochronological series and an extensive database of historical source data on weather conditions. The growth of conifers in lowland and upland Poland depends on the temperature in the cold season, especially in February and March. All available reconstructions based on dendrochronology data represent this time of the year. Summer temperatures were reconstructed using biological proxies and documentary evidence. The latter, however, is limited to the 15th century only. Winter temperature was used as the proxy for annual temperature proxies instead of the more usual use of summer temperature. The MWP occurred in Poland probably from the late 12th century to the first halves of the 14th or 15th centuries. All the analysed quantitative reconstructions suggest that the MWP in Poland was comparable to or warmer than the mean temperature in the period 1951–2000. The coldest conditions in the entire study period were noted in the first half of the 11th century (both winter and summer) and the second half of the 15th century (only winter). The greatest climate continentality occurred in the 15th century. Good agreement was found between the reconstructions of Poland's climate and many reconstructions available for Europe.

Yield analysis of spring barley varieties under conditions of environmental variability

In conditions of increasing continentality of climate in recent decades, spring barley breeding should be aimed at creating drought-resistant, early-ripening, high-yielding varieties with sufficiently high technological qualities of grain. In addition to the economic and biological properties of the variety established by the breeders, external conditions in the region of cultivation also have a significant impact on the stabilization of the yields. The variability of productivity of spring barley varieties was assessed in terms of such traits as stability, ecological plasticity and adaptability in different ecological and geographical conditions. The research was conducted in 2020–2022 on 17 varieties of spring barley in ecological trial in Samara and Rostov regions. The experiment was laid in fourfold repetition with a plot area of 10 m². In the years of research, the "growing region" factor (98.7%) had the greatest influence. Evaluation of the index of environmental conditions (Ij) revealed that the best conditions for the vegetation of spring barley plants were formed in the experiment in the Rostov region (Zernogradsky district) (Ij = +0.99). The yield of the varieties depended not only on the location of the seed-trial ground but also on the year of cultivation. The linear regression coefficient ranged from 0.67 to 1.36, dividing the varieties into responsive, weakly responsive and adaptive to changes in the cultivation conditions. The varieties Zernogradsky 1717 and Zernogradsky 1724 formed the highest yield in the experimental plots and were classified as stable under cultivation under different soil and climatic conditions, with high breeding value, stress tolerance and level of variety stability.

ECOLOGICAL STRUCTURE OF FLORA OF MEADOWS OF THE ROMENSKO-POLTAVSKY GEOBOTANICAL DISTRICT

The article paper deals with the ecological structure of the meadows flora of the Romensko-Poltavsky geobotanical district. The identified species were analysed according to 12 ecological factors, which belong to two groups – edaphic and climatic. In the first group, the plants of meadow lands were studied according to 7 ecological factors, among which sub-mesophytes (174 species or 28,9%) and mesophytes (149 species or 24,8%) prevail in relation to soil water regime. In relation to the soil moisture variability, the dominance of two ecogroups was revealed, they are hemi-hydrocontrastophiles (227 species or 37,8%) and hemi-hydrocontrastophobes (226 species or 37,6%). In terms of soil acidity, sub-acidophytes (275 species or 45,8%) and neutrophiles(244 species or 40,6%) were identified. In relation to the soil salinity of the soil in the studied meadow, phytocoenoses semi-eutrophes (288 species or 48%) are leading. In terms of carbonate content in the soil, hemi-carbonatophobes (235 species or 39,1%) and acarbonatophiles(203 species or 37,8%) prevailed. Hemi-nitrophiles (297 species or 49,4%) prevail in terms of nitrogen content in the soil, and sub-aerophiles (305 species or 50,7%) in terms of soil aeration. The meadow plants of the Romensko-Poltavsky geobotanical district were studied according to5 ecological factors of the climatic group, among which the most prominent were sub-mesotherms (309 species or 51,4%) and sub-microtherms (240 species or 39,9%) in relation to the thermal regime. In terms of climate humidity, sub-aridophytes dominate (233 species or 38,8%). In terms of climate continentality, hemi-continental (258 species or 42,9%) and hemi-oceanic (207 species or 34,4%) are dominant. Sub-cryophytes are the most numerous in relation to the cryo-regime(302 species or 50,2%). In relation to light conditions, sub-heliophytes are represented by the largest number of species (493 species or 82%).

ОЦЕНКА ВЛИЯНИЯ АБИОТИЧЕСКИХ ФАКТОРОВ СРЕДЫ НА УРОЖАЙНОСТЬ И КАЧЕСТВО СЕЛЬСКОХОЗЯЙСТВЕННОЙ ПРОДУКЦИИ СТАТИСТИЧЕСКИМИ МЕТОДАМИ

The paper address the impact of an increase in the carbon dioxide concentration, surface air temperature and a change in a degree of climate continentality on the yield of spring wheat for the territory of Russia and for three grain-producing regions: the Saratov and Chelyabinsk oblasts and the Altai krai. The studies were based on the correlation, variance, and multiple regression analyses. The significance of the influence of the selected factors on the spring wheat is determined both for the territory of Russia and for individual regions. The influence of the degree of climate continentality on the spring wheat grain quality (protein content) in the Saratov oblast is assessed.

ОЦЕНКА РИСКОВ СЕЛЬСКОХОЗЯЙСТВЕННОГО ПРОИЗВОДСТВА САРАТОВСКОЙ ОБЛАСТИ НА ФОНЕ НАБЛЮДАЕМЫХ КЛИМАТИЧЕСКИХ ИЗМЕНЕНИЙ

The paper discusses changes in the temperature and precipitation regimes against the background of ongoing climate change in arid climate. Climatic variability is considered not on the time intervals of equal duration, but during natural climatic periods of the state of the Earth’s climate system: the first and second waves of global warming, the period of stabilization. Differences in the features of changes in the temperature and precipitation regimes on territories differing in a degree of climate continentality are revealed. Against the second wave of global warming, a degree of hydrometeorological risks of crop cultivation in the Saratov oblast is assessed using the probabilistic values of the hydrothermal coefficient.

APPLICATION OF BIG DATA TECHNOLOGIES TO ASSESS THE NATURAL MOISTURE OF THE TERRITORY

Due to the sharp changes in climatic conditions in Western Siberia, the most pressing problem is food security associated with forecasting crop yields. There is a need to estimate the natural wetness of the area on the basis of agroclimatic indicators, among which the sum of active air temperatures and precipitation is currently the most widely used.
 Background. However, for a comprehensive assessment of the wetness of the territory, it is necessary to take into account the climate energy resources associated with evaporation of different time resolutions (day, decades, months, vegetation period, year). The initial meteorological parameters are described in the form of poorly structured information of a large volume. Therefore, various technologies and algorithms of machine processing are used in the work.
 Purpose. The application of big data technologies to assess the natural moisture of the territory
 Materials and methods. With the help of the high-level Python programming language and engineering libraries, a comprehensive assessment of the territory was carried out using the example of Mirny of the Kochenevsky District of the Novosibirsk Region in the context of long-term average data and two years 2019 and 2020. That the use of machine processing technologies related to NoSQL data requests, creation of data set and big data slices allows to store and process meteorological parameters using cloud services of different time resolution. This makes it possible to significantly reduce the time for a comprehensive assessment of the territory according to agroclimatic parameters. As a result of the work, precipitation distribution, temperature, relative air humidity, evaporability, humidification coefficients (Ivanov-Vysotsky and Selyaninov hydrothermal coefficient) were obtained.
 Results. The paper proposes to use technologies of big data processing using Python, including pre-processing of poorly structured hydrometeorological data, execution of NoSQL queries, compilation of summary reports on agroclimatic parameters. Pre-processing consists of processing hourly meteorological data, filling gaps in the data, making slices in big data to process multi-temporal queries (day, month, growing season, year). By the example of Mirny farm in Kochenevsky district of Novosibirsk region (Russian Federation), big data processing was performed to calculate agroclimatic parameters to assess the natural moisture content of the area and yield forecasting.
 Conclusion. The practical significance of the work is as follows:
 - the application of big data processing technologies has significantly reduced the time for the labor-intensive process of assessing agrometeorological parameters;
 - obtained aggregated meteorological parameters of different temporal resolution (hours, days, decades, months) allowed us to identify a strong variability of agroclimatic conditions for the territory of Mirny farm Kochenevsky district, located in the forest-steppe zone of Western Siberia;
 - perform an integral assessment of agroclimatic conditions by calculating the integral indices of moisture, climate continentality, and agroclimatic potential.

Оценка индекса континентальности Западной Сибири на фоне регионального изменения климата

Quantitative assessment of the territory continentality is an urgent task, because in the conditions ofclimatechange, the index ofcontinentalitycan be taken into account when developing geographical forecasts of landscape development. The purpose of this study is to assess the change in the index of continentality of Western Siberia in the conditions of the current trend in climate development. The statistical series of observations on seven meteorological stations in Western Siberia served as the information base of the study. The long-term changes in the average January and average July temperatures, as well as the amount of precipitation for the cold (October-March) and warm (April-September) periods of the year were analyzed. Calculations for the time intervals of 1961–1990 and 1991–2015 allowed us to conclude that the climate continentality of Western Siberia is weakening under the conditions of regional climate development.

Semi-empirical model of the spatiotemporal surface temperature distribution on the plain part of Ukraine

The spatial variation of temperature is found to depend linearly on climate continentality, morphology of the relief, the position of the site with respect to seas, in addition to the usual elevation, latitude and longitude predictors. There are other factors that can have an additional significant influence: big bodies of water, terrain attributes relief, atmospheric factors (local circulation), configuration and aspect of coasts and vegetation. Therefore, these multifactorial influences form the climatic field of temperature.
 In this study, the regional semi—empirical model of the spatiotemporal distribution of the average annual and monthly temperature for the plain part of Ukraine on the basis of the methodology for assessing the influence of height above sea level and geographic coordinates is proposed. Based on the method for determining the altitudinal, latitudinal, and longitudinal gradients of meteorological parameters, we calculated these gradients for annual and monthly air surface temperature for the periods 1961—1990 and 1991—2020.
 Thus, on the plain part of Ukraine, the annual surface air temperature decreases by an average on 0.60—0.63 °C with a shift of 100 m height above sea level, on 0.51—0.55 °C with a shift of one latitude degree to the north, on 0.067—0.071 °C with a shift of one longitude degree to the east. Also, the variations of these annual mean temperature gradients from year to year over the period 1991—2020 are characteristic.
 The seasonal variation of gradients has a pronounced non—monotonic character: highest values of altitudinal gradientare typical for July—August (from –0.63 to –0.73 °C per 100 m), and the lowest values — for April—May (from –0.45 to –0.55 °C per 100 m); highest values of latitudinal gradient are typical for August—September (from –0.60 to –0.70 °С per 1 °N), and the lowest values — for April—May (from –0.20 to –0.35 °С per 1° N); the longitudinal gradients have positive values in June—August (0.074—0.128 °C per 1° E), and negative values in November—March (from –0.228 to –0.154 °C per 1° E).
 We found that the altitudinal and latitudinal gradients of temperature have the most spatiotemporal variability and the longitudinal gradient has the smallest one. Greatest variabilities of temperature gradient values are typical for February—March and July—September, and the least variability — for April—May.
 The analysis of the dynamics of gradient changes in the period 1991—2020 compared to the period 1961—1991 showed the following: the altitudinal gradientvalues increased by 8—13 %. in January and March—May; the latitudinal gradient values increased by ~30 % in December—February and decreased by ~20 % in May—August.
 The proposed semi—empirical model contains a coefficient that takes into account influence of additional effects associated with pronounced orographic and other terrain features. This study presents the numerical values of this coefficient for some specific microclimate regions of the plain part of Ukraine.
 The model estimates of thirty—year monthly mean temperature in Ukraine for the periods 1961—1990 and 1991—2020was calculated. A comparison of the model estimates of of the average annual and monthly temperature for 72 meteostations in Ukraine with their actual values showed a statistically significant correlation (the reliability of the linear approximation is 0.89—0.98). Thus, the presented design of the semi-empirical model makes it possible to quite well restore the annual and monthly temperature on the territory of Ukraine

Биоклиматические варианты оробиома Северо-Восточного Забайкалья

Introduction. The spatial structure of the biota at the regional level of its organization is most closely associated with the climate, expressed primarily through bioclimatic indicators. In the geography of the botanical diversity of Northeastern Transbaikalia, which is characterized by a complex organization of vegetation cover, the influence of a number of important gradients of climatic conditions is expressed. The identification of these gradients was the purpose of this research. Methods and materials of the research. The methodological basis of the research was the ecosystem approach to the identification and evaluation of phytocenotic diversity associated with ecological and geographical factors that determine its spatial differentiation. The geographic and genetic classification of plant communities was used to identify the typological diversity of vegetation. The climatic characteristics of the Northeastern Transbaikalia was given on the basis of key bioclimatic indicators (global model BioClim). The bioclimatic substantiation of the spatial structure was carried out taking into account the principles of identifying the diversity of ecosystems at the regional level. Mapping of the bioclimatic variants of the orobiome was compiled using the clustering of units according to the average values of parameters by the k-means method. Research results and discussion. A joint analysis of vegetation and climate made it possible, for the first time for Northeastern Transbaikalia, to determine the internal structure of ecosystem diversity that develops in the mountains within the framework of an orobiome. It also allowed mapping the spatial organization of ecosystems at the regional level on a climate basis. Using the cluster analysis of climatopes of the main vegetation formations, subdivisions of the orobiome (bioclimatic variants) are proposed. Two variants of the Ist order are expressed through the structure of the vegetation cover of mountain systems: the relatively low Patom highland in the north, and more massive ridges of the strongly dissected North Baikal and Stanovoy highlands in the south. Variants of the IInd order, differing in the degree of continentality and moisture conditions, have specificity in the altitudinal belts and sub-belts of vegetation. Diversity within belts and sub-belts, expressed through the typological diversity of vegetation at the level of formations, classes, and groups of associations, is marked by climatic differences in bioclimatic variants of the IIIrd order. The diversity of climatic conditions that determine the phytocoenotic diversity of Northeastern Transbaikalia is characterized through integral bioclimatic types of orobiome, determined by temperature and moisture supply. Three ombroclimatic types were distinguished by continentality conditions. The influence of the complex orographic structure of a vast mountainous territory, as well as zonal and sectoral patterns in changing climatic conditions, is characterized in their change from continental to extracontinental in according to the degree of climate continentality. The same factors determine the identification of three thermoclimatic types, which are associated with the distinguished altitudinal vegetation belts (mountain tundra, subalpine, mountain taiga). The temperate cold type is expressed in the intermountain depressions and low mountains of the Patom highlands, the cold type is associated with the middle mountains and the lower part of the high mountains (mountain taiga and subalpine belts), and the extra cold type is distinguished in the high mountains of the most massive ridges – Kodar and Kalar. Conclusion. Quantitative interpretation of the climatic conditions of the bioclimatic variants of the orobiome made it possible to give an integral evaluation of the climatic conditionality of the development of basic vegetation formations, the altitudinal belt divisions, and the altitudinal spectra of vegetation in general. The resulting basis can be used for the sustainable development of the region in connection with economic activities in areas adjacent to the Baikal-Amur Railway, for monitoring and forecasting changes in vegetation and ecosystems in general due to climate change and intensification of economic activities in the region.

ESTIMATION OF THE DEGREE OF CLIMATE CONTINENTALITY IN SARATOV REGION AT THE BEGINNING OF THE XXI CENTURY

A quantitative assessment of climate change is given in the territory of the Saratov region at the beginning of the 21st century. As a result of the research, an increase in annual air temperature was noted everywhere - its average value for the region was 7,1°С, the largest increase in average monthly temperatures was observed in winter. An analysis of the annual amount of precipitation showed their increase in the west of the region and in its central part, a decrease in precipitation was observed in the north of the region and in the Trans-Volga region. The conditions of the degree of climate continentality are estimated in different natural and climatic zones: forest-steppe, arid steppe and semi-desert for the period from 2005 to 2020. The calculated indices of climate continentality using the methods of G. Zenker, I. Schrepfer, L.A. Gorchinsky, S.P. Khromov, N.N. Ivanov showed a synchronous trend towards a decrease in the degree of continentality, which is associated with regional warming, which is most pronounced in the cold period.

Projected changes in mean annual cycle of temperature and precipitation over the Czech Republic: Comparison of CMIP5 and CMIP6

The multi-model ensembles like CMIP5 or CMIP6 provide a tool to analyze structural uncertainty of climate simulations. Currently developed regional and local climate change scenarios for the Czech Republic assess the uncertainty based on state-of-the-art Global Climate Model (GCM) and Regional Climate Model (RCM) ensembles. Present study focuses on multi-model spread of projected changes in long-term monthly means and inter-annual variability of monthly mean minimum, mean and maximum daily air temperature and monthly mean precipitation. We concentrate in more detail on the simulation of CNRM-ESM2-1, the driving GCM for the convection permitting ALADIN-Climate/CZ simulation contributing to the local scenarios in very high resolution. For this GCM, we also analyze a mini-ensemble with perturbed initial conditions to evaluate the range of internal climate variability. The results for the Czech Republic reveal minor differences in model performance in the reference period whereas quite substantial inter-generation shift in projected future change towards higher air temperature and lower summer precipitation in CMIP6 comparing to CMIP5. One of the prominent features across GCM generations is the pattern of summer precipitation decrease over central Europe. Further, projected air temperature increase is higher in summer and autumn than in winter and spring, implying increase of thermal continentality of climate. On the other hand, slight increase of winter precipitation and tendency towards decrease of summer precipitation lead to projected decrease of ombric continentality. The end of 21st century projections also imply higher probability of dry summer periods, higher precipitation amounts in the cold half of the year and extremely high temperature in summer. Regarding the CNRM-ESM2-1, it is often quite far from the multi-model median. Therefore, we strictly recommend to accompany any analysis based on the simulation of nested Aladin-CLIMATE/CZ with proper uncertainty estimate. The range of uncertainty connected to internal climate variability based on one GCM is often quite large in comparison to the range of whole CMIP6 ensemble. It implies that when constructing climate change scenarios for the Central Europe region, attention should be paid not only to structural uncertainty represented by inter-model differences and scenario uncertainty, but also to the influence of internal climate variability.

Ecological and topological differentiation of biotopes in the Mountain Crimea

The article provides results of the quantitative score assessment of environmental conditions of plant communities (biotopes) and comparative analysis of the topological (altitude) gradient of changes using the method of synphytoindication and the Mountain Crimean geobotanical zone as an example. Of the 126 biotopes listed for the Mountain Crimea, we selected for the analysis 68 forest, shrub, grassland and petrophytic types, reflecting the patterns of topological differentiation, i.e. β-coenotic diversity within five geobotanical regions and altitudinal zones of the southern and northern macroslopes. In the article, we highlight the specifics of the methodology of field research and data processing, based on geobotanical relevés entered into the database in the TURBOVEG software and selected ecological and coenotic profiles. At the next stage, we assessed the living conditions of the biotopes by applying modern methods and programs TWISPAN, STATISTICA-7. On the basis of key biotopes, we identified combinations within the altitude zones treated as mesocombinations and those within the macroslopes – as macrocombinations. In the article, distribution of biotopes by mesocombinations, macrocombinations and geobotanical regions is provided. The model ecological-coenotic profiles of each geobotanical region of shrub-forest and petrophytic-grass series were built showing distribution of biotopes and graphs of the indicators of major ecological factors. The regularities of altitude changes and the nature of correlation were established. For climatic factors (thermo-, cryoregime, humidity, and climate continentality), we calculated relevant indicators and coefficients used in climatology. The obtained data form the basis for assessing the differentiation of biotopes, comparative analysis of the ecological conditions and forecasting potential changes.

A Multivariate Regression Model to Explain the Altitudinal Distribution of Timberlines on the Eurasian Continent

Abstract The altitude of alpine timberline elevation has been considered to correlate with certain climatic factors. Many related isotherms (e.g., warmest month 10 °C isotherm) have been proposed to explain the altitudinal distribution of alpine timberline at the global scale. However, any climatic index actually has a wide range at the alpine timberline position worldwide. The altitudinal position of the alpine timberline is related to far more than just one climatic factor. Therefore, we developed a multivariable model for timberline elevation variability by collecting data from 473 timberline sites on the Eurasian continent. We analyzed 12 climatic variables that potentially account for timberline variation. Principal component and regression analyses were used to mine four climatic variables. The mean temperature of the warmest month (MTWM), mean temperature of the coldest month (MTCM), climatic continentality (K), and annual precipitation (AP) explained 95% of the variability of timberline elevation. MTWM, MTCM, K, and AP contributed 18%, 41.28%, 34.9%, and 5.82%, respectively, to the altitudinal distribution of alpine timberline on the whole continent; 20%, 44%, 28.86%, and 7.14% in the eastern continent; and 17.71%, 39.79%, 40.21%, and 2.29% in the western continent. We showed that MTWM, MTCM, K, and AP are deterministic factors for the altitudinal distribution of alpine timberline in the Eurasian continent. MTCM and K contributed to explaining the altitudinal distribution of timberline both in the entire, eastern, and western parts of the Eurasian continent. Our research highlights the significance of MTCM for the altitudinal distribution of timberline.