Long-term Average Values Research Articles

Long-term forecast of changes in soil erosion losses during spring snowmelt caused by climate within the plain part of Ukraine

The paper deals with the forecast of changes in erosion soil losses during the spring snowmelt due to climate change in the regions of Ukraine in the middle of the 21st century (during 2031–2050) and at its end (during 2081–2100) compared with the values of the baseline period (1961–1990). The forecast is based on the use of the so-called “hydrometeorological factor of spring soil loss”. This factor is a part of the physical-statistical mathematical model of soil erosion lossduring spring snowmelt, developed at the Department of Physical Geography of Odesa I. I. Mechnikov State (since 2000 — National) University during the 1980s – 1990s. The long-term average value of the hydrometeorological factor is linearly related to the long-term average value of spring erosion soil loss. Therefore, the relative change in the hydrometeorological factor corresponds to the relative change in soil erosion losses. The developed methodology for assessing climate-induced changes in soil erosion losses in five regions of Ukraine (North, West, Center, East and South) takes into account the change in water equivalent of snow cover at the beginning of snow melting, the change in surface runoff and its turbidity, and changes in soil erodibility. The forecast of changes in erosion soil loss was carried out using projections of annual and monthly average air temperatures and precipitation for 2031–2050 and 2081–2100 in accordance with scenario A1B from AR4 of the IPCC. As a result of the research, it was found that both in the middle and at the end of the 21st century a decrease in the rate of soil erosion during the period of spring snowmelt is expected. During 2031–2050, the expected soil losses will be less than corresponding baseline period values within the West region by 79%, within the North and East regions by 81%, and within the Center region by 85%. In the South region, the spring soil losses will be zero due to the lack of snow cover. During 2081–2100 snow cover will be absent not only in the South region, but also in the Center and East regions. In the regions North and West snow cover will remain, but the spring soil erosion losses will decrease by dozens of times and will be so small that they can also be ignored.

Analysis of the Long-Term Soil Respiration Dynamics in the Forest and Meadow Cenoses of the Prioksko-Terrasny Biosphere Reserve in the Perspective of Current Climate Trends

A combined analysis of the current climate trends and the dynamics of soil respiration under soddy–weakly podzolic sandy-loamy soil (Entic Podzol (Arenic)) in the forest and meadow cenoses in the Prioksko-Terrasny Biosphere Reserve (southern part of the Moscow oblast) is performed. During the observation period (1998–2018), distinct trends of an increase in the average annual air temperature (Tair) and aridity of the summer season as well as a decrease in the duration of stable snow cover are observed. A general trend of a decrease in the total CO2 fluxes from the Entic Podzol (Arenic) under a forest and a meadow for all seasons of the year and throughout the year is also observable on this background. The linear trends of a decrease in the annual and fall seasonal CO2 fluxes from the soils in both cenoses are statistically significant (P < 0.05). Over the 21-year observation period, the monthly average CO2 fluxes from soils have tightly correlated with the average monthly Tair (r = 0.78–0.84, P < 0.001). In dry years, the temperature sensitivity of soils expressed via the Q10 coefficient is by 10–12% lower, than in the years with normal moistening. The average long-term values of annual soil respiration (AnSR) in the forest and meadow cenoses amount to 581 ± 54 and 727 ± 71 g C/(m2 year), respectively, with an interannual variation of 20–22%. The AnSR and summer hydrothermal coefficient are the most closely related explaining 51–56% of the variance in annual CO2 fluxes from soils. The warm season (May–October), which coincides with the period of active plant vegetation, accounts for 73–77% of the AnSR. However, the share of the cold season (November–April) in the annual CO2 flux from soils may reach 38–39% in individual years. Expansion of the network of stationary long-term year-round monitoring of soil respiration is a necessary condition for obtaining both more realistic estimates of the CO2 fluxes from soils and predictions of the ecosystem responses to the current and future climate changes.

СРАВНИТЕЛЬНАЯ ОЦЕНКА ФОРМИРОВАНИЯ СТОКА РЕК В КЛИМАТИЧЕСКИХ ЗОНАХ ГОРНОГО ПАМИРА

The research object. The hydrological characteristics of the Gunt and Vanch rivers belonging to the Southwestern and Central climatic zones of the Pamirs and are tributaries of the transboundary Pyanj River are considered. Long-term average values of temperature and precipitation as the main factors affecting the formation of river flows are determined for the period 1944–2016. The state of glaciation in the basins of the respective rivers is estimated. Goal. A comparative assessment of the influence of climatic features and mountain orography on the formation of river flows. Determination of the trend of changes in the climatic conditions of the Gunt and Vanch river basins at different periods of more than 70 years (1944–2016). Research methods. Generalization, systematization of meteorological and hydrological characteristics and determination of their change compared with the base period 1960–1990. Statistical processing of meteorological and hydrological data and establishing a trend of changes in climatic and hydrological characteristics using a differentiated method. Research results. It is shown that the nature of changes in hydrological characteristics, namely the flow of rivers in different climatic zones of the Pamir can differ significantly. On the example of two rivers (Gunt and Vanch) - tributaries of the transboundary Pyanj river, it is shown that the trend of change in the flow of the Gunt river differs from the Vanch river due to the state of glaciation of the river basin. To explain the results the meteorological conditions of the respective river basins and their possible impact on river hydrology were studied. Conclusion. The hydrological characteristics of the Gunt and Vanch rivers in the Pamirs taking into account the meteorological conditions of the respective river basins show that a key factor in improving the state of glaciation and reducing degradation processes, as well as achieving positive trends in the mass balance of glaciers is the presence of sufficient air mass in the glaciation zone. Naturally, this is the key to ensuring a sufficient amount of runoff.

СОСТОЯНИЕ РЕСУРСОВ ЗАЙЦА-БЕЛЯКА (LEPUS TIMIDUS L.) В РЯЗАНСКОЙ И ТУЛЬСКОЙ ОБЛАСТЯХ

The Arctic hare is a traditional favorite hunting object in Russia. One of the main tasks of ecology is the study of populations. The most important quantitative parameter for a biological community is the change in the number of its specimen. On the basis of official data on animal counts over the past 25 years, we have established some characteristics that provide information on the state of the Arctic hare resources in the Ryazan and Tula regions. The aim of this work was to carry out a population analysis of the Arctic hare resources in the south of the Moscow region in the Ryazan and Tula regions over the past 25 years. The population analysis included studying static (the number and density of the hare population, the volume of prey, as well as the long-term average value of the number) and dynamic (the dynamics of the number and volume of prey, the absolute and relative rate of change in the population size) indicators. Primary data on the population of hares were collected using the winter route accounting method. The population density of hares was determined on the total territory of the hunting grounds in the corresponding territory. Basing on the data obtained, it was revealed that over the past quarter of a century, the number of Arctic hares in the Ryazan region has a tendency to decrease. The population density of Arctic hares in 1995 and 2019 in the Tula region remained practically at the same level. The indicator of the Arctic hare kill in both Ryazan and Tula regions tends to decrease.

The Typicality of Hydrothermal Conditions of the Forest Steppe and Their Influence on the Productivity of Crops

Analysis of changes in hydrothermal conditions of growing crops in the forest steppe zone of Ukraine over a period of 2004–2016 showed that by the average monthly air temperature more than a half of the years under study and by rainfall nearly a third of the researched period differed significantly from the average long-term value and were close to extreme weather. Statistical analysis of long-term indicators of the air temperature regime is evidence of a steady trend towards an increase in average annual air temperature with significant fluctuations in indices in separate periods from 7.9 ± 2.9 to 10.0 ± 2.5oС and a decrease in the amount and instability of natural moisture entry. The influence of weather conditions on the formation of productivity of spiked cereals (winter and spring wheat, spring barley) and maize was assessed at the current agrometeorological risks in the forest steppe of Ukraine. Based on the correlation-regression analysis, mathematical models were created that reproduce the dependence of grain yields upon the complex weather conditions of the growing season, the impact of which reached 60–70%. The conditions of eight years (2006–2008, 2011–2014 and 2016), when the hydrothermal index for the vegetation period was 1.13–1.76, turned out to be optimal by hydrothermal indicators to harvest maize yield at 5.83–9.47 t/ha. However, the years of 2005, 2009–2010 and 2015 were unfavorable as they received precipitation by 120 mm lower than a norm or 36% of the norm. The rainfall by 37–61% lower than a norm in June–July and grain yield 3.12–6.51 t/ha were also characteristic of the years mentioned above.

Influence of Abiotic Environmental Factors on the Abundance of Cod Eggs and Cod Larvae in the Southeastern Baltic Sea in 2016

The characteristics of the abiotic environmental parameters obtained during in situ observations and significant for the survival of cod eggs and larvae (water salinity, water temperature, and oxygen content) are presented for the Baltic Sea for 2016. Cod eggs were present in ichthyoplankton during the entire spawning season (March–August). In July and August 2016, the abundance of cod larvae exceeded the long-term average value for the Gdansk Deep. The thickness of the reproductive layer, suitable for cod reproduction, calculated from vertical localization of 11‰ isohaline and 2 mL/L isooxygene, was sufficient for cod egg survival. Layers with acute vertical density gradients were noted in the upper part of the halocline in March–August and also in the surface water layer in the summer period. It is assumed that the lower boundary of the pycnocline in the surface water layer could serve as a food-rich zone of cod larvae concentration.

Climate Change-Induced Changes in the Chemistry of a High-Altitude Mountain Lake in the Central Alps

Mountains are among the most sensitive ecosystems to climate change, and one of the most evident signs of climate-related effect is the continuous net loss of ice from the cryosphere. Several studies showed that meltwater from glaciated and perennially frozen areas can profoundly affect alpine aquatic ecosystems. Here, we present the impressive temporal increase in solutes in Lake Leit, a mountain lake in the Central Alps that is impacted by an active rock glacier. During the last 30 years, concentrations of sulfate and base cations increased by factors of 4 and 3, respectively. Atmospheric deposition, the only catchment external source, could be excluded as possible cause. The inlets have sulfate and base cations concentrations that were up to double the concentrations of the lake outlet confirming the presence of catchment internal sources. The highest concentrations were measured in the springs at the bottom of the rock glacier. Ground surface temperatures of the rock glacier indicated a high probability of permafrost occurrence, while the annual mean air temperature after the mid-1980s showed continuously positive deviations from the long-term average values (period 1961–1990) with increasing values after 2010. δ34S of sulfate in the inlets and the outflow indicated that sulfate in Lake Leit mainly derived from dissolution of gypsum/anhydrite even if its presence is not confirmed by the Geologic Atlas of Switzerland. Because of these results, we postulate the presence of subsurface traces of sulfate-bearing evaporites, probably associated with Triassic metasediments. These deposits are very common in the closer surroundings. We further hypothesize that the thawing of permafrost affects the flow path of water enabling its contact with fresh highly weatherable minerals increasing the overall weathering rate and shifting the relative ionic composition in the discharge toward the ions that originate from the most soluble minerals. This study shows that increased permafrost thawing in the future can influence water quality in high-alpine settings.

The Influence of Storm Events on Metabolism and Water Quality of Riverine and Estuarine Segments of the James, Mattaponi, and Pamunkey Rivers

The frequency and magnitude of storm events is expected to increase with climate warming. Tidal freshwaters may be particularly sensitive to these events owing to their proximity to riverine inputs. Continuous and synoptic water quality data from riverine and tidal freshwater segments of the James, Mattaponi, and Pamunkey Rivers (Virginia, USA) were analyzed to characterize their response to high discharge events. Water quality attributes subject to dilution effects (conductivity, pH) showed negative responses to increasing discharge, which were similar in magnitude among riverine and estuarine segments. Variables associated with sediment transport (turbidity, TSS, E. coli, TN, and TP) showed positive responses to discharge, stronger responses in riverine vs. estuarine segments, and relatively linear responses over the full range of discharge. Variables affected by internal biological processes (CHLa, DO) showed negative responses to increasing discharge, greater sensitivity in the low range of discharge, and stronger responses in estuarine segments. High discharge was associated with reduced chlorophyll-a (CHLa), lower dissolved oxygen, and more heterotrophic conditions (lower production relative to respiration). During unusually high discharge in 2018, annual GPP was reduced to 38% (Pamunkey) and 78% (James) of long-term average values. Inter-estuarine differences in their sensitivity to high discharge reflect differences in forms of primary production, as the phytoplankton-dominated James exhibited rapid recovery in CHLa and GPP between storm events.

Effects of Temperature Variability and Warming on the Timing of Snowmelt Events in Southern Finland during the Past 100 Years

This study analyses the first and last days of snowmelt events and the number of days (duration) between those throughout a water year (September-August). The snowmelt duration (SD) as well as its first (SFD) and last (SLD) days were estimated using daily precipitation and temperature measurements at the Kaisaniemi meteorological station in southern Finland during 1909-2008 as input datasets to a temperature-index snowmelt model. As snowmelt is a sensitive hydrological variable to temperature, this study also evaluated historical variations and trends in November-May (SDt), November-January (SFDt), and March-May (SLDt) temperatures corresponding to SD, SFD, and SLD at Kaisaniemi. The trends in all these parameters as well as their correlations with the well-known climate teleconnections over Finland were investigated. Long-term average values indicated the longest SD was about 131 days between 15 December and 25 April at Kaisaniemi. The SD significantly (p&lt;0.05) shortened by 0.37 (days/year) at Kaisaniemi during 1909-2008 mainly due to the earlier (0.32 days/year) SLD. Such trends in SD and SLD were principally associated with century-long significant warming trends (0.02 °C/year) in both SDt and SLDt. The Arctic Oscillation (AO) was the most influential climate teleconnection for historical variations in SD, SLD, SDt, SFDt, and SLDt at Kaisaniemi.

Influence of Agroclimatic Conditions, Life Form and Host Species on the Species Complex of Wheat Septoria Pathogens

Currently, septoria is the basis of the pathogenic complex on wheat crops in Russia, occupying the predominant position among harmful fungal diseases. In case of severe wheat damage, the crop loss caused by the fungus Z. tritici, makes up from 10–25 to 40–60%. The crop loss caused by the fungus P. nodorum parasitizing is from 10–20 to 30–50% during the years of epiphytoty. The question of the economic significance of P. avenae has not yet been examined completely. However, depending on the area of wheat cultivation and the year of observation, its part in the septorian population may reach up to 76.9%. It was of interest to study in detail the influence of conditions of the specific year, life form, and species of wheat on the formation of the species composition of Septoria in the pathogenic complex of wheat. Among the complex set of factors included in the concept of the environment, a significant role belongs to its abiotic components, namely, climate and weather, but the variety as an environment-forming factor has a decisive role. Our studies were carried out during 2010–2017. During the research period, the weather conditions varied significantly over the years and were not always favorable for the development of plants and formation of a good wheat crop. During the study, deviations in the amount of precipitations during the vegetation period, and, in general, over the year from the long-term average annual values, were noted. The years of 2012, 2014 and 2015 were characterized by the highest moisture supply during the vegetation season. It has been predicted that cooler days of April and May will promote the better development of P. avenae and P. nodorum. P. nodorum receives its predominant development during the years with wetter weather within the vegetation period of wheat, in contrast to Z. tritici more resistant to low humidity. These data demonstrate adaptation of the pathogen to conditions of an increased temperature regime and reduced rainfall amount.

Comparison of productivity indicators for the Far Eastern selection of soybean varieties under adverse climatic conditions with different planting dates

The aim of this study was to determine the relationship between the productivity indicators of soybean varieties of the Far Eastern selection and the climatic conditions of the Russian Far East. We studied the yield, protein content, 1000 seed weight, and the number of beans and seeds per plant, according to the planting date of two varieties: «Batya» and «Khabarovskiy Jubilyar». The duration of the growing season, the sum of temperatures, the amount of precipitation, as well as the Selyaninov Hydrothermal Coefficient were considered as characteristics of the growing season. The period in which the experiment was conducted was unfavorable for the growth and development of soybeans compared with long-term average values. The number of beans per plant, the number of seeds per plant and the yield of «Khabarovskiy Jubilyar» were higher than the corresponding values for «Batya» (the yield of «Khabarovskiy Jubilyar» was 0.8 t/ha higher than «Batya»). Hydrothermal conditions limited the realization of the potential productivity of «Batya», restricting it to 45% of the potential yield. For «Khabarovskiy Jubilyar», this figure was 87%. The relationship between productivity and the length of growth period, as well as hydrothermal characteristics, was established.

Root rot in new cultivars of spring wheat depending on sowing dates

The results of studying resistance of mid-ripening spring wheat cultivars to root rot in the forest-steppe zone of Irkutsk region are presented. The study was conducted in a two-factor field experiment. Factor A – mid-ripening spring wheat cultivars: Tulunskaya 11 (control), Zoryana, Маrsianka, Stolypinka (new cultivars). Factor B – seeding dates: May 10, 20, 30, preceded by fallow. The experimental plot area was 70.0 m2. The experiment was repeated three times. Plot arrangement was randomized. Root rot prevalence was determined during the tillering phase of the crop. In 2018, the sowing dates did not affect the disease due to the long spring-summer drought (May-June) and a higher average daily temperature compared to long-term average values. In arid and cold conditions of May 2019, with the late sowing period (May 30), root rot prevalence was significantly lower than when sowing on May 10 and 20. In 2019, a higher level of the disease was registered than in 2018 by 14.3%. Significant differences in root rot prevalence in both years of research were noted between the control cultivar Tulunskaya 11 and the new cultivars of spring wheat Zoryana and Stolypinka. In the tillering phase of the latter two, disease indicators were lower by 5.6% and 10.5% in 2018, and by 8.8% and 7.9% in 2019, respectively. Маrsianka cultivar was at the control level for this indicator. The best cultivar under study was Stolypinka, which was not only less affected by root rot, but also gave a statistically significant yield increase of 0.16 t/ ha in 2018 and 0.22 t/ha in 2019.

Spatial year-ahead forecast of air temperature and precipitation in large mountain areas

The method for spatial reconstruction of monthly mean air temperature and monthly precipitation is proposed for large mountain areas. Meteorological factor dynamics is described in percent of long-term monthly average values measured “in situ”. It is almost independent of height, exposure and climate of characterized sites and remains the same throughout the mountainous territory. By the example of the Altai-Sayan mountain country covering more than 2,500,000 km2, we averaged (spatially generalized) the data of 11 weather stations and obtained the country's long-term dynamics of monthly mean air temperature and monthly precipitation for 1951–2016. Using a simple moving average of 6–7 recent years of stations observations, we provide a reliable year-ahead prediction of a factor value for any spot of the country without additional data. Modification of RSR and Nash–Sutcliffe efficiency indices is proposed to correct their shortcomings in assessing the quality of various predictive methods and models. The developed method of four-season weather forecast has the quality close to the theoretically best for statistical forecasts.

Ecosystem Service Value Distribution Along the Agroecological Gradient in North-Central Ethiopia

Land use and the associated ecosystem service functions vary with changes in agroecological conditions. This study analyzed the distribution of ecosystem service values along the agroecological gradient in Borena landscape. Land-cover information was extracted from Landsat satellite images; and ecosystem service values were estimated using established global and local databases. Land-cover types were constrained in one or two agroecological zones with varying proportions. Cultivated land covering 53.7% of the total landscape area, plantation forest (32.3%) and grassland (9.4%) land-cover types exist in all agroecological zones, with the highest proportion in the humid highland. The highest long-term average ecosystem service value was observed along the humid highland accounting for about 21.8–33.11 million $US. The sub-humid highland consisted 5.67–8.88 million $US. Ecosystem service value showed a decreasing trend between 1973 and 2001 along all agroecological zones and increased in 2016. Moreover, the highest depletion was found along the humid highland (7.27–18.93 million $US) and least depletion was observed along the cold highland (1.79–4.40). Occurrence of the highest depletion along the most inhabited zone, i.e., humid highland, revealed that many of the impacts are human induced. Agroecological gradient substantially determines the amount and distribution of ecosystem service values. Sustainable land management efforts and proper land-use planning are required with special attention to susceptible zones to conserve and increase ecosystem service values.

Defining a new method to set certainty factors to improve power systems prognosis with fuzzy petri nets

In power systems, faults are unavoidable events. They can cause disastrous problems to operations. In this study, we aim to reduce the bad effects resulting from these faults in order to raise the operation performance. Fuzzy petri nets (FPN) are very important tools used to diagnose and prognosis issues. However, they take constant certainty factors (CFs) and depend upon long-term statistical average values to describe initial places. A new method is introduced here to determine CFs and initial truth degrees in FPN, so they can reflect different operating states and adapt to any changes in conditions in order to improve the prognosis. For this purpose, we define new kinds of CFs in order to take various conditions into account and represent a wide range of their effects on the system. The main purpose of this study is to analyze the system operation at different states under different conditions to determine the state that may cause problems, and take convenient procedures to prevent them. The proposed method is applied on a reliability test system to show its ability to make the FPN model more flexible and cover a wide range of operation cases.

ИСПОЛЬЗОВАНИЕ ДАННЫХ РЕАНАЛИЗА ДЛЯ ИССЛЕДОВАНИЯ ЛЕДЯНОГО ПОКРОВА АЗОВСКОГО МОРЯ

The article presents an analysis of the results of the OSI-450 reanalysis as an alternative data source for the study of the ice cover of the Azov Sea. OSI-450 is the second major version of the OSI SAF Global Sea Ice Concentration Climate Data Record (CDR). The OSI-450 product is available for the period 1979 to 2015.Using licensed software ArcGIS 10.*, a model for data processing was created. The average long-term value of the ice cover for the period 2000–2015 according to the OSI-450 reanalysis data is 23.3 %, according to GIS data – 37.2 %; the maximum and minimum values are 43 % / 69.4 % and 8.2 % / 8 %, respectively. The correlation coefficient with the sum of average monthly air temperatures is minus 0.87 (air temperature for the winter season is a main factor that determines the ice conditions of the Sea of Azov). It is shown that the OSI-450 reanalysis data underestimate the ice extent for the season, but on the whole reproduces the long-term dynamics of the ice cover for the period under consideration. Based on the study, it was concluded that the OSI-450 reanalysis can act as an alternative source of data on the state of the ice cover, but taking into account correction factors.

Spatiotemporal Changes in the Phytoplankton in Lake Baikal during Late Summer: I. Water Temperature and Phytoplankton Abundance

Results of a study of the water temperature and phytoplankton abundance in different regions of Lake Baikal according to 15 expeditions from 1994 to 2013 during late summer are present. The spatial distribution and interannual dynamics of phytoplankton are analyzed. The total abundance of phytoplankton in late summer is shown to be high. Its average long-term value for all of the open area of Lake Baikal is 532 ± 17 thousand cells/L. In Southern Baikal, the west coast is characterized by higher average phytoplankton abundance; in Middle and Northern Baikal, the east coast is rich. No significant differences were found between the hollows of the lake in terms of the development of late summer phytoplankton. The long-term average abundance of phytoplankton in the southern, middle, and northern hollows differs only by ≤1.2 times, but in the middle hollow it is significantly higher than in the northern. In the long-term dynamics, no significant increase in the abundance of late summer phytoplankton was recorded in any of the regions of the lake. The dependence of the total phytoplankton abundance on water temperature is weak; the correlation coefficients between the average annual values ​​of these indicators are ≤0.50.

РЕСУРСЫ ЗАЙЦА-РУСАКА (LEPUS EUROPAEUS PALL.) В РЯЗАНСКОЙ И ТУЛЬСКОЙ ОБЛАСТЯХ

The brown hare has always been a favorite traditional hunting species in Russia. One of the main tasks of ecology is the study of populations. The most important quantitative parameter of a biological community is the change in the number of its individuals. On the basis of the official data of animal counts, we have established some characteristics that provide information on the state of the resources of the European hare on the territory of the Ryazan and Tula regions. The aim of this work was to carry out a population analysis of the resources of the brown hare in Ryazan and Tula regions on the basis of official long-term data. Long-term official data allowed us to determine some population characteristics that provide information on the state of the resources of the traditional hunting species of the brown hare under the conditions of a powerful prey pressure and other anthropogenic factors in the hunting grounds of the Ryazan and Tula regions. The population analysis included the study of static (the number and density of the population of hares, the volume of prey, as well as the long-term average value of the number) and dynamic (the dynamics of the number and volume of prey, the absolute and relative rate of change in the population size) indicators. Primary data on the population of the brown hare were collected using the winter route census methodology. The population density of hares was determined on the total territory of the hunting grounds of the corresponding constituent entity of the federation. Based on the data obtained, it was revealed that during the study period in the Ryazan region, the number decreased by 1308 individuals (by 24.7%). In the Tula region, the number of European hares during the period under study, on the contrary, increased by 1444 individuals (by 20.2%).

Influence of climatic conditions on fire risk in Djerdap National Park (Serbia): A case study of September 2011

The Djerdap National Park in Serbia is vulnerable to fires. The variability of a fire in the Djerdap National Park is studied depending on the impact of climatic conditions. The influence was investigated on a yearly, monthly, and daily basis using data recorded at the meteorological station Veliko Gradiste. Data were analyzed for two periods: 1961-1990 and 1991-2017, and for the year of 2011. Special attention is devoted to the conditions for the emergence of the largest forest fire in the Djerdap National Park in September 2011. In this study, the Angstrom index, the Nesterov index, and method of deficit and surplus of precipitation are used to predict the risk of fire. There was an increased danger of fire in the forests in the period of 1991-2017 compared to the period of 1961-1990. Indices showing fire risk are increased for the months of June, July, and August. The September 2011 is characterized by an increase of average monthly air temperature by 3.7?C and a reduction of the total monthly rainfall of 32.3 mm compared to a long-term average value which favorable influenced to the occurrence of large forest fires.

Изменчивость показателей качества семян Pinus sylvestris L. на территории Забайкальского края

One of the most wildly spread wood species within the territory of Zabaykalsky Krai is Scots pine (Pinus sylvestris L.). Zabaykalsky Krai has a great length both from North to South (about 1000 km) and from West to East (about 800 km). This is responsible for a variety of soil and climatic conditions of growth of this wood species. There are two forest site zones (forest-steppe and Southern Siberia mountain zones) and four forest regions (Zabaykalsky forest-steppe, Baikal mountain-forest, Zabaykalsky mountain-permafrost and Zabaykalsky mountain-forest regions) within the territory of Zabaykalsky Krai according to the List of Forest Site Zones of the Russian Federation and the List of Forest Regions of the Russian Federation. It is necessary to know the long-term average values and limits of variability of seed quality indicators for the forest site zones and forest regions of the region in order to completely and adequately assess the effect of external factors on the population level of forest communities. So far, specific data have not been published for the considered region providing in relation to forest site zoning. The research purpose was to determine the long-term average values and limits of variability of weight of 1000 pcs of seeds, germinative energy and germinability for 2 forest site zones and 4 forest regions of the Krai, as well as for the Krai as a whole. These data can serve as a standard for rate setting of sowing seeds and growing high-quality planting material in forest nurseries for the forest site zone and forest region. One of the available methods for obtaining realistic data on pine forests reproduction in the region is a look back analysis of the materials of the Center for Forest Protection of Zabaykalsky Krai for the period from 1970 to 2016. As a result of the analysis, it was found that the average weight data of 1000 pcs of seeds, germinative energy and germinability for 2 forest site zones and 4 forest regions of the Krai change from North to South and from West to East. They increase in the direction from North to South: weight of 1000 pcs of seeds – by 25.3 %, germinative energy – by 16.5 %, and germinability – by 14.9 %. They decrease in the direction from West to East: weight of 1000 pcs of seeds – by 3.2 %, germinative energy – by 1.3 %, and germinability – by 0.9 %. The average weight of 1000 pcs of seeds for the Southern Siberia mountain zone was 6.0 g, for the forest-steppe zone – 7.5 g; the average values of germinative energy and germinability – 82.8 and 85.9 %, 88.7 and 91.7 %, respectively. All in all for Zabaykalsky Krai, the average weight of 1000 pcs of seeds corresponds to 6.5 g, germinative energy – 85.7 %, and germinability – 88.8 %.For citation: Pak L.N. Variability of Seed Quality Indicators of Pinus sylvestris L. within the Territory of Zabaykalsky Krai. Lesnoy Zhurnal [Russian Forestry Journal], 2019, no. 6, pp. 262–269. DOI: 10.17238/issn0536-1036.2019.6.262