Home – Home – Jornals – Siberian Journal of Forest Science 2023 number 6

The capsule review of the scientific editor for the thematic issue of the Siberian Journal of Forest Science, 2023, number 6 is presented, dedicated to the studies in forest pyrology.

On the territory of Central Siberia, hundreds of forest fires occur annually, spreading over vast areas. An analysis of the dynamics of forest fires showed that in recent decades the number of fires and the burned area have increased significantly. The average area of one fire has also increased, which indicates the insufficient effectiveness of the organization of forest fire protection. The maximum number of fires occurs in the Nizhneangarskiy taiga region, where pine forests predominate, in which cutting have been actively carried out since the middle of the last century. The largest burned area was registered in the Central Siberian plateau taiga region, where forests are inaccessible and a zone control by only remote-sensing instruments has been allocated. The largest number of fires from thunderstorms was also recorded in this forest region (93.1 %). The main number of large and catastrophic fires operated in the control zone. The meteorological factors influencing the occurrence of forest fires are analyzed and regression models of the dependence of the number of forest fires on temperature and precipitation for different forest regions are obtained. The main causes of fires are the emergence of a large number of fires sources due to the intensive economic development of forest areas and increased thunderstorm activity due to climate change. The use of a regression model of the relationship between the number of forest fires and the average air temperature and the amount of precipitation for the fire season allows to qualitatively estimate the system of protecting forests from forest fires. At the same time, in some forest regions, there is a decrease in the effectiveness of protecting forests from fires, the increase in the number of which is due to climate change.

The dynamics of vegetation fires on the territory of the Arctic zone of Siberia (64-74°N, 60-150°E) was studied under the conditions of observed climatic changes at the turn of the XX - beginning of the XXI centuries. In the study area, four sectors with an interval of 20° were considered on the longitude gradient, so that the longitude boundaries for each sector coincided with the boundaries of the basins of the large rivers Ob, Yenisei (with Khatanga), Lena, Yana, Indigirka, and Kolyma. As the initial data, the V. N. Sukachev Institute of Forest, Siberian Branch of the Russian Academy of Sciences fire bank was used, collected from satellite monitoring materials in 1996-2022, as well as materials of reanalysis of meteorological information on the territory of Siberia from open catalogs for more than 100-year observation interval 1900-2022. The paper analyzes the spatio-temporal variation of the main meteorological characteristics, including air temperature, precipitation, lightning activity with details on the longitude gradient. Additionally, the trends of changes in the level of heat and moisture supply and the duration of the fire-hazardous period have been restored. The measure of the relative anomalies of the main meteorological factors in the time interval 2000-2022 in comparison with the average statistical norms of the 100-year period and the relative rate of their change in the modern climate are revealed. Geospatial interpolation was performed by means of geoinformation systems. Qualitatively and quantitatively, the level of connection between the burning of the Siberian Arctic in the period 2002-2022 has been established. depending on the off-season variations of heat and moisture availability.

Weather conditions are one of the important factors, which affects forest fire danger. Taking into consideration different methodical approaches (in particular, to accounting for precipitation) and differences between forestry and natural climatic conditions, also different density the weather stations, the values calculated according by these methods differ significantly in different forest areas. In order to correctly estimate the methods quality and correctly interpret the results which were obtained, it was developed special toolkit allowing to do the necessary preliminary processing and data visualization in the form of an interactive panel. Existing approaches were based on linear Pearson’s correlation coefficient. At the same time this criterion can be applicable in case when the source data are distributed according to normal distribution law. ISDM-Rosleskhoz formed Big Data, which show it is not true. The new approach differs in that the source data are previously transform logarithm method, which increases accuracy of the obtained estimations. The developed toolkit allowed to conduct comparative analysis of the main methods, which are used in Russia. Method of humidity indicator taking into account hygroscopicity (PVG) shows the best results - (30 %), method of humidity indicator 2 (PV-2) is in the second place (26 %), method of humidity indicator 1 (PV-1) is located in the third place (20 %), Nesterov’s method is in the last place (13 %). The number of forest fires doesn’t allow to obtain reliable result in the other area (11 %). The prepared interactive map by the authors in combination with a dynamic graph allows to visualize comparative results to the forest areas level, inside subjects of the Russian Federation thereby simplifying interpretation the obtain results. The total results can be used for improvement forest fire danger scales depending on weather conditions.

Due to the intensive industrial development of the territory of Krasnoyarsk Krai, significant changes have taken place in the vegetation cover and the number of fire sources has increased. Due to climate change, the number of lightning discharges, which are the main cause of forest fires in the underdeveloped northern territories of the region, has also increased. The development of a regional fire hazard scale for weather conditions is caused by the fact that the existing unified federal fire hazard scale for weather conditions does not accurately characterize the fire hazard of forest areas in the region and does not allow rationally regulating the work of forest fire services and forestry. On the basis of data on the number and area of forest fires and the causes of their occurrence, generalizations and analysis of the timing of fires and the causes of fires in the forest areas of Krasnoyarsk Krai were performed. It is revealed, that in modern conditions the area of the region is characterized by an increase in fire activity. Due to the complexity of the relief, the diversity of climatic and forest conditions for each forest area, we have constructed regional fire hazard scales for weather conditions and compared them with the unified federal scale. The use of fire hazard scales developed by us for the forest areas of the Krasnoyarsk Krai will allow timely detection and extinguishing of forest fires and, consequently, reduce damage from forest fires.

To improve forest fire protection, large-scale vegetation fuel maps (VF) are needed. The technology for creating VF maps was developed at the Sukachev Institute of Forest SB RAS. It includes methods for making maps based on available forest inventory data, in the process of a new forest inventory, in the process of forest planning, or autonomous creation of large-scale VF maps for limited areas using aerial or ultra-high resolution satellite images. To apply any of the above methods, it is necessary to determine the types of primary fire carriers (PFC), the main group of vegetation fuels, which, when sources of fire appear, under certain weather conditions, causes the possibility of the emergence and spread of flame combustion throughout the territory. PFC types are reflected on the map itself, and other VF groups are reflected in the attached pyrological description, which is an abbreviated forestry description and information about a PFC type for each forestry plot, taking into account the critical drought class according to weather conditions and the period of a fire season. The article discusses the methodological issues of developing an identifier of PFC types on the example of Krasnoyarsk Priangar’e, since adaptation is required for its use in other regions. An example of the identifier given was used in the visual inventory during the forest management of a number of nature reserves. The result was a GIS-based information database for prompt creation of large-scale VF maps that can be used to assess the current natural fire hazard depending on weather conditions and to predict the behavior of occurring fires.

An assessment of the state of forest lands disturbed by fires, logging and insects in the foothills of the Eastern Sayan Mountains in the forest formations inherent in the study area (Siberian stone pine ( Pinus sibirica Du Tour), fir ( Abies sibirica Ledeb.), Scots pine ( Pinus sylvestris L.), spruce ( Picea obovata Ledeb.), larch ( Larix sibirica Ledeb.), birch ( Betula pendula Roth), aspen ( Populus tremula L.)) as well as in forest crops was carried out. The impact of fires, insects, logging, and windfalls was found to result in degradation of the forest health conditions of all forest formations within the boundaries of the foothills of the Eastern Sayan Mountains. Characteristics of natural reforestation on disturbed areas of forest lands were revealed. Unsatisfactory reforestation was observed on most of the disturbed areas of forest lands due to proliferation of the dense grass cover, the formation of a thick duff, the growth of sphagnum (Sphagnum L.) and the occurrence of frequent fires. In cases where there is a sufficient amount of healthy regeneration, natural reforestation occurs by vegetative propagation of soft-leaved low-value tree species (birch and aspen), which, in turn, inhibit the young immature generation of coniferous trees (including forest plantations) due to shading and competition for soil nutrients.

An assessment has been made of changes in the stocks of forest combustible materials in large grass-green moss fir forests in the southern taiga subzone of the Krasnoyarsk Krai. The object of the study was dark needle coniferous with a predominance of the Siberian fir ( Abies sibirica Ledeb.) of tall grass-green moss forest type, damaged by four-eyed fir bark beetle ( Polуgraphus proximus Blandford). It has been established that the main mortality of trees occurs in trees of medium diameter, which were subjected to significant competitive pressure from large-sized trees. An assessment of forest combustible materials stocks (living ground cover, fallen wood combustible materials and litter) was carried out. It has been established that in disturbed dark needle coniferous stands in the 8-10^th year from the beginning of the bark beetle’s impact, the stock of forest combustible materials increases (from 24.01 to 41.53 t/ha). The increase was mainly due to fallen wood combustible materials (30.84 t/ha). In the disturbed stands, a significant increase in the reserves of the grass-shrub layer was also noted (from 0.31 to 1.93 t/ha).

Forest ecosystems of the Anyuy river basin were chosen as the object of study, which have undergone significant changes due to wood harvesting, starting in the 50-60s of the twentieth century, and catastrophic fires in the late 1990s and early 2000s. The purpose of the study was to study the course of post-fire succession in the coniferous-deciduous forests of the Anyuysky National Park, for which 21 sample plots were established in the mountainous part of the basin of the middle and upper reaches of the Anyuy river, on its the right bank, in places affected by forest fires in different years. Quantitative recording and assessment of silvicultural and forest survey indicators of the stand, the lower stand layer and undergrowth were carried out on the sample plots. During the study, it was found that throughout the surveyed territory, young flat-leaved birch ( Betula platyphylla Sukaczev) trees aged from 15 to 30 years were formed with a single participation of broad-leaved species, such as small-leaved maple ( Acer mono Maxim.), Take linden ( Tilia taquetii C. K. Scheind.), Mongolian oak ( Quercus mongolica Fisch. ex Ledeb.), Manchurian ash ( Fraxinus mandshurica Rupr.) etc. As a result of fires, due to the composition of the stands, native coniferous species disappeared as Ayan spruce ( Picea jezoensis (Siebold & Zucc.) Carrière), white fir ( Abies nephrolepis (Trautv. ex Maxim.) and Korean pine ( Pinus koraiensis Siebold et Zucc.), which were noted in the composition of the undergrowth, and appeared there due to favorable conditions developing for these shade-loving species under the canopy of flat-leaved birch. With movement to the east and with increasing altitude above sea level, the participation of Ayan spruce in the composition of the undergrowth increases, however, in general, the species diversity in the composition of the layers decreases from 19-40 to 4-27 species. The composition of the undergrowth is dominated by flat-leaved birch and Cayander larch ( Larix cajanderi Mayr), the share of the main species accounts for about 60 % of the total amount of undergrowth. Mostly, the undergrowth is reliable (78 %), 56 % of it has a height of more than 1.5 m. In the shrub and grass-shrub layers, representatives of indigenous coniferous-deciduous forests are noted: Manchurian hazel ( Corylus mandshurica Maxim.), Amur barberry ( Berberis amurensis Rupr.), filamentous cornflower ( Thalictrum filamentosum Maxim.), Waldsteinia Maksimovich ( Waldsteinia maximowicziana (Teppner) Prob.) etc.

The patterns of restoration of the ground vegetation after experimental fires of different intensity (924-4275 kW/m) in the southern taiga pine forests of the Nizhnee Priangar’e region are considered. Forest fires, depending on their intensity, lead to a decrease in species diversity (Shannon index), species richness, projective cover and ground biomass of grasses and shrubs. On the 12^th and 13^th years of the pyrogenic succession, the species richness of the grasses and shrubs was 60-75 % represented by species of the pre-fire community. The percent cover of the dominant ground layer Vaccinium vitis-idaea L. was 66-84 % of the pre-fire value. The aboveground biomass of the grasses and shrubs was 43-68 % of the pre fire value. Fires of medium and high intensity led to the death of the moss-lichen layer. After a fire of low intensity, the mosses were preserved in the areas not covered by fire. In the 12^th and 13^th years after the fires, the percent cover of the moss-lichen layer was 15-26 % of the pre-fire value. Pre-fire mosses as Pleurozium schreberi (Willd. ex Brid.) Mitt. and Dicranum polysetum Sw. are restored in the ground cover, and pioneer lichens of the Cladonia genus as: Cladonia botrytis (K. G. Hagen) Willd, Cl. cenotea (Ach.) Schaer., Cl. cornuta (L.) Hoffm., Cl. deformis (L.) Hoffm., Cl. gracilis (L.) Willd appear. Ground fires led to a change in the structure of pre-fire plant microgroups. In the 12^th year after the low-intensity fire, pre-fire microgroups of Vaccinium vitis-idaea -herbs-green moss and Vaccinium vitis-idaea -green moss prevailed. In the 13^th year after a medium-intensity fire, within the boundaries of the pre-fire microgroup of Vaccinium vitis-idaea -lichen-green moss a monodominant microgroup of Vaccinium vitis-idaea was formed. The high-intensity fire led to an increase in the number of plant microgroups. In the ground layer were dominated by plant microassociations as - Cladonia - Polytrichum , Vaccinium vitis-idaea - Polytrichum , herbs- Polytrichum , Polytrichum , Maianthemum bifolium , Vaccinium vitis-idaea - Lycopodium - Polytrichum , Vaccinium vitis-idaea - Cladonia , Cladonia.

The influence of natural ground fire of varying intensity on the growth processes in the stems of Scotch pine ( Pinus sylvestris L . ) trees growing in the Krasnoyarsk forest-steppe was studied. The primary reaction is the decrease in the number of cells in the zones responsible for the formation and development of phloem and xylem cells - cambium, growth by expansion, secondary wall thickening - with increasing in the impact degree of the stem by fire. Thermal impact causes the decrease in moisture in the developing layers of phloem and xylem. These changes in the conditions of cell morphogenesis lead to a decrease in the number of cells produced by the cambium towards the phloem and early xylem tracheids. In the post-fire period, the structure of transport routes (width of rays and their content in tissues), which provide the supply of photoassimilates to developing tissues, changes. The width of the rays in the phloem and xylem increases. The content of rays in the xylem also increases with the degree of impact. In the phloem, the content of rays increases with an average degree of stem damage and decreases with an increase in the degree of damage. At the same time, the content of axial parenchyma in the phloem increases. In the radial and axial parenchyma of the inner bark the content of starch, being reserve pool of carbohydrates for growth processes, varies depending on the degree of exposure to fire on the stems. At the end of the growth season, the number of cells in the formed layer of conductive phloem decreases with increasing in the degree of fire damage to the stem. The volume of the ray system (width of ray and their content), on the contrary, increases significantly with increasing fire impact. In the xylem, as a result of fire exposure, fewer early and late tracheids are formed, their sizes decrease, and the amount of biomass accumulated in the cell walls decreases. In October, after the end of growth processes, there is no starch in the radial and axial parenchyma of the inner cortex.

An experience of eliminating peat-bog fires in summer period on the territory of Sverdlovsk Oblast is summarized in the article. It was found that most peat-bog fires develop from fugitive grassroots fires in May, when forest fire peak is observed in the region. Most often, peak fires occur on abandoned drained peat bogs. When a runway ground fire spreads across an uncovered peat bog in areas with bare peat or with a significant supply of ground combustible materials combustion deepens into a peat deposit and multifocal peat-bog fires are formed. In addition, the detection of fires in drained peatlands in spring is often associated with peat fires that were not extinguished last year. The most effective way to eliminate peat-bog fire is flooding, in which special dams are created up to 0.5 m high, which prevent the discharge of water along the relief elements streams, and channels. The first dam is created in the lowest place of the smoldering centers and then a cascade of additional dams is created up the terrain relief. Each dam should hold the water level up to 0.5 m. It is experimentally established, that by the method of flooding 80 % of all peat-bog fires can be extinguished. Where it is impossible to extinguish fire by flooding, it extinguished with a concentrated stream of water. After the elimination of peat-bog fire it is required long term monitoring of the extinguished area, since it is possible that open smoldering foci will reignite.

An analytical review of satellite navigation systems, devices for receiving and processing spatial information, in the context of their use in monitoring and extinguishing fires in the natural environment, is presented. Satellite navigation systems are considered both in terms of user devices and their global organization. Promising Russian and foreign developments in the field of satellite navigation and information transmission are discussed, which can significantly increase the efficiency of fire extinguishing and the safety of fighting fire in the natural environment. The most optimal option for controlling the forces and means of fire extinguishing has been determined, which provides for the construction of a system that combines the possibilities of using both radio and satellite communication channels. This approach will significantly improve the safety of monitoring and fighting wildfires, as well as organizing a modern reliable and independent decision support system, thereby significantly improving the quality and economic efficiency of forest fire fighting. The necessary changes are proposed that are appropriate to overcome the existing technological gap between Russia and the leading countries in the field of informatization of fighting fires in the natural environment.

Forests on the territory of the Republic of Belarus are potentially fire hazardous. The organization of work to protect forests from fires at the republican and territorial levels is carried out by the Ministry of Forestry, its relevant structural divisions, legal entities involved in forestry, as well as emergency departments (aircraft protection of forests) of the Ministry of Emergency Situations. In the forest fund in 1959-2022. 139.7 thousand fires occurred on a total area of 222.9 thousand hectares. Based on the analysis of long-term statistical data, it was revealed that the main cause of forest fires is the anthropogenic factor. Methods and means for forecasting and monitoring forest fires and regulating the work of forest fire services are presented. A multi-level system for monitoring forest fires using ground, aviation and aerospace methods operates throughout the country, which ensures the efficiency of their detection. Information on fire-prevention arrangement of the forest fund is presented. In accordance with forest fire zoning, the country’s territory is divided into three forest fire zones, which makes it possible to objectively plan labor and financial resources for fire prevention in the forest fund. The main units of forest fire services are fire-chemical stations of various types, as well as points where fire equipment is concentrated. To fight forest fires, aviation equipment, fire trucks, all-terrain vehicles, water delivery tanks, motor pumps of various capacities, forest fire modules, backpack fire extinguishers of various modifications, fire-retardant chemical compositions and other specialized equipment are used. Registration of forest fires is carried out by legal entities engaged in forestry and their higher authorities on the basis of acts on forest fires, and state registration is carried out by the National Statistical Committee. Ways to improve the protection of forests from fires are outlined, ensuring minimization of their area and damage caused.

The article presents the results of thirty years of international cooperation on the problem of forest fires with scientists from Europe and America. During this period, international conferences, meetings, and joint experimental studies were conducted on forest fires modeling and post-fire succession monitoring in the boreal forests of Siberia. The Bor Forest Island Fire Experiment was conducted in 1993 in the Krasnoyarsk Region to study the burning of biomass in the Middle Taiga pine forest. The experiment was a simulated controlled high-intensity forest fire. The experimental fire behavior and fire emissions parameters obtained made it possible to conduct post-fire monitoring and assess the effects of fire on forest components. The Bor Forest Island Fire Experiment was unique in its size and long-term monitoring of post-fire reforestation. In 1996, joint international studies were launched to conduct controlled burning of logged sites in order to reduce fire danger and stimulate reforestation processes in clear-cuts in lowland and mountain fir forests with ground vegetation as mixed grasses and green mosses. In order to study the impact of fires on ecosystem components, experiments were conducted during the same period to simulate fires of varying intensity in Southern Taiga and Middle Taiga pine forests. In terms of the level of comprehensive research and the depth of their study, the experiments are unique and were conducted for the first time for the boreal forests of Russia. After controlled burning and experiments, the process of post-fire reforestation was monitored. Scientific cooperation and exchange of experience with colleagues from other countries have enriched domestic forest fire science with foreign experience and knowledge, and also made the results of research by Russian scientists available to the international scientific community.