Home – Home – Jornals – Siberian Journal of Forest Science 2025 number 2

Climate warming in recent decades has had a strong impact on tree populations, which will either adapt to new conditions or their mortality rate increases. The results of provenance tests can serve as a reliable basis for studying the response of trees to environmental change. Since the early 1990s, modeling of phenotypic traits of populations from climatic factors (seed origin and testing sites) and the use of such models in forestry practice have been developed in foreign countries. The objective of this review is to consider the main approaches to modeling tree responses to climate change based on provenance test data and discuss their application to climate-smart forestry. Individual transfer and reaction functions and more complex models (generalized transfer function and universal transfer and reaction functions) are useful tools for solving problems related to forecasting the response of tree populations (growth, productivity and survival) to climate change and assessing their adaptive potential, developing recommendations for seed transfer (including assisted migration) and climate-smart forest seed zoning, safing and increasing the resource and ecological potential of future forests. The results of historical and current provenance tests in conditions of rapid climate warming have special scientific and practical value. The development of reliable models for forecasting the response of forest-forming tree species populations to changing environmental conditions is possible in the presence of representative data on their phenotypic variability. This requires the formation of databases combining the results of provenance tests data.

The competition of trees for light, moisture and nutrients is usually considered as the main factor of interaction between trees, but this idea is questioned by examples of cooperation or cooperation through natural root grafting. In connection with the discussion of the phenomenon of plant root grafting, the most important question in biology about the relationship between individual species and individuals within a species has been developed. The importance of root grafting lies in its ability to influence the physiology and ecology of grafted trees, however, the processes contributing to the formation of root grafting, the factors involved and their effects are unknown. The question of whether the root grafting is accidental or a natural phenomenon is still controversial. The effect of live stumps on a growing tree remains uncertain. It is known that root grafting provides increased mechanical stability of trees in their resistance to wind and is associated with factors such as variability in root morphology, soil structure and moisture, as well as the degree of mutual root overlap. The frequency of root grafting increases both with the age of the stand and with its density. Pathogens, minerals, carbohydrates, hormones, herbicides, microorganisms and water flow through root grafting, but these processes actually have no quantitative basis. Modeling of water flows between grafted trees in mangrove forests at the quantitative level showed that there is no water exchange between trees of the same size or there is an insignificant amount; water movement occurs from the dominant tree to the oppressed one; water movement occurs from a tree growing in humid conditions to a tree growing in non-scarce conditions, and the amount of water received, compared to its own consumption, it is higher if the partner tree is larger. A quantitative approach to assessing the biological and ecological role of root grafting lays the foundation for understanding their impact on the formation and productivity of a stand.

Hundreds of forest fires are registered annually in Krasnoyarsk Krai. From the analysis of statistical data it follows that the main cause of fires are the population, their activities and life support. The greatest anthropogenic fire hazard is observed in the Central Siberian subtaiga-forest-steppe region. In order to assess the anthropogenic fire hazard of the forests of this forest region, studies were conducted that allowed us to identify the causes of forest fires and the main areas of their occurrence in this territory. Zoning of the forest territory of the Central Siberian subtaiga-forest-steppe region by the degree of anthropogenic fire hazard was developed, taking into account the risks of anthropogenic fire hazard in forestry’s. Regionalization of the forest territory by the degree of anthropogenic fire hazard will be useful in planning a set of preventive fire prevention measures and will help reduce the possibility of forest fires.

Possible causes of damage to pine stands in Krasnoturansky Bor in 2022 were studied. Remote sensing data and indicators characterizing the current state of trees were used for the analysis. NDVI values of different forest areas were considered and the moment and intensity of tree damage were estimated based on these indicators. The spatial distribution of trees by the level of damage along the selected transect was studied and it was shown that the level of damage decreases linearly with increasing distance to the forest edge. Based on the results obtained, it is assumed that the cause of the damage could be a chemical burn of trees caused by herbicides when treating agricultural land near the forest edge to destroy weeds. The patterns of change in the current state of trees after impacts were studied depending on their state before damage and the state of trees before the impact on the crowns. To assess the current and retrospective states of trees, a set of indicators is proposed, including the characteristics of the spectra of the first differences in the widths of annual rings of trees in the damage zone 2-20 years before the date of damage, dielectric indicators of tree tissues, and response functions of remote characteristics of stands. It is shown that with the same visual state of trees before and after damage, their response to the impact differs significantly and some of the trees of condition category 1 according to visual features should be classified as trees with a certain level of weakening as a result of the impact. The use of a set of methods made it possible to assess the response of trees to the impact depending on their initial state before the impact.

The results of a study of the impact of current climate change on the dynamics of turanga (syn. Euphrates poplar), Populus diversifolia Schrenk) radial growth of trees in tugai forests (a form of riparian forest of semi-arid area) of Kazakhstan are presented. The studies were carried out in the study sites (SS) within the floodplains of the Ili river and the Syrdarya river. It has been revealed that since the beginning of intensive warming and aridization of the climate since the late 1990s, the radial increment of Turanga growing in the SS “Ili” has decreased 4-fold, while in the SS “Syrdarya” - 2.5-fold. Climate correlation response functions revealed that climate change since the late 1990s modified reaction of the trees to climate factors in the SS “Ili”. This was expressed in the appearance of their negative reaction to increased April-July air temperatures and a positive reaction to increased June precipitation. Current climate change has not affected the climatic response of trees in the SS “Syrdarya”. Thus, it is shown by dendrochronological study of Turanga that in some cases the response of woody species to climate warming could be offset by other, factors, for example, deficit of available soil moisture and anthropogenic impact. It is assumed that the radial increment values of Turanga trees can be used in the studies of the influence of various hydrological regimes of rivers on tugai forests productivity.

Based on the analysis of long-term forest planning materials of the belt pine forests and a reconstructive survey of the state of pine forests of the Aleus forest massif, which underwent selective cutting, it was established that over 80 years of their use, due to a decrease in the density of tree stands, a significant disorder of the forest cover occurred, and the productivity of pine stands significantly decreased. At the same time, mature and overmature uneven-aged pine stands of medium and low productivity began to significantly dominate in pine forests, which reduced the resistance of the forest cover to the impact of exogenous natural and anthropogenic factors, in particular fires. It is predicted that as a result of such a rate of transformation of the age structure of the pine forest, autonomously existing young stands, middle-aged, maturing pine stands will disappear in the next 80 years. Following this, due to the accumulated forest litter and developed grass and shrub cover, forest fires will increasingly occur, which will activate the forest formation process, worked out by nature over millions of years of the existence of the light coniferous species - pine. To eliminate these undesirable consequences, it is recommended to replace selective cutting with classic narrow-clear-cutting.