Pinus Sibirica Research Articles

Biological productivity of pine stands growing in southern mountain dark taiga of Krasnoyarsk krai

The research is devoted to studying the biological productivity of modal Siberian pine stands of the Siberian taiga zone (southern ecoregions). Forest stands of the IV bonitet class, including Bilberry- and Bergenia-dominated forest types, were studied. The study was based on mathematical modeling of the forest stand growth combined with the conversion-volumetric method for determining the amount of phytomass converted to sequestered carbon. Tables were proposed that reflect the quantitative characteristics of the age dynamics in phytomass and the carbon contained in it. The range of changes in the phytomass in modal Siberian pine stands throughout all age classes in the Bilberry-dominated forest type was from 40.2 to 297.7 t m−3, in the Bergenia-dominated forest type - from 52.6 to 292.1 t m−3. In Siberian pine forests of the IV bonitet class, carbon pools were concentrated in the Bilberry-dominated type from 37.5 to 147.6 t⋅C⋅ha−1, in the Bergenia-dominated type - from 48.1 to 147.2 t⋅C⋅ha−1. The results supplemented the existing database on the biological productivity of taiga forests and can be used in organizing forest monitoring and implementing regional environmental programs, including calculating the carbon cycle.

Genetic polymorphism of mountain-taiga populations of siberian stone pine in Kusnetsky Alatau

Aim. Study of DNA polymorphism of 7 coenopopulations of Siberian stone pine (Pinus sibirica) growing in theKuznetsk Alatau. Methods. Nuclear microsatellite loci developed for P. sibirica were used as genetic markers. Results. 44 allelic variants were identified from 11 nuclear microsatellite loci, which significantly differ in the composition and frequency of occurrence of the studied P. sibirica coenopopulations. The highest level of allelic diversity is found in loci Ps_80612 and Ps_1502048, where 8 and 7 alleles were identified, respectively. The calculation of the main parameters of genetic diversity showed a relatively low level of polymorphism in the studied samples (NA = 3.078; NE = 1.877; HE = 0.445; HO = 0.401). The assessment of the degree of genetic differences between populations using the Nei genetic distance (DN) showed that, despite the low genetic differentiation (DN varies from 0.019 to 0.061), the differences between them can be traced quite clearly. Conclusions. Differences in the level of genetic polymorphism of P. sibirica is defined by the presence of orographic and phytocoenotic barriers between coenopopulations, as well as a high degree of ecological and anthropogenic extremity of individual growth sites.
 Keywords: Pinus sibirica, Kuznetsk Alatau, microsatellites, genetic diversity, heterozygosity.

Stationarity of climate-growth response is only marginally influenced by the soil moisture regime in Western Siberia

Stationary (time-stable) relationships between a tree-ring proxy and climatic drivers are a prerequisite for using tree rings as paleo-climatological archives, but non-stationarity has been detected worldwide. Here we use a classical, temperature-sensitive treeline site in Western Siberia to specifically test the influence of micro-site conditions (wet versus dry) on the stationarity of climate-growth relationships in three co-existing conifer species: Larix sibirica Ledeb., Picea obovata Ledeb., and Pinus sibirica DuTour. We test two commonly used tree-ring proxies, annual tree-ring width (TRW) and maximum latewood density (MXD), using moving windows and the bootstrapped transfer function stability test (BTFS). Summer temperature is the main driver of tree growth in all three species, but non-stationarities exist in all species and both tree-ring proxies. For TRW, we found stationarity only for larch from both micro-sites, while for MXD, we found stationarity for spruce from both micro-sites, and for pine from the wet micro-site. Micro-site variability did not seem to affect stationarity in any systematic way. We highlight the necessity to systematically test the influence of different methods of stationarity tests, since BTFS was more sensitive than moving-window analysis. Taken together, our results underscore the importance of testing the assumption of stationarity for diverse micro-sites, different species and proxies at all sites prior to any tree-ring based temperature reconstruction, since even within one site results can be drastically different.

Changes in Soil Microbial Community Structure Following Different Tree Species Functional Traits Afforestation

The soil microbial community structure is critical to the cycling of carbon and nitrogen in forest soils. As afforestation practices increasingly promote different functional traits of tree species, it has become critical to understand how they influence soil microbial community structures, which directly influence soil biogeochemical processes. We used fungi ITS and bacteria 16S rDNA to investigate soil microbial community structures in three monoculture plantations consisting of a non-native evergreen conifer (Pinus sibirica), a native deciduous conifer (Larix gmelinii), and a native deciduous angiosperm (Betula platyphylla) and compared them with two 1:1 mixed-species plantations (P. sibirica and L. gmelinii, P. sibirica and B. platyphylla). The fungal community structure of the conifer–angiosperm mixed plantation was similar to that of the non-native evergreen conifer, and the bacterial community structure was similar to that of the angiosperm monoculture plantation. Fungal communities were strongly related to tree species, but bacterial communities were strongly related to soil nitrogen. The co-occurrence networks were more robust in the mixed plantations, and the microbial structures associated with soil carbon and nitrogen were significantly increased. Our results provide a comparative study of the soil microbial ecology in response to afforestation of species with different functional traits and enhance the understanding of factors controlling the soil microbial community structure.

Holocene Fire Regime Changes in the Southern Lake Baikal Region Influenced by Climate-Vegetation-Anthropogenic Activity Interactions

Catastrophic fire years that have taken place during the last decade in Siberia, and more generally within the boreal forest, have been directly linked to global warming and had strong repercussions on boreal ecosystems and human populations. In this context the study of the past dynamics of these fires is essential for understanding their links with climate, vegetation and human activity changes on longer time scales than the last few decades. However, few studies on fire dynamics are available for Siberia, and none have been conducted for the entire Holocene period. This study presents the first fire history reconstruction of this area during the Holocene based on charcoals sequestered in sediments of two lakes located on the southern shore of Lake Baikal, in Siberia. The results show a similar trend in the two lakes, with high frequency and high peak magnitude during the Early Holocene and low magnitudes after 6500 cal. yr BP. This difference is interpreted as crown fires versus surface fires. According to pollen records (Dulikha, Vydrino, Ochkovoe) available near the studied lakes, a vegetation transition occurred at the same time. Picea obovata, which has a tree structure prone to crown fires, was dominant during the Early humid Holocene. After 6500 cal. yr BP, conditions were drier and Pinus sylvestris and Pinus sibirica became the dominant species; their tree structure favors surface fires. In addition to vegetation dynamics, the nearby pollen sequence from Dulikha has been used to provide quantitative estimates of past climate, indicating an Early to Middle Holocene climatic optimum between 8000 and 5000 cal. yr BP and an increase in temperatures at the end of the Holocene. These results have been compared to outputs from regional climate models for the Lake Baikal latitudes. Fire dynamics appear to have been more linked to the vegetation than climatic conditions. Over the past 1500 years, the greater presence of human populations has firstly resulted in an increase in the fire frequency, then in its maintenance and finally in its suppression, which may possibly have been due to very recent fire management, i.e., after ca 500 cal. BP.

Novel Materials for Myco-Decontamination of Cyanide-Containing Wastewaters through Microbial Biotechnology

This study examined the effectiveness of decontamination of industrial cyanide-containing water using mycelium-based lignocellulosic materials. These results suggest that fungi biomass and plant substrates can be used successfully in the treatment of wastewater contaminated by cyanide. Fungi were isolated from old wood samples taken from a tailing dam with high cyanide content (more than 20 years in semi-submerged condition). All isolated fungi belonged to the genus Fusarium. Fusarium oxysporum Schltdl. is most effective for biodegradation of cyanide-containing wastewaters (even at low temperatures). The most optimal lignocellulosic composition for production of mycelium-based biomaterial for biodegradation of cyanide wastewater consists of a uniform ratio of Siberian pine sawdust and wheat straw. The high efficiency of mycelium-based materials has been experimentally proven in vitro at 15-25 ° C. New fungal biomaterials are provide decrease in the concentration of cyanide ions to 79% (P <0.001). Large-scale cultivation of fungi biomass was carried out by the periodic liquid-phase cultivation. The submerged biomass from bioreactor was used as an inoculum for the production of mycelium-based materials for bioremediation of cyanide wastewater in situ (gold mine tailing).

Comparative Assessment Of Some Physical And Mechanical Properties Of Wood Of Different Scots Pine Climatypes

For a more efficient and rational use in the production of Scots pine wood of various geographical origin, it is necessary to know its physical and mechanical properties. The purpose of this study was to determine the physical and mechanical properties of wood of 17 climatic ecotypes of Scots pine and to carry out a comparative analysis of the indicators obtained for the studied climatypes separately and when they are grouped into subspecies in accordance with the classification of L.F. Pravdin. The range of the geographical origin of the places of seed procurement is from 47 to 62° north latitude and from 22 to 85° east longitude. The modern density universal testing machine MTS INSIGHT 100 was used for research. As a result of the research, it was found that the density of wood in an absolutely dry state varies from 370 kg/m3 (Kursk climatype) to 524 kg/m3 (Volgograd climatype), and at 12% humidity – from 397 kg/m3 (Kursk climatype) to 550 kg/m3 (Volgograd climatype). The index of the strength of wood of the studied climatypes for compression along the fibres was from 32 MPa (Kursk climatype) to 54 MPa (Volgograd climatype), and for static bending – from 55 to 92 MPa for the Vologda and Ulyanovsk climatypes, respectively. Distribution of Scots pine climatypes into subspecies in accordance with the classification of L.F. Pravdin and the obtained data on the physical and mechanical properties of wood have a certain pattern. The maximum density of wood at 12% moisture is typical for the European Scots pine subspecies is 497±8 kg/m3 , the minimum value of this indicator for the Siberian Scots pine subspecies is 423±30 kg/m3 . An intermediate position is occupied by the subspecies of Lapland pine and Forest-steppe pine with values of 483±16 and 464±12 kg/m3 , respectively. The strength index of wood in the studied subspecies for compression along the fibres ranged from 47±1 MPa (European subspecies) to 33±4 MPa (Siberian subspecies), in the Lapland pine subspecies – 44±2 MPa and somewhat lower in the Forest-steppe pine subspecies – 42±2 MPa. The maximum value of the static bending strength of wood is typical for the European pine subspecies – 78±4 MPa, and the minimum – for the Siberian pine subspecies – 61±14 MPa. This indicator turned out to be equal in subspecies of forest-steppe and Lapland pine and amounted to 72±4 MPa. The practical value of the work lies in identifying the existing differences and variability among climatypes according to the studied physical and mechanical properties of wood and selecting the most promising of them for further breeding purposes

The Ecological State of the Soils of the Industrial City of Usolye-Sibirskoye

The results of a study of the state of soil cover in the sphere of influence of an industrial city in the conditions of Eastern Siberia are presented. In the town of Usolye-Sibirskoye (Irkutsk region), industrial nature use dominates. The acid-alkaline conditions of the soils of the city were transformed relative to the background soils. An assessment of the biochemical activity of soils is given as an integral indicator, which was assessed by the express method. Three groups of soils were identified according to the level of their activity. The diversity of soil microbiocenosis has been established. A tendency towards a decrease in the qualitative composition of microscopic fungi in industrial zones has been noted. It is recommended to increase the planting area of woody vegetation (poplar, birch, Siberian pine, fir, bird cherry, wild rose) and sowing herbs (clover, sweet clover, timothy grass, and bluegrass) to improve the environment.

Внутрипопуляционная изменчивость качества шишек и семян кедра сибирского на плантации с разреженной посадкой

For Siberian stone pine (Pinus sibirica Du Tour), a valuable nut-bearing species, the development of a system of selectively significant signs of crop quality is relevant, which is necessary for the introduction of this species into culture. Were studied the level and nature of variability in the quality of cones and seeds in 32 trees on a 42-year-old plantation with sparse planting trees of 8×8 m (south of the Tomsk region). The used system of traits reflects the sequence of the crop formation process — from cone differentiation to seed ripening. We are establish that the maximum level of variability is observed in characters characterizing deviations in seed embryogenesis, leading to an increase in the proportion of underdeveloped, empty and incomplete seeds. The level of variability of traits caused by the influence of the mother plant is much lower on the features of the establishment, differentiation, and growth of cones (the number of scales and seeds). The signs characterizing the number of different elements of the cones have a normal distribution. Positive asymmetry and kurtosis are characteristic of the distributions of signs reflecting the level of abortion of the ovules at different stages of their development. As the final selection trait with a high level of intrapopulation variability, we are proposing to use the mass of full tree seeds per unit area of the horizontal projection of the crown. The use of this trait is promising for the search for trees combining a narrow crown with a large mass of seeds.

FUNGI COLONIZING CONIFEROUS SEEDLINGS IN FOREST NURSERIES OF MIDDLE SIBERIA

The study was carried out in four forest nurseries of Middle Siberia. Affected seedlings of Scots pine (Pinus sylvestris L.), Scots Siberian stone pine (Pinus sibirica Du Tour), and Siberian spruce (Picea obovata Ledeb.) were collected for molecular phytopathological examination. In total, 14 fungal taxa were identified in the needles and roots of the plants. The most dominant among them were Sydowia polyspora (Bref. Tavel) E., Didymella glomerata (Corda) Qian Chen L. Cai, Cladosporium herbarum (Pers.) Link, Lophodermium seditiosum Minter, Staley Millar, Phialocephala fortinii C. J. K. Wang H. E. Wilcox and Cadophora finlandica (C. J. K. Wang H. E. Wilcox) T. C. Harr. McNew. The richness of the fungal taxa was higher in the needles than in the roots of all the tree species studied. The obtained results could be used for implementing more effective phytosanitary measures in the studied nurseries.

Distribution of 137Cs in lichens, mosses and pine needles along the transect from the north to the south of Western Siberia

The 137Cs content in mosses (Hylocomium splendens), lichens (Cladonia stellaris) and the needles of the Siberian pine (Pinus sibirica) and the common pine (Pinus sylvestris) along the transect from the north to the south of Western Siberia from N. 67.5° to N. 55° has been investigated. The appearance of 137Cs here is linked to the nuclear weapon tests at Novaya Zemlya. The measurements have shown that at all sampling points south of N. 59.6° there is a very sharp decrease in the 137Cs specific activity in all components of the ecosystem (in mosses and lichens by about 20 times, and in the needles of conifers by 100 times) instead of a smooth decrease. This fact can be explained by the existence of the global atmospheric circulation consisting of three circulation cells in the Northern hemisphere. It is just around N. 60° that the boundary between the Polar cell and the circulation cell of midle latitudes is drawn. At this boundary, the counter surface air flows of these cells (in our case, a contaminated flow from the north and a clean one from the south) collide and generate the upward air flows here that take 137Cs away. In addition, there is water vapor condensation in the upward flows resulting in snowfalls, rains and thunderstorms. And with these precipitation events, large amounts of 137Cs should have fallen out to the north of the Polar cell boundary during the Novaya Zemlya tests. The areas south around of N. 60° have been supposed to remain clean, which is what is being observed.

Effects of large-scale forest fire followed by illegal logging on the regeneration of boreal forests in Mongolia

We aimed to test the hypothesis that large-scale forest fire followed by illegal logging inhibits the regeneration of boreal forests in Mongolia. For this purpose, we compared regeneration of the forest between five stands in a large-scale post-fire site, i.e., (1) undisturbed stand in the unburnt and remaining forest, (2) stand disturbed by illegal logging in the unburnt and remaining forest, (3) stand disturbed by forest fire, (4) stand disturbed by forest fire followed by illegal logging and located in proximity to the remaining forest, which acts as a seed source, and (5) stand disturbed by forest fire followed by illegal logging and located far from the remaining forest, which acts as a seed source. The stand disturbed by logging showed similar species composition of regenerated individuals as the undisturbed stand. In the stand disturbed by logging, Picea obovata and Pinus sibirica were abundant because of advance regeneration on the intact forest floor. In the stand disturbed by forest fire and that disturbed by forest fire followed by illegal logging, Larix sibirica and Betula platyphylla were abundant, and the regenerated individuals of these two species were new individuals after the disturbances. L. sibirica was abundant in the stand disturbed by forest fire because the mother trees survived the forest fire because of their thick bark. B. platyphylla was abundant in the stand disturbed by forest fire followed by illegal logging because the mother trees of L. sibirica were logged and the seeds of B. platyphylla are able to disperse further than that of L. sibirica. However, in the stand disturbed by forest fire followed by illegal logging that was located far from the remaining forest, the regeneration was much reduced because only few seeds, including that of B. platyphylla, were dispersed into this stand and sprouts of B. platyphylla were damaged by the logging operation. In addition, the regeneration of L. sibirica and B. platyphylla was likely to have been reduced for several years after the forest fire because of the loss of safe sites for their invasion by the changes of the forest floor conditions. Therefore, it is likely that large-scale forest fires that are followed by illegal logging inhibit the regeneration in many parts of the post-fire site and those parts will change into open forests of B. platyphylla or grassland.

Молекулярно-генетический анализ популяций Pinus sylvestris L. и Pinus sibirica Du Tour в Пермском крае на основании полиморфизма ISSR-PCR маркеров

DNA polymorphism has been studied, indicators of genetic diversity and genetic structure of 3 populations of Pinus sylvestris L. and 3 populations of Pinus sibirica Du Tour in the Perm Krai have been determined. In the populations of P. sibirica, 102 ISSR-PCR markers were found, of which 88 were polymorphic (P95 = 0.863), and in the populations of P. sylvestris — 113 ISSR-PCR markers, 100 of which were polymorphic (P95 = 0.885). The populations of the two studied species of woody plants are characterized by high genetic diversity. At the same time, in P. sibirica, the indices of genetic diversity were slightly higher (HE = 0.195; ne = 1.335; na = 1.330) than in P. sylvestris (HE = 0.166; ne = 1.268; na = 1.212). The analysis of the genetic structure showed that the coefficient of genetic subdivision (GST) in the two studied species of the genus Pinus are similar and amount to 0.320 in P. sibirica and 0.303 in P. sylvestris. The populations of Siberian pine and Scots pine are characterized by an average degree of genetic differentiation, since the interpopulation component accounts for 32.0% and 30.3% of the genetic diversity of these species, respectively. Using the Mantel test, a high correlation was found between genetic and geographical distances in P. sibirica populations (R2 = 0.6871), while P. sylvestris showed a low correlation (R2 = 0.0649). The data obtained are relevant for the preservation of the gene pools of the studied two species of the genus Pinus in the Perm Krai.

Two-Species Forests at the Treeline of Siberian Mountains: An Ecophysiological Perspective under Climate Change.

In an underexplored region of the East Sayan mountains, ecophysiological traits of two conifers, Pinus sibirica Du Tour and Abies sibírica Ledeb., have been studied. The goal was to predict which of the species co-dominating the same habitat is more vulnerable under prospective climate change. Along a transect from the treeline to the floodplain, photosynthetic pigment content and electron-transport rate (ETR) were measured in needles of neighboring trees of the species. From 570 to 1240 m a.s.l., P. sibirica does not suffer from stress factors during the growing season, while A. sibirica does. The latter is reflected in a decrease of pigment content and ETR with the increase of altitude. A stronger climate-change trend (probably to more dry and warm conditions) will likely favor the shift of P. sibirica upper in altitudes, and only under the pine shelter might the fir survive the changes.

Nutrient loads and ratios both explain the coexistence of dominant tree species in a boreal forest in Xinjiang, Northwest China

The resource ratio hypothesis (RRH) and the nutrient-load hypothesis (NLH) state that species coexistence is mediated by the ratios and loads (availability), respectively, of multiple limiting resources. However, few attempts to quantify these effects in mature forest ecosystems have been attempted to date. Data were collected from 300 quadrats (20 m × 20 m) spread across a 12-ha (400 m × 300 m) boreal forest dynamics plot in the Kanas Reserve of Xinjiang, Northwest China. Torus translation tests were used to analyze associations between dominant tree species and specific microhabitats. Linear mixed models were used to assess how soil nutrient availability and nutrient ratios affected the abundance and basal area of specific tree species, as well as how these effects varied across life stages. Two shade-tolerant species, Picea obovata and Pinus sibirica, exhibited opposite relationships with soil nitrogen (N) and phosphorus (P) content. Picea obovata was associated with microhabitats with high N:P ratios, while P. sibirica preferred microhabitats with low N:P ratios. The light-demanding Betula pendula was most abundant at low N and P sites. Another light-demanding species, Larix sibirica, did not show any significant habitat preferences. Furthermore, N:P ratios mainly affected species abundance, while N and P contents largely impacted basal area. Soil nutrient effects on species distributions weakened with tree age (from saplings to adults). Different microhabitats in the boreal forest had distinct soil resources. Both nutrient ratios and loads were correlated with the distribution of dominant boreal tree species, though these effects weakened as trees grew, especially for shade-tolerant species. Overall, niche partitioning due to resource variation may alleviate interspecific competition and contribute to species coexistence, and this study provides convincing proof of the importance of both nutrient ratios and loads on maintaining boreal forest diversity.

Экспресс-оценка физиологического состояния древесных растений по диэлектрическим характеристикам тканей ствола

Dielectric spectroscopy methods for estimating the state of trees were considered. Dielectric characteristics describe cell membranes and conductivity of plant tissues. A pulsed Fourier transform dielectric spectrometer of an original design was used to measure the values of dielectric characteristics. The spectrometer was connected to a portable computer, which was used to control and power it. The device design allows to expressly (in about 1s) receive information on the dielectric characteristics of the tree trunk tissues in the frequency range from 1 to 100 kHz and to process, visualize and save the results of measurements on a computer in the field conditions. Tree state estimates obtained with the pulsed Fourier transform dielectric spectrometer were compared with the visual tree characteristics and radial growth data. It is shown that there are differences in the values of dielectric characteristics in trees of different state categories and with different values of radial growth. Dielectric spectroscopy data, unlike subjective qualitative visual indicators of tree state, are quantitative and objective. The data can be obtained much faster and with less effort compared to estimates of tree characteristics by radial growth. The described method was used to estimate the state of Siberian pine (Pinus sibirica), Siberian fir (Abies sibirica) and Siberian spruce (Picea obovata) in forest plantations of the Baikal region. Studies were carried out both in control (undamaged) plantations and in those affected by bacterial infection. It is shown that the proposed method can be applied to the express state estimation of trees and the level of their damage.

Метеорологическая обусловленность семеношения кедра сибирского (Pinus sibirica Du Tour)

The dynamics of Siberian stone pine sexual reproduction in the South-Eastern part of the West Siberian Plain was studied by 13-year stationary observations. The stand age was 160–180 years, the average tree height was 22 m, and the average diameter of the trunk at breast height was 53 cm. On average, 50–60 trees were analyzed annually (in different years from 25 to 100). Cones were counted and samples were collected annually from August 10 to August 20. The resercher (usually the author of this paper) climbed each tree, knocked down the cones with operating tools (a bat and a rod), and then their number was counted on the ground. A sample of 10–15 cones was taken from each tree. Afterwards, a complete morphological analysis was performed: the number of sterile and fertile scales, and underdeveloped and developed seeds were counted. Developed seeds were analyzed by the X-ray method. To determine the weight, only perfectly full seeds selected by the X-ray pattern were used. Information on weather conditions was used according to data from the Tomsk station of Roshydromet. The main factor in the cone initiation was the amount of precipitation during 2 years before the start of this process: with an increase in the amount of precipitation, the number of cones increases. However, the final seed productivity depends to a greater extent not on the number of initiated cones, but on the success of their further development. The most important stage in the cone development was spring in the year of pollination and the main negative factor was late frosts. The degree of their negative impact is determined by the sum of the effective (above 5 °C) mean daily temperatures at which the return of frost with temperature from –3 to –4 °C occurred. Complete abortion of cones occurred only when the sum of effective temperatures was 150–180 °C. The same frost at the accumulated temperature sum of 100–150 °C killed a significant part of the cones, and the rest strongly disrupted the development. When the sum of accumulated temperature was about 50 °C, a strong frost significantly increased the loss of seedbuds at all stages of their development, thereby reducing the number of full seeds. The average temperature of September in the pollination year was an important factor in seed production. The loss of seedbuds increased significantly with its increase. The only important trait that is formed in the year of cone maturity is the weight of full seeds: it increases with the amount of precipitation from April to June of the current year.

Elemental Composition of Needle Foliage of Pinaceae Forest Forming Species in the Territory with Cumulative Environmental Damage (South Baikal Region)

The article is dedicated to the issues of sustainable development of territories with cumulative environmental damage on the basis of improving environmental analysis techniques of forest ecosystems health in Baikal region. The authors discuss the processes related to degradation of dark coniferous forests due to the emissions of pulp and paper industry. The factors affecting the development and producing capacity of forest stand are pointed out, namely highly acidic soil and heavy metals pollution. The data obtained by X-ray fluorescence analysis of needles are presented. They prove the presence of 20 chemical elements in the forest forming species of Pinaceae: Abies sibirica, Pinus sylvestris, Pinus sibirica, Picea obovata. The elemental composition of needles after the enterprise was closed is not over the exposure limit for conditionally toxic elements. The territory where the research was carried out is suitable for agriculture, tourism and recreational activities. The obtained data were used to implement new techniques of inspecting forest vegetation health.

Lateglacial and Holocene vegetation and environmental change in the Jom‐Bolok volcanic region, East Sayan Mountains, South Siberia, Russia

This study presents the first centennial‐scale multi‐proxy record from the East Sayan Mountains, which are part of the central Asian ‘water tower’ massif. The record from Lake Kaskadnoe in the Jom‐Bolok area shows changes in vegetation and climate since c. 14.2 cal. ka BP. Although the study site is in an area with active volcanism, there is no clear evidence that volcanic eruptions influenced the local vegetation. At c. 14.2–12.9 cal. ka BP, regional climate was sufficiently warm and moist to allow scattered growth of Picea, Larix and Betula nana around the lake. A cooling episode at c. 12.9–11.5 cal. ka BP is coincident with the Younger Dryas and led to the predominance of shrub tundra in the basin. Cool and moist conditions c. 11.5–9.0 cal. ka BP resulted in the spread of Pinus sibirica in the catchment of Lake Kaskadnoe. The Middle Holocene, c. 9.0–4.5 cal. ka BP, featured a warmer and drier regional climate, which led to a decrease in high‐elevation dark conifer forest. Subsequently, the onset of the Neoglacial and a cooler climate is indicated by the spread of Larix sibirica and Pinus sibirica in the study area. Lateglacial and Holocene moisture conditions in the East Sayan Mountains have primarily been controlled by the interaction of the westerlies and the East Asian Summer Monsoon and show a drying trend through time; long‐term insolation changes affected both the Monsoon and regional temperatures. The pattern of moisture decrease in the latter part of the Holocene is seen at sites in adjacent regions of the central Asian mountains.

The Role of Phytohormones in the Induction of Somatic Embryogenesis in <i>Pinus sibirica</i> and <i>Larix sibirica</i>

The contents of auxin (indole-3-acetic acid, IAA), cytokinins, and abscisic acid (ABA) were determined in explants (megagametophyte and embryo), proliferating embryonal-suspensor mass (ESM), and non-embryogenic callus of Pinus sibirica and Larix sibirica. Furthermore, the localization of hormones in the cells was studied with immunohistochemical analysis. It was shown that the formation of embryogenic cultures in both species is associated with the content of phytohormones and their localization in cells. In L. sibirica the content of IAA in ESM was about 100 times higher than in non-embryogenic calli. At the same time, a low ABA content was characteristic of embryogenic cultures. Non-embryogenic callus contains an increased content of cytokinins and ABA. The transition of somatic cells to the path of embryogenic development is characterized by elongation of cells, their asymmetric division, and localization of IAA at one of the ends of elongated cells. Non-embryogenic callus consisted of isodiametric, actively dividing cells.