Комплексная характеристика биологического разнообразия кедровых лесов на южном пределе их распространения в Западной Сибири

Сосна сибирская (кедр сибирский) ( Pinus sibirica Du Tour) имеет три экологические формы, определяющиеся условиями возобновления и формирования древостоев: возобновление свежих гарей, возобновление под пологом лиственных пород и формирование кедрового подроста под пологом светлохвойных пород, но не достигающего верхнего полога. Первые две формы возобновления наблюдаются в экотопах соответствующих условиям произрастания сосны сибирской, но сценарии формирования кедровников различны. Исследования проводились в двух типах лесорастительных условий: Западно-Саянский округ горно-таежных и подгольцово-таежных кедровых лесов (Абазинское участковое лесничество) и Южно-Хакасский округ горно-таежных темнохвойных лесов (Матурское и Копьевское участковые лесничества). В Абазинском лесничестве усредненная периодичность плодоношения кедрового насаждения составила 5 лет, а в Кузнецком Алатау - 3 года. Плодоношение кедра - прогнозируемое явление, но разнос и прорастание семян кедра - сложные процессы, связанные с зоохорным распространением и мощным воздействием трофического фактора потребителей орехов. По радиальному приросту деревьев, определенному по пням на лесосеках (санитарные рубки) Абазинского лесничества, кедровники имеют пирогенное происхождение, хороший рост в течение жизни и усыхание без потери прироста. В современной истории лесоведения вспышечная активность корневых патогенов встречается впервые. Прогноз возобновления усыхающих кедровников в среднегорной части Западного Саяна положительный. В Кузнецком Алатау подроста кедра недостаточно и лесовозобновление в крупнотравных типах леса возможно только со сменой пород. Вырубка древостоя, как и его усыхание с последующим разрастанием травостоя, способствует росту плотности населения потребителей кедровых орехов и соответственно исключает возобновление кедра. Сохранение подроста на вырубках 30-летней давности дало положительные результаты формирования плодоносящих кедровников. Организация орехопромысловых зон с запретом рубки кедра и его последующее усыхание привели к экономическим потерям ценной древесины и побочного ресурса прижизненного использования кедровых насаждений. Siberian stone pine ( Pinus sibirica Du Tour) has three ecological forms, determined by the conditions of renewal and formation of forest stands: renewal of fresh burnt areas, renewal under the canopy of deciduous trees and the formation of the Siberian stone pine undergrowth under the canopy of light coniferous species, but not reaching the top canopy. The first two forms of renewal are observed in ecotopes corresponding to the growing conditions of the Siberian stone pine, but the scenarios for the formation of the forests are different. The study was carried out in two types of forest conditions: the Western Sayan district of mountain-taiga and subgoltsy-taiga Siberian stone pine forests Abaza forestry district) and the South Khakass district of mountain-taiga dark coniferous forests (Maturskoe and Kop’evskoe forestry district). In Abaza forestry, the average periodicity of fruiting of the Siberian stone pine stands was 5 years, and in the Kuznetsk Alatau - 3 years. Fruiting of the Siberian stone pine is a predictable phenomenon, but the spread and germination of the Siberian stone pine seeds are complex processes associated with zoochoric distribution and the powerful influence of the trophic factor of nut consumers. According to the radial growth of trees, determined from stumps in cutting areas (forest health felling) of the Abaza forestry, Siberian stone pine forests are of pyrogenic origin, have good growth throughout life and dry out without loss of growth. In the modern history of forestry, outbreak activity of root pathogens occurs for the first time. The forecast for the regeneration of drying Siberian stone pine forests in the mid-mountain part of the Western Sayan is positive. In Kuznetsk Alatau, the Siberian stone pine regrowth is insufficient and reforestation in large grass forest types is possible only with a change in species. The cutting of the tree stand, as well as its drying out with the subsequent growth of the grass stand, contributes to an increase in the population density of consumers of the Siberian stone pine nuts and, accordingly, excludes the regeneration of the trees. Preservation of undergrowth in clearings 30 years ago has yielded positive results in the formation of fruit-bearing Siberian stone pine forests. The organization of nut fishing zones with a ban on Siberian stone pine logging and its subsequent drying out led to economic losses of valuable wood and a by-product resource during the lifetime use of the Siberian stone pine stands.

In the Baikal Region, there is no phenological isolation between Siberian stone pine (P. sibirica Du Tour) and Siberian dwarf stone pine (P. pumila (Pall.) Regel) since the timing of their 'flowering' coincides. Morphologically intermediate individuals, supposedly natural hybrids,occur not very often. In the west half of Stanovoye upland area four regions were investigated: Barguzinskiy, Baikalskiy, Verchneangarskiy and the Severo-Myiskiy mountain ridges. Interspecific natural hybridization was found to take place in several overlapping regions of the species' ranges; however there are some differences in frequency of natural hybrid occurrence between regions as well as within each region. Great numbers of natural hybrids are found only in a specific habitat which occurs rarely and occupies a relatively small area. At the north-east coast of Lake Baikal the lakeside zone is occupied by Siberian stone pine forests with moderate participation of Siberian dwarf stone pine in the undergrowth. The natural hybrid are widespread everywhere. The ratio of fructiferous Siberian stone pine, Siberian dwarf stone pine and natural hybrid was found to be approximately 300:10:1. About 90% of the examined natural hybrids took an intermediate position between the two parental species by most features (structure of needles, shoots, and crown), i.e. representing putatively the first generation hybrids. Therefore, in contrast to the parental species they are subjected to the destructive effect of snowbreak (broken off or dislocated from part of the root system). Like the Siberian dwarf stone pine the natural hybrid has specific root sources forming from latent buds. Therefore, the hybrids are not subjected to ageing, as well as have no internal limitation of age and size. Siberian dwarf stone pine, Siberian stone pine and their natural hybrid grow together in the Upper Angara delta in the bog regions. In the most productive sites the ratio of fructiferous Siberian dwarf stone pine, Siberian stone pine and natural hybrid amounts approximately to 60:3:1. The ratio of fructiferous Siberian dwarf stone pine and natural hybrid reaches about 20:1 in the less productive sites where Siberian stone pine is sterile. Analysis of cone structure showed that the natural hybrid have substantially increased in comparison with the species' mortality and aplasia of reproductive structures at all stages of the generative cycle, from differentiation of the seed-bearing scales to differentiation of the embryo. The portion of the ovules, which develop into the valuable seed with differentiated embryo, amounted in Siberian dwarf stone pine to 69%, in Siberian stone pine to 44%, and in natural hybrid to 25%. Thus, the fertility of natural hybrid in the Upper Angara Delta substantially decreased in comparison with the pure species; however, it was demonstrated that natural hybridization between Siberian dwarf stone pine and Siberian stone pine species occurred.

Stone pine forests in Siberia are unique for their origin, area dynamics, comprehensive productivity, and biospherical role. They are mainly mature forests for the most regions. The regeneration has two main tasks: (1) to organize the rational and ecological felling for the Siberian stone pine trees, (2) to increase young growth. In the past, the main aim of the forest management was wood production. The basic elements were mainly technical exploitability and felling ages, traditional cleaning cutting, and ”continuous” artificial regeneration, which are not suitable for the Siberian stone pine forests. New practices of the forest management and new theoretical principles have been developed by our Institute, including comprehensive evaluation, selection and growth, and creating new felling technology. Qualitative evaluations of every stand and every tree in the Siberian stone pine forests should be made.

Background. Siberian Stone pine (Pinus sibirica Du Tour) is one of the major forest-forming species at West Siberia. Climate change and anthropogenic impact lead to reduction of Siberian stone pine forests at the southern limit of distribution in lowland part of the species range. Materials and methods. Five Siberian Stone pine stands from the trailing edge in transit zone between southern taiga and forest-steppe in West Siberia were studied. Genotypes of 104 trees on 25 allozyme loci coding for 15 enzymes were determined using starch gel electrophoresis. Results. We evaluated genetic diversity, differentiation and population subdivision of Siberian Stone pine from the trailing edge in West Siberia. About 2 % of total genetic diversity was related with differences between populations (FST = 0,021). Conclusions. In our study at the southern limit of distribution in lowland part of Siberian Stone pine range there is no indication of genetic depauperation and increased differentiation in small isolated stands due to recent climate change and anthropogenic impact.

Under the canopy of the parent native berry-green-moss Siberian stone pine forest and derivatives berry-green-moss pine and birch forests on the Urals, using the previously proposed complex of light, root, and integral competition indices of the stand, a comparative analysis of the parameters of the Siberian stone pine undergrowth is carried out. Under the canopy of Siberian stone pine forest two main determining factors have a negative complex effect on the growth of the Siberian stone pine undergrowth: the light competition of the stand (the level of photosynthetically active radiation interception by its canopy) and, almost equal to it, the root competition for soil nutrition. Under the pine forest canopy with the combined negative effect of factors of light and root competition of the stand on the development of Siberian stone pine undergrowth, light competition is decisive. The effect of the root competition is less than almost two times. Under the birch forest canopy the main factor determining the development of Siberian stone pine undergrowth is the light competition of the stand. The connection with the root competition of stand is not expressed.

Рассмотрено влияние конкуренции древостоя средневозрастного сосняка бруснично-чернично-зеленомошного, пройденного выборочной рубкой ухода (прореживание), на возобновление и развитие подроста кедра сибирского под его пологом на Среднем Урале. При ежегодной разной интенсивности возобновления кедра обильное появление его всходов наблюдается в первые два года после рубки. Основным фактором, определяющим дальнейший рост и развитие подроста кедра, является уровень перехвата пологом древостоя фотосинтетически активной радиации (световая конкуренция). Корневая конкуренция соснового древостоя за почвенное питание менее выражена, что предполагает определённую адаптацию подроста кедра к ней. Introduction. The abundance of Siberian stone pine undergrowth (Pinus sibirica) under the canopy of derivative pine stands and small-leaved stands, that are considered to be potential Siberian stone pine forests, is observed rangewide. At the same time, the influence of competition of these stands on the regeneration and development of Siberian stone pine undergrowth under their canopy has not been sufficiently studied. The goal of this research is to analyze the competition of the cowberry-bilberry-green moss pine forest stand against the Siberian stone pine undergrowth. Objects and methods. The research was carried out on the basis of the micro-ecosystem approach using the earlier proposed and tested set of light, root and integral competition indices of stands under the canopy of a 75-year-old cowberry-bilberry-green moss pine forest in the northern part of eastern macro-slope of the Middle Urals after a selective care felling. The record of parameters of the stand, environment and Siberian stone pine undergrowth was made in 106 circular plots with a radius of 7 m. The undergrowth age was determined to within one year by the number of annual terminal shoots increase. The dynamics of annual generation of one-year seedlings was reconstructed according to the age structure of the undergrowth and the empirical coefficient of the survival curve. Results. Against the background of almost continuous annual Siberian stone pine regeneration of different intensity (0.1–0.8 ths. trees/ha) under the canopy of pine forest, an abundant emergence of Siberian stone pine seedlings is mainly observed in the first two years (1.7 and 1.3 ths. trees/ha) after the care felling for the stand (thinning). In 28 years after felling, the parameters of 23-35-year-old Siberian stone pine undergrowth growing in the gaps of the stand (in place of felled single trees) exceed the parameters of the trees growing in the areas under a closed canopy, where trees were not cut down by 1.5-1.8 times; in former technological corridors (skidders) - by more than twice. But over the past five years, the averaged vertical growth of terminal shoots of undergrowth is negatively closely related (R2 = 0.68) with light competition of the stand (the level of photo-synthetically active radiation interception by the canopy), and the relationship with its root competition for soil nutrition is expressed to a lesser extent (R2 = 0.31). The tightness and reliability of negative relationship (R2 = 0.68) of the average growth of terminal shoots with the complex index of integral competition of the stand, which characterizes the joint influence of these factors, is closely related to the private index of light competition. Conclusion. The thinning of pine forest by selective felling helps to reduce the competition of the stand, contributes to the successful subsequent regeneration of Siberian stone pine and development of its undergrowth. With the combined influence of factors of light and root competition of the stand, light competition is the decisive one. Less expressed root competition suggests a certain adaptation of Siberian stone pine undergrowth to the conditions of pine forest.

Destructive processes are taking place in boreal forests all over the planet, driven and catalyzed by climate change and the subsequent impact of forest pests. In Siberia, this pattern is most pronounced in Siberian stone pine forests on the southern border of the taiga zone. Taking into account the social significance of the village Siberian stone pine forests, the aim of the study has been to assess the condition of the forest cover of the Luchanovo-Ipatovsky Siberian stone pine forest in the Tomsk Region. In 2016–2017, there were 2 foci of the Siberian moth on its territory, and subsequently, stem pests have actively multiplied. A complete ground survey has been carried out on the lands of the forest area and a visual assessment of the sanitary condition of Siberian Stone pine (Pinus sibirica Du Tour) trees has been given. 21 sample plots have been laid, 45 samples of wood cores have been taken proportionally from living, shrinking and dead trees. Also, the interpretation of satellite images of the Luchanovo-Ipatovsky Siberian stone pine forest for the period from 2015 to 2023 has been carried out. It has been established that 75 % of the forest area under study is occupied by Siberian stone pine stands. The provision of undergrowth for preliminary generations is unsatisfactory. Statistical analysis has shown that stem pests have damaged trees of different generations and different diameters (p = 0.09 > 0.05 and p = 0.30 > 0.05, respectively). The course of growth with the age trend removed in groups of trees of different conditions has revealed the absence of a reliable difference in radial increment before the mass reproduction of the Siberian moth (p = 0.06 > 0.05), but it has appeared after the population outbreak (p = 0.04 < 0.05). It was the trees weakened by the Siberian moths that have been attacked by stem pests. According to our data, the total area of 2 isolated foci of the Siberian moth reproduction has been 34 ha (10 % of the total area of Siberian stone pine stands). It was in these foci that the mass reproduction of stem pests has occurred. An assessment of the disturbed areas has shown that their size is approximately 235 ha, or 70 % of the territory of Siberian stone stands. Ground-based studies have confirmed the results of space imagery interpretation, and in the medium term, a decrease in the forest-forming role of Siberian stone pine in this forest area is expected, up to the complete destruction of pure-composition stands and the ones with significant participation of Siberian stone pine in 1/2 of the current area of these stands.

The total area under the Siberian stone pine forests in Russia is 39.5 million hectares, 57.2% of which are in Eastern Siberia, including 17.5% in Irkutsk region. However, human economic activities lead to a permanent reduction in the area of Siberian stone pine forests. For example, many Siberian cities emerged in places where Siberian stone pines once flourished. Mass fires are cause enormous damage to pine nut gathering. Exploration and development of the Kovykta gas and condensate field also led to the reduction in the area of Siberian stone pine forests and in yields. In this article we have presented the retrospective analysis of pine nut business to identify its features and significance for the area, to determine the possibility of its revival. The authors provided the analysis of pine nut business on example of Zhigalovskii fir farm (FF) in Irkutsk region. It has been found that pine seeds harvesting was inefficient during the Soviet time although there were a lot of activities for the organization of pine nut business. We believe that despite the existing problems, pine nut business has the necessary prerequisites for development and great demand. Pine nut business is considered as an alternative to illegal logging. Based on that experience the prospects for development of local economy are considered

A putative interspecific hybridization in Pinaceae family was investigated. Very rarely the physiological methods were involved in hybridization processes that occurs in the hybrid zones. It is well known that in most gymnosperms, the plastid genome is inherited from the paternal component while the mitochondrion is inherited from the maternal one. Therefore functioning pattern of organelles in the hybrid plant can suggest parent, from which they were inherited. The aim of this study was to indirectly establish the inheritance energy-transducing organelles (mitochondria, chloroplast) according to their functioning. Current year needles from Siberian Stone Pine (Pinus sibirica Du Tour) and Japanese Stone Pine (Pinus pumila (Pall.) Regel) as parent species and their putative hybrids were collected from Baikal Region. The photosynthesis rate was determined by using the spectrophotometer. The study of emission CO2 under dark respiration of needle was conducted with laser optical-acoustic gasanalyzer. The quantity was measured at 1, 2 and 3 hour after experiment start. The rate of the photoreduction ferricyanide potassium was characterized by the primary photochemical processes activity at the level of photosystem II. Comparison of pure species was shown that Japanese Stone Pine had higher functional activity of chloroplast as compared with Siberian Stone Pine in spite of the fact that they are growing in similar environment conditions. Two of three analyzed hybrids had decreased activity of their chloroplasts. Unfortunately, in this case we can't conclude if the chloroplasts were inherited from Siberian Stone Pine or from Japanese Stone Pine. Chloroplast activity of the third hybrid was approximately similar to that of Japanese Stone Pine suggesting that its chloroplasts were inherited from this parent. Consequently, the Siberian Stone Pine and the Japanese Stone Pine were maternal and paternal, respectively parents of the hybrid. Compared to the Siberian Stone Pine, the Japanese Stone Pine had higher dark respiration rate. The hybrid respiration rate was similar to that of the Japanese Stone Pine suggesting that the hybrid inherited mitochondria from this species. Our findings indicated that the P. pumila exhibited particular ecological plasticity and this phenomenon is attributable to its high potential activity of photosynthetic and respiratory processes. These physiological features explained the large transcontinental natural habitat of Japanese Stone Pine.

Приведены результаты исследования состояния 44-летних лесных культур сосны кедровой сибирской, произрастающих в лесостепной зоне Тюменской области, в условиях дендрария Сибирской лесной опытной станции (ЛОС) города Тюмень. Изучение состояния древостоя проведено на двух временных пробных площадях (ВПП), заложенных на участках с разной схемой размещения деревьев. Деревья на участке 1 (ВПП-1) высажены по схеме 4х4 метра, на участке 2 (ВПП-2) – со схемой посадки 2,5х1 метр. Установлено, что древостой кедра сибирского на участке со схемой размещения деревьев 4х4 м является среднеполнотным, растущим по II классу бонитета, при схеме посадки 2,5х1 м – высокополнотный и характеризуется III классом бонитета. Наименьшими таксационными параметрами характеризуется древостой на участке 2 (ВПП-2) со схемой размещения 2,5х1 м. Значения средней высоты и диаметра на высоте 1,3 м на 20-35% меньше в сравнении с аналогичными показателями на участке 1 (ВПП-1) при схеме размещения 4х4 м. Полученные различия основных таксационных показателей статистически значимы. По показателям санитарного и жизненного состояния лесные культуры кедра сибирского на участке 1 характеризуются как здоровые, на участке 2 – ослабленные. Сухостойные деревья в количестве 2% от общего числа деревьев зафиксированы только на ВПП–2. Количество здоровых по состоянию деревьев на участке со схемой посадки 4х4 м в 1,8-3 раза больше в сравнении с участком со схемой посадки 2,5х1 м. При этом, количество ослабленных, сильно ослабленных и отмирающих деревьев, в среднем, в 1,5-4 раза меньше. По показателю относительной высоты (H/D) древостой на участке 1 (ВПП-1) характеризуется как биологически устойчивый. На участке 2 с более загущенным произрастанием деревьев кедра сибирского, значение относительной высоты которых больше 100 (H/D>100), составляет, в среднем, 15% от общего количества деревьев на ВПП. По полученным данным можно рекомендовать сосну сибирскую кедровую для плантационного выращивания в защитных лесах в условиях лесостепной зоны Тюменской области со схемой посадки 4х4 метра. The article provides the results of the analysis of the state of 44-year-old Siberian stone pine forest growing in the forest-steppe zone under the arboretum conditions of the Siberian Forest Experimental Station of the city of Tyumen. The study of the state of pine stands on the two temporary sample plots (TSP) with different tree planting patterns was carried. The trees on TSP -1 were arranged according to the 4x4 meter pattern, on TSP-2 – with a 2.5x1 meter planting pattern.. It was founded that the Siberian stone pine stand on TSP-1 was medium stocked, growing according to the II productivity class, in the case of the TSP-2 the stand was fully stocked and was characterized by the III productivity class. The TSP-2 stand was featured by the lowest taxation specifications. Indices of the average height and diameter at 1.3 m level were 20-35% less if compare with the same indices of the stand on TSP-1. The obtained differences of the main pine stands taxation indicators are statistically significant. According to the indicators of sanitary and vital state, Siberian stone pine forest crops on the site 1 were considered as healthy ones, on site 2 – as weakened. Dead standing trees amounted 2% of the their total number were located on TSP-2 only. The number of healthy trees on a plot with a 4x4 m planting pattern was 1.8-3 times higher compared to a plot with a 2.5 x 1m planting pattern. At the same time, the quantity of weakened, severely weakened and dying trees was on average 1.5-4 times less. According to a tree slenderness coefficient (H/D), the stand on TSP-1 is considered as biologically stable. On TSP-2, with more dense trees stand, with index of slender coefficient that was more than 100 (H/D>100), constituted on average, 15% of total number of trees on a TSP. Based on the data obtained, Siberian stone pine (Pinus sibirica Mayr.) can be recommended for plantation growth in protective forests under the forest-steppe zone of the Tyumen region with a planting pattern of 4x4 meters.

The research of 26-year-old mixed plantations of Siberian spruce and Siberian stone pine cultivated by biogroups of about 300 pcs/ha (2–5 stone pine seedlings alternating 4–9 spruce seedlings in a row) has shown that the damage rate by moose to them is much lower than to pure stone pine plantations or the mixed ones of Siberian stone pines and Scots pines we have studied before. The share of biogroups containing damaged stone pine trees is 18 %. A third of this number is plantations with damage to all the trees. This is most pronounced in biogroups of 4 to 5 stone pines as well as in case of frequent alternation of biogroups in a row. 76 % living stone pines have been preserved (89.3 % of them without damage to the stem). About two thirds of them (about 500 pcs/ha) grow in the crown of spruce trees adjacent to stone pine biogroups. Prolonged exposure to growing in a spruce tree crown negatively affects the growth of a stone pine’s central shoot and crown. We are the first in the Middle Urals to propose a scheme for cultivating sustained productive mixed plantations of Siberian stone pines and Siberian spruce trees (or Norway spruce trees). Stone pines are planted in biogroups of 2–3 seedlings, beginning the planting strictly on one side of the site. The first biogroup in odd-numbered rows (1, 2, 3, 5, etc.) is planted after 3 spruce seedlings from the beginning of the row, the second and subsequent biogroups in these rows – after 9 spruce seedlings. The first biogroup in even-numbered rows (2, 4, 6, 8, etc.) is planted after 9 spruce seedlings from the beginning of the row, maintaining this sequence until the end of the row. Every row in mixed plantations is concluded with planting no less than 3 spruce seedlings. During silvicultural treatment procedures natural regeneration is completely removed: softwoods – by mechanical means, and hard woods – by ringing or injection of environmentally friendly water-based chemicals. These measures reduce or eliminate the appearance of coppice and, accordingly, food reserve for wild animals. Spruce trees adjacent to stone pine biogroups are cut down while lightening and thinning, which creates the possibility for the growth of stone pines. The proposed method for cultivating plantations of Siberian stone pines and Siberian spruce trees has been patented. It can be introduced into silvicultural practice in the taiga zone where stone pines are grown.

The small spruce bark beetle Ips amitinus is a widespread species in many European countries that has been actively spreading into Northern Europe in the recent decades. In Russia, I. amitinus is present in the western, northwestern, and northern regions of the European part, with a tendency for range expansion. The species was first recognized in West Siberia in 2019 by characteristic morphological features and molecular genetic analysis. This bark beetle is abundant on Pinus sibirica in Siberian pine forests located near settlements within Tomsk and Kemerovo provinces, and is also sporadically found on the Siberian spruce Picea obovata. It colonizes the upper trunk and branches of standing and windfall trees. In the outbreak foci this bark beetle causes catastrophic drying of Siberian pines, starting from the crown top. This pattern of tree drying was noted for the first time near settlements in Yashkinsky District of Kemerovo Province in 2014, and now outbreak foci of I. amitinus exist in all the Siberian pine forests in this district. The population growth of I. amitinus was probably facilitated by dry and hot summer weather in the southeast of West Siberia during the last decade, in 2011 and 2012, and also by heavy winter snowfalls leaving numerous snapped tree branches which are easily colonized by the pest. In Tomsk Province, the most active outbreak focus of I. amitinus appeared in 2018 in the Siberian pine forest near Luchanovo and Ipatovo, following an outbreak of the Siberian moth Dendrolimus sibiricus. The invasion of I. amitinus in Siberia may increase the degradation rates not only of the gene-reserve Siberian pine forests but also of other dark coniferous stands.

The 40-year-old plantations of Siberian stone pine laid out as a permanent seed plot have been studied. The research purpose is to study the integrity, state and main forest inventory parameters of the Siberian stone pine plantations on the southern line of the species range at the end of first age class; to determine the role of natural renewal of trees and shrubs on the development of the Siberian stone pine plantations; to improve process solutions for efficient renewal of high-value biological resources. The research uses the methods generally accepted in forestry, forest science and forest inventory. It is found that the integrity of Siberian stone pine on the site is about 31 % (678 pcs/ha), wherein 406 pcs/ha are without damage to the trunk. Only about 25 % of Siberian stone pine trees grow under low shade, the rest of them are constantly shaded by natural renewal and have varying degrees of suppression. No generative organs were found in 44-year-old Siberian stone pine trees. At the initial stage of plantations growth, the main factor negatively affecting the integrity and state of trees is the damaging of Siberian stone pine by moose. Traditional improvement thinning with leaving stumps that produce many shoots of deciduous species attracts moose to the site in winter, where they use young growth of deciduous species and the covered with needles part of Siberian stone pine as forage. Subsequently, in the absence of tending, natural renewal negatively affects the Siberian stone pine trees, inhibiting growth and formation. It is necessary to remove the negative influence in the mixed biocenosis in order to prevent further deterioration of the Siberian stone pine state. This requires completely different technological solutions for forestry activities such as ringing or injection of trees of natural renewal, causing drying at the root, which significantly reduces or eliminates the emergence of deciduous young growth. This will decrease the attractiveness of the site for moose and minimize their impact on Siberian stone pine. The clear drying of surrounding trees will enhance the illumination of Siberian stone pine crowns and improve their soil nutrition, ensuring good root, trunk, and crown growth and accelerating the beginning of the formation of generative organs. These technical solutions can be used throughout the forest zone for the artificial cultivation of the high-value species – Siberian stone pine. For citation: Terekhov G.G., Andreeva E.M., Stetsenko S.K. Evaluation of Siberian Stone Pine Plantations at the End of the First Age Class. Lesnoy Zhurnal [Russian Forestry Journal], 2021, no. 6, pp. 56–68. DOI: 10.37482/0536-1036-2021-6-56-68

Siberian stone pine (Pinus sibirica Du Tour) is one of the most common trees in Siberia. Its natural range is from the Ural Mountains to the Aldan river and from the Arctic Circle to northern Mongolia. The climate in natural Siberian stone pine sites influences the whole plant organism, particularly its needle structure, and the response to this occurs at specific morphological and anatomical levels. The genotypical and environmental effects on needle structure in different Siberian stone pine ecotypes are very little known. One effective way to examine and to separate genotypical effects from environmental ones is by using a common garden experiment. The purpose is to analyze morphological and anatomical needle variability in Siberian stone pine marginal populations that have been grown in provenance plantations in southern West Siberia, Russia. The needle samples were collected in the provenance plantation located 30 km south of Tomsk (the southeastern West Siberian Plain, southern limit of the taiga zone, optimum site conditions for Siberian stone pine). We investigated the grafts of mother trees taken from natural sites. Four ecotypes were selected for the study. Three ecotypes originated from northern (Urengoy), western (Neviyansk), and eastern (Severobaikalsk) marginal populations. The fourth, the Tomsk ecotype, was a local control. The local Tomsk ecotype grows on a site where natural conditions are worse due to reduction of mean annual temperature and increase of the humid factor northward, humidity reduction eastward and its rise westward. Variability of 10 needle morphological and anatomical characteristics was studied. The northern ecotype had smaller needle length (28%), leaf cross-section area (21%), mesophyll area (29%), mesophyll cell size (27%), and conducting bundle area (16%) but the number of stomata per unit leaf area increased by 16% over the local Tomsk ecotype. The resin canal area, epidermal and hypodermal cell thickness, and stomata size were equal to both the northern and local ecotypes. The leaf cross-section and mesophyll area in the western ecotypes decreased by 20% and 23%, respectively, but stomata size increased by 12%. The needle length, mesophyll cell size, conducting bundle area, resin canal area, the number of stomata per unit leaf area, and epidermal and hypodermal cell thickness did not differ significantly from the same characteristics in the Tomsk ecotype. The leaf cross-section area, mesophyll area, and mesophyll cell size in the eastern ecotype decreased by 22%, 37% and 20% respectively, as compared with the local ecotype. All other studied needle characteristics did not differ from the local ecotype. The common morphological and anatomical parameters did not change from south to north and from west to east (resin canal area and hypodermal cell thickness) and parameters varied in each ecotype. For example, needle length, conducting bundle area, and the number of stomata per unit leaf area changed along latitude but did not change along longitude. Conversely, stomata size and epidermal cell thickness changed along longitude but did not change along latitude. Thus the morphological and anatomical characteristics were specific for each ecotype. The parameter variability of the needle structure is hypothesized to relate to graft geographical provenance that depends on genotype and adaptation properties of mother trees.

On the example of Siberian stone pine, seed productivity was analysed in two stands that differed in origin and formation conditions. The cone yield was analysed in years with different levels of seed production in the period from 2016 to 2019. In terms of the number of cones per tree, the sub-settlement Siberian stone pine forest was 2-3 times superior to the taiga Siberian stone pine forest. The level of individual variability in the number of cones in the near-settlement Siberian stone pine forest was significantly lower than in the taiga forest. There is reason to believe that the high level of variability is likely related to a more pronounced differentiation of the stand by crown size. The number of dead ovules in the Siberian stone pine forest in settlement is 60-70% higher than in the taiga forest. Due to high “mortality” of ovules and high variability of this trait, the number of filled seeds in the near-settlement Siberian stone pine forest is much lower, and variability in the number of complete seeds is much higher than in taiga Siberian stone pine forest. When there are few filled seeds in a cone, the size of each of them increases. Therefore, the average weight of one filled seed is higher in the subsettlement Siberian stone pine forest than in the taiga forest. Thus, the quality of the cones in the years of average and especially high yield in the near-settlement Siberian stone pine forest is much lower, and the level of variability of the traits that characterise it is much higher, and the distribution of the traits is characterised by a pronounced negative kurtosis. Obviously, these peculiarities of the near-settlement Siberian stone pine forest are related to human interference in the course of its development, which disturbed the course of natural selection and deformed the genotypic composition of the population.