Search

The interaction of the main forest-forming species of Siberia: Siberian spruce (Picea obovata Ledeb.), bush birch (Betula fruticosa Pall.), Scots pine (Pinus sylvestris L.), aspen (Populus tremula L.), Siberian larch (Larix sibirica Ledeb.), and Siberian stone pine (Pinus sibirica Du Tour) with agro-gray soil is considered. The study is carried out in a special long-term experiment with forest crops, initiated by prof. N. V. Orlovskiy in 1968-69 in the southern taiga on the territory of the Kemchug Upland. It was revealed that biological characteristics and successional position of tree species significantly influence all components of the phytocenosis. The biggest changes were recorded under the canopy of early successional coniferous (larch) and small-leaved (birch and aspen) species, while late successional species – spruce and cedar – at this stage significantly limit the development of subordinate layers. Over the 45-year period of growth of forest crops, the soil profile is formed due to the differentiation of the arable substrate of the soil-forming species into genetic horizons. The influence of the forest canopy on planted agro-gray soil occurs gradually and intensifies with the growth and development of crops, the formation of a litter horizon and covers all soil properties. Active modern soil formation affects the mineral soil layer 0–10 (13) cm. Vertical flows of matter and energy entering the soil in the process of increasing capacity and intensity of the biological cycle are the main factor in the formation of the soil profile. The development of soil under forest crops under the conditions of a long-term zonal experiment was noted.

The character of restorative forest successions after catastrophic disturbances is largely determined by their initial stage. The natural regeneration of tree and shrub species has been investigated, taking into account the influence of herbaceous vegetation on this process in two clear cut area at the site of the 2017 windfall in near Moscow Region. The type of clear cut area is mixed herbs with predominance of reed grass. The soil-forming rocks are sandy loam and light loam. Accounting for the natural renewal of tree and shrub species and soil vegetation cover was carried out on circular test plots with an area of 10 m2 , located at different distances from the edges. 102 species of herbs were found. Clearings differ in the species composition of herbaceous vegetation. The Jaccard similarity index was 37.3 %. This difference is due to the presence of rare species, the most represented species are found in both clear cut area. In clear cut area No. 1, 17 species of trees and shrubs were noted, and in clear cut area No. 2, 13 species. Scots pine (Pinus sylvestris L.), silver (Betula pendula Roth) and moor (Betula pubescens Ehrh.) birch, and aspen (Populus tremula L.) dominated in both clearings. Successful regeneration of pine trees was noted at a distance of no more than 50 m from the forest wall. Small-leaved species are found throughout in the clear cut area. The amount of natural reforestation of pine significantly exceeds the amount of birch and aspen, at the same time, pine is much inferior to these species in height. Among herbaceous plants, the renewal of pine is most hindered by the reed grass (Calamagrostis arundinacea (L) Roth.), and among deciduous species – aspen. For the successful formation of pine stands, it is recommended to carry out thinning.

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 problem of changing tree species in protective afforestation remains poorly covered. The dynamics of species’ change in poplar (Populus L.) protective forest belt growing next to the forest crops of the Scotch pine (Рinus sylvestris L.) is discussed in the article. A forest belt 450 m long and 10 m wide grows in the steppe zone near the village of Shigaikulbash, Buzdyaksky District of the Republic of Bashkortostan. Accounting plots are laid every 50 m. Reliable pine undergrowth in the forest belt, poplar undergrowth was not found on any of the accounting plots. Comparative characteristics of pine undergrowth (density, average age, stem height, and diameter) and the condition of poplar trees were compared for 2008 and 2020. It was revealed that there was a change in the design of the forest belt from openwork to dense, there is a partial shrinkage of poplar, in some areas there is an exit of pine undergrowth to the first tier. For both periods, the highest density of pine (over 1.5 thousand trees/ha) was detected at a distance of up to 200 meters from pine forest crops, the lowest density (no more than 0.4 thousand trees/ha) – in the center of the forest belt. In 2020, the category of small undergrowth was not found, most of it is large undergrowth, some of which have entered the reproductive phase. The drying of poplar trees is observed. This was facilitated by a complex of reasons: the complete absence of agrotechnical care in the forest belts, a drought that has been recurring for several years and the maximum age of trees in the conditions of the steppe. There is no poplar undergrowth along the entire length of the forest strip. A similar pattern is observed in neighboring forest belts, which allows to make a conclusions about the actual change of balsam poplar (Populus balsamifera L.) to Scotch pine in protective forest belts, which should be accompanied by logging and agrotechnical tillage on the edges of forest belts, followed by the formation of a young pine tree stand of openwork design.

In a comparative vein, the existing and potentially possible methodological methods for delimiting zonal-provincial associations of forest-bog and peat-bog complexes are analyzed. It is shown that on geomorphological differences of locations under conditions of continuous interaction with climate elements, soils and vegetation, their relatively autonomous development in time and space is carried out. On the example of the northern part of the Ob and Tom interfluve, in accordance with the criteria of such relative autonomy, natural indicator variations in the taxation and phytocenotic structure of indigenous marsh forests and, for comparison, dry valley pine forests are characterized. In the ranks of their modern typological and morphosculptural organization, causal relationships of ecosystem diversity and productivity with water and mineral growing conditions are considered, which clearly affect the composition of the age generations of the «mother» forest stands, undersized undergrowth and juvenile renewal groups. On the basis of the dimensions of the positive elements of the phytogenic micro- and mesorelief, large-hillock and cushion-like surfaces of oligotrophic and mesotrophic pine forests with mossy-lichen-shrub vegetation are typified, in peat deposits of which permafrost aquicludes and ice lenses-migratory are regularly localized. In especially moistened eutrophic pine forests with grass-mossy and low-grass vegetation, the phytogenic relief is considered in the system of different-height, scattered and merged tussocks, as well as near-stem mounds, which are formed by frameworks of skeletal roots draped with coniferous-leaf litter, grass rags, green Bryidae Engl. and hypnum Hypnales W. R. Buck et Vitt tows mosses. Taking into account these and a number of other factors, the trend of ambiguous settlement of self-sowing and pine Pinus L. undergrowth under the canopy of «mother» forest stands is estimated. Phytocenotic and inventory indication of pine forests, based on the system-sampling method of assessment, expands the understanding of the comparative range of variability in the structure of both marsh and upland pine forests that have reached the climax or approached the stages of self-development.

Analysis of the success of reforestation after a fire is the most important task of forestry. For these purposes, in the summer of 2021, aerial photography was carried out from a Phantom 4 pro UAV (Unmanned Aerial Vehicle) of a 15-year-old burnt-out (2006) along the north-western border of the Botanical Garden of Petrozavodsk State University (Republic of Karelia). In addition to this, a full-scale survey was carried out at the registration sites. Before the forest fire, rocky Scots pine (Pinus sylvestris L.) trees grew. The work was carried out in order to assess the state of natural renewal after a fire along rocky outcrops by combining the processing of aerial photography data with field surveys. As a result of photogrammetric processing, an orthophotomap with a spatial resolution of 4.6 cm/pix, a height map and three-dimensional point clouds were reconstructed. To analyze the quantitative distribution of the territory according to the species composition, the trees were pinned on the orthophotomap according to the registration areas of field surveys, as a result of which the quantitative distribution of tree species was determined in the ratio of 64 % Scots pine and 23 % of drooping birch (Betula pendula Roth) (other species were not identified). Field surveys showed that after the fire, a viable young stand of mixed composition with a predominance of Scots pine (71% of the total number of tree species) was formed. In addition to Scots pine, drooping birch (22 %), aspen (Populus tremula L.) and gray alder (Alnus incana (L.) Moench) (3.5 % each) participate in the formation of young stands on this burned-out area. These indicators are consistent with the analysis of the orthomosaic of the area (the error is less than 10 %). When comparing the height of plants on three-dimensional clouds of points with field measurements, it was possible to reliably determine only the height of plants for a large generally accepted category (> 1.5 m). The maximum height of Scots pine trees in the study area is 6 m, and the average values varied from 3.5 to 4.5 m, which indicates the success of reforestation after burning on rocky outcrops.

The reproduction of cedar-deciduous forests of the Far East, due to their intensive transformation by logging and fires, is becoming a necessary condition for the preservation of not only valuable tree species, food and medicinal plants, but also a unique animal world-with the Amur tiger Panthera tigris tigris Kitchener and the Far Eastern leopard Panthera pardus orientalis (Schlegel). Along with the preservation of undergrowth and fine-grained wood species, it is necessary to make extensive use of the natural processes of spreading Korean pine Pinus koraiensis Siebold & Zucc. seeds in the areas covered by industrial logging. The most important of them will be the creation of certain environmental conditions, the structure and composition of plantings attractive to animals and birds, contributing to the distribution of nuts over the area of destroyed stands. The formation of a certain composition of trees that favorably affect the renewal of cedar, as well as the preservation of the optimal post-harvest completeness of the stand, allows us to successfully ensure the natural renewal of cedar forests in large areas of coniferous-broad-leaved forests. It is especially important to create attractive environmental conditions for spotted nutcracker Nucifraga caryocatactes (Linnaeus) and nuthatches Sitta Linnaeus, which are 90 % of the main carriers of pine nuts over long distances-up to 5 km from the source. When carrying out industrial logging and logging of forest care, it is possible to plan and create the necessary environmental conditions for birds quite successfully.

Investigation was carried out in virgin spruce forests in the upper reaches of the Pechora river in middle taiga condition. It was show that spruce forests of different types are characterized by common features of the structure of stands and undergrowth. There was a large variability of trees in volume of stem and undergrowth height. Investigated stands formed a cyclical-multi-age type of age structure. The calculated data obtained using spatial statistics and analyses of point processes were presented. It was found that in spruce forests is expressed regardless of forest types, the group distribution of young individuals of woody plants, which passes into random distribution at more late stages of generation. The spatial relationships between woody plants tested using the cross-correlation function gij(r) show that the undergrowth is attracted to each other at distances of up to 1 meter. There were no spatial interrelation between the undergrowth and the trees. Trees demonstrated independent from each other placement in the area. The density of trees in the area and their phytosocial status are determining the intensity of competitive relations between woody plants in the indigenous spruce communities of the upper reaches of the Pechora River.

The results of the study of the quantity and state of understory of young’s regeneration after partial logging of 20 to 53 % logging intensity in mature pine forests of Pogorel’skiy pine forest are shown. Evaluation of logging operations showed that under the canopy of the remaining part of tree stands, forest site remain close in terms of the stands that are not logged. A comparative analysis of the number and life status of pine undergrowth has been carried out in pine­herbal­green moss and cowberry – herbal­green moss. Before logging, regeneration, taking into account the life condition of the undergrowth, was assessed as insufficient and partial renewal was required for regenerations. It was noted that after the first stage of partial logging in high­grade pine forests, a large number of viable young growth appeared. The number of undergrowth on the skidtaril was less compared to cut strips. However, in the runways, 4–5 years after cutting and self­seeding, there were 3 times more than in cut strips. Thus, at all 7 sites after cutting there is a sufficient number of conditionally large undergrowth, for 4 of them it exceeds the specified minimum several times. Even a weak cutting intensity of 20 % stimulated the regeneration process, but a high number of pine undergrowth is characterized by a weakened condition, which indicates a lack of lighting and the need for and the possibility of carrying out a second partial cutting. It is shown that the best preservation and subsequent renewal of pine after cutting are marked at a cutting intensity of 35 %. An increase in the intensity of cutting up to 53 % contributes to the appearance of a large number of shoots and self­seeding, while the small, medium, large undergrowth is highly damaged mechanically. We made a conclusion about the effectiveness of using the forestry measures that stimulate the forest renewal process.

The paper studies the number of seeds of woody plants falling on coal dumps of Kuzbass located in the northern and southern parts of Kuznetsk basin and in the mountain taiga belt of the lowlands of the Kuznetsk Alatau, as well as the number of regenerations, including shoots and young undergrowth. Large quantities of birch seeds (from 200 thousand to 2 million seeds per ha, and in the favorable conditions of growth in the forest in the mountain taiga belt of the Kuznetsk Alatau up to 4 million seeds per ha) fall on the dumps. To a smaller extent, the seeds of aspen, poplar and willows, and to an even smaller degree of Scots pine, fall on the dumps. In the mountain taiga belt, Siberian fir seeds have been registered. The number of seeds and forest regenerations on dumps depend on the shape of the meso- micro- and nanorelief, which causes the uneven distribution of shoots and undergrowth. The best conditions for natural regeneration are in favorable ecological niches characterized by pronounced microrelief, the presence of scattered, moist, loess-like carbonate rocks with a developed humus accumulating embryozem. Natural reforestation under unfavorable environmental conditions (with the exception of sea buckthorn) is slow.

On the basis of the accounting of undergrowth in 5 gradations of crown closure density of Scots pine (Pinus sylvest-ris L.) stands, growing on the dumps in 4 ecological-geographic areas of Kuzbass, inverse relation of parameters of renewal from hydrothermal coefficient of the district is established. Optimum conditions develop in a steppe kernel where the number of shoots, seed production and undergrowth reaches 110 thousand trees per hectare with crown closure of 50 % and density of forest stand of 0.75 thousand trees of the II class of age on 1 hectare. At decrease or increase of forest canopy density of the main tree stand layer quantitative characteristics decrease. The smallest amount of undergrowth is recorded in the mountain-taiga area – from 0.4 to 23 thousand trees per hectare with a tendency to increase in the process of increasing crown closure. Areas of the northern forest-steppe and the southern forest-steppe on quantitative signs of renewal are intermediate. The number of undergrowth has high direct correlation dependence on the size of the current fructification of forest stands – around a steppe kernel ripens to 3.7 million seeds on 1 hectare, in mountain and taiga – to 0.39 million seeds on 1 hectare. Sowing qualities of seeds – the weight 1000, energy of germination and viability, and morphometric characteristics of 2-year seedlings, which are grown up from them – height, diameter and point of a vital state between ecological-geographic areas have no statistically reliable distinctions, but the characteristics stated above, than in the stands on zone soils. It testifies to usefulness of dumps’ conditions for natural regeneration of Scots pine, high actual reproductive opportunities for pine stands in forest-steppe areas and a steppe kernel, and also potential opportunities of the stands in the mountain and taiga region of the southern Kuzbass.

Accumulation of organic matter in spruce green moss Piceetum hylocomiosum and pine lichen Pinetum cladinosum forest communities after windfall was investigated. Phytomass of Piceetum hylocomiosum stand is 51.8 t • ha-1, and Pinetum cladinosum stand is 7.5 t • ha-1. Phytomass in the disturbed stands is 3.5 times less than in undisturbed spruce forest and 15 times less than in undisturbed pine forest. The undergrowth accumulates 2.8 t • ha-1 in spruce forest, and 0.9 t • ha-1 in pine forest after windfall. Number of trees, volume of wood, stock of organic matter was determined in coarse woody debris subject to decay class. Most of the dead trees (77–97 %) belong to the second decay class. Reduced competition for light and mineral nutrients influences the intensity of organic matter accumulation by tree plants. We detected that increasing radial growth of spruce and fir began before windfall. This demonstrates the stand drying. However, maximal rate of annual ring increment (2.03–2.17 mm for spruce and 3.98–4.07 mm for fir) was observed in 2009–2010 years. After windfall radial growth of undergrowth increased 2 times in Piceetum hylocomiosum and 7.7 times in Pinetum cladinosum. Height increment of spruce and fir understorey increased 2.2–2.6 times in spruce forest. As compared with undisturbed ecosystems height increment of pine understorey is 1.2–2.0 times higher on windbreak in Pinetum cladinosum.

As a result of quantitative «microecosystem» analysis of structural and functional relationships between biogeocenosis components in coniferous forests, the leading role of stand-edificator's root competition factor has been identified in determining the undergrowth and lower layer plant’s growth, compared with its «light» competition. Considering the dominant role of a tree stand root competition in the formation of other forest biogeocenosis components, new definition of «forest» as «underground-closed dendrocenoecosystem» have been proposed.