The historical methods of forests research at fixed sites continue to be the most reliable way of collecting information about the processes of tree stand formation, differentiation, and the onset of various age stages. The article presents the results of 70 years of observations at a permanent sample plot located in waterside buffer forests at Lake Karasye in the Yemtsovsky Training and Experimental Forestry District of the Obozersky Forest Management Unit (Plesetsky District, Arkhangelsk Region). Baseline surveys were carried out and the permanent sample plot was established in 1952 under the guidance of Associate Professor V. I. Kalinin. Subsequently, measurements were repeated by students under the guidance of professors of the Northern (Arctic) Federal University (previously Arkhangelsk Forest Technology Institute and Arkhangelsk State Technical University). Long-term monitoring shows that, despite the old age, the stand continues to be highly productive. The stand evolves through tree-fall dynamics, with shadetolerant spruce regenerating successfully in the gaps forming after the fall of old pine and larch tree. Studies show that a spruce forest with an admixture of larch, pine and birch is replacing the mature pine-larch tree stand. The forest register data show the area occupied by larch stands in the Arkhangelsk Region is gradually declining. This may be due to the tendency to underestimate of the larch share during valuation inventories. The conservation measures such as excluding stands comprising 30 or more percent of larch from logging plans have proved ineffective. Monitoring in permanent sample plots shows that the stand's growing stock composition will usually change from larch to spruce. To ensure larch restoration at the limit of its distribution range in the Arkhangelsk Region, actions to promote its regeneration and artificial planting are needed.

В связи с высокой экологической ценностью естественных сосновых древостоев, ограниченных Белым морем, авторами было проведено исследование роста сосны (Pinus sylvestris L.), произрастающей по береговой линии на территории Архангельской области.Остается открытым вопрос о том, применимы ли таксационные нормативы для таких древостоев.Особенности приморских сосен связаны с повышенной ветровой нагрузкой, а также специфичными условиями роста на песках.Полевые исследования проведены летом 2022 г. на территории острова Ягры (Приморский район, г.Северодвинск), а также в районе г.Онега (Онежский район).Всего произведены измерения на 18 пробных площадях в разных типах леса.В большинстве случаев доминантным видом напочвенного покрова выступает черника (Vaccinium myrtillus L.).Сравнение того, как соотносятся средние диаметры и высоты со средними возрастами, позволило отметить существенное влияние ветровой нагрузки и освещенности на динамику роста приморских насаждений сосны.Выявленные особенности роста отличаются от показателей таблиц хода роста как для северотаежных и притундровых сосновых древостоев Архангельской области, так и для притундровых сосен

This study assessed the effect of patch scarification and mounding on the physical properties of the root layer and the success of tree planting in various types of forests. This study was conducted on 12 forest sites in taiga forests of the European part of Russia. A total of 54 plots were set up to assess seedling survival; root collar diameter, height, and heigh increment were measured for 240 seedlings to assess growth. In the rooting layer, 240 soil samples were taken to determine physical properties. The study showed that soil treatment methods had no effect on bulk density and total porosity in Cladina sites. However, reduced soil moisture was noted, particularly in mounds, resulting in increased aeration. In Myrtillus sites, there were increased bulk density, reduced soil moisture, and total porosity in the mounds. Mounding treatment in Polytrichum sites resulted in reduced soil moisture and increased aeration porosity. In the Myrtillus and Polytrichum sites, patch scarification had no effects on physical properties. In Polytrichum sites, survival rates, heights, and heigh increments of bareroot Norway spruce seedlings in mounds were higher than in patches; however, the same did not apply to diameter. In Cladina and Myrtillus sites, there was no difference in growth for bareroot and containerised seedlings with different soil treatments. Growing conditions and soil types should be considered when applying different soil treatment methods to ensure high survival rates and successful seedling growth.

Rutting is the main type of deep soil disturbance caused by clear-felling operations. Here, we evaluated basic soil physical properties in ruts at various soil depths after the passage of logging machinery. The present study was carried out in North Eastern Russia. In total, we measured rut depth at 160 points along wheel tracks, and collected soil samples. Samples (n = 420) from two soil horizons (0-10 cm and 10-20 cm) were taken, both from ruts and from undisturbed soil (control). The correlation analysis showed a direct significant relationship between rut depth and soil bulk density (po = 0.662, p < 0.001). An inverse significant relationship was found between rut depth and total porosity (po = -0.667, p < 0.001), and an inverse moderate relationship between rut depth and the porosity of aeration (po = -0.496, p < 0.001). Similar patterns were observed at a depth of 10-20 cm in the soil layer. The Kruskal-Wallis criterion revealed that the change of the physical properties was lowest in shallow ruts (1-15 cm). In all cases, we found that the physical properties of the control differed from the physical properties of middle (15-30 cm) and deep (>30 cm) ruts. Thus, it is necessary to reduce the formation of middle and deep ruts in particular.

The purpose of the research is to analyse the successful creation of an artificial pine forest by seeding and develop recommendations for the guaranteed reproduction of pine stands in Northern European Russia. In recent decades, there has been a steady decline in the share of pine stands and their replacement with low-value and low-yielding tree species. We surveyed 12 permanent sample plots that were laid out in various variants of forest crops. The taxation parameters were obtained by a standard analysis of the experimental data. The evaluation parameters of the stands vary within the following limits: the average diameter of the pine trees varied from 21.9 to 30.9 cm; the total basal area of the pine varied from 19.1 to 38.8 m(2).ha(-1); the average height of the pine varied from 20.1 to 26.8 m; the number of growing trees varied from 754 to 1 952 ha(-1); the pines varied from 382 to 762 ha(-1); the growing stocks of stands varied from 416 to 608 m(3).ha(-1). The distribution of pine trees by thickness steps showed that all the studied samples were close to the normal distribution curve. The results of the correlation and multidimensional analyses showed that the creation method of the forest crops had a significant impact on the value of the taxation parameters. It was found that the best options for growing pure pine stands that can be recommended for practical production are plots with a large share of soil cultivation and the size of the seedbed.

The paper presents the structural features of birch forests in terms of diameter and the ratio of the average height of birch and spruce in mixed birch-spruce stands. In the work, the method of automated identification of crowns of individual trees was used for the subsequent analysis of the features of decoding birch-spruce stands. The result of the presented technique is a set of contours of tree crowns in a forest, obtained automatically. Works on the segmentation of aerial photographs obtained with the use of UAVs and the isolation of individual crowns, determination by the spectral characteristics of the species of each tree are presented quite rarely, but this direction is quite promising. The established deciphering features can be useful to specialists who decipher these forest stands. The article presents materials of trial plots and analysis of comparison with tabular materials, a calculation algorithm for determining the average height and diameter according to the obtained dependencies of decryption and taxation indicators.

Abstract One of the most essential renewable resources in the world is the forest. An important issue in the forest industry today is the lack of relevant, reliable and regularly updated information on forest resources. Over the years, this problem has been addressed through labour-intensive field methods. However, in a competitive market and development of high-tech data collection and analysis tools, another issue becomes apparent – the low reliability and detail of the existing remote automated tools of data acquisition on forest resources. The research presented in this article is aimed at addressing this issue. The results of the work built on modern methods and approaches will provide an impetus for the introduction of digital technologies to many business processes of the forest industry.

This study aims to determine the impact of forest harvesting machinery on the temporarily moist soil of spruce forests (Picea abies Karst.) during the summer. For research purposes, we investigated 23 sites of the boreal forest in the European North of Russia (Arkhangelsk region) where logging operations had been carried out using harvesters and forwarders (CTL, cut-to-length harvesting). In the 15 years after logging, the sites were monitored for changes in physical soil properties and the depth/width of ruts and vegetation. In freshly cut areas, the depth of the ruts was linked to the amount of logging residue that had been used to strengthen skidding trails. After 15 years, the ruts were smooth but had not disappeared entirely. The average depth of the ruts decreased from 36 cm to 18 cm during the period under review. At a depth of 0-10 cm, the soil bulk density of the section between the control area and the wheel track increased by 19-27% within the first two years. At a depth of 10-20 cm, the soil bulk density only increased by 16-17% within the two-year period. After 15 years, the soil bulk density had decreased to the extent that there were no signs of heavy machinery movement. The natural restoration of vegetation in the ruts was affected by the presence of stagnant water in the initial post-logging period. Ruderal species and species with broad ecological amplitude to environmental factors grew over the skid trails. 15 years after logging, this overgrowth had stabilised, with the biodiversity level in the control area approaching its pre-logging state. Primarily, the renewal of the cutting areas occurred through species such as birch (Betula pendula Roth.) and aspen (Populus tremula L.). The highest amount of undergrowth (more than 30,000 ha(-1)) was detected 6-8 years after logging. This then decreases in areas that were cut down earlier. There are environmental consequences of clearcutting (using the CTL system) on temporarily moist soil. To prevent the formation of deep ruts, it is recommended to leave 15-20 kg m(-2) of felling residue.

Currently, a series of multi-temporal satellite images are available, which make it possible to obtain systematic information about objects of observation.The dynamics of changes over time allows you to analyze various scenarios of these changes and compare them with the results of field surveys.The study of dynamic processes over time is an urgent problem of satellite images processing.The dynamic process of overgrowing felling is a process that takes place over many years or even decades.A methodology for thematic processing of multispectral space imagery is proposed and implemented.The algorithm of the work is based on the analysis of different vegetation indices for assessing reforestation at clearings.

To improve the accuracy of the assessment of forest area from aerial photographs by automated decoding, it is necessary to study of the degree of tightness and interrelation forms between decryption and evaluation indexes. The purpose of the study is to identify the most reliable (optimal) dependencies between these indicators and the subsequent development of equations in their calculation. The interrelations of the taxation diameter and decoding indicators of the forest stand such as: height and diameter of the crowns are revealed. As a result of the analysis of the dependencies between the fullness and closed canopy revealed a weak relationship.

Assessment of forest regeneration using remote sensing data is a priority scientific research topic worldwide today. Threshold values for successful reforestation can be defined using multi­temporal satellite scenes and indices for analysis of vegetation on cutting and burned areas. The analysis of successful reforestation has practical value for Russian government organizations for transferring burned and cutting lands to forest cover land. The rate of reforestation depends on climate, soil conditions in the region of studies. Collection of field data and the studies were carried out in northern and middle taiga of Arkhangelsk Oblast. This territory belongs to boreal forest. Calculations of spectral indices for each research object were made using multi­temporal scenes for 20 years based on Google Earth Engine platform. Optimal spectral index was selected based on the analysis of collected data. The optimal threshold values of the index for transferring pixel of satellite imagery to forest cover land were found using this data. Optimal spectral index for transferring non­forest cover to forest cover land SWVI was selected. The optimal threshold value for transfer to forest cover land equals 80 % recovery of the index after a disturbance in forest cover. Method for transferring land to forest cover land was developed based on analysis of dynamic of the spectral index. The result was the spatial layer of transferring land to forest cover land in 2018 on the territory of Severodvinsk and Onega forestry district of Arkhangelsk Oblast.

The research relevance is driven by the need to study the patterns of changes in the physical properties of soil for prediction the recovery period after anthropogenic impact. The aim of the research was to establish the space-time patterns of changes and restoration of the podzolic soil physical properties during natural regrowth after cuttings. The study objects are located in the taiga forest zone on small-scale clear cuttings with fellings of 5, 18 and 28 years old. The initial plots are represented by the mature stands of blueberry forest with pine domination. Cuttings were carried out with the use of gasoline chainsaws for trees felling, and a skidding tractor for skidding. Clearing of cutting areas was realized simultaneously with timber harvesting by laying slashes on the skidding trails. In order to establish current characteristics of the studied areas, the evaluation of natural reforestation was carried out by laying out 215 test sites (5 x5 m) along the transects. In order to determine the soil physical properties on technological elements of cuttings (cutting strip, skidding trails) and control 288 samples were selected: 96 of forest litter (O), podzolic (E), illuvial (BF) soil horizons each. The results obtained at different times of cuttings have shown that the physical properties of sandy soils are dynamic over time. In 5 years after cutting soil compaction is detected, especially on the skidding trails, which affects the increase in bulk density (by 15-59 %) with a decrease in total porosity (8-11 %) and porosity of aeration of the upper horizons (8-23 %). Reliable compaction is observed in the forest litter and podzolic horizon, while in the illuvial horizon such difference is not proven. In 18 years soil compaction is detected. However, there are processes of soil decompression which are related to active reforestation of tree species and period passed after cutting. In 28 years the physical properties of soil were restored to their original values. We have established a moderate correlation between the bulk density of soil and cutting age (r = -(0.44 +/- 0.11)), as well as between the bulk density and the number of natural reforestation samples (r = -(0.31 +/- 0.10)), which contribute to soil decompression after cutting.

Оценка лесовосстановления по спутниковым снимкам и создание системы мониторинга является важной задачей на сегодняшний день. Российские и зарубежные ученые проводят исследования в этом направлении, но анализ лесовосстановления является сложной темой исследования в отличие от выявления вырубок и гарей по спутниковым снимкам. Лесовосстановление также является сложным, многофакторным процессом, зависящим от множества факторов. Данная статья описывает мировой опыт создания различных методик для мониторингалесовосстановления, используя различные подходы анализа данных и сенсоры, установленные на спутниках. В рамках статьи рассмотрено применение оптических, радарных снимков и данных, полученных с лидарных сенсоров. Это попытка структурировать накопленный опыт в данной сфере и сгруппировать разработанные методики для анализа их преимуществ и недостатков. Тип сенсора определяет длительность периода мониторинга. Радарные данные позволяют определять процесс лесовосстановления до 60 лет в отличие от оптических сенсоров, которые имеют значительно меньший период оценки лесовосстановления. Применение радарных данных может быть ограничено стоимостью работы и сложностью обработки радарных данных, поэтому использование тех или иных методик может иметь финансовые ограничения. Данный обзор показывает все основные методы оценки лесовосстановления. Assessment of reforestation using satellite images and creation of a monitoring system is an important task today. Russian and foreign scientists are conducting research in this direction, but the analysis of reforestation is a complex topic of research in contrast to the detection of cuttings and burned areas by satellite images. The process of reforestation is a complex, multi-factor process depending on many factors. This article describes the world experience of creating different methods for monitoring forest regeneration and uses different approaches to data analysis and sensors installed on satellites. In the framework of article was considered using of optical, radar images and data obtained from lidar sensors. This is an attempt to structure the accumulated experience in this field and group the developed methods to analyze their advantages and disadvantages. Data from different sensors have different monitoring period. Radar data allow determining the process of reforestation up to 60 years in contrast to optical sensors, which have a much shorter period of reforestation assessment. The using of radar data were limited by the cost of operation and complexity of radar data processing and using of certain techniques may have financial limitations. This review showed all the main methods of assessment of reforestation.

In this work, physical and chemical properties of the upper horizons of podzolic light loamy soil were investigated 21–23 years after forest cutting. This was after the first shift of long-term, gradual felling was carried out by tree-length logging in wintertime in mixed conifer stands of the Middle Taiga of the Arkhangelsk Region in Russia. The increased density of the forest litter composition was observed. This was especially the case on skidding trails. On the forest floor of skidding trails subjected to a greater stress caused by timber skidding, lower total porosity and aeration porosity was observed, in comparison with the cutting strip and natural forest. It was established that timber skidding during wintertime does not affect the density of podzolic horizon composition. An inverse pattern was observed here: the total porosity and the aeration porosity became higher and were close to the optimum values for plant growth (54.16–52.99% and 15.72–19.97%). In the podzolic horizon on skid roads, comparison to the natural forest showed a significant reduction of phosphorus mobile forms and an increase in the amount of absorbed bases, which is the result of grassy vegetation overgrowth and natural birch regeneration. On skidding trails and cutting strips, the organic matter content and total nitrogen significantly increased, which is related to a change of light intensity, the composition of living ground cover and vigorous decompositions of the organic horizon and woody residues. In cutting areas, a system mosaic of soil cover developed, which differed according to favourable conditions for tree species regeneration, compared to the control stands.

The results of research on the state, structure and productivity of forest stands at a stationary object - a natural monument "S.V. Alekseev's Improvement Thinning of 1951" are represented in the article. The analysis of field observations showed that improvement thinning increases forest stands productivity as well as can be an effective preservation measure for keeping Sukachev's larch in optimum growth conditions. Successfulness of focused formation of pure and mixed larch stands in comparison with control stand without thinning is established. Experimental areas after improvement thinning of 1951 (3 objects) and after second improvement thinning of 2000 by the S.V. Alekseev's method (3 objects) were studied in 2014. A control experimental area without improvement thinning was chosen (1 object). Areas assortment structure of forest stands was defined. Its analysis in 2014 showed that areas after improvement thinning of different intensity by reserves (from 60 to 70 %) and trunks quantity (from 50 to 81 %) forest stands with different trunks quality, accretion and assortment structure were formed. Mixed larch forest stands formed by improvement thinning from the best hardwood trees have more productivity in comparison with the pure stands. An experiment with leaving on only larch trees allows forming pure larch stand rare for the natural conditions of the Russian European North.

современные проблемы дистанционного зондирования Земли из космоса.2018.т

The article presents the results of research of grey alder Alnus incana L. stands on the territory of the Arkhangelsk Oblast within the North-taiga and Dvina-Vychegda taiga regions of the European part of the Russian Federation. The areas of grey alder stands in the period from 1978 to 2010 increased from 2.1 to 43.3 thousand ha in connection with the transfer to the forest fund of the former rural forests. Earlier forest inventory standards for this category of stands in the region were not developed. To compile a height and volume table, it was used the technique of I. I. Gusev (1971), which allow to minimize amount of sample trees. This technique is universal and can be used for other tree species. The field data collection was carried out on the territory of Kargopol, Velsk, Nyandoma, Arkhangelsk forestry units, the Kenozersky National Park and Dendrological Garden of the Northern Research Institute of Forestry. The result of the field work for the periods from 2013 to 2015 was 124 sample plots and 120 measured model trees for alder stand study. The developed tables are based on extensive field material (model trees and sample plots). Processing of field data was conducted by standard methods in forestry. Height grades’ table is used to determine the average height level of the stand. Volumes table is used to determine the growing stock levels for thickness grades. These tables meet the requirements of forestry practice, are used in the growing stock calculations. Development of height grade and volume tables based on known regularities of the homogeneous forest stands structure. Trees stands, which medium trees have the same forest inventory characteristics ( g, h and f ), are characterized by the same average volume for separate thickness grades, regardless of age, fullness, productivity rate and other characteristics of forest stands.

The regularities of the structure, growth, productivity of grey alder modal stands on the territory of the Arkhangelsk region were studied. As a result, we developed stand assortment tables by the relascopic circular plot method for commercial wood, radii of circular plots for trees with coefficients of 0.5 m(2)/ha and 1.0 m(2)/ha, transition tables from the stump diameter to the breast height diameter. The developed standards are intended for alder stand taxation on the felling areas of the clear-felling and selection system by the relascopic circular plot method in the Arkhangelsk region within the Northern taiga and Dvina-Vychegda taiga regions of the European part of the Russian Federation. Field data was collected in the Kargopol, Velsk, Nyandoma and Arkhangelsk forestries, Kenozero National Park, dendrological garden of the Northern Research Institute of Forestry. We used field data obtained from 2013 to 2015 (124 sample plots for grey alder studying with measuring of 120 model trees). The quantitative diversity of experimental materials is justified by the method used to construct the rank scales. The field data processing was carried out by methods generally accepted in forest inventory. The proposed new approaches to the use of the relascopic circular plot method (especially on sites of partial cutting), sufficiently high accuracy and low labour intensity contribute to the use of this method in forest inventory.

Conservation and restoration of larch is an important task of timber industry complex of the Arkhangelsk region because of the special qualities of wood. Taking into consideration the complexity of taxation and the high cost of field research, the paper analyzes the experience of research work on the definition of larch with the use of data of close mapping satellite acquisition based on binary classification algorithm. The crowns of the trees of the Siberian larch were allocated in the geoinformation environment QuantumGIS using the information collected in the field. As the initial data the very fine images GeoEye-1 were used (the spatial resolution - 0.5 m per pixel; the spectral resolution - 3 visible ranges, the nearest is infrared). Several crowns of trees were selected at the image. They were marked in the field with the use of global positioning devices. On the basis of the selected standards of crowns the binary classification algorithm was applied. The apparent advantage of the paper is the classification of decoding signs of larch: a larch crown is of light purple color at a combination of channels the nearest infrared spectrum - red - green; reflected sunlight in the dense stands gives the information not only about a sparse larch crown, but the second tier, often changing the tone in dependence on its composition and the structure of the soil cover. The result of the algorithm is the raster grid. Its cells are the probability of belonging of a pixel to the required class. The experimental estimation of the threshold value was conducted for the cut-off purpose of the pixels for which the probability of belonging to the class of "larch" was low. A sufficient threshold of reliability was 0.5. The reference value of the larch outlines mostly coincides with the obtained classified pixels of the image. There is a high reliability of the obtained data in comparison with the field studies. The resulting technique of automated decoding of larch can be applied for the other species at the forest inventory of the Arkhangelsk region.