Forest Growth Conditions Research Articles

Фаутность еловых древостоев северо-таежного района Архангельской области

The results of studying the defectiveness of spruce forests in the northern taiga zone of the Arkhangelsk Region are presented. Defectiveness has a significant impact on the sanitary condition, marketability and sustainability of forest plantations. The study has been conducted from 2020 to 2023 using materials obtained from sample plots laid in mature spruce plantations, modal in terms of basic taxation parameters. Before starting the field work, the cartographic databases have been studied. The sample size has been determined by the variability of the taxational diameter of the main species and the experiment accuracy. In each test area, all trees have been enumerated by species, diameter at a height of 1.3 m and by condition categories. For each tree, the presence of defects affecting marketability and fruit bodies of wood-destroying fungi has been noted. To determine the age of the trees in the sample plot, core samples have been taken from the root collar. To study the patterns of the defectiveness spread and obtain mass material, statistical survey sites have been laid on fresh cuttings. When rot has been detected on the stump, the diameter of the rot has been measured and its type and stage have been determined. The age of the trees has been determined by the annual rings on the stumps. In the presence of rot, age has been determined by correlation with the diameter of the stump. The trees have then been grouped by their respective age classes. In the course of the research, defectiveness indicators have been studied and analyzed in various forest growth conditions. It has been revealed that with an increase in the age class, the occurrence of all defects increases. The most obvious dependence has been recorded for rots. The amount of rots varies from 5.1 to 29.0 %, depending on the type of forest growth conditions. The proportion of rots decreases with the deterioration of forest conditions. The most common wood-destroying fungus is the root sponge (Heterobasidion annosum (Fr.) Bref.). There is an increase in the incidence of wood-destroying fungi in trees with increasing diameter. The average stage of butt rot has been 2.8. The study of the defectiveness will improve the accuracy of assessing the resource potential of coniferous plantations in the Arkhangelsk Region.

Особенности восстановления хвойно-широколиственных лесов

The article is devoted to the problem of restoration of cut down forests in the forest area of coniferous-broad-leaved (mixed) forests of the centre of the European part of Russia. Due to the intensive use of forest resources, in order to rationally plan their restoration, there is a need for systematic assessment of the natural and artificial restoration of the main forest-forming species. For areas with a developed network of transport routes, the problem of deterioration of the species composition of forests, as well their qualitative condition as a result of prolonged and intensive forest exploitation is currently increasing. This has determined the purpose of the study, which has been carried out through a field survey of undergrowth and forest planations of forest-forming species according to the methodology by A.V. Pobedinsky and the standard methodology for undergrowth inventory. Young stands of natural (undergrowth) and artificial (created by planting) origin in coniferous-broad-leaved (mixed) forests of the European part of Russia after clear-cutting of trees have become the object of the study. An analysis of the structre of production and demand (according to the survey data) has shown that preference is given to harvesting birch (40 % of the volume cut down). The results of comparing the growth characteristics of the younger generation of tree species, taking into account the age and density of their growth, has allowed us to conclude that the undergrowth adapts easier and faster mainly to the growing conditions B4, B3, C3, C4, A4, A3, and occasionally B2, compared to forest plantations. In many cases, spruce plantations created by planting in the bottom of a furrow are completely destroyed (get soaked) or remain in a volume that does not provide satisfactory reforestation. Cases of exposure of the root system of spruce plantations at the age of 22, which have been created by planting in the dump, have been revealed. Based on experimental data, it has been established that productive young stands of natural origin are successfully formed in the forest area of coniferous-broadleaved (mixed) forests of the Yaroslavl, Moscow and Nizhny Novgorod Regions. Criteria for the inventory of undergrowth and young growth of soft-wooded broad-leaved species have been proposed. Proposals have been developed to improve the efficiency of reforestation measures in forest-growing conditions corresponding to the A4, B4, C4, as well as in the A3, B3 and C3 conditions. The positive effect of raspberries on self-seeding of the main forest-forming species has been noted. The self-sown plants in such areas is 1.0–1.5 thousand pcs/ha.

An Improved Grid-Based Carbon Accounting Model for Forest Disturbances from Remote Sensing and TPO Survey Data

Forest disturbance is one of the main drivers of forest carbon flux change. How to accurately estimate the carbon flux caused by forest disturbance is an important research problem. In a previous study, the authors proposed a Grid-based Carbon Accounting (GCA) model that used remote sensing data to estimate forest carbon fluxes in North Carolina from 1986 to 2010. However, the original model was unable to track legacy emissions from previously harvested wood products and was unable to consider forest growth conditions before and after forest disturbance. This paper made some improvements to the original GCA model to enable it to track fluxes between all major aboveground live carbon pools, including pre-disturbance growth and growth of undisturbed forests, which were not included in the initial model. Based on existing timber product output (TPO) survey data and annual TPO records inversed from remote sensing data, we also worked to clarify the distribution ratios of removed C between slash and different wood product pools. Specifically, the average slash ratio for North Carolina was calculated from the difference between the C removed and the C flowing into the wood product as calculated from TPO survey data. County- and year-specific ratios were then calculated using the annual TPO records obtained from remote sensing and TPO survey data, dividing the removed remaining C into pools P1, P10, and P100, which were then applied to each 30 m pixel based on the county and year to which the pixel belonged. After compensating for these missing legacy emissions and adjusting forest growth rates from Forest Inventory and Analysis (FIA) data, we estimated a net carbon sink of 218.1 Tg of the flux associated with live aboveground biomass and harvested wood products from North Carolina woodlands over the 25-year study period (1986–2010). This estimate is close to the greenhouse gas emission and sink data provided by the U.S. Department of Agriculture for North Carolina and is comparable to estimates reported by several other studies.

Assessment of the heartwood contribution to carbon accumulation in Pinus sylvestris L. trees under different forest site conditions

BackgroundThe heartwood (HW) proportion in the trunk of mature trees is an important characteristic not only for wood quality but also for assessing the role of forests in carbon sequestration. We have for the first time studied the proportion of HW in the trunk and the distribution of carbon and extractives in sapwood (SW) and HW of 70–80 year old Pinus sylvestris L. trees under different growing conditions in the pine forests of North-West Russia. MethodWe have examined the influence of conditions and tree position in stand (dominant, intermediate and suppressed trees) in the ecological series: blueberry pine forest (Blu) – lingonberry pine forest (Lin) – lichen pine forest (Lic). We have analyzed the influence of climate conditions in the biogeographical series of Lin: the middle taiga subzone – the northern taiga subzone – the transition area of the northern taiga subzone and tundra. ResultsWe found that the carbon concentration in HW was 1.6%–3.4% higher than in SW, and the difference depended on growing conditions. Carbon concentration in HW increased with a decrease in stand productivity (Blu-Lin-Lic). In medium-productive stands, the carbon concentration in SW was higher in intermediate and supressed trees compared to dominant trees. In the series from south to north, carbon concentration in HW increased by up to 2%, while in SW, it rose by 2.7%–3.8%. ConclusionsOur results once again emphasized the need for an empirical assessment of the accurate carbon content in aboveground wood biomass, including various forest growing conditions, to better understand the role of boreal forests in carbon storage.

Плотность всходов сосны обыкновенной в сосновых лесах под влиянием выбросов Карабашского медеплавильного комбината и лесных пожаров

We assessed the features of natural pine regeneration in forests with different ages of ground fires in the Southern Urals depending on the level of heavy metal pollution. Using the materials obtained from 81 sample plots laid in maturing, mature and over-mature pine forests of natural origin in three types of forest growth conditions (TFGC 1 – TFGC 3), the relationship between the density of pine seedlings and the state of forest stands (crown density, stand age, vital status index), with the characteristics of vegetation condition (total number of species, total projective cover of herb-shrub layer, projective cover of bryophytes layer), with external influences (pollution level, distance from emission source, duration of fire disturbance), and with the methodological features of the study (accounting year) was analyzed. The high variability of estimates of the density of pine seedlings did not allow us to identify the relationship between the density of seedlings and the level of pollution and/or fire disturbances. The density of seedlings is nonlinearly related to the protective cover of the herb-shrub layer. With increasing coverage of the herb-shrub layer, the density of seedlings increased in areas with high levels of pollution and decreased in areas with background pollution.

Predictions of Carbon Stock in the Southern Moscow Region Forests Under Different Forest Use Scenarios

The results of forest simulation modelling of the dynamics of carbon pools and fluxes in forest ecosystems under different forest management scenarios were considered on the example of the Dankovsky forest enterprise (south of the Moscow region, subzone of coniferous-broadleaved mixed forests). The impact of such changes in forest management practices, as the reserve regime, the reduction in the proportion of forest lands as a result of residential development, and zoning of the territory with an emphasis on increasing the recreational use of forests on the carbon balance was analysed. In computational experiments, a set of Russian models was used: the dynamic model of a forest stand FORRUS-S, the model of soil organic matter dynamics Romul_Hum, the model of the hydrothermal regime of soils SCLISS. Calculations were performed for a time period of 100 years at the forestry unit level, and were also aggregated at the level of the entire forestry district. The diversity of types of forest growth conditions (FGC), together with the species diversity and the initial different ages of stands, determined significant variations of the calculated indicators of forest stands’ production, the quantity and quality of plant litter entering the soil. For all cases, model estimates of changes in carbon reserves occurred in the forest stands within the initial 40–60 years with a subsequent decrease in the calculated values. Under the conservation scenario, an increase in the organic substances reserves in forest litter and soil was observed: for FGCs C2 and C3, an increase over 100 years was approximately 5–10 kg m–2, for the remaining FGCs — at the level of 2–3 kg m–2 in terms of carbon. Under the economic use scenarios, a relative “levelling” of forest enterprise area towards the lower end of the spectrum was shown in terms of soil carbon reserves. The maximum ecosystem carbon stock was calculated for FGC C2 and C3, the minimum — for A5 and C4. Depending on the scenario, over 100 years, the total net sequestration of carbon by the forests of the Dankovsky forest enterprise (with a total area of forested land of 6836 ha) was estimated within the range of 0.15–0.57 Tg.

Comparison of transpiration activity of Quercus robur L. and Acer campestre L. trees under different conditions of moisture supply in the Viiskova ravine

Determining the role of trees in the water cycle and their impact on soil moisture and atmospheric humidity is crucial. This study aimed to investigate the patterns of leaf transpiration in Quercus robur and Acer campestre in a maple-oak forest under varying water supply conditions. The research was conducted in the lower third of the lower third of the north-facing slope and the middle third of the south-facing slope in the Viiskova ravine. A silvicultural and taxation survey of model trees was conducted on both sample plots, where the plantations are moderately dense. The diurnal course of transpiration patterns of these deciduous species was studied throughout the vegetation period. This physiological process reached its highest values in both species on the north-facing slope during the summer months, especially in Quercus robur. On the south-facing slope, in May and June, the average daily transpiration values in both species were almost indistinguishable. During the remaining months of the vegetation period, the intensity of water evaporation by Quercus robur leaves was statistically higher than that of Acer campestre. It was established that on the south-facing slope, under more arid conditions, this process is less active. This pertains to the daily transpiration loss of water by leaves per unit of their mass, monthly transpiration, and the intensity of this process per tree. The difference between the results of water loss by the leaves of a single Quercus robur and Acer campestre tree is significant and is attributed to the lower transpiration rate of Acer campestre, except in May and June under xerophytic conditions, as well as the smaller leaf mass of this species. Both Quercus robur and Acer campestre are hydrostable medium-transpiring species. The maple forest on the north-facing slope evaporates 30.6% more moisture per 1 ha per vegetation period than on the south-facing slope. The results obtained indicate that Acer campestre in a maple-oak forest, under fresh and dry forest-growing conditions, does not pose a significant competition for moisture for Quercus robur when they grow together. The results obtained can be used to develop effective forest management strategies in maple-oak forest

The state and structure of beech primaeval forests in the “Zacharovanyi Krai” National Nature Park

The relevance of the study is determined by the need to preserve natural values, which are considered the heritage of all mankind, namely the primaeval forests and old-growth beech forests of the UNESCO World Natural Heritage. The aim of the research was to study the state and structure of the beech primaeval forest in the national nature park “Zacharovanyi Krai”. For the study, a permanent sample plot of 1 ha (100×100 m) was laid down in the prevailing forest type – moist pure beech forest. This plot is located in the optimal forest-growing conditions for European beech (Fagus sylvatica L.) within the Vyhorlat-Hutyn volcanic ridge of the Ukrainian Carpathians. It was found that the beech forest stand on the plot is pure in composition and complex in form, characterised by different development phases (age groups by diameter): the first layer stand belongs to the mature age group (senile), the second layer – to the middle-aged group, and the third – to the pole (virginal). It was determined that 95% of the primaeval forest stock is the stock of the first layer, while the share of commercial trees of the first layer is 89% (66% of the total volume of stem wood of trees on the permanent sample plot). The main types of damage in the site are caused by abiotic factors. As a result of such damage, 43 m3‧ha-1 of deadwood was recorded, characterised by all 5 stages of decomposition. Under the canopy of the stand, 10,375 pcs‧ha-1 of undergrowth was recorded, of which the share of beech is 88%. Beech undergrowth is weakly differentiated by age groups: it was recorded only in the group of 7-year-olds and older and well-differentiated by height groups. By age group, undergrowth belongs to the juvenile-immature age state. The herbaceous cover is typical for nemoral forests. The presence of stationary research plots in the National Nature Park “Zakharovanyy Kray” makes it possible to constantly monitor the trends of natural development of the ecosystem – the beech primaeval forest

Strategies and challenges of artificial forest reproduction in the forest-steppe zone: Experience of the Korsun-Shevchenkivskyi forest enterprise branch

One of the key problems that arise in the reproduction of forests in the paradigm of sustainable development of the forest industry is the volume of reforestation, which requires its correlation. This problem requires attention, since effective afforestation and reforestation determine the stability of the ecosystem and the importance of forest resources for the conservation of biodiversity in the forest sector. The purpose of the study is to investigate the features of artificial forest reproduction in the conditions of the forest-steppe climatic and geographical zone. The methodological basis for organising observations included field survey of planting material plots, monitoring the state of crops on the area, conducting analytical substantiation of progressive experience, and evaluating the final results obtained. The study was conducted in the Korsun-Shevchenkivskyi forest enterprise branch of the state enterprise “Forests of Ukraine”. The dynamics of annual volumes of artificial forest reproduction, considering the predominant tree species during 2012-2021, is presented. Additionally, the advantages and disadvantages of transplanting of main and related species in the presented forest conditions were analysed. During this period, there is a fluctuation in the volume of artificial forest reproduction in the forest districts under study. With regard to the transplanting of main and related species, it is worth noting its advantages in ensuring biodiversity and rapid forest regeneration. However, there are disadvantages, such as the possibility of losing genetic diversity and considering local conditions for effective seating. As a result, the study helped to determine the trends and features of forest reproduction in these forest districts, and to note the advantages and disadvantages of transplanting of the main and related breeds in various forest-growing conditions. The enterprise is actively implementing measures for forest reproduction, focusing on intensive planting of forest crops. This is achieved by placing plantations in areas that have been subjected to continuous sanitary and reforestation logging. One of the key tasks of the enterprise is to ensure high productivity of forest crops in the region. For this purpose, significant amounts of reforestation work are carried out, including systematic soil preparation and careful selection of optimal species for specific conditions. Considering the recommendations of forest management, an integrated approach to reforestation is reflected, which ensures sustainable and productive ecosystems in the region. The developed strategies can serve as an important tool for introducing innovations in the field of forestry

Influence of Forest Growth Conditions on the CO2 Emissions from the Soil Surface in the Middle Taiga Pine Forests of the Komi Republic, Russia

Influence of Forest Growth Conditions on the CO2 Emissions from the Soil Surface in the Middle Taiga Pine Forests of the Komi Republic, Russia

First report of Leptosphaeria biglobosa 'brassicae' causing leaf spots in Eutrema japonicum in Yunnan, China.

Wasabi (Eutrema japonicum) is a root vegetable that is cultivated at large scales in southwestern China. In November 2021, approximately 40% of plants in a forested plantation in Dadishui, Yunnan Province, China (25.47°N, 103.22°E), showed leaf spot symptoms. The early symptoms were small black spots that gradually expanded into irregular brown to black lesions (0.5-1.5 cm), which were restricted by leaf veins. Yellow halos were observed at the outer edges of necrotic lesions. To identify the causal agent, we collected 20 diseased leaves and obtained fungal isolates from symptomatic leaf tissues. Following surface sterilization with 75% ethanol for 30 s, the tissues were cultured on potato dextrose agar (PDA) plates and incubated at 25°C under a 12 h light/12 h dark light cycle. After 7 days of incubation, a total of 12 isolates were obtained through single-spore culture. All isolates had similar colony morphology, and produced fluffy white mycelia and yellow pigment after 1 week of PDA culture at 25°C, and blackish- brown mycelium, tan pigment, and conidia after 2 weeks. The conidia were hyaline and cylindrical, with an average size of 4.6 μm × 2.2 μm. These morphological characteristics similar to the description of Leptosphaeria biglobosa (Shoemaker et. al, 2001) and Leptosphaeria maculans (Vincenot et al. 2008). Genomic DNA was extracted from mycelium of isolate SK-1, which was harvested from 10-day-old PDA culture using a FAST plant genomic DNA Extraction Kit (Biomed, China), following the manufacturer's instructions. The species-specific primers LbigF, LmacF, and LmacR (Liu et al. 2006) were used for identification via polymerase chain reaction (PCR). A 444-bp fragment characteristic of L. biglobosa 'brassicae' (Lbb), and a 330-bp of L. maculans 'brassicae' (Lmb) were amplified, respectively. Internal transcribed spacer (ITS) sequences (592 bp), part of the 5' end of beta-tubulin (968 bp), and actin (899 bp) were also amplified using the primers ITS1/ITS4, BT1/BT2, and ACTF/ACTR (Vincenot et al. 2008), respectively. PCR was performed in a volume of 25 μL containing 12.5 μL 2 × T5 Super PCR Mix (Tsingke Biotech, Beijing, China), 1 μL 10 μM primer (Tsingke Biotech), 1 μL DNA template, and an aliquot of sterile water to attain the total volume. The thermal cycler settings were 5 min at 98°C; 35 cycles of 10 s at 98°C, 10 s at 58°C, and 30 s at 72°C; and extension for 2 min at 72°C. The ITS sequence of isolate SK-1 (GenBank accession no. OQ216838), the partial β-tubulin gene sequence (OQ241183), and the actin gene sequence (OQ241184) indicated 100% query cover and 100% identity with L. biglobosa (DQ458906), Lbb strain B3.6 (AY748995), and Lbb strain 2379-4 (AY748949), respectively. Phylogenetic analysis (King et al. 2022) also identified of isolate SK-1 as Lbb. To determinate its pathogenicity, isolate SK-1 was grown on PDA incubated at 28°C for 2 weeks, and conidial suspensions were prepared at a concentration of 106 conidia/mL. Then, 15 leaves of 4-month-old E. japonicum seedlings were needle-wounded on the front and inoculated by syringe injection of 10 μL of the appropriate conidial suspension. We used 10 μL of the sterilized distilled water as the control under forest growth conditions. All inoculation sites were covered with cotton strips and moistened with 1.0 mL sterile water to maintain humidity. After 12 days of incubation, the leaves developed symptoms similar to those observed in the field, and the fungus was reisolated from diseased leaves, whereas the controls remained healthy. Based on these results, we identified L. biglobosa 'brassicae' as the causal agent of leaf spot on E. japonicum in China. This fungus has been reported to cause blackleg in many Brassica crops in China such as Brassica napus (Fitt et al. 2006), Brassica oleracea (Zhou et al. 2019), B. juncea var. tumida (Deng et al. 2020), Brassica rapa subsp. pekinensis (Yu et al. 2021). To the best of our knowledge, this is the first report of L. biglobosa causing leaf spots in E. japonicum in China. Our data provide a basis for disease management in E. japonicum production in China.

Запасы углерода в 40-летних культурах сосны обыкновенной

The paper presents an assessment of carbon stocks in components of above-ground phytomass of the tree layer of 40-year Scots pine crops (Pinus sylvestris L.) growing in different forest conditions of the Baltic-Belozersky taiga region of the European North of Russia. The studied pine crops were created on fresh, unsodded clearings with a low degree of litter in lichen, lingonberry and bilberry types of forest growth conditions, which are characterized by significant differences in bioproductive potential. It was found that the smallest carbon pool is formed in the stand of a 40-year pine stand of lichen-type culture-phytocenosis (16.59 t/ha), the largest – in the blueberry type of habitat conditions (69.41 t/ha). In artificially created 40-year lingonberry pine forest, carbon stocks in the above-ground phytomass of the tree layer have an intermediate position (44.40 t/ha). The highest relative value of bound carbon is reached in such component of aboveground phytomass as trunk wood. The share of carbon stocks in this fraction of the total aboveground phytomass of the forest stand of the studied pine cenoses varies from 59.5 % in lichen type of habitat conditions to 75.6 % in blueberry one. Branches and needles have close quantitative values of carbon stocks and similar structure of differentiation along the forest typological gradient, occupying a secondary position in the carbon pool of the forest stand of the studied artificial pine forests after stem wood. The proportion of carbon bound by these fractions of aboveground phytomass of the stand decreases from the least productive lichen pine forest to the more productive blueberry pine forest. The share of carbon accumulated by stem bark in the total carbon pool of aboveground phytomass of the stand of the studied artificial pine forests tends to decrease from lichen pine forest to blueberry pine forest. The fraction of dry branches has the smallest percentage of carbon stocks in the tree stand in all studied forest conditions (2.3–5.9 %). For citation: Klevtsov D.N., Tyukavina O.N. Carbon Stocks in 40-year Scots Pine Crops. Lesnoy Zhurnal = Russian Forestry Journal, 2023, no. 5, pp. 195–203. (In Russ.). https://doi.org/10.37482/0536-1036-2023-5-195-203

Bioresource potential of honey-making lands during the succession of forest vegetation

The results of the studies of honey-making lands on forest and non-forest lands of the forest fund of the Kemerovo region are presented. The assessment of honey-making resources by categories of forest lands for honey collection and bioresource potential of lands for honey collection in the process of succession of forest vegetation was carried out. The study of the species composition of honey plants was carried out in 2018–2022 on various categories of lands. The research was carried out in accordance with the generally accepted methods of conducting research in beekeeping. The accounting of honey plants was carried out on transects and discount areas using the methodology of forest taxation. It is established that microclimatic and forest-growing conditions of honey-making lands change during the succession of forest vegetation. Siberian pea-tree, willow family, Tartarian honey-suckle and edible honeysuckle, forest raspberry and the representatives of herbaceous phytocenoses - Siberian garden angelica, rosebay willowherb - are noted on clearings with high honey productivity. Honey productivity of the lands not covered with forest vegetation, on clearings, and in taiga forests is 229.4 kg/ha. The bioresource potential of the lands for honey collection amounted to 68,464 kg on forest lands not covered with forest vegetation within the radius of the apiary on the area of 414 hectares. The honey stock of 88,600 kg makes it possible to keep 738 bee colonies on the registration plot. The obtained reliable scientific information from the practical side is necessary for the adjustment of forest plans of the territories and for the timely planning and organization of the territory of apiaries.

Биоэкологическая характеристика уникальных природных и искусственных популяций дуба на полупустынных ландшафтах Волгоградской области

Биоэкологическая характеристика уникальных природных и искусственных популяций дуба на полупустынных ландшафтах Волгоградской области

Shyshatska sand arena: History, current state, and prospects of afforestation

Non-afforested lands in Ukraine are the primary instrument for increasing the forest cover of the territory The issue of sand afforestation is relevant in the context of climate change. Treeless sand arenas are a source of dust storms, and deflationary processes that occur lead to negative consequences that are quite difficult to correct in the future. The purpose of this study was to summarise the experience and achievements of the branch “Myrhorod Forest Enterprise” of the State Specialised Commercial Enterprise “Forests of Ukraine” in afforestation of mobile sands in the conditions of the Forest-Steppe of Ukraine. Forest stands are established using one-year-old Scots pine seedlings on sandy soils to achieve the set goal. Testing is conducted using planting material grown under various conditions – in the open ground and in a greenhouse. Extended periods for establishing forest stands beyond agrotechnical terms are examined during the late spring and summer periods using rejuvenated planting material with partially damaged root systems. The current state of plantings within the Shyshatska sand arena is analysed. It is established that in general, the territory of the arena is represented by the entire range of types of forest conditions ranging from bors to mixed broad-leaved forests. The prevailing types of forest-growing conditions are given, among which dry and fresh forests are distinguished. Subors and su-deciduous forests are represented on small areas. Deciduous types of conditions are located mainly in the drained areas of the Psel River floodplain. The main forest-forming species on the territory of the arena is Scots pine, which occupies more than 60% of the territory. Also in the lowlands and floodplains of the Psel River stands of Black Alder and Common Oak grow. In the conditions of bors, Scots pine grows in III – Va bonitet class. In richer conditions, subor and su-deciduous forest cultures have better indicators and have a class I-II bonitet, but there are not many of them. The results of this study can be used in the afforestation of sandy lands in the Forest-Steppe of Ukraine and adjacent regions

Methodology for determining the suitability of soils for afforestation in plain part of Ukraine

Purpose. To develop a methodology for assessing forest suitability for certain varieties of unproductive soils. Methods. There are used the classical methods of soil science, agrochemistry, forest science, forest management, typology and mathematical statistics. Results. The principles of forest typology are the basis for determining the suitability of soils for forestation. Its essence lies in a comprehensive study of soil properties (soil morphometry, chemical composition) and forestry characteristics of forest stands, as well as an analysis of the grass-shrub layer by ecomorphs. The results of studies of the combined study of the productivity of forest stands and the properties of the main varieties of unproductive soils (sandy, eroded and skeletal) in different natural zones of the plain part of Ukraine are presented. Determination of the suitability of soils for forestation was assessed according to three categories: 1) unsuitable for forestation and conditionally suitable for forestation (very dry, very poor, toxic, with a limited rhizosphere zone, inaccessible or hardly accessible for cultivation); 2) limited suitability for forestation (dry and poor soils); 3) suitable for forestation. Packages of markers have been developed, on the basis of which it is possible to assess both their forest suitability and determine the type of forest growth conditions of non-forest lands. When compiling markers, preference was given to such soil indicators, which, along with informativeness in relation to soil quality, did not require complex methods of determination. The composition of markers includes morphological, physical, agrochemical parameters and depends on the type of soil. Conclusions. The developed packages of markers are the basis for the scientifically based creation of forests on unproductive lands, on which forest vegetation did not grow before. Their use in afforestation increases its efficiency and makes forests more resistant to adverse environmental factors. The Methodology is intended for forestry specialists, it can be used at enterprises, institutions of the forest sector, forest design organizations, as well as in related industries concerned with the protection and rational use of natural resources. The methodological developments can be included in the curricula of secondary and higher forestry-oriented education institutions.

Влияние клена ясенелистного (Acer negundo L.) на естественное возобновление сосны обыкновенной в Барнаульском ленточном бору

The influence of ash-leaved maple (Acer negundo L.) on the natural regeneration of scots pine in the Barnaul ribbon forest in different types of forest growing conditions is considered. It was found that the ash-leaved maple forms a dense, closed undergrowth up to 10 m high in moist forest-growing conditions (A3), whereas in fresh forest-growing conditions (A2) it was noted only once. The closeness of the undergrowth of maple in the grass forest is 0,8…1,0 units, while the undergrowth with a predominance of local plant species (Siberian mountain ash, goat willow) in the grass forest has a closeness of no more than 0,5 units, in the fresh forest no higher than 0,2…0,4 units. The undergrowth of maple strongly obscures the components of the forest located under it: living ground cover and undergrowth. The shading of the living ground cover leads to its significant transformation, with a change in the floral composition and structure. Shading of the undergrowth leads to a complete absence of seedlings, self-seeding and the actual undergrowth of the common pine, interrupting the process of natural renewal. Using the obtained values of illumination under the canopy of the forest, it was found that in a grassy forest with a maple understory, the relative illumination is no more than 7,9 %, whereas in a grassy and fresh forest with an undergrowth of local species, 29,5…47,9 %. The density of pine undergrowth in a fresh forest with undergrowth of local species is 7,5…17,5 thousand units/ha, which is 3–7 times more than in a grass forest with undergrowth of local species. There is a close positive relationship between the relative illumination under the forest canopy and the density of undergrowth (r = 0,830). Ash-leaved maple acts as an aggressive undesirable breed, which limits the most important environmental factor — illumination, leading to the disappearance of pine undergrowth under the canopy of the forest.

Рост и развитие лесных культур сосны обыкновенной, созданных посадочным материалом с закрытой и открытой корневой системой, в различных условиях Республики Татарстан

The results of studies concerning the growth and development of Scots pine (Pinus sylvestris L.) forest plantations created by using seedlings with a root-balled system (RBS) and their comparison with forest plantations created by using ordinary seedlings with an bareroot system (BRS) in various forest-growing conditions in the Republic of Tatarstan are presented. Measurements of biometric parameters of plants were carried out in an amount that ensures the accuracy of average statistical indicators within 5 %. For each plant, the height, the annual growth of the axial shoot in height, the diameter at the root neck, the length of the main and lateral roots were measured. Research materials have established that forest plantations of Scots pine, created on lighter soils in forest conditions B1–3, are significantly behind in development from forest plantations created on soils richer in agrochemical characteristics C1–3. The creation of forest plantations on such soils requires the use of fertilizers and other measures of agrotechnical care for plantings. When creating forest crops with seedlings with BRS in forest conditions D2–3, on soils with a heavy granulometric composition (ordinary and leached chernozems), a significant decrease in the growth rate of seedlings was revealed. The use of planting material grown under the conditions of a closed root system (BRS) for the creation of forest plantations of Scots pine in the conditions of the Republic of Tatarstan requires further scientific justification. The results of using planting material with a root-balled system are ambiguous and require an appropriate pilot test.

Current state and productivity of Scots pine modal stands of the Forest Steppe of Ukraine

The development of regulatory and reference support for the inventory assessment of the state of modal stands is an urgent issue, since it allows obtaining reliable and up-to-date information on the current state of existing forests. The purpose of the study was a statistical substantiation of the division of pine stands into groups by region of growth and stand composition, and their detailed inventory characteristics with an analysis of the distribution in the Forest-Steppe and their productivity. To conduct the study, a stand-wise database of the Production Association “Ukrderzhlisproekt” for Forest-Steppe zone of Ukraine was used. Using a number of non-parametric criteria for evaluating samples (Kruskal-Wallis one-way analysis of variance, the median criterion, Jonckheere-Terpstra test), the study established a difference in the stands parameters of the samples under study and divided the stands of the Forest-Steppe zone into four groups. The main task was to describe the current state of modal pine stands of the Forest-Steppe zone of Ukraine for selected groups, with a detailed distribution of areas and stocks according to the main stand parameters According to the results of the database analysis, it was found that about 92% of the total area of pine stands of the Forest-Steppe zone are artificial forests. Depending on the region of growth, the stands were divided into the left- and right-bank parts of the Forest-Steppe, in composition – into pure and mixed stands. Within the groups under study, the distribution of areas and stocks of pine stands was analysed according to site index classes, types of forest-growing conditions, forest types, relative stand density, and age groups. Site index classes in all groups are dominated by high site index stands of I and Ia site index classes. The proportion of high-grade mixed stands is greater compared to pure stands. In terms of the forest-growing conditions, stands in condition B2 dominate in all groups under study. From the left bank to the right bank, there is an increase in soil fertility from condition B to condition C, and this dependence is also observed from pure to mixed stands. Productivity in terms of the average growing stock of mixed stands of the rightbank and left-bank parts of the Forest-Steppe is very close and considerably less than the stocks of pure stands. The presented research results can be used by scientists as a description of the modal inventory characteristics of the Forest-Steppe region and for the grouping of experimental data when compiling forestry and forest inventory standards

Increasing Fuel Loads, Fire Hazard, and Carbon Emissions from Fires in Central Siberia

The vast Angara region, with an area of 13.8 million ha, is located in the southern taiga of central Siberia, Russia. This is one of the most disturbed regions by both fire and logging in northern Asia. We have developed surface and ground fuel-load maps by integrating satellite and ground-based data with respect to the forest-growing conditions and the disturbance of the territory by anthropogenic and natural factors (fires and logging). We found that from 2001 to 2020, fuel loads increased by 8% in the study region, mainly due to a large amount of down woody debris at clearcuts and burned sites. The expansion of the disturbed areas in the Angara region resulted in an increase in natural fire hazards in spring and summer. Annual carbon emissions from fires varied from 0.06 to 6.18 Mt, with summer emissions accounting for more than 95% in extreme fire years and 31–68% in the years of low fire activity. While the trend in the increase in annual carbon emissions from fires is not statistically significant due to its high interannual variability and a large disturbance of the study area, there are significantly increasing trends in mean carbon emissions from fires per unit area (p < 0.005) and decadal means (p < 0.1). In addition, we found significant trends in the increase in emissions released by severe fires (p < 0.005) and by fires in wetter, dark, coniferous (spruce, p < 0.005 and Siberian pine, p < 0.025) forests. This indicates deeper burning and loss of legacy carbon that impacts on the carbon cycle resulting in climate feedback.