Forest Origin Research Articles

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.

Influence of wild ungulates on the secondary succession of an Apennine silver fir forest after windthrow

Windstorms are natural factors in vegetation dynamics, but their intensity is increasing and undermines the forest resilience. Post-event interventions depend on forest types and management purposes. To promote mixed stands that are less susceptible to windthrow than monocultures, natural tree regeneration is usually recommended. However, wild ungulates attracted by the increased food supply in the new clearings can influence the secondary succession and slow down vegetation recovery. The impact of ungulate pressure on secondary successions in blowdown areas is still poorly known, especially in Mediterranean areas, which is particularly vulnerable to climate stressors. We investigated this topic using a monospecific silver fir (Abies alba) forest of artificial origin in the Apennines as a model system. The forest was left to natural succession after a severe windthrow in 2015, offering the opportunity to establish an ungulate exclosure experiment to analyse vegetation changes over six years. For the whole plant community, cover and height, α-diversity (species richness, Shannon and evenness indexes), and species composition were recorded yearly, together with tree seedling density, in open and fenced plots at increasing distances from the forest edge. Ecological and functional traits (proportion of light-demanding and forest specialists, endo-/epi-zoochorous species), and life-forms of the community samples were also analysed. Overall, we found that ungulates significantly influenced the dynamic trajectories of secondary succession. The effects on plant cover and diversity were negative and increased with distance from the forest edge. The presence of ungulates favoured generalist species and endozoochorous taxa. However, distance from the forest edge strongly reduced the latter effect. The average density of tree seedlings was overall high (ca. 10,000/ha), but it was strongly reduced by ungulates for three deciduous species and A. alba, the most browsed species. Natural recolonization after windthrow in Apennine pure silver fir stands may favour the formation of mixed, less susceptible forests, but the current ungulate pressure slows down this process, especially in the areas furthest from the forest edge.

Forestry and mensuration characteristics of pine stands in the recreation and health-improving forests in the Left Bank Steppe

The study of forestry and stand mensuration characteristics of pine stands in recreational and health-improving forests of the Left Bank Steppe was conducted based on forest management materials. The distribution of pine stands in the recreational and health-improving forests of the region by location, origin, forest types, age groups and classes, site classes, and relative density of stocking was analyzed. For pine stands within the forest areas of green belt) (sites where forest activities are permitted), indicators of the use of forest potential by modal pines were calculated to compare reference stands. It was found that the pine plantations in the recreational and health-improving forests of the region grow in an area of more than 83 thousand hectares. In terms of area, man-made pine stands significantly dominate, the share of which is 93.6 % of the total area, the rest of the area (6.4%) is occupied by pine forests of natural origin. The predominance of pine stands within green belt was revealed. Their proportion is 76.1 % of the total area, including the forestry zone - 59.7 % and the forest park zone – 16.4 %. The significant area of the investigated pine plantations (37% of the total area) is located in the conditions of a fresh oak-pine (mixed) forest on transitional, relatively poor soils (subor in Ukrainian). The most part of forest is middle-aged stands (59.3 % of the total forest area and 70.5 % of the total stock of wood). Moreover, pine forest of I (39,2 %) and II (31,1 %) site classes and 0.7–0.8 density dominated (73.5 %). The rate of utilization of the forest potential by modal pines within forest areas of green belt compared reference stands is relatively low and reaches 63 %.

The oak forest of the Dendropark “Оlexandria”. Part 1. From indigenous to anthropogenically transformed plantation

This study aimed to determine the level of preservation of primeval forest criteria and the extent of anthropogenic transformation in the old-growth oak forest of the Dendropark “Оlexandria”. This age-old oak forest of natural origin covers an area of 31.8 ha with 1413 oaks. Another 8.8 ha of the oak plantations with 462 oaks belong to artificial landscape compositions.For over 200 years of existence since the creation of the Dendropark “Оlexandria”, the oak forest has preserved a number of criteria characteristics of virgin forests. In particular, it kept the complex mosaic-tiered forest structure. The indigenous associations of oak forests of hazel-ash (Quercetа (roboris) coryloso-aegopodiosum) and Tatar maple-stellar (Quercetа (roboris) acerioso (tatarici) stellariosum) remained. The dominant species, Quercus robur, retained the function of a unifier with a share in the first tier of 70–100 %. The floristic core of the main forest-forming species has been preserved too.The oak forest is a habitat for many woody and herbaceous plants of the local flora, including threatened species. The oak forest is characterized by high structural complexity, particularly a diverse epiphytic lichen flora, the presence of rare species, and 15 indicator species of old-growth forests and virgin forests. The oak forest is a habitat for 62 species of birds, mostly inhabitants of forests. A large part of the oak forest contains dead wood of the uniflorus species and its companions in various stages of decomposition.The anthropogenic interference in the oak forest has been long and varied. Since the foundation of the park and subsequently, the oak forest has been subjected to excessive fragmentation and introduction of introductions, creating decorative landscape compositions within the oak forest, mainly in the central part. This caused significant ecotonisation of the oak forest and displacement of Q. robur.Current research has revealed a number of criteria that classify the oak forest as a successor to the primeval forest, which gives the oak forest an exceptional value.

Особенности ассимиляционного аппарата изолированных популяций сосны (Большой Соловецкий остров)

The study results of the assimilation apparatus in the populations of Scots pine (Pinus sylvestris) and Shore pine (Pinus contorta) isolated from the mainland on the Bolshoy Solovetsky Island are presented. Three sites of bilberry pine forest of natural origin, Shore pine and Scots pine in bilberry habitat conditions are presented. Scots pine needle parameters were determined in the pine forest of natural origin and in the cultures of Shore pine. It was revealed that the parameters of the average needle in the natural pine forest and in cultures (Scots pine) are quite similar. The mass of the average needle, width and thickness do not really differ, but only the length and area differ. The mass of needles per branch is also not reliably different. It was revealed that the mass of needles on the branch is 169...181 g, the mass of average needles 14...15 mg, the length totals to 28 and 36 mm in cultures. At the same time, all the parameters are significantly lower than those of pine on the mainland (Primorsky district of the Arkhangelsk region). It was found that the parameters of Shore pine needles in cultures are higher than those of Scots pine in cultures by about 1,5–2 times. The life expectancy of the needles of the Scots pine (determined by weight) is 7 years in natural pine forests and 5 years in cultures. It was revealed that the most significant role is played by needles up to 4 years in the Scots pine and up to 5 years in the Shore pine. It is shown that the length of needles formed in different calendar years differs markedly. It is established that three-year cyclicity is traced in the dynamics of needle length. It was determined that the needle length of the current year is influenced by its size of the previous year. It was revealed that in the studied conditions the position in the crown does not affect the parameters of needles, i. e. the part of the crown (upper, middle, lower) has no influence.

Формирование структурно-функциональной организации молодняков сосны обыкновенной (Pinus sylvestris L.) смешанного искусственно-естественного происхождения в условиях сосняков ягодникового и разнотравного Среднего Урала

Restoration of forests, the study of the processes of formation of their structure and productivity, is currently one of the most urgent tasks. The features of the formation of 12-year-old forest plantations and the concomitant natural regeneration of Scots pine (Pinus sylvestris L.) were studied under the conditions of berry pine forest and forb pine forest of the Middle Urals, on trial plots established in accordance with the existing requirements. For each Scotch pine (Pinus sylvestris L.) tree, the diameter at the middle height and height were measured, and the volume of the trunk in the bark was calculated. The rank distribution of trees was carried out by calculating their reduction numbers, determining the amplitude of the reduction numbers and subsequent distribution into 5 main classes. In the 12th year after planting, the survival rate in the berry pine forest was 47.0%, and in the forb pine forest - 35.3%. In the berry pine forest, taking into account the concomitant natural regeneration of Scots pine (Pinus sylvestris L.), a pine forest of artificial and natural origin is being formed, and in the forb pine forest, a pine forest of natural and artificial origin is being formed. The process of natural renewal of Scotch pine (Pinus sylvestris L.) took place over several years. Scots pine (Pinus sylvestris L.) trees of natural origin are 2-7 years younger in biological age than trees of artificial origin. Pine trees of artificial origin in the berry pine forest significantly exceed the average diameter at the middle of the height, height and trunk volume of the same trees in the forb pine forest. Pine trees of natural origin in the berry pine forest are significantly superior in average diameter at the middle of the height to trees in the forb pine forest, but they are significantly inferior to them in the average trunk height and practically do not differ in the average volume of the tree trunk. Trees of artificial origin in terms of diameter at the middle of the height, height and volume of the trunk significantly exceed trees of natural origin both in the berry pine forest and in the mixed grass pine forest. The distribution of trees by diameter and height in young forests of artificial and natural origin, both in the berry pine forest and in the forb pine forest, is characterized by a distribution close to normal. The distribution of trees of artificial and natural origin in the berry pine forest and the forb pine forest in terms of trunk volume is distinguished by left-sided asymmetry and sharpness. When distributed by rank height classes, a significant reduction in the level of variability of biometric indicators is provided. However, in natural young stands, a very high level of variability in stem volume in the bark remains. Both in artificial and natural young stands, the main (86.3-97.5%) stock of trunk wood in the bark falls on trees of I-III height classes. In the forb pine forest, artificial and natural young stands had almost the same reserve values, which confirms the formation of young pine stands of natural artificial origin. In the berry pine forest, birch renewal does not represent significant competition to pine. In the forb pine forest, birch creates serious competition for pine and, probably, the formation of deciduous-coniferous plantations and oppression of pine.

Close-to-Nature Forestry Measures in East Polissia Region of Ukraine

The article discusses close-to-nature forestry measures for the natural regeneration of pure and mixed pine forests. It is shown that successful natural regeneration of high value tree species takes place after uniformly gradual logging and progressive strip felling as final cutting operations in pure pine forests in fresh or moist oak-pine forest stands on sandy soil, resulting in the development of natural young pine forests with mixed composition. The article analyzes the state of natural regeneration after the first cycle of transformation felling operations in pure even-aged pine stands aimed at converting them into mixed pine forests of natural origin. Systems of close-to-nature silvicultural measures for restoration, development, improvement and regeneration of forest stands in the process of continuous cover forestry have been elaborated.

Разновозрастность сосновых древостоев как фактор гармонизации системы лесохозяйственных мероприятий в ленточных борах Алтайского края

The ratio of the same- and uneven-aged pine forests in various types of ribbon forests in Altai Krai, as well as the patterns of forming natural pine plantations, is determined. This issue is important for the harmonization of the entire set of forest management activities in the study area. The research is based on the analysis of an electronic database that contains information on the forest fund of 11 forest districts in Altai Krai (more than 268 thousand stratums with a total area of 1014 thousand ha). With the help of queries using filters and summary tables, a sample of natural plantations with a predominance of Scotch pine (Pinus sylvestris L.) was obtained. For each plantation in the sample, the number of age generations and the distributions of the area of the same- and uneven-aged pine forests by forest districts, forest types, and quality classes were determined. Statistical data processing included cluster analysis and chi-squared test. Pine forests of natural origin in the study area consist mainly of 2-3 pine generations. The share of uneven-aged forest stands accounts for 79.6% of the area. Same-aged pine forests occupy 20.4% of the area. During the transition from damp to very dry growing conditions, the proportion of uneven-aged pine forests increases. In the future it is planned to improve the existing systems of improvement thinning in mature, declining stands of forest-steppes and ribbon forests in the Altai-Novosibirsk forest growing district considering the ratio of the same- and uneven-aged pine forests. The improvement of the system of forest management activities should be performed on a forest-typological basis in combination with the division of plantings into high- and low-quality.

Динамика напочвенного покрова в биотопах сосновых лесов при фрагментации, вызванной пожарами, в условиях лесостепной зоны

The ground cover in the forest plant community is the most dynamic structure. We analyzed the ground cover in the pre- and post-fire period in the forest community of a pine forest of natural origin, not damaged by fires, but located on the border of the harem. The study was carried out in biotopes of pine forest (Voronezh region, Educational and Experimental Forestry Enterprise of Voronezh State Forestry Engineering University named after G.F. Morozov) by describing the ground cover of the transect in several types of forest of areas undamaged by fire: dry forest, raw forest, subor. Over the past decade, the total number of ground cover species in the pine forest has been preserved (63 species), their species composition is changing. The greatest species diversity is characteristic of suborea. By 2022, steppe and meadow plants, primarily cereals, will appear in the flora, which indicates a change in environmental conditions. Ground lichens have completely disappeared, as well as 19 species of indicator plants, six of which are included in the Red Book of the Voronezh Region. There was a change in the structure of plant groups. Along with the indicator species, meadow and steppe species appear in the groups. The total projective coverage of the ground cover decreased from 80 to 68 %, as well as the projective coverage of the thicket (from 60 to 50%), mosses (from 80 to 70%), lingonberries (from 40 to 30%) in groups.

STATЕ OF NATURAL OAK FORЕSTS OF ZHMERYNSKE FORЕSTRY

The article shows the problems of researching the state of natural oak forests of the branch "Zhmerynske LH", which is in the functional structure of the regional forestry and hunting economy department of Vinnytsia region. In the research material of the article, an analytical review of the specialized enterprise's forest management database is carried out. The result of the analysis of forest management data and visual inspection within the forest areas of the Zhmerynske Forestry Branch is the determination of the taxonomic indicators of oak forest plantations of seed and vegetative origin. The preserved natural oak stands within the forest areas of the branch "Zhmerynske Forestry" grow in optimal forest and vegetation conditions. The vast majority of natural oak stands grow in fresh hornbeam forests and less in wet hornbeam forests. It has been established that natural oak forests within the forest fund of a forestry enterprise are represented by vegetative and seed plantations by origin. Analytical data show that there is a tendency to reduce the share of natural oak forests within the enterprise. It has been determined that the enterprise is dominated by oak forests of natural origin with a share of 9-10 units of oak, mostly 110 years old. The area of these plantations is the maximum and amounts to 159.3 hectares. It was found that the oak stands are characterized mainly by the 2nd class of bonita. The average stock ranges from 310-342 m3/ha. The result of the research is the establishment that in natural oak forests there is almost no sustainable natural regeneration of the main forest-forming species. Also, based on visual inspections, it was found that in the conditions of fresh pile, natural regeneration of oak is not found in the existing forest types.

Osobliwości formowania borów sosnowych różnej genezy na Piaskach Przytiasmyńskich

The article elucidates the formational patterns of Przytiasmyń pine forests of natural and artificial origin. The paper characterizes the current state, species composition and phytocoenotic structure of Przytiasmyń pine forests, and notes factors of their formation; the ecological-coenotic analysis of the studied plant groups has been carried out as well. A numerical-statistical method has been used to assess the degree of compliance of the phytocenosis with habitat conditions.

Amplified Drought Alters Leaf Litter Metabolome, Slows Down Litter Decomposition, and Modifies Home Field (Dis)Advantage in Three Mediterranean Forests.

In Mediterranean ecosystems, the projected rainfall reduction of up to 30% may alter plant–soil interactions, particularly litter decomposition and Home Field Advantage (HFA). We set up a litter transplant experiment in the three main forests encountered in the northern part of the Medi-terranean Basin (dominated by either Quercus ilex, Quercus pubescens, or Pinus halepensis) equipped with a rain exclusion device, allowing an increase in drought either throughout the year or concentrated in spring and summer. Senescent leaves and needles were collected under two precipitation treatments (natural and amplified drought plots) at their “home” forest and were left to decompose in the forest of origin and in other forests under both drought conditions. MS-based metabolomic analysis of litter extracts combined with multivariate data analysis enabled us to detect modifications in the composition of litter specialized metabolites, following amplified drought treatment. Amplified drought altered litter quality and metabolomes, directly slowed down litter decomposition, and induced a loss of home field (dis)advantage. No indirect effect mediated by a change in litter quality on decomposition was observed. These results may suggest major alterations of plant–soil interactions in Mediterranean forests under amplified drought conditions.

Сравнительная оценка сукцессионной динамики древесных фракций ельников южной тайги

Relevance. The native forests can be recognized as endangered formations of the European North of Russia. They are benchmarks of forest sustainability for comparative assessment with forests of other origin and use, what determines the relevance of research on their structural features. The purpose of the research is to conduct a comparative assessment of dynamic processes in the native forests of spruce formations of the southern taiga subzone of various successional positions (phases of dynamics) in the time trend of their development. Material and methods. Native spruce forests of different ages of the southern taiga subzone of the Central Forest Biosphere Reserve (Tver region) and the Kologrivsky Forest Reserve (Kostroma region) were researched various dynamic characteristics and successional position — climax, demutation, digressive. In the biogeocenoses of the sample areas, the age of trees and the presence of rot were determined, age series were built, the volumes of trees in age generations were calculated. All the tree fractions of the analyzed spruce forests were arranged in one time series: stands, current tree fall and deadfall — from retrospective values (– 60 years) to prospective values of the age limit of trees of the first generations of stands (+ ~ 300 years). The processes of dynamics of volumes of the wood fraction of native spruce forests of various successional positions in a long time space with different rates of accumulation and decomposition of wood biomass are described. Results and discussion. The processes of accumulation of biomass and the formation of age structures of biogeocenosis are 4 to 7 times slower than the processes of decomposition of the dying biomass of woody decay. Wood-destroying fungi of the saprotrophic complex “adjust” the activity of the decomposition process of wood decay to the dynamics of wood accumulation by the stand, maintaining the balance of accumulation and decomposition of woody biomass in the forest community. The correlation dependence of the increase in the values of tree infestation with wood-destroying fungi in age generations with an increase in their age is expressed in correlation coefficients from r — 0.89 at mr — 0.07 and t — 11.8 (spruce grove 1) to 0.99 at mr — 0.004 and t — 245 (spruce grove 4). The connection in both cases is very high, almost functional, which can be interpreted as a pattern. Conclusion. In native virgin forests, the balance of reproducible and decomposable wood is preserved as one of the most important criteria for the sustainable functioning of forest communities. This position can be regarded as an important fact of the evolutionary functional structure of forests.

Nursery Roosts Used by Barbastelle Bats, Barbastella barbastellus (Schreber, 1774) (Chiroptera: Vespertilionidae) in European Lowland Mixed Forest Transformed by Spruce Bark Beetle, Ips typographus (Linnaeus, 1758) (Coleoptera: Curculionidae)

Białowieża Primeval Forest (BPF, approx. 1700 km2) is an important forest area in Europe from the point of view of the protection of natural diversity. BPF is covered with old mixed tree stands of mostly natural origin. Norway spruce is a tree species in BPF and covers approx. 27% of its area. Between 2012 and 2017 a large outbreak of the bark beetle Ips typographus (Linnaeus, 1758) took place in the forest, which transformed the stands and left many dead standing trees. At that time salvage logging had begun but was stopped due to protests by scientists and activists and for legal reasons. As a result of research conducted using a radiotelemetry method in 2020, we found that the Western barbastelle bat Barbastella barbastellus (Schreber, 1774) chooses nursery roosts in dead Norway spruce trees, showing ecological plasticity by colonizing a newly available resource. Based on this, we found that the Western barbastelle has a preference for a type of roost rather than a tree species. Insect outbreaks in forests of primary, natural, or semi-natural origin are one of the natural factors that shape the habitat. Removal of dead standing trees disrupts these processes, and in this particular case results in the disappearance of a newly appeared ecological niche.

Habitat-dependent Culicoides species composition and abundance in blue tit (Cyanistes caeruleus) nests.

Wild birds are hosts of Culicoides from as early on as the nesting stage when constrained to their nests. However, the environmental factors which determine the abundance and composition of Culicoides species within each bird nest are still understudied. We sampled Culicoides from Eurasian blue tit (Cyanistes caeruleus) nests found in 2 types of forests located in southern Spain. Firstly, we monitored the abundance of Culicoides species in bird nests from a dry Pyrenean oak deciduous forest and a humid mixed forest comprising Pyrenean and Holm oaks throughout 2 consecutive years. During the 3rd year, we performed a cross-fostering experiment between synchronous nests to differentiate the role of rearing environment conditions from that of the genetically determined or maternally transmitted cues released by nestlings from each forest. We found 147 female Culicoides from 5 different species in the birds' nests. The abundance of Culicoides was higher in the dry forest than in the humid forest. Culicoides abundance, species richness and prevalence were greater when the nestlings were hatched later in the season. The same pattern was observed in the cross-fostering experiment, but we did not find evidence that nestling's features determined by the forest of origin had any effect on the Culicoides collected. These results support the notion that habitat type has a strong influence on the Culicoides affecting birds in their nests, while some life history traits of birds, such as the timing of reproduction, also influence Culicoides abundance and species composition.

Естественное возобновление сосны в городских лесах города Тюмени (на примере экопарка «Затюменский»)

There is given the data of assessment of the success of natural renewal in the recreational pine forests of natural origin of the Zatyumenskypark in the city of Tyumen. It was found that according to the total number of vital pine undergrowth, the process of natural reforestation of pine forests is characterized as unsatisfactory. With a decrease in recreational influence, there is a decrease in the amount of non-viable pine undergrowth. In pine trees characterized by stage IV of recreational digression, the amount of non-viable pine undergrowth is 35% of the total. There is the appearance under the canopy of pine stands of birch and maple undergrowth, in terms of the amount prevailing in comparison with the undergrowth of pine. An assessment of the state of natural reforestation of pine trees in areas of the ecopark that are less exposed to recreational impacts showed a mass concentration and active growth of viable pine undergrowth of various high-altitude categories in the “windows” between the trees, which indicates the successful renewal of pine under appropriate conditions. In order to preserve, improve and increase the renewable potential and successful natural reforestation process of pine plantations of the Zatyumensky Ecopark in Tyumen, it is proposed to conduct temporary fencing of forest areas that are in critical condition at the last stages of recreational regression for the period of their restoration; redirecting the flow of recreation to more recreationally sustainable areas of the ecopark; creation of natural curbs along the landscaped road and trail network of aboriginal (acacia, raspberry, rose hips, etc.) and introduced (western thuja, etc.) wood-shrub species, which will be a natural obstacle for recreationists and create aesthetics of the park landscape. In pine plantations characterized by weak recreational attendance, it can be proposed to reduce the relative completeness of tree stands to 0.7-0.6, followed by measures to promote natural regeneration (loosening, mineralization, partial removal of undergrowth, etc.).

Взаимосвязи физико-механических свойств древесины и закономерности их изменения внутри ствола березы

The physical and mechanical properties of standing wood are not constant along the tree height and diameter. They also differ depending on the tree species and conditions of its growth. So, the research purpose is to identify patterns of change and interrelations between the parameters of density, compressive strength and sound propagation velocity along the wood fibers inside the stem of a birch tree growing in the forests of the Middle Volga region of Russia, where such research had never been conducted before. The work was carried out on two sampling areas laid out by standard methods in birch forests of natural origin with average productive capacity on the territory of the Scientific-Experimental Forest District of the Volga State University of Technology in the Mari El Republic. The average age of the birch trees is about 70 yrs, breast height diameter is 30 cm, and height is 28.5 m; 14 sample trees were studied; 0.5 m long chucks were cut out from their stems at a height of 1.3 m from the butt end and at relative heights of 0.25H, 0.5H, and 0.75H. Experimental work was carried out in a laboratory environment with modern technical facilities using standard procedures. Mathematical models describing the changes in the parameters stated above and the interrelations between them with regard to the stem diameter at relative heights were obtained. The research results generally confirmed the findings of other researchers on densitograms and other physical and mechanical properties of wood within the tree stem. However, the features listed above were revealed for birch trees growing under such conditions; in particular, it concerns the ratio of strength and density, as well as the wood strength and the velocity of sound propagation through the fibers. The results obtained have both scientific and practical value as a basis for the development of a non-destructive method for predicting technical properties of standing wood as well as timber for producing assortments for special purposes. For citation: Fedyukov V.I., Chernov V.Yu., Chernova M.S., Tsoy O.V. Interrelations of Wood Physical and Mechanical Properties and Patterns of Their Change within the Birch Stem. Lesnoy Zhurnal [Russian Forestry Journal], 2021, no. 6, pp. 150–159. DOI: 10.37482/0536-1036-2021-6-150-159

Influence of forest technical measures on the reproduction of rare phytorification in forest ecosystems of the Forest Steppe of Ukraine

An interesting aspect is the issue of acquiring natural features by artificially created tree plantations on the territory of the forest steppe zone of Ukraine. This paper analyzes the conditions of emergence and formation of new habitats rare plant species populations in different types of artificial trees and shrubs of the Forest Steppe of Ukraine. Complexes of natural and anthropogenic factors of necessary conditions creation for realization of this process are defined. The peculiarities of the negative impact of various economic measures on the reduction of the number of individuals of sozophyte plants and even the disappearance of some of their populations are reflected. The peculiarities of the negative impact of various economic measures on the reduction of the sozophyte plants individuals’ number and even the disappearance of some of their populations are reflected. To improve the protection of sozophytes in the forests of the forest steppe zone, it is advisable to review the implementation of certain methods of forest management measures. In particular, it is necessary to completely ban continuous felling in forests of natural origin and the allocation of biofields for natural reforestation. To improve the condition of forest coenoses of protective plantations, including field protective forest strips, it is necessary to conduct a series of experiments with the subsequent development of technology for their coenotic correction in order to increase the general ecological, including phytososological, significance. The implementation of a set of phytomeliorative measures in the creation of protective forest plantations to some extent will help prevent possible climate change, local disasters and will have a positive impact on the processes of crop formation. The creation of sustainable forest plantations will allow the application of environmental protection measures using the regulatory and protective functions of forest ecosystems. Compliance with all these conditions will contribute to the manifestation of various environmental measures for the development and conservation of biological diversity.

Features of coarse woody debris volume formation in fresh sudibrova conditions in Zmiini islands tract of Kaniv Nature Reserve

Dead wood (woody debris) is an important component of forest ecosystems. It performs a number of ecological and environmental functions. The article studies the peculiarities of the formation of coarse wood detritus volume and its qualitative structure in forests in the conditions of fresh sudibrova of the Zmiiini Islands tract of Kaniv Nature Reserve. The study of dead wood was carried out in 140-year-old pine-oak forests of natural origin on a permanent sample plot (0.24 ha) by identifying and measuring of standing and lying deadwood components. It was found that dead wood in the forest ecosystem was formed due to the dying of trees of five species: common oak (Quercus robur L.), Scots pine (Pinus sylvestris L.), Norway maple (Acer platanoides L.), small-leaved lime (Tilia cordata Mill.) and common hornbeam (Carpinus betulus L.), and has a volume 56.3 m3·ha–1. Dead wood volume is dominated by standing dead trees — 82.1%, and the share of lying dead wood, respectively, is 17.9%. The main part of dead wood volume is formed by two tree species — common oak and Scots pine, the share of which together is 94.3%. Common oak and Scots pine is characterized by a predominance of standing dead wood, while for other tree species — lying dead wood. In general, dead wood is formed by detritus of I–IV classes of destruction, at the same time detritus of class II decomposition has a significant advantage (70.5%), recently dead wood has a much smaller share (I class, 24.8%), and other classes of destruction have insignificant shares, which together do not exceed 5.0%. No woody detritus of the last (V) class of destruction was detected. Volume of standing dead wood is 46.2 m3·ha–1, and is formed by whole and broken dead trees. In terms of species composition, common oak has a significant advantage (74.5%), Scots pine has a much smaller share (25.1%), and the share of Norway maple is insignificant (0.4%). The total standing dead wood volume is dominated by wood of class II destruction (33.0 m3·ha–1, 71.4%) compared with class I (13.2 m3·ha–1, 28.6%). Lying dead wood is represented by four classes of destruction (I–IV), however, no woody debris was found at the late (last) stage of decomposition (class V). In terms of volume, the second class of destruction has an absolute advantage (6.7 m3·ha–1, 66.3%), much less class III detritus (2.3 m3·ha–1, 22.8%). Lying dead wood of common oak is represented by all four classes of destruction, among which III (40.5%) and I (33.3%) classes predominate. Lying dead wood of other tree species is characterized by the predominance of II or III classes of destruction. The main factors in the formation of woody detritus in the pine-oak forest in the Zmiiini Islands tract could be the impact of adverse climatic conditions (long periods without precipitation in summer), which led to the weakening of individual trees and their death, gusts of wind that broke individual tree trunks, low-intensity snow breaks, and the influence of biotic factors (insects, pathogens).

Reconstruction of Low-value Plantings as an Element of Sustainable Forest Management in the South of the Russian Far East

The article presents the research results of low-value oak plantations in which, in the first half of the 90s of the XX century, measures were taken to reconstruct these objects by forest plantation development created by planting Korean cedar seedlings in previously prepared corridors in the south of Primorsky Krai. The paper analyzed the variability of the main taxation characteristics of the created stands according to the following indicators: average height, average diameter, volume of growing stock as of 2021. The capacity for survival of plants in stands, diameter distribution were studied. According to the research results, it was found that the work performed on the reconstruction of oak forests of mixed origin, despite the admitted deviations from the reconstruction project, has led to positive results. To achieve the best results, it is necessary to adjust the rate of planting seedlings per hectare of the area. The optimal planting rate is 1-1.5 thousand of pcs/ha. It is advisable to increase the distance between plants in the planting row up to 1.5 -2.5 m. After reconstruction works, it is necessary to provide for forest tending in the plantations aimed at creating optimal conditions for the formation of valuable cedar-broad-leaved plantations. It is concluded that it is advisable to carry out the work on reconstruction of low-value plantations of coppice and mixed origin in the southern regions of the Russian Far East in order to achieve the goals of sustainable forest management of the region's forests, including the preservation of their biodiversity.