Forest Information Research Articles

Spatial Distribution of Fine Roots in Pinus tabuliformis and Populus tomentosa and Their Competition in Soils Response to Nutrient Availability and Proximity

Developing high-efficiency mixed forests or converting low-efficiency pure forests into near-natural mixed forests with optimal structure and function is a crucial aspect of forest management. In the initial stages of afforestation or stand improvement, fertilization and planting distance significantly influence the formation and development of mixed forests. This study investigated how nutrients and planting distance affect root competition between five-year-old Chinese pine (Pinus tabuliformis) and one-year-old Chinese white poplar (Populus tomentosa) and identified the factors influencing the competitive ability of these two species. Field planting experiments used three fertilization gradients (63 g·m−2, 125 g·m−2, and 250 g·m−2) of Stanley compound fertilizer with an N:P:K ratio of 2:1:1 and two planting distances (25 cm and 50 cm). Each experimental group was planted in circular plots with a radius of 0.5 m, yielding a total of nine plots. The effects of different fertilization concentrations and planting distances on root distribution were analyzed both horizontally and vertically. Pearson correlation analysis was used to assess the relationship between roots and soil nutrients, while Levins’ niche overlap formula evaluated the differences in root competition between the species. Furthermore, principal component analysis quantified the relationships between impact factors and the root competitiveness of the two species. Results indicated that both species primarily allocated their fine root biomass to the shallow 0–10 cm layer. Pinus tabuliformis primarily extended to the southwest, while Populus tomentosa predominantly grew to the north. Both species exhibited enhanced root growth at moderate nutrient concentrations of 125 g·m−2. At a planting distance of 50 cm from Pinus tabuliformis, Populus tomentosa seedlings demonstrated superior root growth compared to those planted 25 cm apart. Pinus tabuliformis demonstrated greater competitive ability in the deeper 10–30 cm soil layers compared to Populus tomentosa, which showed the opposite pattern in the shallow 0–10 cm layers. Furthermore, available phosphorus (contribution rate of one impact factor on the competitiveness indexes, CR: −0.998), organic matter (CR: −0.978), total nitrogen (CR: −0.947), and alkali-hydrolysable nitrogen (CR: −0.937) significantly negatively impacted the competitiveness indexes of Pinus tabuliformis. The fine root surface area, volume, and length of Populus tomentosa also significantly negatively affected its competitiveness indexes, with all contribution rates exceeding an absolute value of 0.847. Results indicated that the root distributions of Pinus tabuliformis and Populus tomentosa overlapped spatially, with each species exhibiting advantages in different regions. Therefore, in future plantation reconstruction and forest management, it is essential to thoroughly evaluate root, soil, and fertilizer factors, adjusting planting distances accordingly, to effectively mitigate competition between the two species and successfully establish a mixed forest.

The role of root systems of Pinus sylvestris L. during the formation of secondary pine forests in deforestation in the Kola North

The role of the roots and root systems of Pinus sylvestris L. in the formation of secondary pine forests in the cuttings of the Kola North was studied. It has been established that in pine seedlings in disturbed areas, root and shoot systems are formed quite quickly. Already in the I-th grade of age, characteristic morphological signs of root systems appear, the feeding areas of trees begin to overlap each other. The bulk of the roots (80–85%) is concentrated in the upper 20-centimeter soil layer. A linear relationship between the taxation indicators of trees and the mass of root systems has been revealed. The conducted studies have shown that the formation of forest communities of Scots pine in the cuttings of the Kola North, their stability and productivity are directly dependent on the degree of development of individual roots and root systems as a whole.

Exploring environmental and climate features associated with yellow fever across space and time in the Brazilian Atlantic Forest biome.

The Atlantic Forest Biome (AFB) creates an ideal environment for the proliferation of vector mosquitoes, such as Haemagogus and Sabethes species, which transmit the Yellow Fever virus (YFV) to both human and non-human primates (NHP) (particularly Alouatta sp. and Callithrix sp.). From 2016 to 2020, 748 fatal cases of YF in humans and 1,763 in NHPs were reported in this biome, following several years free from the disease. This underscores the imminent risk posed by the YFV. In this study, we examined the spatiotemporal distribution patterns of YF cases in both NHPs and humans across the entire AFB during the outbreak period, using a generalized linear mixed regression model (GLMM) at the municipal level. Our analysis examined factors associated with the spread of YFV, including environmental characteristics, climate conditions, human vaccination coverage, and the presence of two additional YFV-affected NHP species. The occurrence of epizootics has been directly associated with natural forest formations and the presence of species within the Callithrix genus. Additionally, epizootics have been shown to be directly associated with human prevalence. Furthermore, human prevalence showed an inverse correlation with urban areas, temporary croplands, and savannah and grassland areas. Further analyses using Moran's Index to incorporate the neighborhoods of municipalities with cases in each studied host revealed additional variables, such as altitude, which showed a positive correlation. Additionally, the occurrence of the disease in both hosts exhibited a spatio-temporal distribution pattern. To effectively mitigate the spread of the virus, it is necessary to proactively expand vaccination coverage, refine NHP surveillance strategies, and enhance entomological surveillance in both natural and modified environments.

Generic and Specific Models for Volume Estimation in Forest and Savanna Phytophysiognomies in Brazilian Cerrado.

The Cerrado has high plant and vertebrate diversity and is an important biome for conserving species and provisioning ecosystem services. Volume equations in this biome are scarce because of their size and physiognomic diversity. This study was conducted to develop specific volumetric models for the phytophysiognomies Gallery Forest, Dry Forest, Forest Savannah, and Savannah Woodland, a generic model and a model for Cerrado forest formation. Twelve 10 m × 10 m (100 m²) (National Forest Inventory) plots were used for each phytophysiognomy at different sites (regions) of the Federal District (FD) where trees had a diameter at breast height (DBH; 1.30 m) ≥5 cm in forest formations and a diameter at base height (Db; 0.30 m) ≥5 cm in savanna formations. Their diameters and heights were measured, they were cut and cubed, and the volume of each tree was obtained according to the Smalian methodology. Linear and nonlinear models were adjusted. Criteria for the selection of models were determined using correlation coefficients, the standard error of the estimates, and a graphical analysis of the residues. They were later validated by the chi-square test. The resultant models indicated that fit by specific phytophysiognomy was ideal; however, the generic and forest formation models exhibited similar performance to specific models and could be used in extensive areas of the Cerrado, where they represent a high potential for generalization. To further increase our understanding, similar research is recommended for the development of specific and generic models of the total volume in Cerrado areas.

Devastation of the cerrado of mato grosso do sul and the advance of arenization in the pardo river watershed

Despite the significant biodiversity in the Cerrado, the process of occupation, subsequent economic cycles, and intensification of agriculture in a predatory manner have caused profound alterations in this biome. This study analyzed changes in land use and land cover in the Cerrado of Mato Grosso do Sul between 1985 and 2022 by mapping and also investigating the formation and dynamics of sand dunes in the Bauru sedimentary basin, focusing on the Pardo River watershed. MapBiomas Network data, collection 8, were used for land use and land cover analysis. Arenization foci cartography was conducted using brightness index 2 based on Sentinel-2 satellite images in Sentinel Application Platform software. The historical analysis of land use and cover in the Cerrado of Mato Grosso do Sul revealed a rapid transformation of the landscape, with a drastic reduction of native vegetation and an intensification of large-scale monocultures. Between 1985 and 2022, the Cerrado of Mato Grosso Sul lost 4.6 million hectares of native vegetation (forest formations, savannahs, grasslands, and wetlands), representing 24.54% of this territory. Recent changes in land use include pasture-soybean and pasture-eucalyptus. In the Pardo River watershed, arenization foci cover an area of 17,834.34 hectares, with varying dimensions ranging from less than 1 hectare to 376.41 hectares. The arenization process occurs in different slope compartments, such as the base, slope, and interfluves. The physical and chemical characteristics of Quartzipsamments, such as low organic carbon content in soil, are associated with high rates of surface exposure and weakened load-dependent structures, leading to degradation. Arenization occurs where natural vegetation has been suppressed and soil has been depleted by poorly managed production processes.

Fire-sensitive and threatened plants in the Upper Paraguay River Basin, Brazil: Identifying priority areas for Integrated Fire Management and ecological restoration

Extreme wildfires present an ever-increasing problem in different landscapes around the world. Here, we explore recent wildfires to prioritize recovery efforts and mitigate effects of future wildfires in the Pantanal, the largest continuous wetland in the world. Using ecological niche modeling (ENM), we categorize affected areas based on potential levels of degradation by fire and the predicted suitability for threatened and fire-sensitive plants. Based on this information, we identify key areas for fire prevention. Under land cover change scenarios predicted for 2050, approximately 25 % of the land cover under future threat will have potentially high biomass accumulation. We identified 1272 km2 in priority areas with forest formation, with restoration cost of at least US$ 576,189. This case study provides an analysis workflow that can be used to assess other wildfire-threatened parts of the world. These results can inform public policy to establish new fire brigades, conservation efforts using Integrated Fire Management, and restoration areas to mitigate biodiversity loss.

Post-Pyrogenic Successions in Oak-Korean Pine Forests with Schisandra chinensis and Corylus mandshurica in Sikhote-Alin

This article discusses the results of long-term stationary studies of the formation and development of oak-cedar pine forests with magnolia berry and hazel growing in the Southern and Middle Sikhote-Alin. Considered here are the peculiarities of stands decline, seed-based reforestation, as well as the tree species growth and development courses during the process of reforestation successions in areas with different intensity of fire exposure. Following persistent ground fires, the stands decline is most intensive in the first 5 years, with decay rates and the number of surviving trees varying in different types of burnt areas. The most active seed-based reforestation occurs on post-fire sites mainly during the first 2 years, with birch, aspen and other early stage species predominating. The rate of annual growth of the young generation of trees is the most intensive on plots significantly damaged by fire, in serial species (birch, aspen, Maak’s bird cherry, etc.) they are an order of magnitude higher than in climax broadleaved and coniferous species. Determination of dominance indices, equally dependent on the numbers of undergrowth, thin and large trees, showed that during reforestation successions after both rapid and persistent lowland fires, the phytocenotic importance dynamics in Korean pine, Mongolian oak and other forest forming species has its own peculiarities.

The vascular plant species of different protection levels in the ecosystems of the regional landscape parks of the Ukrainian Polissia

The Ukrainian Polissia is a distinctive region in terms of biodiversity, with a significant number of northern and boreal species and communities, as well as Central European species in the Western Polissia. The research region stretches from west to east for 750 km, and from north to south for 120–150 km. In the northeast direction, its territory gradually narrows to 50–80 km and constitutes a significant part of the important ecological corridor of Eastern Europe. Background. The natural conditions of the Ukrainian Polissia are favorable for the formation of coniferous, broadleaf and mixed forests, which are zonal communities here. The widespread distribution of fluvioglacial sediments causes the predominance of sandy sod-podzolic soils and associated pine forests. The high groundwater table and the low surface area contribute to the development of eutrophic peat bogs. All this leads to the formation of a diverse vegetation cover, which contributes to the representativeness and significant preservation of floristic and coenotic diversity. One of the key roles in the protection of rare species of phytodiversity in the Polissia region of Ukraine belongs to multifunctional protected areas, including the category of “regional landscape parks”. They cover more than 200 species of vascular plants of the Polissia region, with diffe­rent conservation statuses – from the international level of protection to the regional one. Materials and Methods. The study was conducted using conventional field (route-based, geobotanical descriptions of key areas) and desk methods. The species names are given according to the International Plant Names Index, and their belonging to the protected categories is based on the conservation criteria and protection levels accor­ding to the regulatory documents. Results and Discussion. The materials of the research of phytodiversity of five regional landscape parks (Prypiat-Stokhid, Nadsluchanskyi, Ptashynyy Rai, Mizhrichenskyi, Yalivshchyna), in particular rare species, are presented, as evidenced by their diversity, including a number of glacial relics, endemics and borderline species located at the southern or eastern border of the distribution area. Conclusions. The study has revealed that the rare vascular plant flora of the Polissia regional landscape parks is represented by 56 species included in the Red Data Book of Ukraine, 145 species under regional protection of three oblasts of the Polissia region, nine species from Appendix I of the Bern Convention, four species from Appendix II of CITES, and three species included in the European Red List. Two RLPs are the most sozologically representative in the study area: Nadsluchansky (six species of international protection statuses, 30 species of the Red Data Book of Ukraine, 107 species of regional protection level) and Mizhrichynsky (14 species with international protection statuses, 28 species of the Red Data Book of Ukraine, 51 species of regional protection level), which is determined by the peculiarity of natural conditions, habitat diversity and area of the territories. regional landscape parks as a category of nature reserve fund of regional status within the Polissia region of Ukraine cover most of the representative habitats, which include a corresponding number of rare species of different levels of protection, namely: forest (87 species), herbaceous (85 species), marsh (36 species) and aquatic (30 species) habitats.

VEGETATION COVER DYNAMICS OF THE ECOLOGICAL CORRIDORS OF MAYO-KEBBI WEST IN CHAD FROM 2009 TO 2019

This study highlights the application of remote sensing and Geographic Information Systems (GIS) in monitoring vegetation formations in the Mayo-Kebbi West province. The general objective of this study is to contribute to better management and conservation of vegetation formations in the Lere-Binder wildlife reserves, Sena-Oura National Park, and the Yamba Berte forest formation. The spatio-temporal evolution of vegetation was analyzed using Sentinel imagery from 2009 and 2019. The results and matrix analyses showed that 42.86% of the land cover units (grassland, shrubland to woodland, and flood zone) experienced a regression of 7.6 ha per year, while 57.14% (water bodies, fields, gallery forest, and open forest) showed progression. It is noteworthy that the main factors driving vegetation degradation are agriculture, livestock farming, logging, charcoal production, and gold mining.

Natural forming of vegetation cover on black coal mining dumps in the environs of Kopeysk (Chelyabinsk Oblast)

The article considers the current forming of vegetation and biotopes as a result of natural overgrowth of territories disturbed during black coal mining in the environs of Kopeysk town (Chelyabinsk Oblast). The 88 species of vascular plants were detected on the waste banks and spaces between them, the 7 species of vascular plants are woody species. It has been established that in the process of natural overgrowth of dumps, forest and meadow plant communities are actively formed from pioneer ruderal and halophytic communities. By methods of multidimensional statistics, 15 phytocoenochores have been determined and the discriminate of which is d identified by the tree species, which are forming the forest canopy. The identified plant communities are characterized by specific regimes of the fundamental abiotic factors of biotopes and make up a series of biotopic and coenotic substitution, forming a sylvant (forest) and pratant (meadow) successional series. It has been shown that in the process of natural overgrowth, the formation of forest (primarily birch) and meadow coenoses proceeds in parallel, and the invasive species Acer negundo L. plays an active role in sylvatization. It has been established that the leading hand in the formation of the coenotic structure of communities belongs to soil mineralization, acidity, aeration and variability of soil moisture. The obtained data on biotopes and successional series can be used in the development of the biological stage of landfill revegetation after coal mining impacts with the formation of woody or grass plant communities.

The Role of Root Systems of Pinus sylvestris L. during the Formation of Secondary Pine Forests in Deforestation in the Kola North

The Role of Root Systems of Pinus sylvestris L. during the Formation of Secondary Pine Forests in Deforestation in the Kola North

The spruce bark volatiles and internal phloem chemical profiles after the forest gap formation: the annual course

Abstract Our study explores the impact of sudden gap formation on the bark volatile and internal chemical profiles of Norway spruce trees during the initial dry year of research plot 2018 following gap formation. We investigated the annual variation in two main physiological traits of Norway spruce trees at the forest edge (FE) and in the forest interior (FI): bark monoterpene (MT) emission spectra and internal phloem MT composition. Given that gap formation increases the solar radiation dose and temperature for trees at the forest edge, we hypothesized that the concentrations of airborne terpenes released from the tree bark and internal phloem terpenes will increase as a consequence of induced tree defenses. Our findings demonstrate significant increases in both airborne terpene concentrations and internal terpene composition in trees at the forest edge compared to the control trees in the forest interior. This study provides novel insights into the annual dynamics of bark monoterpenes following forest edge establishment and underscores the physiological changes experienced by trees in response to the gap formation.

DIFFERENTIATION AND STRUCTURE OF FOREST STANDS IN THE VORSKLA RIVER VALLEY WITHIN THE BOUNDS POLTAVA REGION

The article examines the forest vegetation of the Vorskla River, addressing the issue of spatial differentiation, structure, and dynamics of changes in tree species. Scientific investigation demonstrates that the forest type and the stand’s structure are influenced by ecological factors such as soil type, climate, water regime, and flora and fauna. Within the Vorskla River valley, 27 forest formations with a total area of 72,353.2 hectares (12.8% forest cover) have been identified. Based on morphometric indicators, the forest formations are categorized as follows: 3 large formations, 6 medium-sized formations, 10 small formations, 6 tiny formations, and 1 local formation. The dominant formations are Pineta silvestris covering 34,970.3 hectares (48.33%), Querceta roboris covering 20,693.1 hectares (28.6%), and Alneto glutinosae covering 5,800.2 hectares. The formations with the smallest areas are Ulmeto laevis covering 13.8 hectares (0.02%), Ulmeta glabrae covering 57.09 hectares (0.08%), Saliceta fragilis covering 48.09 hectares (0.07%), Gleditsia triacanthos covering 19.9 hectares (0.03%), Carpineta betuli covering 14.8 hectares (0.02%), Acereta tatarici covering 41.2 hectares (0.06%), and Acerata pseudoplatani covering 18.5 hectares (0.03%). The Piceeta abietis local formation is covering 5.7 hectares (0.01%).

Природне лісовідновлення сосни на зрубах без застосування заходів сприяння

Mass drying of pine forests in Polissya ambiguously demonstrated that the dominant monocultures of single-tiered, same-age forestry origin have low biological stability. This necessitates the transformation of the forest fund of artificial origin into natural forests. The article evaluates the prospects of «passive» natural renewal of pine – without use of activities to facilitate natural renewal of forest and without the creation of even partial forest cultures, but with activities to care for natural renewal. The study of the natural renewal of pine was carried out on the Troyaniv Forestry of the branch «Horodotske lisove hospodarstvo» (Horodotsk Forestry). Information is given on the dynamics of the number of natural renewal of pine during 2020-2023. It was established that self-sowing generations of pine can initially reach a significant density (30-43 thousand of plants per 1 ha), however, the decisive condition for the formation of stable natural young forest is the action of pathological factors. The greatest losses of self-sowing (90-95% of the total number of dead shoots) were caused by damage to the roots by the larvae of the common cockchafer. However, due to the high initial density, the forest's potential for self-regeneration is still maintained.

Модель формирования березово-еловых насаждений в условиях южной тайги Русской равнины

The results of 30 years or research on the formation and growth of birch forests from the subcanopy spruce population in the conditions of the Russian Plain southern taiga are presented. The studies have been carried out on 19 permanent sample plots (PSPs). They were laid in regionally representative sorrel-blueberry birch forests aged 15–115 years with high density and productivity. The birch plantations on the PSPs belong to the same natural age series. The majority of spruce trees appeared under the canopy of birch forests up to 40 years old. As the birch trees aged, the age structure of spruce trees changed from even-aged to conditionally even-aged. Based on the study of the dynamics of the number of trees, the vertical structure of stands, the growing stock and the total stem wood stock, the age stages of development of the spruce population in the birch forests up to 120 years old have been determined. They are regeneration, young growth, polewood and maturation. The end of the maturation stage occurs at the birch tree age of 120 years. At the same time, the average spruce tree age in the first and second layers is 90 years. The duration of the stages varies from 10 years (the young growth stage) to 40 years (the regeneration and maturation stages). To determine the time of onset and end of other age stages of the subcanopy spruce population, the studies in birch forests older than 120 years are needed. The work performed has made it possible to propose a model of the joint formation of birch forests and the subcanopy spruce population, in which the main taxation characteristics are given for all elements of the stand: age, number of trees, the sum of the cross-section of the stems, the stock of the growing and dead wood, as well as total productivity. According to the model, by the age of a birch of 120 years, the total productivity of modal plantations will be about 950 m3/ha and the growing stock of the stand will be about 490 m3/ha. The share of spruce wood will be 28 % or about 150 m3/ha. After the birch forest decay, a low-density spruce forest of the 3rd quality class can form in its place.

Effects of forest gap formation and deadwood enrichment on oribatid mites (Acari: Oribatida) vary between regions

Most forests in Central Europe are subject to human management, especially timber harvesting, which alters soil conditions by creating gaps in the forest canopy and reduces the availability of deadwood. However, consequences of these management practices, in particular the combined effect of gap formation and deadwood removal, have been largely neglected. Here, we investigated the abundance, diversity and community composition of oribatid mites (Acari: Oribatida) in forests where deadwood availability and gap formation were manipulated in a full factorial design (Control, Gap, Deadwood, Gap + Deadwood). Forest gaps of about 30 m in diameter were established by felling trees, which were subsequently removed (Gap) or left on site as deadwood (Gap + Deadwood). Nearby forest sites without gaps were enriched with the equal amount of felled trees (Deadwood) or left untreated (Control). Experimental treatments were established at 29 forest sites including deciduous and coniferous stands in three regions of Germany, i.e. the Swabian Alb, Hanich-Dün and Schorfheide-Chorin in the south, center and north, respectively. One year after establishment of the treatments, we sampled 10,777 individuals and 104 species of oribatid mites. Deadwood addition significantly increased the density of oribatid mites in the Hainich-Dün from 24,036 to 46,658 ind. m-². Specifically, species of Oppiidae with relatively short life cycles and high reproductive output benefited from the additional deadwood supply, resulting in shifts in community compositions between treatments with and without deadwood. By contrast, mean oribatid mite density decreased from an average of 64,083 in controls to 36,621 ind. m-² in forest gaps of the Schorfheide-Chorin and the Swabian Alb. Presumably, adverse abiotic conditions, mainly amplified drought, induced higher mortality rates in these regions. Overall, deadwood addition and forest gap formation had strong effects on oribatid mite communities, although the magnitude of each effect was similar between forest types and largely determined by regional context. This emphasizes that the effects of forest management practices on oribatid mite communities cannot be generalized across regional scales, suggesting that management plans should carefully consider regional differences.

Fine-scale genetic structure and phenotypic divergence of a passerine bird population inhabiting a continuous Mediterranean woodland.

Genetic differentiation between populations inhabiting ecologically different habitats might appear because of limited dispersal and gene flow, which may lead to patterns of phenotypic divergence and local adaptation. In this study, we use dispersal, genotypic (24 microsatellite loci) and phenotypic (body size and clutch size) data to analyse patterns of genetic structuring and phenotypic divergence in a blue tit (Cyanistes caeruleus) population inhabiting a continuous and heterogeneous woodland along a valley. The two slopes of the valley differ in their forest formations and environmental conditions. Findings showed that most blue tits reproduced within their natal slope. Accordingly, microsatellite analyses revealed that populations of blue tits established in the two slopes show subtle genetic differentiation. The two genetic populations diverged in clutch size, exceeding the level of differentiation expected based on genetic drift, hence suggesting divergent selection (or other processes promoting divergence) on this life-history trait. Our findings reveal that restricted dispersal and spatial heterogeneity may lead to genetic differentiation among bird populations at a surprisingly small scale. In this respect, it is worth highlighting that such differentiation occurs for an organism with high dispersal capacity and within a continuous woodland. Moreover, we show that small-scale ecological differences, together with limited gene flow, can result in selection favouring different phenotypes even within the same continuum population.

Assessment of the Biomass of Coniferous–Deciduous Forest by the Example of the Chashnikovo Training and Experimental Soil Ecological Center of Moscow State University

Abstract The aim of this work is to assess the contribution of the components of plant community—biomass and mortmass of tree stands, undergrowth, living ground cover, and forest litter—to its total organic matter pool. The study object is represented by a coniferous-deciduous forest located in the Solnechnogorsk city district of Moscow oblast and characterized by five permanent 50 × 50-m test plots laid in it. The greatest contribution to the total organic matter mass of the studied plant communities is made by perennial parts and mortmass of the forest stand (to 87% and 14%, respectively). The proportion of phytomass of deciduous trees in stand comprises from 32 to 98%, which is connected with the incomplete forest restoration succession. The contribution of forest litter does not exceed 3%. Low litter reserves (0.18–1.21 kg m–2) and the destructive type of all litters are not typical for spruce forests. The floristic composition and the ecological–coenotic structure of the living ground cover are typical for the subzone of coniferous-deciduous forests; and its contribution to the total productivity of forest biogeocenosis is insignificant. The spatial pattern of litter reserves and of the biomass of the living ground cover within the biogeocenoses is disturbed in comparison with typical spruce forests due to the high proportion of deciduous species in the forest stand. Their participation in the tree layer is typical for the final stage of formation of a secondary coniferous forest during succession and causes a slight increase in the intensity of the biological cycle, which is indicated in our case by a decrease in the reserves and a simpler structure of litters. Since the biomass and mortmass of tree stand contribute most to carbon sequestration by forest biogeocenoses, these components require a detailed assessment during monitoring surveys, the purpose of which is to evaluate carbon reserves of land ecosystems.

Dynamic strain aging and negative strain rate sensitivity in coarse-grained Al0.3CoCrFeNi high entropy alloy under hot compression

This study investigates the deformation behavior of coarse-grained (CG) Al0.3CoCrFeNi alloy under hot compression, revealing notable strain rate sensitivity (SRS) and dynamic strain aging (DSA) phenomena. DSA is observed at temperatures between 1223 K and 1373 K, exclusively at lower strain rates (0.5 s−1 – 1 s−1), while higher strain rates (≥5 s−1) exhibit DSA absence. Non-compact {112} slip activation on dislocation forest structures is proposed as the driving force behind DSA. Negative SRS behavior at 1223 K is attributed to Ni–Al cluster-based solid solution strengthening. Activation energy calculations highlight lattice diffusion and partial dislocation constriction as contributors to hot deformation. Consistency is observed in the activation volume (V*) calculation, indicating dislocation forest formation (127–519 b3, b = Bureger's vector), diminishing to 22–46 b3 upon DSA initiation. The alloy displays delayed dislocation hardening/softening transition due to CG's impact on retarding dislocation accumulation. This behavior stems from a higher V* at yielding, prolonging the typical transition observed in fine-grained alloys with lower V*. The study elucidates the intricate interplay of microstructure, strain rate, and deformation mechanisms in CG Al0.3CoCrFeNi.

The Dynamics of Fire Activity in the Brazilian Pantanal: A Log-Gaussian Cox Process-Based Structural Decomposition

We present a novel statistical methodology for analyzing shifts in spatio-temporal fire occurrence patterns within the Brazilian Pantanal, utilizing remote sensing data. Our approach employs a Log-Gaussian Cox Process to model the spatiotemporal dynamics of fire occurrence, deconstructing the intensity function into components of trend, seasonality, cycle, covariates, and time-varying spatial effects components. The results indicate a negative correlation between rainfall and fire intensity, with lower precipitation associated with heightened fire intensity. Forest formations exhibit a positive effect on fire intensity, whereas agricultural land use shows no significant impact. Savannas and grasslands, typical fire-dependent ecosystems, demonstrate a positive relationship with fire intensity. Human-induced fires, often used for agricultural purposes, contribute to an increase in both fire frequency and intensity, particularly in grassland areas. Trend analysis reveals fluctuating fire activity over time, with notable peaks in 2018–2021.