Distribution Of Trees Research Articles

Modelling the Geographical Distribution Pattern of Apple Trees on the Loess Plateau, China

The Loess Plateau, known for its fragile ecosystems, is one of the traditional apple-producing regions in China. Although some management measures are needed to enhance sustainable agriculture in response to the rising pressure of climate change, the geographic distribution of apple trees considering multiple variables has not been considered. In this study, we used three software (the maximum entropy model, IDRISI, and ArcGIS) to simulate the potential distribution of suitable habitats and range shifts of apple trees in the near present and near future (i.e., the 2030s and the 2050s) under two climate scenarios (the Shared Socioeconomic Pathways (SSP)1-26 and SSP5-85), while taking a variety of environmental factors into account (e.g., temperature, precipitation, and terrain). After optimization, the class unsuitable habitat (CUH) changed the potential distribution pattern of apple trees on the Loess Plateau. Currently, the areas of lowly suitable habitat (LSH), moderately suitable habitat (MSH), highly suitable habitat (HSH), and CUH were 7.66 × 104, 2.80 × 104, 0.23 × 104, and 18.05 × 104 km2, respectively. Compared to the centroid estimated under the climate of 1970–2000, the suitability range of apple trees was displaced to the northwest in both the 2030s and the 2050s in SSP5-85 (i.e., 63.88~81.30 km), causing a larger displacement in distance than SSP1-26 (i.e., 40.05~50.32 km). This study demonstrates the possible changes in the spatial distribution of apple trees on the Loess Plateau in the near future and may provide a strong basis for future policy making.

The Fine Root Distribution and Morphology of Mature White Poplar in Natural Temperate Riverside Forests under Periodically Flooded or Dry Hydrological Conditions

Fine roots are a key component of carbon turnover in the terrestrial environment. Therefore, their distribution allows for the estimation of areas of carbon in the soil. The vertical distribution of roots is the result of both the tree species and various environmental factors. Research on the architecture of root systems most often includes seedlings and young trees growing under experimental conditions; however, little is known about trees in their natural habitats. The aim of this study is to analyze the fine root distribution of mature white poplar trees in natural riverside temperate zone forests of Central Europe (Poland) periodically flooded and in dry hydrological conditions. The length, diameter, and area of the fine roots, as well as the specific root length (SRL) and specific root area (SRA) of white poplar were measured in three layers of the soil, 0–10 cm, 10–20 cm, and 20–30 cm depths, in three forest sites. Two of the sites experience periodic floods, and one has been without flooding for 80 years, due to the construction of a flood embankment. The highest values of the lengths and surface areas of the poplar fine roots were observed at a depth of 0–10 cm at all sites. Soil moisture was positively correlated with the analyzed root parameters. The presence of understory plant roots contributed to the reduction in the fine root length of poplar in the subsurface layer, compared to the site that was not affected by the presence of plants other than poplar. The distribution of fine roots, the most dynamic part of the plant root system, reflects the most active areas in the soil profile. The presented research will allow for a better understanding of the functioning of natural riverside ecosystems, as well as show the great adaptability of white poplar fine roots to various conditions in the soil.

Pine Wilt Disease in Northeast and Northwest China: A Comprehensive Risk Review

Pine wilt disease (PWD) caused by the pine wood nematode (PWN) is China’s most serious forest disease in recent decades. Its complex disease system with unclear pathogenesis and differentiated pathogenicity makes it challenging to manage and control. PWD has spread rapidly in Northeast and Northwest China in recent years, exceeding previous predictions and the traditional understanding of its potential distribution. This paper reviewed the comprehensive risk of PWD in Northeast and Northwest China through the occurrence of influencing factors. Regarding PWN’s temperature resistance, all regions of China are suitable for PWD. In terms of altitude, the PWD system is mainly distributed below 1000 m. In China, Pinus and Larix species are confirmed host trees of PWN, while Monochamus alternatus and M. saltuarius are confirmed vector insects of PWN. In this case, PWD may occur in all low-altitude pine forests in China. Northeast China has a higher risk than Northwest China due to its distribution of suitable host trees and vector beetles at low altitudes. To confront the threat, two scientific bottlenecks are required to be demonstrated. The first is the pathogenicity of Chinese PWN strains to Chinese Picea and Abies species. The other is the geographical distribution and highest altitude distribution of other Monochamus species in the Palaearctic region of China and their PWN transmission ability. We also suggest strengthening plant quarantining in Northeast China. In conclusion, this review comprehensively analyzes the risk of PWD in Northeast and Northwest China in terms of temperature, altitude, host trees, and vector insects. It provides a new perspective and reference for the management and research of PWD in China.

Propagation of an idealized infection in an airway tree, consequences of the inflammation on the oxygen transfer to blood

A mathematical model of infection, inflammation and immune response in an idealized bronchial tree is developed. This work is based on a model from the literature that is extended to account for the propagation dynamics of an infection between the airways. The inflammation affects the size of the airways, the air flows distribution in the airway tree, and, consequently, the oxygen transfers to blood. We test different infections outcomes and propagation speed. In the hypotheses of our model, the inflammation can reduce notably and sometimes drastically the oxygen flow to blood. Our model predicts how the air flows and oxygen exchanges reorganize in the tree during an infection. Our results highlight the links between the localization of the infection and the amplitude of the loss of oxygen flow to blood. We show that a compensation phenomena due to the reorganization of the flow exists, but that it remains marginal unless the power produced the ventilation muscles is increased. Our model forms a first step towards a better understanding of the dynamics of bronchial infections.

An analysis of stand-level size distributions of decay-affected Norway spruce trees based on harvester data

Key messageWe studied size distributions of decay-affected Norway spruce trees using cut-to-length harvester data. The harvester data comprised tree-level decay and decay severity recordings from 101 final felling stands, which enabled to analyze relationships between size distributions of all and decay-affected trees. Distribution matching technique was used to transfer the size distribution of all trees into the diameter at breast height (DBH) distribution of decay-affected trees.ContextStem decay of Norway spruce (Picea abies [L.] Karst.) results in large economic losses in timber production in the northern hemisphere. Forest management planning typically requires information on tree size distributions. However, size distributions of decay-affected trees generally remain unknown impeding decision-making in forest management planning.AimsOur aim was to analyze and model relationships between size distributions of all and decay-affected Norway spruce trees at the level of forest stands.MethodsCut-to-length harvester data of 93,456 trees were collected from 101 final felling stands in Norway. For each Norway spruce tree (94% of trees), the presence and severity of stem decay (incipient and advanced) were recorded. The stand-level size distributions (diameter at breast height, DBH; height, H) of all and decay-affected trees were described using the Weibull distribution. We proposed distribution matching (DM) models that transform either the DBH or H distribution of all trees into DBH distributions of decay-affected trees. We compared the predictive performance of DMs with a null-model that refers to a global Weibull distribution estimated based on DBHs of all harvested decay-affected trees.ResultsThe harvester data showed that an average-sized decay-affected tree is larger and taller compared with an average-sized tree in a forest stand, while trees with advanced decay were generally shorter and thinner compared with trees having incipient decay. DBH distributions of decay-affected trees can be matched with smaller error index (EI) values using DBH (EI = 0.14) than H distributions (EI = 0.31). DM clearly outperformed the null model that resulted in an EI of 0.32.ConclusionsThe harvester data analysis showed a relationship between size distributions of all and decay-affected trees that can be explained by the spread biology of decay fungi and modeled using the DM technique.

The Origin and Distribution of Tea Trees and Tea in China

The Origin and Distribution of Tea Trees and Tea in China

Origin, distribution and domestication of the carob tree (Ceratonia siliqua L.)

The carob tree, which is a member of the Fabaceae family, is an agrosilvopastoral tree whose pre-Mediterranean tropical origin appears well established on the basis of genetic, fossil and physiological data. C. siliqua has recently been successfully introduced from the Mediterranean basin to other parts of the world that have a Mediterranean climate. In terms of its domestication, there is paleobotanical, philological, ecological and historical evidence to suggest that the species was spread by people from Arabia, where it took refuge during the Ice Age, to Mesopotamia and then on to the western Mediterranean. This ?eastern refugium hypothesis? (ERH) postulates the existence of a single refuge for the carob tree in the eastern Mediterranean and a dissemination by humans to the west of the region concomitant with its domestication. However, recent results of phylogenetic and fossil analyses have revealed the existence of a western refuge, thus refuting the single ERH hypothesis and supporting local use and domestication of the carob tree from native populations throughout the Mediterranean. This paper advances other arguments of a historical, philological, ecological and sociocultural nature that support the existence of a western refugium and also emphasise the important role played by the Romans and particularly by the Arabs and Andalusians in the propagation and domestication of the carob tree in the western Mediterranean.

Mangrove tree growth, diversity, and distribution in tropical coastline ecosystems

Mangrove tree growth, diversity, and distribution in tropical coastline ecosystems

Improved parametrisation of a physically-based forest reflectance model for retrieval of boreal forest structural properties

Physically-based reflectance models offer a robust and transferable method to assess biophysical characteristics of vegetation in remote sensing. Forests exhibit explicit structure at many scales, from shoots and branches to landscape patches, and hence present a specific challenge to vegetation reflectance modellers. To relate forest reflectance with its structure, the complexity must be parametrised leading to an increase in the number of reflectance model inputs. The parametrisations link reflectance simulations to measurable forest variables, but at the same time rely on abstractions (e.g. a geometric surface forming a tree crown) and physically-based simplifications that are difficult to quantify robustly. As high-quality data on basic forest structure (e.g. tree height and stand density) and optical properties (e.g. leaf and forest floor reflectance) are becoming increasingly available, we used the well-validated forest reflectance and transmittance model FRT to investigate the effect of the values of the “uncertain” input parameters on the accuracy of modelled forest reflectance. With the state-of-the-art structural and spectral forest information, and Sentinel-2 Multispectral Instrument imagery, we identified that the input parameters influencing the most the modelled reflectance, given that the basic forestry variables are set to their true values and leaf mass is determined from reliable allometric models, are the regularity of the tree distribution and the amount of woody elements. When these parameters were set to their new adjusted values, the model performance improved considerably, reaching in the near infrared spectral region (740–950 nm) nearly zero bias, a relative RMSE of 13% and a correlation coefficient of 0.81. In the visible part of the spectrum, the model performance was not as consistent indicating room for improvement.

Street trees and mental health: developing systems thinking-informed hypotheses using causal loop diagraming

We considered the relationship between street trees and mental health with the aim of developing systems thinking-informed hypotheses to improve the implementation and evaluation of this popular nature-based solution (NBS). We integrated qualitative and quantitative evidence using causal loop diagraming (CLD), and then further analyzed and extended these diagrams with the aid of systems archetypes to identify key system structures. From these CLDs, we identified three systems thinking-informed hypotheses: 1) although there are many ways in which street trees may improve mental health, tree health is critical in realizing many of these benefits and minimizing dis-benefits; 2) communities which have benefited from street trees in the past are more likely to be able to advocate for additional trees, further entrenching historical inequities in street tree distribution; and 3) efforts to address these inequities through new tree planting initiatives may ultimately fail or even exacerbate existing challenges if they do not include sustained resources for tree maintenance, with direct and indirect impacts on inequities in mental health. Using a systems thinking lens was a useful way to deeply consider a purported but under-theorized co-benefit of a popular nature-based solution and identify policy-relevant hypotheses to guide future research.

Application of aerophotogrametry in inventory poplar plantation

In the forest stand-wise inventory of Serbia, data is obtained using terrestrial methods - using complete (total) and partial measurement. Foreign experiences show that part of the information about forests can be obtained on the basis of aerial images - using aerial photogrammetry methods. In this sense, the goal of this work was to assess the possibility of applying aerial photogrammetry in the process of collecting information in poplar plantations, planting spacing 5 x 5 m, aged 10, 15, 20 and 25 years. The reliability of data obtained on the basis of air images was determined by comparison with data obtained by terrestrial measurement. The results of the research only partially confirmed foreign experiences about the possibility of applying aerial photogrammetry in forest inventory. A comparative analysis of the numerical elements of the stand read directly from the images, such as the number of trees, height and crown area, and derived elements - diameter on breast height, basal area and volume of the stand in relation to the values obtained by terrestrial surveying methods, indicated the possibility of limited use of aerial photogrammetry in the inventory of these forests. The differences were reflected in the reading of lower values of crown areas and tree heights, which is why mathematical models predicted lower values of diameters on breast height. This was reflected in the displacement of the tree distribution to lower diameter degrees, consequently leading to differences in the basal area and the volume of the researched plantations in relation to the values obtained by terrestrial surveying. Therefore, as an optimal solution in specific conditions, a combined inventory is imposed, which sublimates the positive characteristics of the tested methods.

THE RELATIONSHIPS OF TAXONOMIC AND STRUCTURAL ATTRIBUTES ON ABOVE GROUND CARBON BIOMASS OF TROPICAL DRY FORESTS IN PHOU KHAO KHOUAY NATIONAL PARK, LAOS

Forest ecosystems play an integral role in climate regulation through carbon sequestration and storage. Tropical forests in Laos have undergone major degradation which threatened the standing biomass and carbon sequestration potential of these forests, apart from altering the dynamics of the ecosystem. In this study, species diversity and forest structure were assessed through 32 0.25-ha study plots representing 3 major forest types in Phou Khao Khouay Nation Park, Laos. The findings found a total of 5,477 individuals, 188 species belonging to 57 families. H. pierrei was the most dominant tree species (IVI =9.29%) among 138 species in DEF; A. grandis and L. fenestratus were the most co-domimant species (IVI=8.57%) among 126 species of MDF and P. merkusii covered the grestest IVI (20.02%) among 54 species in MCF. Individual tree distribution was inversed J-shape in all forest types suggesting good regeneration and recruitment potential. Significant differences of taxonomic and structural between 3 forest types showed through Kruskal-Wallis test with p-value < 0.05. Above ground carbon biomass decreased with decreasing species richness, basal area and volume through forest types, specifically 184.00±66.79 Mg/ha in DEF; 107.57±7.90 Mg/ha in MDF and 110.99±7.69 Mg/ha in MCF. Taxonomic and structural attributes contributed positive effects on above ground carbon biomass. Biodiversity conservation should be a key component of the UN Reducing Emission from Deforestation and Degradation strategy (REDD+).

Floristic diversity and rarity assessment along altitudinal gradient in diverse forest types of Pithoragarh, Kumaun Himalaya, Uttarakhand, India

Present study was carried out in four different forest types (Sal, Pine, Oak and Deodar) of Kumaun Himalaya along altitudinal gradient 650 to 2200 m asl. A total 337 species of vascular belonging to 280 genera and 98 families were recorded from the present study. Of these, 303 species were Angiosperms (252 Dicotyledons and 51 Monocotyledons), 3 Gymnosperms and 31 Pteridophytes and their distribution in different life forms, i.e., trees (53 spp.), shrubs (74 spp.), herbs (196 spp.) and climber (14 spp.). Among angiosperms Asteraceae (37 spp.) was dominant family followed by Poaceae (24 spp.), Fabaceae (24 spp.) and Lamiaceae (21 spp.). In Gymnosperms only two family (Pinaceae and Cupreceae) was recorded. A total of 31 species of Pteridophytes were recorded from present study. 49 species recorded in IUCN criteria (2022–23) one species were Vulnerable one near threatened and 47 were under least concern.

Out of Madagascar, repeatedly: The phylogenetics and biogeography of Dombeyoideae (Malvaceae s.l.)

Dispersals have been shown to be critical to the evolution of the long isolated but megadiverse flora of Madagascar and the surrounding islands of the western Indian Ocean, but we are just beginning to understand the directionality of these dispersals. With more than half of its species occurring in the western Indian Ocean region (WIOR), the paleotropical subfamily Dombeyoideae provides a particularly useful case study through which to better understand the biogeography of the WIOR, and yet its biogeography is poorly understood. Here we sampled six molecular markers from all 20 genera in the Dombeyoideae to reconstruct the most complete phylogeny to date for the subfamily. From this, divergence times, calibrated with three fossils (two dombeyoid, one malvoid), and ancestral range estimations were hypothesized. Biogeographic stochastic mapping (BSM) analyses on the maximum clade credibility tree were completed and compared to BSM analyses on 1,000 trees randomly sampled from the posterior distribution of trees resulting from the dating analysis. We found the Dombeyoideae crown node diverged ca. 53 million years ago out of a broad ancestral range involving all three major areas of its distribution: Madagascar, Africa, and Asia. The majority of diversification and dispersals in the subfamily occurred within the last ca. 10 million years, mostly from the Pliocene onwards. There were roughly five dispersals from Madagascar to Africa (and only one in reverse), at least six from Madagascar to surrounding islands of the WIOR (Mascarenes and Comoros), and one dispersal from Madagascar to Asia (and ca. 1 in reverse). Other long-distance dispersals included one from Africa to St. Helena and one from Africa to Australasia, both from within the most widespread clade, the Cheirolaena & allies clade, and one dispersal from Asia to Africa. Critically, the Dombeyoideae provide strong evidence for considering the island of Madagascar as a source for the colonization of continents, as well as the surrounding islands of the WIOR. Furthermore, narrow sympatry was a key process in the evolution of the subfamily, particularly in Madagascar and the Mascarenes.

Impacts of spatial scale and resolution on species distribution models of American chestnut (Castanea dentata) in Pennsylvania, USA

American chestnut (Castanea dentata) was once a foundational tree species of eastern North American hardwood forests before its functional extinction due to an invasive chestnut blight first described at the beginning of the 20th century. Ongoing research to develop a blight-resistant American chestnut through traditional breeding or transgenic means is promising. However, restoration of American chestnut will require a thorough understanding of its spatial distribution and habitat suitability to both find surviving mature trees to enhance the genetic diversity of experimental blight-resistant trees and to identify optimal restoration sites. While many studies have modeled the spatial distribution of American chestnut trees, few have addressed how adjusting spatial scale and resolution impact the predictive ability of species distribution models (SDMs) for the tree species. In this study, we used Maxent to model American chestnut distribution at coarse resolution (238 m) across the state of Pennsylvania and fine resolution (3 m) within French Creek State Park in the southeastern portion of the state. Pennsylvania was chosen as our study area due to its central location in American chestnut’s pre-blight range. Results indicate that the spatial extent of the study area and ranges of environmental variables included in the models influence which variables are most predictive of chestnut distribution. This study suggests that environmental variables such as soil content, soil pH, and elevation are all strong predictors of American chestnut habitat, but their importance varies by resolution. This study also investigates how spatial scale and resolution influence the predictive ability of American chestnut SDMs and offers a workflow for locating restoration sites by first modeling species distribution at a coarse scale and broad extent to identify patches of suitable habitat, then focusing resources on fine scale modeling of species distribution local to those suitable patches.

On the Inclusion of Adaptive Potential in Species Distribution Models: Towards a Genomic-Informed Approach to Forest Management and Conservation

Ecological modeling refers to the construction and analysis of mathematical models aimed at understanding the complexity of ecological processes and at predicting how real ecosystems might evolve. It is a quickly expanding approach boosted by impressive accelerations in the availability of computational resources and environmental databases. In the light of foreseeing the effect of climate change on forest ecosystems, the branch of ecological modeling focusing on species distribution models (SDMs) has become widely used to estimate indices of habitat suitability and to forecast future tree distributions. However, SDMs are usually informed based solely on environmental data without any reference to the genetic makeup underlying responses to the environment, the possibility of exchanging variants helping to persist in situ, or the capacity to chase suitable conditions elsewhere. Among the main evolutionary processes that may complement forecasts of range shifts are local adaptation and gene flow, i.e., the occurrence of genetic variants conferring a population the optimal fitness in its own habitat and the exchange of adaptive alleles between populations. Local adaptation and gene flow could be described by indices of genetic diversity and structure, genetic load, genomic offset, and an admixture of genetic lineages. Here, we advocate for the development of a new analytical approach integrating environmental and genomic information when projecting tree distributions across space and time. To this aim, we first provide a literature review on the use of genetics when modeling intraspecific responses to the environment, and we then discuss the potential improvements and drawbacks deriving from the inclusion of genomic data into the current SDM framework. Finally, we speculate about the potential impacts of genomic-informed predictions in the context of forest conservation and provide a synthetic framework for developing future forest management strategies.

Detecting renewal states in chains of variable length via intrinsic Bayes factors

Markov chains with variable length are useful parsimonious stochastic models able to generate most stationary sequence of discrete symbols. The idea is to identify the suffixes of the past, called contexts, that are relevant to predict the future symbol. Sometimes a single state is a context, and looking at the past and finding this specific state makes the further past irrelevant. States with such property are called renewal states and they can be used to split the chain into independent and identically distributed blocks. In order to identify renewal states for chains with variable length, we propose the use of Intrinsic Bayes Factor to evaluate the hypothesis that some particular state is a renewal state. In this case, the difficulty lies in integrating the marginal posterior distribution for the random context trees for general prior distribution on the space of context trees, with Dirichlet prior for the transition probabilities, and Monte Carlo methods are applied. To show the strength of our method, we analyzed artificial datasets generated from different models and one example coming from the field of Linguistics.

Enhancing monitoring of mangrove spatiotemporal tree diversity and distribution patterns

AbstractSpatiotemporal information on mangrove species assemblage of natural, disturbed, and rehabilitated is an essential prerequisite for effective strategies for biodiversity conservation and management. However, appropriate field‐based sampling strategies of spatial heterogeneity still hamper the detection of the species distribution and its temporal development. An increasing amount of remote sensing data seems the perfect way to tackle these challenges. With this article, we fill this gap by presenting a review of the challenges and limitations to assess the current status of species diversity. We conclude that species discrimination based on remote sensing techniques is still limited by atmospheric contamination and tidal fluctuations. The lack of accurate information on the spatiotemporal development of species diversity and forest structure further curtails an understanding of functional indicators and the predictive power of modeling approaches. Nevertheless, multi‐source remote‐sensing techniques could seemingly capture the landscape heterogeneity and support systematic sampling designs. Spatially balanced (systematic) training and validation data are necessary to compile robust spatiotemporal information, supporting reliable predictions for optimizing restoration efforts. A systematic sampling of spatiotemporal ecological information is vital to derive the historical state of mangroves, detecting their degradation, and predicting future patterns of species distribution that are generally crucial for restoration, and particularly to rehabilitate species diversity.

FPGA-Based Updatable Packet Classification Using TSS-Combined Bit-Selecting Tree

OpenFlow switches are being deployed in SDN to enable a wide spectrum of non-traditional applications. As a promising alternative to brutal force TCAMs, FPGA-based packet classification is being actively investigated. However, none of the existing FPGA designs can achieve high performance on both search and update for large-scale rule sets. To address this issue, we propose TcbTree, an FPGA-based algorithmic scheme for packet classification. Specifically, at the algorithmic side, i) a two-stage framework consisting of heterogeneous algorithms is proposed, where most rules can be mapped into several balanced trees without rule replications, ii) for the remaining few rules, a centralized TSS (Tuple Space Search) architecture together with a real-time feedback scheme is designed to enhance the efficiency of TSS search on FPGA, and iii) a tree dilution method is designed to equalize rule distribution in trees, so that the latency of tree search can be reduced. At the hardware side, i) an efficient data structure set is designed to convert tree traversal to addressing process, which breaks the constraints of limited tree depth and imbalanced node distribution, and ii) distinct from fully pipelined designs, multiple levels of parallelism are efficiently explored with multi-core, multi-search-engine and coarse-grained pipelines herein. Experimental results using ClassBench show that, with the implementation of TcbTree on FPGA, the average classification throughputs for 1k, 10k, 32k and 100k rule sets achieve 788.8 MPPS, 404.3 MPPS, 237 MPPS and 41.8 MPPS, respectively, and the update throughput for all benchmark rule sets is above 1 MUPS.

Рост и формирование культур сосны при рекультивации дражных отвалов

The results of studying the parameters of 12-year-old Scotch pine cultures, created by planting along the furrows on sewage sludge and on felling-slash areas, are considered. The cultures were established on plots in the pine forest type with a dark coniferous mossy-bilberry layer. It has been established that the survival rate of plants on drag dumps turned out to be almost 16 % less than in felling-slash for forest plantations on sewage sludge. There were no significant differences in significant differences between pine crops on sewage sludge and felling-slash areas in terms of average diameter and height of the trunk. There were no significant differences in significant differences between pine crops on sewage sludge and felling-slash areas in terms of average diameter and height of the trunk. There were no fundamental differences in the distribution of trees by growth classes between crops on sewage sludge and on felling-slash areas. It has been established that pine trees of I and II rank growth classes on sewage sludge are significantly larger in diameter than trees on felling-slash areas. There were no significant differences in the height of the tree trunk by growth classes between the trees on the sewage sludge and the felling-slash area. The relative height of the trees on the sewage sludge was significantly lower than that of the trees on the felling-slash area. This indicates that, with a significant loss of trees, the rows of crops on the sewage sludge turned out to be of a less density, which ensured the enhanced growth of trees of all growth classes along the thickness of the trunk. The natural renewal of tree species on the sewage sludge was 1,2, and in the felling-slash 1,1 thousand trees per 1 ha. As part of the natural renewal on the sewage sludge, only coniferous species are represented, on the felling-slash area — deciduous and coniferous species. The projective cover of the living ground cover on the sewage sludge was uneven and amounted to 40…50 %, and reached 100 % in the felling-slash. The results obtained indicate the need for preliminary reclamation to improve the physical and mechanical properties of the soil.