Forest Soil Properties Research Articles

Ecosystem carbon stock variation along forest stand ages: insight from eastern coast mangrove ecosystem of India

BackgroundThe mangrove ecosystem has the highest carbon sink potential which significantly contributes to bringing carbon neutrality. Understanding the carbon stock dynamics along the age of forest stands in the mangrove forest ecosystem is of significance for managing the forests and their carbon accumulation. This study aimed to estimate the forest structural attributes, biomass and total ecosystem carbon stock (TECS) of old natural (age > 50 years) and young planted (age ~ 20 years) mangrove forest stands at Bichitrapur Mangrove Reserve Forest in eastern coast of India. We also attempted to understand the interrelationship of structural attributes, biomass and soil properties in the mangrove forests. To achieve the results, twenty random plots were established (size: 20 m × 25 m) and suitable allometric equations along with species-specific wood density values were used to estimate the biomass and carbon stock.ResultsAltogether, 29 plant species (18 exclusive and 11 associate species) were recorded. The mean total biomass (± SE) and soil organic carbon (at 30 cm depth) were 165.31 ± 20.89 t ha−1 and 40.20 ± 1.24 t C ha−1 for young stands, and 586.12 ± 56.74 t ha−1 and 49.68 ± 2.39 t C ha−1 for old stands, respectively. Among mangrove species, Avicennia marina contributed the highest vegetation biomass in both forest stands (59.72 t ha−1 and 262.28 t ha−1 in young and old stands, respectively), followed by Avicennia officinalis (35.05 t ha−1) and Sonneratia apetala (26.09 t ha−1) in young stand and Avicennia alba (169.28 t ha−1) and Avicennia officinalis (115.58 t ha−1) in old stand. The mean TECS was 235.62 ± 27.34 t C ha−1. The contribution of vegetation and soil to TECS was 63% and 37% in the young stand, whereas in the old stand it was 83% and 17%, respectively. The correlation analyses revealed that mean stand height (r = 0.87), basal area (r = 0.99), soil nitrogen (r = 0.76), potassium (r = 0.78), and carbon (r = 0.80) were significantly positively correlated with total biomass at p < 0.01.ConclusionsOur results demonstrate that old mangrove forest stands store substantially high carbon stock than young planted forest stands, implying the role of forest age in determining the carbon storage potential of mangrove ecosystems.

Forest local community perception on sengon pest and disease and forest soil properties

Abstract Banten Forest Management Unit (FMU) is undertaking an effort to develop sengon (Falcataria falcata) as a wood-producing commodity alongside teak, acacia, and mahagony. Local farmers carrying out sengon propagation assist in this development effort. Improper practices of propagating and cultivating sengon and the need for more public knowledge regarding pests and diseases that attack sengon raise questions regarding the public’s perception of cultivation techniques and control of plant pests and diseases. Training on sengon cultivation and introducing pests and diseases on sengon plants was held on 25 November 2023 at the Cigembor Wood Collecion Place (WCP), inten Jaya Village, Lebak, Banten. In total, 30 participants who were members of a forest local community (LMDH) at Perum Perhutani FMU Banten attended this activity. The training method involves presentations and direct practice in the field. The results of the pre- and post-test evaluation showed an increase of 25% in knowledge of pests and diseases in sengon plants and 10% in knowledge of sengon cultivation. The test results also showed that 8 out of 10 participants could differentiate between forest pests and diseases. Furthermore, 10 out of 10 participants knew the harvest age for sengon. In general, this training increased the participants’ knowledge and experience in cultivating sengon and identifying pests and diseases in sengon plants.

Wildfire burn severity and post-wildfire time impact mechanical and hydraulic properties of forest soils

Vegetation contributes to the overall slope stability and is recognized as an environmentally friendly nature-based solution. Wildfires burn and denude vegetated slopes, thus increasing the risk of shallow landslides and debris flows. However, little attention has been given to assessing the effects of burn severity and the time elapsed since a wildfire on the hydro-geomechanical properties of burned slopes. This study performed a series of standard laboratory tests to evaluate the shear strength and saturated hydraulic conductivity (ksat) of forest soils collected from moderate-low (ML) burned, moderate-high (MH) burned, and unburned (UB) test plots. The plots were sampled one, four, and six months after the March 2022 wildfire in Uljin County, South Korea. The results show that the continuous deterioration of roots highly depended on the burn severity. The root biomass of ML- and MH-burned soils was consistently lower than those of the UB soils. The root deterioration reduced the shear strength of the soils temporally. The burned soil's cohesion intercept was 1.80–2.30 times lower than that of the UB soil six months post-wildfire, with the friction angle unaffected. One- and four-months post-wildfire, ksat of the burned soils was 1.22–3.15 times lower than the UB soil. Such lowered ksat was due to the fine ash-clogged pores and hydrophobic layers beneath the soil surface. However, six months post-wildfire, the burned soils' ksat increased by approximately twice that of the pre-wildfire condition because of macropore flow passages formed by impoverished roots. The appreciation of sand fraction, depreciation of fines content, and weakening of hydrophobicity over time have also emphasized their role in the temporal shifts in the properties of the ML- and MH-burned soils. The documented results herein can be incorporated into rainfall infiltration and stability analyses of wildfire-affected slopes, landslide susceptibility mapping, and mitigation measures design.

Advances in Remote Sensing for Monitoring Soil Conditions in Forest Ecosystems: Techniques, Challenges, and Applications

ABSTRACT Advances in remote sensing technologies have revolutionized the monitoring of soil conditions in forest ecosystems, providing valuable insights into soil moisture, nutrient content, and degradation without requiring physical access to remote areas. This article explores the application of key techniques, including satellite-based L-band radiometry, UAV-enabled LiDAR, and visible–NIR spectroscopy, in assessing forest soil properties. Challenges such as canopy interference, spatial resolution limitations, and data validation are discussed, alongside innovative solutions like machine learning and high-resolution digital elevation models. Case studies highlight the effectiveness of remote sensing in addressing environmental and forestry challenges, such as tracking the effects of climate change, logging, and erosion. By integrating advanced imaging technologies with ground-based observations, remote sensing supports sustainable forest management, conservation practices, and ecological research. Future developments in sensor technology, data integration, and machine learning hold promise for even greater precision and scalability in forest soil monitoring.

Characterization and prediction of hydraulic properties of traffic-compacted forest soils based on soil information and traffic treatments

Key messageThe hydraulic properties of compacted and rutted soils were evaluated through in-situ infiltration experiments and predicted based on soil texture class and traffic treatments. A significant decrease in saturated soil water content and soil hydraulic conductivity at saturation was observed. The resulting soil hydraulic parameters, when integrated into a soil water transfer model, effectively simulated water dynamics in these impacted forest soils, providing a crucial first step toward developing decision support tools for real-time trafficability. This approach can assist forest managers in minimizing the extent of soil compaction.ContextTo overcome trafficability issues of forest soils induced by heavy logging machinery, planning support tools are needed to determine suitable soil moisture conditions for traffic.AimsThis study aimed to identify the soil properties that differ significantly between undisturbed and compacted soils and to provide several estimation tools to predict the hydraulic properties of compacted soils beneath the skid trails.MethodsFour hundred seventeen water infiltration tests were conducted on 19 forest sites, mostly in North-eastern France, and analysed with the BEST method to estimate the hydraulic properties of the skid trails and undisturbed soils. The hydraulic properties of the skid trails were predicted thanks to linear mixed effect models using a bulk treatment effect, a site effect, or a skid trail degradation score. The predicted hydraulic properties were tested using a water flow model to assess their relevance regarding the prediction of water dynamics in skid trails.ResultsThe compaction effect was only significant for the logarithm of the hydraulic conductivity at saturation (log10(Ksat)) and the soil water content at saturation (θsat). For the skid trails, θsat was reduced by - 0.02 and − 0.11 m3m−3 in the 0 − 10 cm and 15 − 25 cm layers respectively, compared to undisturbed topsoil (0 − 10 cm). log10(Ksat) was reduced by − 0.38 and − 0.85 for skid trails in the 0 − 10 and 15 − 25 cm soil layers respectively, compared to undisturbed topsoil. The use of a pedotransfer function, in replacement of water infiltration tests, and their combination with the same correction coefficients proved to efficiently simulate the difference in water dynamics between skid trails and undisturbed forest soils.ConclusionEstimation of soil hydraulic properties based on in situ water infiltration experiments proved efficient to simulate water dynamics in compacted and rutted forest soils. Yet, further studies are needed to identify the most adapted pedotransfer function to forest soils and to test the generalisation of our findings in different conditions, especially deeply rutted soils (rut depths > 12 cm).

Биологическая активность горных почв Западного Кавказа после сведения леса

A study of a set of indicators characterizing the ecological state of forest soils in the mountains of the North-Western Caucasus under broad-leaved and mixed forests has been conducted. The aim of the study has been to assess changes in the biological activity of soils of different genesis after deforestation. The objects of the study have been rendzina, gray forest and gray forest-steppe soils of forest and disturbed ecosystems of the Republic of Adugeya at altitudes from 500 to 1635 m above sea level. Logging plots of different ages (from 10 to 40 years old) after deforestation have been considered. The analyzed indicators have included: the content of total and active carbon, the activity of soil enzymes (catalase, invertase, dehydrogenase, urease, phosphatase), the number of bacteria, as well as an integral index of the biological properties of the soil. The correlation of these indicators with hydrothermal conditions, density of soil structure, penetration resistance, medium reaction, hydrolytic acidity, total absorbed bases and other soil parameters has been evaluated. The level of biological activity of soils in logging areas in the low mountains of Adygea depends on the relief and the timing of restoration after deforestation. Even after several decades of restoration of woody vegetation on the slopes of 12–15° there is no complete return of biological activity to the values of Greyic Phaeozem Eutric of the background forest area. 40 years after logging, the integral index of biological properties of gray forest soil is still 17 % lower than in the control plot. The biological activity of post-forest soils can change in three main directions. On steep slopes, with severe disturbance of the soil and vegetation cover due to the operation of heavy machinery, the integral index of the biological properties of soils decreases by 25–40 % or more without a tendency to recovery. At an average level of disturbance in plots with slight slopes, after an initial decrease, the soils are restored to control values. Restorative successions with intensive development of herbaceous flora and the turf process with slight disturbance can lead to an increase in biological activity above the control values in just 2–3 years. Comprehensive biodiognostic studies using an integral index of the biological state of the soil have revealed, in general, increased stability of low-mountain terrain soils (gray forest and forest-steppe) compared to the soils of the middle mountains of Adygea (rendzina soils). The main degradation factor that reduces the biological activity of soils disturbed by logging is erosion.

Effects of Litter Removal and Biochar Application on Soil Properties in Urban Forests of Southern China

Urban forests are crucial components of cities, serving as vital ‘green lungs’ that embody urban civilization and sustainability. Despite their significance in maintaining the urban environment and ecological functions, management practices for urban forests can be unreasonable at times. This study investigated the impact of two common practices, litter removal and biochar application, on soil properties in an urban forest in Changsha city, China. The aim was to understand how these practices affect soil carbon, nutrients, and microbial activity in urban settings. The results showed that soil water content (SWC), pH, available phosphorus (AP), and soil microbial biomass carbon (SMBC) were significantly reduced in areas where litter was removed compared to areas where litter was retained. Conversely, biochar application led to a significant increase in SWC, pH, AP, and SMBC. The treatment alone had no significant effects on total nitrogen (TN), soil organic carbon (SOC), and soluble soil organic carbon (SSOC) in the examined urban forests. However, the SOC and SSOC contents significantly increased over time with biochar application. Our results demonstrated that the influences of litter removal and biochar application on soil property were attributed to the regulation of AP and SMBC in the studied urban forests. This study provides a scientific basis and reference for understanding the sustainable management of urban environments and guiding future conservation efforts in urban greening spaces.

Assessing the compression properties of Gravel-bearing forest soil in northeast China’s seasonally frozen regions under Freeze-thaw cycles and varying gravel content

Due to climate change, human activities and natural disturbances in high-latitude permafrost and seasonally frozen areas are gradually increasing, attracting more attention from scholars. However, research primarily focuses on soil biology and chemistry in these regions, with limited exploration of their mechanical properties, especially compression properties. This study aims to evaluate the effects of gravel content and freeze–thaw (F-T) cycles on the compression properties of coarse-grained layered forest soil from northeast China’s seasonally frozen regions, with the goal of predicting the soil’s compressive changes under heavy mechanical loads. Specifically, using uniaxial confined compression tests (UCCT) on 252 disturbed soil samples (including two soil layers: AB and Bhs; six gravel contents; and seven F-T cycles), three characteristic compression coefficients—precompression stress (σpc), compression index (Cc), and swelling index (Cs)—were measured. Additionally, scanning electron microscopy (SEM) was used to analyze the mesostructure evolution of coarse-grained gravel-bearing soil. Volume changes of samples were measured after 15F-T cycles with varying gravel contents. Results indicate non-linear effects of gravel content and F-T cycles on σpc. Gravel content below 50% positively influences σpc, while content above 50% increases soil pore content, decreasing σpc. Cc and Cs exhibit an approximately negative correlation with gravel content and initially increase followed by a decrease with more F-T cycles. Moreover, the σpc and Cc of the AB layer are higher than those in the Bhs layer, likely due to differences in clay and organic carbon contents. Notably, the observed trends differ from previous studies on other soil types such as farmland and paddy fields. This study fills a gap in understanding the compression characteristics of layered gravel-bearing forest soil in seasonally frozen regions, providing valuable insights for evaluating soil compression in both seasonally frozen and permafrost regions, and understanding mechanical vehicle-soil interactions. It also lays the theoretical groundwork and provides data support for constructing compression models of layered gravel-bearing forest soil.

Modelling and mapping the abundance of lingonberry (Vaccinium vitis-idaea L.) in Norway

Lingonberry (Vaccinium vitis-idaea L.) grows in a range of nature types in the boreal zone, and understanding factors affecting the abundance of the plant, as well as mapping its spatial distribution, is important. The abundance of the species can be an indicator of ecosystem changes, and lingonberry can also be a source for commercial utilisation of berry resources. Using country-wide data from 6404 field plots of the Norwegian national forest inventory (NFI), we modelled the relationship between lingonberry cover and airborne laser scanning (ALS) and satellite metrics and bioclimatic variables describing the forest structure, terrain, soil properties and climate using a generalised mixed-effects model with a quasipoisson distribution. The validation carried out with an independent set of 2124 NFI plots indicated no obvious bias in predictions. The most important predictors were found to be interactions between dominant tree species, stand basal area and latitude, as well as the reflectance in the near-infrared band from Sentinel-2 satellite imagery, the dominant height based on the ALS variable and the long-term mean summer (June–August) temperature. The results provide an indicator of the effects of global warming, as well as the possibility of giving forest management prescriptions that favour lingonberry and locating the most abundant lingonberry sites in Norwegian forests.

Effects of LongTerm Application of Mineral Fertilizers and Manure on Agrochemical Properties of Gray Forest Soil, Crops Productivity and Carbon Sequestration

The effect of long-term application of increasing doses of mineral (from N90P75K100 to N360P300K400) and organic (cattle manure from 25 to 100 t/ha) fertilizers on the fertility of gray forest soil was studied in the micro-plot experiment. Over 9 years, 0.81–3.24 t/ha of nitrogen, 0.68–2.70 t/ha of P2O5 and 0.90–3.60 t/ha of K2O were applied with mineral fertilizers. Manure supplied 43–173 t/ha of dry matter, 16–65 t/ha of Corg, 0.85–3.41 t/ha of Ntot, 0.65–2.59 t/ha of P2O5 and 0.86–3.46 t/ha of K2O. In the yield the mineral fertilizer system exceeded the organic one by an average of 29%. At extreme doses (N360P300K400 and 100 t/ha of cattle manure) mineral fertilizers reduced crop productivity more strongly than organic fertilizers. A direct linear relationship was found between the doses of mineral and organic fertilizers and the increase in the content of available P2O5 and K2O in the soil. Application of extreme doses of fertilizers did not lead to saturation of the soil with available forms of phosphorus and potassium. Long-term application of organic fertilizers increased the soil pH(KCl) by 0.4–1.3 units and mineral fertilizers decreased it by 0.8–1.4 units. Annual application of mineral fertilizers increased soil Corg content by an average of 0.02–0.04% per year, and organic fertilizers – by 0.08–0.17% per year. Manure application at 100 t/ha over 9 years led to the saturation of the soil with organic carbon. The C : N ratio in the soil under a mineral fertilizer system was decreased, while it with the organic system was increased. An approach to calculate the carbon sequestration efficiency for the assessment of different agronomic practices is proposed. It is shown that the carbon sequestration efficiency of the organic fertilizers was 15% higher than that of the mineral fertilizers.

Connecting forest soil properties with ecosystem services: Toward a better use of digital soil maps—A review

AbstractThe soil supports many ecosystem services (ES) essential to human well‐being. Rapid developments in digital soil mapping (DSM) allow the mapping of soil types and soil properties with improved resolution and accuracy. However, the potential of DSM to improve the assessment and mapping of ES is not fully exploited. To better understand this potential, we synthesized the peer‐reviewed literature. We examined what empirical studies reveal about the role of soil properties in the assessment of four major ES provided by the forest: (I) timber production, (II) soil carbon storage, (III) regulation of water flow and provision of clean water, and (IV) the soil as a habitat for organisms. Results revealed that soil properties are strongly related to the provision of ES. Therefore, using DSM could greatly improve the assessment of the ES provided by forests. Several variables were related to specific ES regardless of region or ecosystem types, but others were found to be situation‐specific (climate and soil type) and need to be considered at the proper scale or within a proper land classification framework. DSM products have the potential to greatly improve the assessment of ES by turning qualitative relationships between soil and ES to quantitative ones. This could also lead to the discovery of new soil–ES relationships. For this potential to be realized, progress should be made in mapping the most crucial soil parameters with greater precision and in promoting the use of soil parameters in ES assessment.

Chemical properties of agricultural and forest soil of different blocks of Bargarh district, Odisha, India

Chemical properties of agricultural and forest soil of different blocks of Bargarh district, Odisha, India

Soil organic carbon, pH, and ammonium nitrogen controlled changes in bacterial community structure and functional groups after forest conversion

IntroductionLand-use changes significantly impact soil properties in forests, which is an area of concern. Therefore, the effects of changing forest types on soil microbial communities and their functions in northern subtropical forest regions need to be further researched.MethodsWe used 16S rDNA sequencing and Functional Annotation of Prokaryotic Taxa (FAPROTAX) to assess the variation of soil bacterial communities and potential functions related to carbon (C) and nitrogen (N) cycling in two soil layers (0–10 and 10–30 cm) after the conversion of the secondary masson pine (Pinus massoniana, PM) forest to plantations of slash pine (Pinus elliottii, PE) and Chinese fir (Cunninghamia lanceolata, CL) located in Jingde County, Anhui Province, China.ResultsThe study found that converting coniferous secondary forests to coniferous plantations resulted in a notable increase in soil pH and a decrease in nitrate nitrogen and organic carbon contents. Additionally, soil microbial diversity increased significantly, and microbial community structure changed, particularly in the topsoil. These changes might affect the C- and N-cycling mediated by soil bacteria. The analysis revealed a significant decrease in the abundance of functional groups associated with C-cycling and a significant increase in the abundance of functional groups associated with N-cycling, particularly those associated with denitrification. Soil organic carbon, pH, and ammonium nitrogen were the most critical variables affecting changes in the soil microbial community.DiscussionThese findings provide valuable information for ecological restoration and future sustainable forest management.

Influence of Xanthan Gum-Based Soil Conditioners on the Geotechnical Properties of Soils

The impact of climate change has become increasingly severe in forests, where droughts and strong winds on the one hand and extreme rainfall events on the other hand can damage forest ecosystems. To mitigate the effects of drought and enhance soil water retention capacity, three types of soil conditioners (SCs), labeled SC_R, SC_CG, and SC_ZZC, were developed as part of the European project ONEforest. All the conditioners are based on Xanthan gum and have different types and amounts of fillers with diverse cellulose fiber lengths. These can offer the potential to optimize the SC characteristics, e.g., water absorption, water retention, and mechanical stability. This paper focuses on the influence of fillers in the SCs on the geotechnical properties of forest soils from Ljubelj in the Alpine part of Slovenia (S1), Catalonia, northeastern Spain (S2), and Heldburg, Germany (S3). The results show an increase of 53% to 100% in the water absorption of treated soil. A less favorable impact of the SCs was found on the drained shear strength and the compressibility. The drained shear strength of untreated forest soils in a saturated state was S1 c′ = 4.4 kPa, φ′ = 33.5°; S2 c′ = 1.4 kPa, φ′ = 30.0°; and S3 c′ = 12 kPa, φ′ = 28.0°. The addition of SCs results in a reduction in the drained shear strength of saturated mixtures. The reduction depends on the dosage of added SC—whether it is a low (L) or a high (H) dosage. For instance, when the soil S1 was treated with a low dosage of the soil conditioner SC_R, it demonstrated a cohesion (c′) of 11 kPa and a friction angle (φ′) of 27.0°. However, increasing the dosage of the SC_R led to a decrease in both the cohesion and the friction angle for the same soil (c′ = 7.7 kPa, φ′ = 25.0°). Additionally, the type of soil conditioner also impacts the drained shear strength. Among the mixtures with a high dosage of the SC_R, SC_CG, or SC_ZZC, those containing the SC_CG with the longest fibers stand out, demonstrating the highest friction angle. Therefore, longer fibers can be a promising component of the SCs to reduce the negative influence of XG on the mechanical properties of treated soils.

Decomposing benefits: Examining the impact of beech deadwood on soil properties and microbial diversity

Deadwood is an important element of forest ecosystems that affects many of its components, including the soil environment. Our research is an attempt to determine the role of decaying wood in shaping the properties of forest soils in mountain ecosystems. The aim of our research was to present the influence of beech deadwood on physicochemical properties and microbiological diversity of soils. The research was carried out in the Baba Góra Massif at its northern exposure. The research plots were established in the altitude gradient at 600, 800 and 1000 m above sea level. On each plot, samples were taken from decaying wood, from the soil directly under the decaying log, and a soil sample 1 m from the log as a control. We determined the basic properties of the samples, that is pH, C and N concentration and lignin content. The enzymatic activity and additionally, the taxonomic composition of soil bacterial and fungal communities was determined in the collected samples. Our research indicates the important role of decaying beech wood in shaping the properties of forest soils. We noted a positive effect of decaying wood on the properties of the tested soils. Soils affected by deadwood were characterized by significantly higher pH, C and N concentrations compared to control soils, regardless of their location in the altitude gradient. Additionally, we found that soils affected by decaying wood are characterized by a different composition of microorganisms regardless of their location in the altitude gradient. In control soil the fungal and bacterial alpha diversity were lowest compared with the deadwood and soil under the influence of deadwood. Our results may have practical applications in the management of forest ecosystems. The presented results indicate the possibility of leaving deadwood in order to improve its basic physicochemical properties and increase microbial diversity.

Физические и физико-химические свойства почв рекреационных территорий г. Воронежа

Using the example of four key sites, soil formation factors, morphogenetic features of soils exposed to recreational stress are described, and the physical and physico-chemical properties of the soils of the studied territories are studied. Keywords: PHYSICAL PARAMETERS OF SOILS, PHYSICO-CHEMICAL PARAMETERS OF SOILS, GRANULOMETRIC COMPOSITION, HUMUS, RECREATIONAL LOAD, PROPERTIES OF FOREST SOILS

Effects of grazing on soil properties in mediterranean forests (Central-Eastern Spain)

Traditional management practices, such as grazing, can have adverse impact on soils. Despite an extensive body of literature exploring the effects of grazing on soil and plants worldwide, there is a notable lack of research on its impacts in Mediterranean forests within the Iberian Peninsula Furthermore, there is a knowledge gap on the enzymatic activities and basal respiration of soil in forest after grazing. To address these gaps, this study aimed to investigate the impact of grazing on various important physicochemical and biological soil properties along with vegetation richness in a Mediterranean forest located in Castilla-La Mancha (Central Eastern Spain). Relative to undisturbed sites, grazing significantly reduced soil water content (−53%) and available water (−59%). However, soil hydraulic conductivity remained unaffected by animal trampling and the soil water repellency observed in ungrazed sites disappeared. Grazed soils experienced a slight increase in pH (+18%). Among the biochemical properties studied, only dehydrogenase showed a significant increase (+100%) while basal respiration exhibited a notable decrease (−24%). Grazing resulted in a reduction of plant species richness (−34%) indicating a loss of biodiversity in grazed areas. The observed significant alterations in key soil and plant properties due to livestock activity suggest that grazing has the potential to modify the overall soil quality of these sites. Certain variables that exhibited noteworthy differences between grazed and ungrazed sites could serve as indicators of grazing impacts in Mediterranean forests. These indicators may be considered proxies for establishing effective land management strategies to mitigate degradation in the Mediterranean forest ecosystem.

Restoring soil properties in the Hyrcanian forests from machine induced compaction: Reforestation of N2‐fixing black alder (Alnus glutinosa (L.) Gaertn.)

AbstractAmong the various species of trees, black alder (Alnus glutinosa (L.) Gaertn.) is one of the most commonly used trees for the reforestation and restoration programs of degraded forestlands in the Hyrcanian forest, particularly in the skid trails. The effects of reforestation with black alder on the recovery of litter (thickness, C, N, C/N) and soil physicochemical, biochemical, biological, and microbial properties in the skid trails with three levels of compactions were examined over a 27‐year period. Results showed that the litter characteristics such as thickness, carbon (C), nitrogen (N), and C/N were at the highest level in low intensity traffic as compared to those of medium and frequent intensities. Results showed that the values of total porosity, macroporosity, aggregate stability, silt, and clay were at the lowest level in the natural stand. The highest values of soil pH, C, C/N ratio, and C storage were recorded under the skid trail with frequent machine passages. The restoration values of soil physical and chemical properties were significantly higher in the low level of machine traffic after a period of 27 years where black alder reforestation was performed on the skid trails, as compared to the medium and frequent machine traffic levels, as well as the undisturbed area. Black alder litter affected soil nitrogen and the maximum amounts of earthworm density and dry mass. This also includes fine root biomass. These data were recorded in the trails with low machine traffic as compared to those of medium and frequent traffic. The results clearly showed that black alder is effective in reaching the objectives of restoration programs, given that it promotes soil organic matter, builds up soil structure via root‐soil feedback, and improves the soil by creating a major source of nitrogen through enhancing the nitrogen cycle.

The impact of root systems and their exudates in different tree species on soil properties and microorganisms in a temperate forest ecosystem

BackgroundThe species composition of tree stands plays an important role in shaping the properties of forest soils. The aim of our research was to determine the influence on soil properties of the root systems of six species of trees which form forest stands in the temperate climatic zone. The research covered areas including six tree species – Scots pine (Pinus sylvestris L.), European larch (Larix deciduas Mill.), English oak (Quercus robur L.), English ash (Fraxinus excelsior L.), European beech (Fagus sylvatica L.) and European hornbeam (Carpinus betulus L.). In our study, we determined the characteristics of the roots and the amount of carbon excreted alongside their exudates. Enzymatic activity, and the composition and diversity of the fungi and bacteria, were also determined in addition to the basic physicochemical properties of the soil samples.ResultsA strong relationship between the root characteristics and soil properties, including the pH, basic cation content and phosphorus content, was confirmed. In addition, the enzymatic activity of phosphatase, β-glucosidase, N-acetyl-β-D-glucosaminidase and β-D-cellobiosidase were positively correlated with the root characteristics. The study on soil bacteria across different tree species revealed Proteobacteria and Actinobacteriota to be the most abundant phylum. Fungal analysis showed Basidiomycota and Ascomycota as the dominant phyla. Ascomycota dominated in hornbeam and oak soils. Mortierellomycota was remarkably more present in pine soil.ConclusionsThis analysis of root systems and soil properties confirmed the distinctness of ash stands, which were also more abundant in various microorganisms. It was also found that soils affected by different tree species were characterised by varied fungal and bacterial composition. The ash had particularly beneficial impact on soil microbiota.

Properties of dark gray forest soil in the cultivation of cereals according to various basic processing systems

The purpose of the research is to establish the influence of various systems of basic dark gray forest soil processing with prolonged use on the transformation of the most important fertility elements. The results of prolonged (1988-2022) exposure to processing systems in the grain-steam crop rotation are presented: dead fallow, winter rye, spring wheat, spring barley, in the northern forest-steppe of the Tyumen region of the Russian Federation. The basic tillage systems were compared: dump, non-dump, combined, differentiated, flat-cut, surface. The peculiarities of the transformation of fertility elements under prolonged exposure to basic processing systems of varying intensification degrees are determined. It was found that the long-term use of basic treatment systems of varying minimization degrees in conditions of complex chemicalization ensured the formation of water-physical properties, nutritional conditions and phytosanitary conditions in their values slightly inferior or close to the control version of the dump processing system. Tillage systems with minimization elements reduced the energy efficiency coefficient in comparison with the dump system against the background of fertilizer application by 4.5‑11.5%, against the background without fertilizers – by 7.7‑18.4%. The lowest decrease in efficiency in comparison with the dump processing system for both nutrient backgrounds was for the combined processing system – 4.5‑7.7 %.