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Forest litter's biochemical activity was examined in iron-illuvial podzols and podzolized podburs (Albic Podzols and Entic Podzols), considering (1) variations in edaphic and climatic conditions, and (2) levels of anthropogenic pollution. In the first case, blueberry (BPF), lingonberry (LinPF), and lichen (LicPF) pine forests in the middle taiga subzone and LinPF in the northern taiga subzone and at the boundary with the forest-tundra zone were studied. In the second case, soils from pine forests at different distances from the impact zone of the Pechenganickel Mining and Metallurgical Combine were analyzed. The study examined how the "ground cover–litter" system affected soil enzymes and chemical properties (pH, C, N, P, K, S, Cu, Ni). The forest litter in the middle taiga's LicPF exhibited 1.5–1.8 times higher invertase and phosphatase activities compared to BPF and LinPF. The decrease in mean daily temperature by 2–3°C resulted in a corresponding decline in catalase activity by 58 and 69%, urease activity by 43 and 52%, and invertase activity by 51 and 28%. The activity of enzymes in the forest litter did not significantly vary with the level of copper and nickel contamination, suggesting a strong adaptive potential in the microorganisms-soil system. The discussion revolves around using soil biochemical activity for monitoring forest biogeocenoses. [ABSTRACT FROM AUTHOR]

Calophyllum brasiliense is a hydrophilous tree species widely distributed in Brazil. It often dominates tropical swamp forests and shows morphophysiological responses to flooding and sensitivity to water deficits. To investigate the edaphic influence on the xylem structure of this species, wood samples were obtained from adult C. brasiliense trees in two soil types, Podzol and Histosol, both covered by lowland Atlantic Forest, in a coastal plain in southern Brazil. The sandy texture of Podzol and its microrelief often lead to more mesic conditions compared to Histosol, which is an organic and hydromorphic soil. Permanent slides with histological sections and dissociated material were prepared for qualitative and quantitative anatomical analysis. Principal component analysis and mean comparison tests were performed to assess variations in anatomical traits between soil conditions. Vessel density and fiber length were higher in trees from Podzol compared to Histosol, while the width of the rays was greater in Histosol. Additionally, the cross-sectional area and mean lumen diameter of vasicentric tracheids were larger in populations from Histosol than in Podzol. Furthermore, Vulnerability and Mesomorphy indices showed higher values in Histosol compared to Podzol. While the response associated with vessel occurred in density (higher in Podzol), the response in tracheid is reflected in cell diameter (higher in the soil with more water: Histosol). This publication is likely the first to demonstrate intraspecific variation of vasicentric tracheids in a hydrophilous species. The anatomical structure and functional implications of the observed variations are discussed regarding the efficiency and safety of the conductive system, considering the ecology of the species and the characteristics of the sampled soils. [Display omitted] • The xylem structure of C. brasiliense is closely related to its hydrophilous status. • More numerous vessels and narrower vasicentric tracheids occur in mesic soil: Podzol. • Narrower fibers occur in the hydromorphic and more unstable soil: Histosol. • Vasicentric tracheids and vessels form a tridimensional water conduction network. [ABSTRACT FROM AUTHOR]

A dense concentration of old-growth forest and a wet, cold climate promote mineral weathering and leaching in coastal temperate rainforest soils. Our objective was to assess soil development and soil organic carbon (SOC) distribution across 18 soil profiles in remote, upland terrain of southeast Alaska where pedon data are sparse. We made soil morphological observations, collected samples, and completed laboratory analyses to measure SOC content, pH, and particle size distribution. The survey of upland backslope soils included north- and south-facing hillslopes derived from three lithologies (slate, metavolcanic, and phyllite). The soils across all sites were very gravelly (51.8 ± 20.4% coarse fragments), acidic (mineral soil pH 4.85 ± 0.45), and moderately deep (96.56 ± 37.80 cm); thin, broken E horizons were underlain by thick, carbon-rich spodic horizons. Soil development was relatively consistent as demonstrated by the Profile Development Index with values from 15 to 26 and Podzolization Index values spanning 8 to 14. A mean pedon SOC stock of 198.02 ± 81.42 Mg C ha−1 (n = 18) was calculated using data collected for all upland organic and mineral soils from our work. The accumulation of SOC was similar among soils formed from contrasting lithologies with averages of 182 ± 15.70 Mg C ha−1 for slate, 188 ± 53.80 Mg C ha−1 for metavolcanic, and 218 ± 124 Mg C ha−1 for phyllite. Our work contributes to soil morphological observations, laboratory data, and SOC stock estimates required to better constrain and model pedogenic processes and SOC stock in remote forests where data sets are limited. [ABSTRACT FROM AUTHOR]

The spread of Ganoderma disease in oil palm plantations is affected by several factors, one of the most significant being the soil type. Different soil types influence the availability of nutrients and moisture, which can affect the growth and spread of Ganoderma. This study investigates the impact of spodosols and ultisols on soil macronutrient dynamics and their effect on microbial populations, ultimately influencing Ganoderma distribution. Using a nested sampling design, we collected data from 120 palms across 411 hectares. We analyzed the impact of soil type (sand, ultisol) on soil pH, organic carbon, macronutrients (P-total, P-Bray, Exchangeable K, Exc-Mg, Exc-Ca), and bacterial and fungal populations at 1 m, 2 m, and 3 m distances from infected and healthy palms. Data analysis employed Two-Way ANOVA. The results reveal that soil pH and organic carbon positively influenced Ganoderma incidence in spodosol soil. At the same time, macronutrients P-total, P-Bray, and K had positive interactions with the disease in both soil types. Conversely, Exc-Mg and Exc-Ca showed positive interactions in spodosol soil but negative interactions in ultisol soil. Nitrogen had no significant impact on spodosol soil. Regarding microbial populations, ultisol soil exhibited higher bacterial populations around infected palms (23.4% at 1 m and 12.5% at 3 m). Spodosol soil showed higher bacterial populations further away (2.3% at 1m and 41.3% at 3 m). Fungal populations were higher in ultisol soil compared to spodosol soil for infected palms (27.01 x 106 cfu/g and 26.00 x 106 cfu/g, respectively). This study highlights the complex interplay between soil type, macronutrients, microbial populations, and the spread of Ganoderma. These findings inform the development of effective disease management strategies for oil palm plantations. [ABSTRACT FROM AUTHOR]

Aims: To improve soil phosphorus (P) testing in silvicultural systems, we assess microdialysis to study concentrations and establish a standard methodology to assess soil diffusive P and in-vivo translocated sap flow P under variable rates of P carryover from a previous rotation across various soils. Methods: Soils were collected from each treatment in the field and analyzed in laboratory conditions. Soils were analyzed for diffusive soil P using microdialysis and Mehlich III for comparison. Sap flow P measurements were collected in the field from 16 trees, one tree per treatment and replication over four hours. Results: Spodosol soils had higher diffusive P levels than Alfisol soils. On average, diffusive P increased by 137% in Spodosol and 166% in Alfisol from pre- to post-planting of a new stand. In the Alfisol, diffusive P showed a strong relationship with tree height, while no significant association was observed in the Spodosol. The Mehlich III soil extractions were positively related to the Alfisol but not the Spodosol. Microdialysis samples collected from the trees responded to changes in fertilization rates and were shown to be positively related to tree heights and Mehlich soil P tests. Atmospheric conditions substantially impacted sap flow P, with samples collected in full sunlight showing an average increase of 100% compared to overcast conditions. Conclusions: These findings demonstrate the potential of microdialysis as a valuable tool for soil P testing and its application in addressing complex questions related to P translocation and tree physiology in silvicultural settings. [ABSTRACT FROM AUTHOR]

Post-agrogenic transformation of fallow soils leads to changes in soil carbon content, the molecular composition of humic substances, and rates of organic matter stabilization, which can affect climate change on the planet. In this regard, we analyzed the molecular composition of humic acids isolated from natural and fallow soils in the southern Taiga zone of northwest Russia. Different-aged soils on fallow lands represent a model of soil transformation in time, and data on the transformation of soil humic acid molecular composition make a significant contribution to the understanding of soil organic matter stabilization aspect issues. In this case, the molecular structure of humic acids isolated from natural and fallow soils in northwest Russia was analyzed. To study the molecular composition of HAs, the elemental composition was analyzed, and 13C (CP/MAS) NMR spectroscopy of HAs isolated from different aged abandoned soils and soils of different types of use was carried out. The obtained data showed that with the increasing age of soils in the fallow state, there is an increase in the carbon content of humic acids as well as a decrease in nitrogen content. As a result of the increasing age of soils in the fallow state, there are dynamics in the content of aromatic structural fragments in humic acids: 34% for 40 years old, 28% for 80 years old, and 31% for 120 years old. This is due to changes in the precursors of humification and the further transformation of plant residues in the soil. Re-involved fallow land soils lead to an increase in the content of aromatic structural fragments in the composition of HA in relation to HA extracted from mature soils. The lowest content of aromatic structural fragments was observed in the humic acids of 130-year-old agricultural soil, which is associated with the long-term application of organic fertilizers. [ABSTRACT FROM AUTHOR]

Thinned steep forests are particularly vulnerable to soil physical degradation. Retaining deadwood logs from thinning operations on the forest floor can potentially mitigate soil physical degradation by modifying its physical properties through increased carbon content in steep regions. We aimed to investigate the effect of spruce deadwood logs from thinning operations on the physical properties of a loamy sand Podzol soil in a steep (30°) temperate spruce forest in Bavaria, Germany. The soil organic carbon (SOC) content was 56% higher under deadwood logs compared to the control areas (p‐value = 0.097). Deadwood logs also increased the soil water repellency by 13% (p‐value = 0.269), while decreasing the soil shear strength by 35% (p‐value = 0.001). Shear strength and water repellency strongly correlated with SOC content, with r = −0.87 and r = 0.86, respectively. Although retaining deadwood logs seems a promising carbon sequestration strategy, it can adversely affect soil shear strength and water repellency and potentially lead to soil degradation. Therefore, the choice to keep deadwood logs on the forest floor may align with specific management goals. [ABSTRACT FROM AUTHOR]

The soil microbiome is composed of various communities that play an important role in the existence of ecosystem services and the sustainable functioning of ecosystems under high anthropogenic loads. The transition of soils to a fallow state and their subsequent transformation lead to a notable alteration in the taxonomic composition of the soil microbiome, impacting the biochemical processes within the soil and its fertility levels. The object of this study comprised different-aged fallow soils of the southern taiga in the vicinity of Ban'kovo village, Leningrad region. The method comprising the high-throughput sequencing of 16S rRNA gene fragments using an Illumina MiSEQ sequencer was used to analyze the microbial community. The general processing of sequences was carried out with the dada2 (v1.14.1) package. It was found that the morphological organization of fallow soils has significant differences from the native podzol. In fallow soils, there are signs of leaching expressed in the accumulation of leached mineral particles, which indicates the degradation of the fallow–arable horizon. At the same time, there is a decrease in the content of P2O5 and K2O and an increase in the content of N-NH4 and N-NO3 in fallow soil. The analysis of alpha diversity index values showed that the highest level of alpha diversity in the microbial community is characteristic of 40-year-old soil, the alpha diversity index decreased with the increasing time of the fallow state, and the lowest alpha diversity index was observed in the native podzol. According to the values of the beta diversity index, a high correlation between the soil microbiome and the physicochemical characteristics of the soil was revealed, which indicates the formation of functional specialization in the studied microbial communities. As a result of the study of the taxonomic composition of microbial communities in fallow soils, it was found that the most represented microbial communities in fallow soils belong to Nitrosomonadaceae (Pseudomonadota), Mycobacterium (Actinobacteria), Nitrospira (Nitrospirota), and Luteolibacter (Verrucomicrobiota). The duration of post-agrogenic transformation is the leading factor influencing the changes in microbial communities; so, with an increase in the time that soils were in a fallow state, an increase in the oligotrophic microbial community was observed. [ABSTRACT FROM AUTHOR]

Premise: In frequently burned southeastern USA pine‐grassland communities, wiregrass (Aristida stricta and A. beyrichiana) are dominant bunchgrasses whose flowers are infected during flowering by a smut fungus (Langdonia walkerae). We hypothesized that because prescribed fire timing affects wiregrass flowering patterns, it could affect smut incidence (occurrence of smut on plants) and severity of infection in inflorescences and spikelets. Because soil order could influence plant susceptibility, we hypothesized that these patterns would differ between soil orders. We hypothesized differences between species as representative of geographic variation in this ecosystem. Methods: We surveyed the incidence and severity of L. walkerae in wiregrass populations (85 populations at 14 sites) that had been prescription burned at different times during the previous year. We used binomial regressions to test whether incidence and severity differed by burn day, soil order, or species, with site as a random effect. Results: Fires that occurred in the winter were associated with significantly lower incidence than fires later in the year (as the months progressed into summer). Plants growing on Spodosol soils were significantly less likely to be infected than those on other soils. More variation in incidence, however, was explained by site, suggesting that site‐specific characteristics were important. Smut severity in inflorescences and spikelets was greater overall in populations of A. stricta than in southern populations (A. beyrichiana). Conclusions: Our findings indicate that fire timing and soil order affect L. walkerae incidence in wiregrass plants, but neither appears to be associated with greater severity. Patterns of smut infection are related to site history and geographic variation. [ABSTRACT FROM AUTHOR]

Pine-green moss forests on Podzols exhibit high susceptibility to fire. Subsequent to wildfire, soot and charcoal enter the soil profile and accumulate in the upper part of the podzolic horizon (E). This process results in the development of a greying pyrogenic podzol horizon (Epyr). The maximum concentration of pyrogenic components accumulates in the surface layer of Epyr, which is 1 to 4 cm thick and the darkest in colour. The comprehensive soil descriptions showed the existence of a fine pyrogenic layer between the forest floor and mineral horizon. This layer was not analysed. The current shift in science towards assessing the environmental aspects of soil organic matter dynamics requires a more detailed study of the soil profile. We suggest distinguishing the pyrogenic organic mineral sub-horizon of the Eopyr as the upper Epyr layer. Our results show this sub-horizon contains sand, humus, detritus, and charcoal. It forms around 6%–22% of the entire organic matter pools in the biologically active part of the soil (0–30 cm). Further research is needed to obtain reliable qualitative and quantitative data on Eopyr. [ABSTRACT FROM AUTHOR]

Boreal lands have long been considered unsuitable for agriculture. Climate change projections support a shift towards increased agricultural production in boreal ecosystems via land use conversion. Depending on the conversion protocol, the new plough layer may variably reflect the properties of different soil depths. This study assessed how adding mineral or organic fertilizer sources to distinct soil layers within ploughing depth (0–15 cm [topsoil] or 15–30 cm [subsoil]) affects nutrient uptake and crop productivity. Locally relevant organic waste fertilizers (dairy manure [DMN], recirculating aquaculture system supernatant [SUP] and slurry [RAS]), were compared against mineral fertilizer. Tall fescue was used to verify agronomic responses. Starting available nutrient concentrations were balanced as necessary with mineral N and P fertilizers. Except for NH4‐nitrogen, both soils were of apparent similar fertility (total C < 1%); unfertilized, neither could support significant plant growth. Subsoil‐based growth was fast but limited in time reflecting immediately available nutrients. Topsoil led to delayed, extended growth. This might be due to dichotomous priming effects: during the duration of the experiment up to 36% of subsoil carbon was lost, while the topsoil gained up to 49% carbon, most apparent for DMN. While RAS led to the greatest N and P acquisition efficiencies for topsoil, it had no such effect for subsoil, suggesting distinct fixation and mineralization processes. Dissimilar C cycling and nutrient acquisition for the two soil depths indicates that site‐specific considerations that include soil health parameters with commonly tested available nutrients are needed where podzols are farmed after land‐use conversion. [ABSTRACT FROM AUTHOR]

The values of heterotrophic (HR) and total soil respiration for the Entic Carbic Podzol under a coniferous–broadleaved forest in the south of Moscow oblast (54.89° N, 37.56° E) calculated using the Romul_Hum model and a new version of the EFIMOD3 system of models are reported. The results of soil respiration modeling correlate well with the field measurement data. The Romul_Hum model better simulates the HR intensity of the studied soil in wet years as compared with dry years, when it somewhat overestimates the HR values. The spatially explicit modeling of HR and root respiration using EFIMOD3 takes into account the variation of carbon pools and fluxes associated with the distribution of the plant litterfall and hydrothermal conditions under the forest canopy. The results show that the HR intensity differs approximately twofold in early and middle growing season, and the HR values in individual parts of the simulation site at the same dates differ more than 3.5-fold. The spatial and temporal variation of soil respiration influences the accuracy of estimates for the carbon budget in forest ecosystems. The used models are efficient tools for analyzing the changes in carbon stocks and soil respiration and estimating carbon sink in forest ecosystems, including the tasks related to forest management. [ABSTRACT FROM AUTHOR]

Post-agrogenic transformation of fallow soils leads to changes in soil carbon content, the molecular composition of humic substances, and rates of organic matter stabilization, which can affect climate change on the planet. In this regard, we analyzed the molecular composition of humic acids isolated from natural and fallow soils in the southern Taiga zone of northwest Russia. Different-aged soils on fallow lands represent a model of soil transformation in time, and data on the transformation of soil humic acid molecular composition make a significant contribution to the understanding of soil organic matter stabilization aspect issues. In this case, the molecular structure of humic acids isolated from natural and fallow soils in northwest Russia was analyzed. To study the molecular composition of HAs, the elemental composition was analyzed, and 13C (CP/MAS) NMR spectroscopy of HAs isolated from different aged abandoned soils and soils of different types of use was carried out. The obtained data showed that with the increasing age of soils in the fallow state, there is an increase in the carbon content of humic acids as well as a decrease in nitrogen content. As a result of the increasing age of soils in the fallow state, there are dynamics in the content of aromatic structural fragments in humic acids: 34% for 40 years old, 28% for 80 years old, and 31% for 120 years old. This is due to changes in the precursors of humification and the further transformation of plant residues in the soil. Re-involved fallow land soils lead to an increase in the content of aromatic structural fragments in the composition of HA in relation to HA extracted from mature soils. The lowest content of aromatic structural fragments was observed in the humic acids of 130-year-old agricultural soil, which is associated with the long-term application of organic fertilizers.

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The objectives of the research were to: (1) assess the strength of relationships between the soil thermal and hydrophysical properties, (2) evaluate the strength of association of evapotranspiration of spring wheat crop with soil thermal and hydrophysical properties, and (3) estimate the ranges of the thermal and hydrophysical properties of the sandy Haplic Podzol during the growing period of spring wheat in 2022. The study included instrumental simultaneous measurements of meteorological data, soil water retention curve, soil moisture content (SMC) and thermal properties. Actual evapotranspiration was calculated according to the Allen equation. Spearman's rank correlation coefficients showed that the increase in SMC from 0.10 cm3 cm−3 to 0.26 cm3 cm−3 resulted in a significant increase in thermal conductivity (r = 0.81, p < 0.001), volumetric heat capacity (r = 0.93, p < 0.001) and thermal diffusivity (r = 0.94, p < 0.001). Actual evapotranspiration also rose with the increasing SMC (r = 0.91, p < 0.001) and matric water potentials (r = 0.61, p < 0.05). As a consequence of the changes in SMC, the Spearman's rank correlation coefficients supported the strong positive relationships of actual evapotranspiration with volumetric heat capacity (r = 0.97, p < 0.001), thermal conductivity (r = 0.96, p < 0.001) and thermal diffusivity (r = 0.96, p < 0.001). Pearson correlation coefficients also supported the strong input of thermal inertia to the actual evapotranspiration (r = 0.88, p < 0.01). During the whole period of observations, actual evapotranspiration varied from 0.05 to 0.59 mm hr−1, soil thermal conductivity – from 0.225 to −1.056 W m−1 K−1, volumetric heat capacity – from 1.057 to 1.889 MJ m–3 K−1, heat diffusivity from 0.189 to 0.559 mm2 s−1, and thermal inertia – from 516 to 1412 J m−2 K−1 s−0.5. [ABSTRACT FROM AUTHOR]

The relevance of the Arctic regions' study is rapidly increasing due to the sensitive response of fragile ecosystems to climate change and anthropogenic pressure. The microbiome is an important component that determines the soils' functioning and an indicator of changes occurring in ecosystems. Rybachy Peninsula is the northernmost part of the continental European Russia and is almost completely surrounded by Barents Sea water. For the first time, the microbial communities of the Entic Podzol, Albic Podzol, Rheic Histosol and Folic Histosol as well as anthropogenically disturbed soils (chemical pollution and human impact, growing crops) on the Rybachy Peninsula were characterized using plating and fluorescence microscopy methods, in parallel with the enzymatic activity of soils. The amount and structure of soil microbial biomass, such as the total biomass of fungi and prokaryote, the length and diameter of fungal and actinomycete mycelium, the proportion of spores and mycelium in the fungal biomass, the number of spores and prokaryotic cells, the proportion of small and large fungal spores and their morphology were determined. In the soils of the peninsula, the fungal biomass varied from 0.121 to 0.669 mg/g soil. The biomass of prokaryotes in soils ranged from 9.22 to 55.45 μg/g of soil. Fungi predominated, the proportion of which in the total microbial biomass varied from 78.5 to 97.7%. The number of culturable microfungi ranged from 0.53 to 13.93 × 103 CFU/g in the topsoil horizons, with a maximum in Entic Podzol and Albic Podzol soils and a minimum in anthropogenically disturbed soil. The number of culturable copiotrophic bacteria varied from 41.8 × 103 cells/g in a cryogenic spot to 5551.3 × 103 cells /g in anthropogenically disturbed soils. The number of culturable oligotrophic bacteria ranged from 77.9 to 12,059.6 × 103 cells/g. Changes in natural soils because of anthropogenic impact and a change in vegetation types have led to a change in the structure of the community of soil microorganisms. Investigated tundra soils had high enzymatic activity in native and anthropogenic conditions. The β-glucosidase and urease activity were comparable or even higher than in the soils of more southern natural zone, and the activity of dehydrogenase was 2–5 times lower. Thus, despite the subarctic climatic conditions, local soils have a significant biological activity upon which the productivity of ecosystems largely depends. The soils of the Rybachy Peninsula have a powerful enzyme pool due to the high adaptive potential of soil microorganisms to the extreme conditions of the Arctic, which allows them to perform their functions even under conditions of anthropogenic interference. [ABSTRACT FROM AUTHOR]

This work aimed to investigate, in detail, the elemental and molecular composition of soil samples collected from the various horizons of an Amazon spodosol profile by combining the atomic technique laser-induced breakdown spectroscopy (LIBS) with two molecular techniques, i.e., Raman and fluorescence spectroscopies. The emission lines of the elements Fe, C, Si, Mg, Al, Ti, Ca, and K with various relative intensities were detected by using LIBS. In particular, C appeared to accumulate in the transition horizon and was proven to be mostly humified by fluorescence analysis. The Raman peaks detected at 465 cm−1 and 800 cm−1 corresponded with the symmetric stretching and bending modes of O-Si-O and Si-OH, respectively. Small shifts toward higher frequencies and slight increases in the width and full width at half maximum (FWHM) of the quartz band at 465 cm−1 appeared in the Tr to K2 horizons, which could be ascribed to a local distortion caused by the high contents of Al of kaolinite mineral phases, as also shown by the LIBS data. Thus, a small amount of kaolinite mineral phase and K measured by LIBS would be present also in the A1 to E2 horizons. The lifetime fluorescence was almost constant in the surface and middle horizons, whereas it increased sharply in the transition horizon and then decreased slightly in the kaolin horizons, which confirmed the presence of more humified recalcitrant organic matter in deeper soil horizons. In conclusion, the combined use of the three spectroscopic techniques appeared to be a very promising approach for studying Amazon soils. [ABSTRACT FROM AUTHOR]

Deadwood is a key component of forest ecosystems, but there is limited information on how it influences forest soils. Moreover, studies on the effect of thinning-derived deadwood logs on forest soil properties are lacking. This study aimed to investigate the impact of thinning-derived deadwood logs on the soil chemical and microbial properties of a managed spruce forest on a loamy sand Podzol in Bavaria, Germany, after about 15 years. Deadwood increased the soil organic carbon contents by 59% and 56% at 0–4 cm and 8–12 cm depths, respectively. Under deadwood, the soil dissolved organic carbon and carbon to nitrogen ratio increased by 66% and 15% at 0–4 cm depth and by 55% and 28% at 8–12 cm depth, respectively. Deadwood also induced 71% and 92% higher microbial biomass carbon, 106% and 125% higher microbial biomass nitrogen, and 136% and 44% higher β-glucosidase activity in the soil at 0–4 cm and 8–12 cm depths, respectively. Many of the measured variables significantly correlated with soil organic carbon suggesting that deadwood modified the soil biochemical processes by altering soil carbon storage. Our results indicate the potential of thinned spruce deadwood logs to sequester carbon and improve the fertility of Podzol soils. This could be associated with the slow decay rate of spruce deadwood logs and low biological activity of Podzols that promote the accumulation of soil carbon. We propose that leaving thinning-derived deadwood on the forest floor can support soil and forest sustainability as well as carbon sequestration. [ABSTRACT FROM AUTHOR]

The establishment of a network of monitoring sites (term in Russian—«carbon polygons») for monitoring climatic processes as well as the emission and deposition of carbon compounds in various ecosystems is one of the priority tasks in the field of climate and biosphere conservation in the world. This paper presents the results of the study of the soil sections of the «Ladoga» carbon monitoring site. Folic Podzol (Arenic) and Fibric Histosol were considered. These soils are widely represented in the southern taiga subzone and can be used as benchmark monitoring soil sections. As a result of the analysis of chemical parameters, it was revealed that Fibric Histosol and Folic Podzol (Arenic) are characterized by an acidic reaction of pH, pronounced podsolization, and peat accumulation. Fibric Histosol stores a significant amount of soil organic matter (SOM) up to 42.95 kgC/m2. In the analysis of the molecular composition of humic acids (HAs) extracted from the studied soils, it was found that HAs from Fibric Histosol were characterized by a relatively high content of aromatic structural fragments (27–41%), while in Folic Podzol (Arenic), aliphatic structural fragments prevailed (up to 70%). The increase of aromatic structural fragments in the HAs composition indicates the stabilization and conservation of SOM. The creation of a monitoring network will make it possible to identify the main trends of SOM accumulation, determine the conditions under which accumulation occurs, and calculate its contribution to climate change on the planet. [ABSTRACT FROM AUTHOR]

The genesis and fertility of soils are determined by the processes of transformation, migration and accumulation of matter, energy and information. It is proved that these processes determine the intensity of the development of podzol formation in soils, gleying, and the soddy process. It is shown that it is more profitable to grow on more cultivated soddy-podzolic soils, from an energy point of view. Winter wheat, on less cultivated - perennial grasses. On less cultivated soils, there is a greater risk of crop failure under adverse weather conditions. It is proposed to carry out an information assessment according to the multiple correlation equations. It is proved that the information-energy assessment of soils is necessary for the correct characterization of the genesis and fertility of soils. [ABSTRACT FROM AUTHOR]

This paper shows the changes in soil properties in the fourth year after the application of two kinds of environmentally burdensome wastes. One of the wastes was mineral—carboniferous rock from a coal mine, and the other one was organic—post-fermentation sludge from an agricultural biogas plant. The wastes were applied once to a soil of poor quality—a Podzol. The hypothesis to be verified was that one-time application of waste carboniferous rock and/or post-fermentation sludge to a soil has a beneficial effect on the physical status of the soil, and the changes in the soil properties have a permanent character. Also, based on the experiment results, we suggested how these types of waste should be applied to soil. For that purpose, an assessment was performed of the durability, range, and character of changes in soil properties, inter alia: soil texture (PSD), total organic carbon content (TOC), particle density (PD), bulk density (BD), total porosity (TP), air capacity (FAC), air permeability (FAP), sampling moisture (SM), field water capacity (FC), available water (AWC), unavailable water (UWC), and hydraulic conductivity (Ks). Some soil properties have been improved by the use of post-fermentation sludge and the combined application of the two wastes. These were the following soil properties: PSD, TOC, BD, TP, and SM. However, changes to the soil air-water properties (FAC, FAP, FC, AWC, UWC, and Ks) were unfavorable. The effect of the waste's application was permanent, as differences in soil properties were still visible in the fourth year after their addition. The observations made in the course of the experiment indicate that natural utilization of wastes requires a lot of consideration and should be focused on keeping the balance in the relations between the environmental functions of the soil. [ABSTRACT FROM AUTHOR]

Utilization of sewage sludge during phytoremediation of territories and its introduction as fertilizer for energy crops requires testing for phytotoxicity of the soil cover, which will allow determining an ecologically safe dose of its use and minimizing the negative impact on agroecosystems. It will also contribute to the formation of optimal productivity of agrophytocenoses as well as optimize the nutrition conditions for intensive growth and development of cultivated plants. The research conducted an analysis of the impact of the increase in phytotoxicity of sod-podzolic soil from the introduction of fresh sewage sludge and its composts with various organic materials (sawdust of coniferous trees, straw of grain crops) on the formation of biomass productivity of energy willow during a repeated cycle of cultivation. Regression and correlation analyses were used to build a mathematical model of biomass productivity under the influence of changes in the phytotoxicity of podzol soil due to repeated introduction of sewage sludge under the energy willow. The obtained regression dependences show that the formation of phytotoxicity of sod-podzolic soil is most affected by the increase in the content of Pb and Cd. However, the introduction of the norm of fresh SS within 80 t/ha did not lead to an increase in the content of these heavy metals above the maximum allowable concentrations, although it contributed to an increase in phytotoxicity to an above average level. The maximum predicted productivity, depending on the content of mobile forms of heavy metals in the soil, is about 60 t/ha at a content of Cd = 0.25; Ni = 1.1 Pb = 4.6 mg/kg soil. As the phytotoxicity of the soil increases to an above-average level (phytotoxic effect 40--46%), the intensity of biomass accumulation of energy willow slows down somewhat. In general, after a repeated cycle of using the plantation during the 4-year growing season of energy willow in all options where fertilizers were applied, the productivity of wood biomass increased significantly compared to the control option by 7.7--17.4 t/ha and with the smallest significant difference between the indicators of the research options 4.23 t/ha. [ABSTRACT FROM AUTHOR]

An experiment using leaching columns was conducted for 72 weeks to determine the impact of biochar treatment on a sandy Spodosol. Biochar treatment was found to have a positive impact on soil chemical properties. The treated topsoil had higher exchangeable K, Ca and Mg compared to the control. Due to low clay and organic matter content, much of the cations released by biochar could not be retained in that zone. This is evidenced by the increased concentration of elements in leachates collected from the leaching columns. It means that a significant portion of the nutrients, initially in insoluble form, was susceptible to leaching or podzolization. Some of the nutrients were transported downwards and subsequently retained in the spodic horizon. The biochar treatment increased soil pH, total C and the CEC of the spodic layer with the CEC increase being positively correlated with C content. Notwithstanding, the ameliorative impact of biochar treatment is at best short-term. The application of high amounts of biochar is necessary to raise soil fertility to the level suitable for crop production. Hence, it is recommended that biochar be applied in combination with some NPK fertilizers to sustain crop growth/production in the long term. [ABSTRACT FROM AUTHOR]

Purpose: The aim of the research was to study the direction, dynamics, and features of the restoration of the main ecological functions of different podzolic soils disturbed by oil pollution. Materials and methods: Soil contamination with crude oil was carried out in field experiments at two sites near St. Petersburg, Russia. Loamy soddy-podzolic soil (Umbric Albeluvisol) and sandy illuvial-ferruginous podzol (Podzol), the most common in the region, were the objects of study. Key indicators were used to investigate the dynamics of self-purification processes of oil-contaminated soils: (1) the rate of carbon dioxide emission by the soil, which quantitatively characterizes the mineralization of petroleum hydrocarbons by microorganisms, was determined by the absorption method in laboratory conditions; (2) toxicological rate of soils and water extracts from them was determined by eluate and substrate bioassay; (3) the value of aboveground biomass and the projective vegetation cover were determined by direct weighing out and visually. Content of petroleum products in soils was determined by infrared spectrometry. Results and discussion: Self-purification and self-recovery dynamics in the oil-contaminated soils differed significantly depending on the soil type. The rate and intensity of oil biodegradation in the sandy podzol due to the activity of microorganisms, as well as the rate and degree of restoration of vegetation cover, were significantly lower compared to the soddy-podzolic soil, despite the same level of oil pollution. Podzol was characterized both by a higher degree of toxicity and a lower rate of its decline compared to the soddy-podzolic soil. The soddy-podzolic soil at the maximum level of pollution restored the disturbed basic ecological functions in 4 years. In podzol, with a comparable high pollution level, by the end of the fifth year, acute toxicity remained and there was practically no vegetation. Conclusions: The factors affecting the rate of oil degradation should be associated primarily with the chemical and microbiological parameters of soils and the characteristics of the vegetation growing on them. Different levels of stability of the loamy soddy-podzolic soil and sandy podzol in conditions of oil pollution, and the peculiarities of the processes of their natural recovery, should be taken into account in environmental regulations, when determining the maximum permissible residual oil concentrations in soils, as well as in the development of effective methods for their reclamation. [ABSTRACT FROM AUTHOR]

Ants are among the soil mesofauna that cause significant bioturbation at the location of their nests. They can have significant impact on the preservation of soil features and on post-depositional artefact distribution. Moreover, there is discussion on the natural or anthropogenic nature of so-called 'pit-hearth' features dating to the Mesolithic. Such features are common in parts of the Netherlands, NW Belgium, and NW Germany, and form an important body of evidence in the study of hunter-gatherer landscape use. However, it has been hypothesized that these features represent ant nests burnt due to climate-related wildfires, instead of anthropogenic pit hearths, and are therefore of little archaeological value, other than as a potential proxy for climate conditions. Considering the lack of direct evidence on underground characteristics of ant nests, we investigated the characteristics of two wood ant nests: Oone abandoned and one accidently burnt in a wildfire c. 10 years earlier. We trenched through the ant nest remains and used micromorphology to study the characteristics of the ant-influenced soil profiles. The surface domes of the ant nests had disappeared, leaving behind a bowl-shaped depression. In the burnt ant nest, a thin band of charred litter-like organic material was all that was left over from the burned superstructure. These depressions seem not to reach deeper than the top of cemented podzol Bhs-horizons. Surrounding and underneath the depression, extensive networks of tunnels and chambers were found in the B- and C-horizons. If archaeological artefacts had been present on the site, they would have become buried and moved to the top of the B-horizon. Any soil features would have been destroyed. Moreover, the extensive tunnel and chamber network extending from the depression would potentially affect the botanical record and the OSL signal of the deposits. Comparison of our results with Mesolithic pit-hearth features shows substantial differences between the two types of remains. Ant nest depressions do not extend into (cemented) podzol B horizons, whereas Mesolithic pit hearths typically have their base in the C horizons. The extensive tunnelling in B- and C-horizons of large ant nests has not been observed in Mesolithic pit-hearth features. On the other hand, the large amount of charred humus and charcoal fragments in Mesolithic pit hearths are lacking in the burned ant nest we studied. We therefore conclude that Mesolithic pit-hearth features are not the result of the burning down of ant nests, but should be regarded as anthropogenic features. • « The domed nests of red forest ants become bowl-shaped depressions when abandoned or destroyed affecting artefact distribution and features. • They make extensive networks of galleries and chambers in podzol B- and C-horizons. • Burning of ant nests leaves very limited charred litter-like remains. • Anthropogenic Mesolithic pit-hearths have more and different types of charred organic remains. • Moreover, pit-hearths lack galleries and chambers. [ABSTRACT FROM AUTHOR]

Application of different types of feedstocks and conditions of their pyrolysis can result in different properties and sustainability of biochar during changes (aging) of its properties in soils. The aim of the studies was to assess the consequences of aging of biochar in soil for a content of adsorbed film water and a density of oxygen-containing functional groups on its surface. Sampling of soil and biochar was conducted in May and July of 2021 in a plot experiment with an applied rate of biochar of 20 t.ha−1 in 2016. WP4-T dew point potentiometer was used for measurements of relationships of potentials of adsorbed film water and its content in soil and biochar. Infrared Fourier FSM 2201/2202 spectrometer was applied for determination of densities of oxygen-containing functional groups on surface of biochar in a mid-infrared spectrum. Results showed that retention capacity of adsorbed film water by soil increased from May to July, possibly because of increasing content of hydrophilic organic compounds of plant origin. Aging of biochar in soil also resulted in an increase of retention capacity of adsorbed film water on its surface. The results of infrared Fourier spectroscopy confirmed that densities of oxygen-containing functional groups on the surface of biochar increased from May to July at spectra of wavenumbers of 1,600–1,400 cm−1 and 1,400–1,100 cm−1. [ABSTRACT FROM AUTHOR]

Albic podzols under pine forests are more prone to fires on the planet. The influence of fire extends to all soil components, including chemical properties, microbiological characteristics, and the composition and structure of soil organic matter, which persists for a long time. Here, we present the results of a study of the morphological, physicochemical, and microbiological properties and features of soil organic matter (SOM) in the albic podzols of pine forests (Pinus sylvestris L.) not exposed to fires for a long time (from 45 to 131 years). The study areas are characterized by different numbers of old fires (from four to five) that occurred over the previous several centuries in various territories of the Russian Federation such as Central Siberia (CS) and the European North (EN). In general, the albic podzols developing in CS and EN are characterized by similar morphological and physicochemical properties, with high acidity and poor mineral horizons. In terms of the lower vegetation layer and stand parameters, forest communities at the CS sites have a lower density and species diversity than those in EN. The ground cover is almost completely restored 45 years after the surface fire. The upper mineral horizon of albic podzols in EN contains higher PAHs in comparison with similar horizons of the CS sites. In the soil of EN pine forests, the MB content in the mineral horizons is, on average, three times higher than those in CS. Differences were also found in the qualitative composition of the studied soils' microbiomes. The EN soil communities are represented by a wide variety of bacteria and fungi. The presented soil parameters can be used as a reference in assessing the increasing impact of fires on pine forests and podzols. [ABSTRACT FROM AUTHOR]

The application of sewage sludge as a fertilizer in podzols soil ambiguously affects the peculiarities of the accumulation of certain chemical elements in various organs of the Jerusalem artichoke plants. Experimental factors in the study were different doses of sewage sludge from sludge maps of wastewater treatment plants and its compost with cereal straw, included together with the compensatory dose of mineral fertilizers to the norm N90P90K90 in the Jerusalem artichoke plantation. Determination of the content of chemical elements in soil and plants was carried out by X-ray fluorescence analysis. According to the results of research, it was established that the change of mineral nutrition conditions of Jerusalem artichoke causes significant changes in the chemical composition of its tubers and vegetative mass. Studies have shown a clear positive effect of increasing doses of SS on increasing the content in tubers: K - to 7.9%, Ca - to 1.9, Fe - to 1.9, in green mass: O - to 31.8%, K - to 31.6, Ca - to 24.9, Mg - to 5.9, Mn - to 0.7, Fe - to 0.4 and K - to 34.5%. The coefficients of biological absorption for most chemical elements are more than 1, but for O, Al, Si, Fe, these figures were less than 1. Regression models of phosphorus, potassium, calcium and magnesium content in the vegetative mass of Jerusalem artichoke indicate a high and moderate dependence of these indicators on their content in Jerusalem artichoke tubers and soil. [ABSTRACT FROM AUTHOR]

Agricultural development in northern polar areas has potential as a result of global warming. Such expansion requires modern soil surveys and large-scale maps. In this study, the abandoned arable experimental field founded by I.G. Eichfeld one century ago in Salekhard city (Russian Arctic), located in the polar circle, was investigated. Our aims were to assess the nutritional soil properties and their spatial variability. For spatial assessment and mapping, ordinary kriging (OK) and inverse distance-weighted (IDW) methods were employed. We found that due to long-term agriculture use, the soil cover was represented by a unique Plaggic Podzol (Turbic) that is not typical of the region. The soil was characterized by relatively low soil organic carbon (SOC) content, high acidity and a high content of plant-available forms of phosphorus in the humus-accumulative horizon. The results showed that some properties (pH H2O, pH CaCl2) were characterized by large-scale heterogeneity and showed clear spatial dependence. However, some properties (ammonium and nitrate nitrogen, basal respiration) showed a pure-nugget effect, presumably due to experimentation with fertilizer over a long period of time. [ABSTRACT FROM AUTHOR]

Iron (Fe) colloids dominate the soil solution Fe and these colloids potentially act as vectors for nutrients and contaminants in soil. The question remains which factors, that is, gradients in soil chemical characteristics with depth or physical processes, cause vertical mobilisation and immobilisation of Fe colloids in soils. This question was addressed by characterising the change in concentration, size and composition of Fe colloids in a podzol profile and by relating these changes to soil properties along the profile. Pore waters were analysed with Flow Field Flow Fractionation (FlFFF‐UV‐ICP‐MS) to overcome the artefacts typically obtained when using filtration for fractionation. Pore water was obtained by centrifugation of field moist samples taken from an Albic Podzol. The samples were taken within a depth of 110 cm, at eight depths corresponding to different horizons. The pore water Fe concentration increased with depth and peaked at 66 μM in the E horizon just above the Bh horizon, beyond which, it sharply decreased to only 9 μM. The pore water Fe concentration correlated strongly with dissolved organic carbon (DOC). The high‐resolution size fractionation analysis with FlFFF suggested that the Fe colloids (<100 nm) in the pore water not only consisted of Fe‐organic carbon (OC) complexes, but also of mineral Fe colloids associated with organic matter (OM), as indicated by the colloid size (>5 nm) and by the relatively large Fe/OC ratio that exceeds the complexation capacity of natural OM. The smallest mineral Fe colloids dominated in the Ah1 horizon, while the larger mineral colloids increased with increasing depth, explaining the rise in total Fe towards the Bh horizon. This suggests that Fe complexation with OM and stabilisation of mineral Fe colloids with OM explain colloidal Fe in the pore water. The adsorption of the OM at the top of the Bs horizons is likely the primary mechanism of DOC retention in the Bh horizon. Below this depth, the concentration of DOC was very low, resulting in low Fe concentration in the pore water. The colloids (<100 nm) are considerably smaller than the soil pore size distribution and increase in size with depth, which suggests that straining was not a significant mechanism for colloid retention. This study demonstrates that OM plays a key role in the transport of Fe colloids in acid sandy soil. Highlights: Depth profile of pore water Fe in a podzol is studied to investigate colloid migration processesPore water colloids are characterised by Flow Field Flow FractionationFe colloids consist of complexes with OM and mainly larger mineral colloidsNatural OM plays a key role in the transport of Fe colloids in acid sandy soil [ABSTRACT FROM AUTHOR]

This study determined the rate of decomposition of fine roots and leaf litter from birch, larch, and pine, and compared the impact of fine root decomposition and leaf litter on carbon, nitrogen, and phosphorus accumulation in various regenerated and reconstructed forest ecosystems. The control plots were located on podzol soils in managed forest non-degraded habitats. Over a one-year experimental season, the decomposition of birch and larch fine roots released less carbon in comparison to leaf litter. The carbon mass-loss rates were 16% for birch roots and 15% for larch roots, while for birch and larch litter, the rates were 36% and 27%, respectively. For nitrogen, mass-loss rates were 48% for birch fine roots and 60% for larch and pine fine roots, whereas for pine and birch litter the rates were 14%, and 33% for larch litter. The results of our study prove the important role of fine root input to the soil's carbon, nitrogen, and phosphorus pool and additionally their significance for CO2 sequestration within the studied regenerated terrestrial ecosystems. [ABSTRACT FROM AUTHOR]

Soil organic matter largely controls the ecosystem functions of soil and is a source of energy and a nutrient substrate for the soil microbial community as well. The postagrogenic dynamics of organic matter stock (content of organic carbon, Corg; total nitrogen, Ntot; and their ratio, C/N), basic soil properties, and indicators of soil microbial and enzyme activities are analyzed for the chronosequence of Retic Albic Podzol (southern taiga zone, Kostroma oblast, Russia). Different plots of the chronosequence have been withdrawn from agricultural use 11, 16, and 40 years ago. The stratification ratios (SRs) 0–5 : 5–10, 0–10 : 10–20, and 0–10 : 20–30 cm layers for Corg and Ntot contents are also estimated. A statistically significant increase in the contents of Corg and Ntot during the postagrogenic succession is observed in the topsoil layer of the old arable horizon (0–5 and 5–10 cm) as well as an increase in the stratification of their distribution, especially after a closed tree canopy has developed on the former arable land. Postagrogenic succession promotes an increase in the soil basal respiration rate and the content of microbial biomass, the maximum values of which are most often recordable in the soil under a 40-year-old secondary small-leaved forest. During the natural reforestation of the former arable lands, a statistically significant increase in the phosphatase activity is observed within the entire old arable horizon. The peaks of oxidoreductase activity correspond to the stages of succession with the maximum uptake of easily decomposable plant litter. Over the 40 years of postagrogenic succession, all analyzed parameters (except for pHKCl) have increased in a statistically significant manner at all considered depths of the old arable layer, with the highest annual increase in 0–5-cm layer, most enriched for organic matter. [ABSTRACT FROM AUTHOR]

To examine the role of soil properties in influencing tropical fungal communities, soils were collected from Barito Ulu in central Borneo across an edaphic gradient ranging from clay-rich ultisols to sandy spodosols and from the upper and lower horizons and were subjected to high-throughput Illumina sequencing of the ITS1 region. The fungal community was clearly distinct between contrasting soils and depths, but the diversity metrics did not show significant differences. Differentiation by depth was more marked as the soils became less fertile. There were few marked impacts on fungal phyla or functional guilds at a broad level, but Ascomycota were more abundant in less acidic soils with a narrower C:N ratio. The forests of South-east Asia remain an underexplored frontier for fungal diversity studies. [ABSTRACT FROM AUTHOR]

In the long-term after atmospheric deposit onto a forest ecosystem, Cs-137 becomes incorporated into the biogeochemical cycle of stable elements and progressively reaches a quasi-equilibrium state. This study aimed at determining to what extent Cs-137 activity distribution in tree vegetation could be predicted from that of stable caesium (Cs-133) and potassium (K), which are known to be stable chemical analogues and competitors for Cs-137 intake in tree organs. Field campaigns that focused on beech trees (Fagus sylvatica L.) were conducted in 2021 in three French forest stands with contrasted characteristics regarding either the contribution of global vs. Chornobyl fallouts, soil or climatic conditions. Decades after Cs-137 fallouts, it was found that more than 80% of the total radioactive inventory in the system remained confined in the top 20 cm mineral layers, while organic layers and beech vegetation (including roots) contributed each to less than 1.5%. The enhanced downward migration of Cs-137 in cambisol than podzol forest sites was presumably due to migration of clay particles and bioturbation. The distribution of Cs-137 and Cs-133 inventories in beech trees was very similar among sites but differed from that of K due a higher accumulation of Cs isotopes in roots (40–50% vs. < 25% for K). The aggregated transfer factor (Tag) of Cs-137 calculated for aerial beech organs were all lower than those reported in literature more than 20 years ago, this suggesting a decrease of bioavailability in soil due to ageing processes. Regarding their variability, Tag s were generally lower by a factor 5 at the cambisol site, which was fairly well explained by a much higher value of RIP (radiocesium immobilisation potential). Cs-137 concentrations in trees organs normalized by the soil exchangeable fractions were linearly correlated to those of Cs-133 and the best fit was found for the linear regression model without intercept indicating that no more contribution of the foliar uptake could be observed on long term. Provided that the vertical distribution of caesium concentrations and fine root density are properly measured or estimated, Cs-133 was shown to be a much better proxy than K to estimate the root transfer of Cs-137. • Beech trees contributed to less than 1.5% of the total Cs-137 inventory. • The signature of Cs-137 foliar uptake could not be observed anymore in the long term. • Root uptake of Cs-137 was much higher at podzol than cambisol sites. • Partitioning of both Cs inventories among tree organs differed from that of K. • Cs-133 was shown a better proxy than K to assess root uptake of Cs-137. [ABSTRACT FROM AUTHOR]

The establishment of a network of monitoring sites (term in Russian—«carbon polygons») for monitoring climatic processes as well as the emission and deposition of carbon compounds in various ecosystems is one of the priority tasks in the field of climate and biosphere conservation in the world. This paper presents the results of the study of the soil sections of the «Ladoga» carbon monitoring site. Folic Podzol (Arenic) and Fibric Histosol were considered. These soils are widely represented in the southern taiga subzone and can be used as benchmark monitoring soil sections. As a result of the analysis of chemical parameters, it was revealed that Fibric Histosol and Folic Podzol (Arenic) are characterized by an acidic reaction of pH, pronounced podsolization, and peat accumulation. Fibric Histosol stores a significant amount of soil organic matter (SOM) up to 42.95 kgC/m2. In the analysis of the molecular composition of humic acids (HAs) extracted from the studied soils, it was found that HAs from Fibric Histosol were characterized by a relatively high content of aromatic structural fragments (27–41%), while in Folic Podzol (Arenic), aliphatic structural fragments prevailed (up to 70%). The increase of aromatic structural fragments in the HAs composition indicates the stabilization and conservation of SOM. The creation of a monitoring network will make it possible to identify the main trends of SOM accumulation, determine the conditions under which accumulation occurs, and calculate its contribution to climate change on the planet.

Current levels of pollution of the main environmental media (atmospheric precipitation, soils, and leaves of seven plant species) were compared on the basis of data of the complex monitoring in the immediate vicinity of one of the largest emission sources of SO2 and heavy metals in Northern Europe. Despite the recent significant decrease in emissions, the environmental pollution near their source in 2001–2011 remained extremely high. The background level was exceeded for SO2 in the air (hundreds of times), as well as for Ni and Cu in snow (thousands to tens of thousands of times), in the upper organic horizon of Podzols (hundreds to thousands of times), and in plant leaves (tens to hundreds of times). Though the input of Zn and Mn with snow is increased, their concentrations in soil remain close to the background, and plants suffer from acute deficit of these important microelements. The immediate vicinity of the copper-nickel industrial complex represents that rare case of anthropogenic impact, when its intensity and duration are accompanied by a strong damage to vegetation, even to its complete destruction. This, in turn, results in a combination of additional indirect adverse environmental factors: disturbance of the water regime of ecosystems and landscapes, changes in the microclimate, soil degradation (deterioration of soil properties and morphology), and quantitative and qualitative changes of biological cycling of elements. [ABSTRACT FROM AUTHOR]

The properties of a sandy Ferric Podzol over fluvioglacial deposits and the root mass of its 0–20 cm layer with Pinus sylvestris L. fine roots (≤3 mm in diameter) have been studied in a mid-taiga cowberry-type pine stand. Keeping in mind the structure of the phytogenic field of a tree, the study is subdivided into trunk, crown, and gap zones. The root mass of the forest floor and the mineral horizons are found to change in different directions in the these zones. In the forest floor, the trunk zone is more saturated with roots than the gap zone, while the trend in the soil mineral layer was the reverse. The highest root biomass is associated with sites that are the richest in soil nutrients and organic matter (NPKC). The cellulolytic activity and ecophysiological parameters of the microbiota vary in the studied horizons. Cellulolytic activity in the forest floor is the highest near tree trunks, while the spatial variation of this parameter in the mineral body of the soil is less pronounced. A correlation is detected between the contribution of root respiration to total СО2 emissions from the soil surface and the biomass of fine roots (≤3 mm) in the 0–20 cm soil layer. The effect of the soil thermal regime on root mass in different zones of the phytogenic field is studied. Soil temperature variation due to the redistribution of solar energy by the canopy results in a higher root mass in areas receiving more heat. The zone with better heated soils is the canopy gaps. The effect of the temperature of the root mass of the soil is more explicit in the mineral layer. The results of this study can be used in environmental monitoring and in predictive assessments of the effects of climate change on boreal forest ecosystems. [ABSTRACT FROM AUTHOR]

Being a macronutrient, phosphorus (P) is the backbone to complete the growth cycle of plants. However, because of low mobility and high fixation, P becomes the least available nutrient in podzolic soils; hence, enhancing phosphorus use efficiency (PUE) can play an important role in different cropping systems/crop production practices to meet ever-increasing demands in food, fiber, and fuel. Additionally, the rapidly decreasing mineral phosphate rocks/stocks forced to explore alternative resources and methods to enhance PUE either through improved seed P reserves and their remobilization, P acquisition efficiency (PAE), or plant's internal P utilization efficiency (IPUE) or both for sustainable P management strategies. The objective of this review article is to explore and document important domains to enhance PUE in crop plants grown on Podzol in a boreal agroecosystem. We have discussed P availabilities in podzolic soils, root architecture and morphology, root exudates, phosphate transporters and their role in P uptake, different contributors to enhance PAE and IPUE, and strategies to improve plant PUE in crops grown on podzolic soils deficient in P and acidic in nature. [ABSTRACT FROM AUTHOR]

Being a macronutrient, phosphorus (P) is the backbone to complete the growth cycle of plants. However, because of low mobility and high fixation, P becomes the least available nutrient in podzolic soils; hence, enhancing phosphorus use efficiency (PUE) can play an important role in different cropping systems/crop production practices to meet ever-increasing demands in food, fiber, and fuel. Additionally, the rapidly decreasing mineral phosphate rocks/stocks forced to explore alternative resources and methods to enhance PUE either through improved seed P reserves and their remobilization, P acquisition efficiency (PAE), or plant's internal P utilization efficiency (IPUE) or both for sustainable P management strategies. The objective of this review article is to explore and document important domains to enhance PUE in crop plants grown on Podzol in a boreal agroecosystem. We have discussed P availabilities in podzolic soils, root architecture and morphology, root exudates, phosphate transporters and their role in P uptake, different contributors to enhance PAE and IPUE, and strategies to improve plant PUE in crops grown on podzolic soils deficient in P and acidic in nature.

Mixing tree species is a forest management strategy put forward to increase and stabilize primary productivity. Yet, little is known about soil organic carbon (SOC) storage in mixed species forests, particularly under water shortage. In this study, we used a tree diversity experiment in southwestern France to assess the interactive effects of water availability (via irrigation) and mixing tree species (monocultures of pine (Pinus pinaster) and birch (Betula pendula) versus mixed plots of pine‐birch and pine‐birch‐oak (Quercus robur)) on SOC stocks in the forest floor and across five mineral soil layers (0–5, 5–15, 15–30, 30–60 and 60–90 cm deep). We found that SOC stocks were negatively affected by irrigation in the forest floor due to an increase in decomposition rates. However, SOC stocks were positively influenced by both the mixing of tree species and irrigation in the mineral soil, particularly at the 15–30‐cm soil depth. This is because root niche partitioning in mixed plots and an increase in tree biomass in irrigated plots may have resulted in greater organic matter inputs through rhizodeposition and the incorporation of microbially‐derived compounds. These preliminary results indicate that SOC dynamics and its response to biotic and abiotic factors are strongly dependent on soil depth. Our data further highlight that the positive effect of mixing trees on SOC stocks was higher in irrigated plots, thereby contradicting the idea that tree mixture effects are expected to be greater when environmental conditions are harsher. We conclude that mixing tree species can increase SOC stocks in the short term in temperate forests, even if the exact mechanisms remain to be identified. Highlights: Effects of mixing trees and increasing water availability on SOC are depth dependent.Increase in SOC stocks occurred mainly at the mid‐soil depth (15–30 cm).Effects of tree mixture on SOC were greater when soil water availability was high. [ABSTRACT FROM AUTHOR]

Hydrophilic-hydrophobic properties of organic matter and the content and distribution of water-soluble organic matter (WSOM) in soils of the Subpolar Urals are discussed. It is shown that the type of predominant vegetation in the system of altitudinal zones controls the amount and nature of soil organic matter (SOM). The litter of moss–lichen vegetation of the alpine tundra is enriched in hydrophobic compounds (up to 24.0%). In the grass communities of the subalpine zone, hydrophilic fractions of the SOM predominate (first fraction, 42.4–77.0%; second fraction, 0.3–12.6%). Woody vegetation of the mountainous forest zone is specified by an increased content of hydrophobic lignin-containing fractions (16.4–34.8%). Permafrost-affected soils of the alpine tundra are characterized by an increased hydromorphism leading to the accumulation of compounds associated with Fe and Al (up to 75.4%) in mineral horizons. The calculation of the WSOM carbon stock indicates that it reaches 0.3 to 9% of the total carbon stock in the soil profiles. [ABSTRACT FROM AUTHOR]

Long-term monitoring of forest soils is necessary to understand the effects of continued environmental change, including climate change, atmospheric deposition of metals, and, in many regions, recovery from acidic precipitation. A monitoring program was initiated in 2002 at five protected forest sites, primarily Spodosol soils, in Vermont, northeastern USA. Every 5 years, ten soil pits were sampled from random subplots in a 50 × 50-m plot at each site. Samples were taken by genetic horizon and, to reduce variability and improve comparability, from four specific layers: the combined Oi/Oe layer, the combined Oa/A layer, the top 10 cm of the B horizon, and 60–70 cm below the soil surface (usually the C horizon). The samples were archived and a subset analyzed for carbon, nitrogen, and exchangeable cations. After four sampling campaigns, the average coefficients of variation (CVs) at each site had a broad range, 10.7% for carbon in the Oa/A horizon to 84.3% for exchangeable Ca2+ in the B horizon. An investigation of variability within the upper 10 cm of the B horizon across a 90-cm soil pit face showed similar CVs to the entire site, emphasizing the need for consistent and careful sampling. After 15 years, temporal trends were significant in the Oa/A and B horizons at two of the five sites, with one site showing an increase in carbon concentration in both layers along with increases in both exchangeable Ca2+ and Al3+ in the B horizon, perhaps linked to recovery from acidification. The monitoring program plans to continue at 5-year intervals for the next century. [ABSTRACT FROM AUTHOR]

The post-anthropogenic and soil cover transformations of former agricultural soils on the abandoned lands in the Russian Arctic territory are poorly investigated due to the active growth of the city complexes and increasing area occupied by agricultural lands. That is lead to an increase in the area of the arable lands surrounding the polar urbanized territories. Today, most of that land allocated for agricultural needs has been abandoned or affected by other types of land use. This study aimed to investigate the abandoned lands surrounding some of the settlements in the central part of the Yamal region. The soil diversity, morphology, and chemical and agrochemical properties were investigated with special reference to the specific transformations that occur to fallow lands under permafrost-affected cryogenic-ecosystem conditions. Analysis of data show that these soils are characterized by features relating to both, previous (and existing), anthropogenic impacts and natural processes such as cryogenic mass transfer. The degradation of the arable humus-enriched horizon was not as pronounced as it has been in more humid boreal environments over recent decades. The organic carbon content in topsoil depends on the land use and varied considerably among the soil types. The former arable topsoil horizon has been stable over time in terms of its morphological features and agrochemical state. Despite the high soil acidity levels, thenutrient content in the anthropogenically impacted soils was still high, even though being abandoned for 20 years.

Improvement of carbon sequestration in soils for a more sustainable environment and prevention of climate change require not only knowledge about soil organic carbon (SOC) stocks, but also about interactions between land use and total amount and distribution of carbon. In North Germany (state: Schleswig-Holstein) about 925 soil profiles in the four dominant geological regions [Weichselian glacial region, the sandy outwash region (Lower ―Geest), the Saalian glacial region Higher ―Geest), and the marshland with alluvial deposits] were sampled down to at least the 90 cm depth. Carbon content, pH, bulk density, and grain size distribution were analyzed for the major characteristic soil horizons. The four dominant geological regions possess different SOC stocks as well as SOC contents. The total amount of SOC stored within the representative soil profiles down to the 90 cm depth was analyzed for three depths: 0 – 30, 30 – 60, 60 – 90 cm; for the total area of Schleswig Holstein (15.369 km²), they summed to 244 Mt. SOC stocks, however, differed depending on the land use management system and clay content. Arable soils were most sensitive to soil deformation and the higher the clay content the less rigid they were, if the SOC to clay ratio were used as an index for structural quality. Grassland topsoils showed the highest SOC stocks and a mediate structural quality. The latter was highest for forest soils, which, however, had a higher SOC content but, at the same time, a less fertile SOC composition (litter with high C: N ratio). Further research on the carbon composition (labile, active, intermediate, or passive pools) would help to get a better insight into the role of SOC on soil strength and soil functions.

The Balkan Peninsula is the southernmost border of podzol distribution in the northern hemisphere. So far, podzols have been recorded and studied at three sites in Serbia, including Mt. Golija, Mt. Goe and Mt. Jablanik, and this paper reveals the results of a pedological and phytocoenological study conducted at a new site on Mt. Jelova Gora. Podzols are most often formed in coniferous forests, while they less frequently occur in deciduous forests, like on Mt. Jelova Gora. In the investigated area, podzols were found in the montane achidophilous beech forest with blueberry (Vaccinio-Fagetum moesiacae montanum Fuk. 1969) and the montane beech forest with holly (llici-Fagetum montanum Gajic 1979), in which they had not been recorded before. The parent rock (quartz conglomerate) plays a key role in the formation of podzols on Mt. Jelova Gora, together with the occurence of blueberry (Vaccinium myrtillus L.), which slows down the transformation of organic waste, is a producer of raw humus, and thus an indicator of acid reaction soils. Finally, it should be pointed out that podzol is a very rare soil type, which is highly interesting for the relevant scientific and professional circles in Serbia and the entire Balkan Peninsula. [ABSTRACT FROM AUTHOR]

Podzols are characterised by mobilisation of metals, particularly Al and Fe, and dissolved organic matter (DOM) in topsoil horizons, and by immobilisation in subsoil horizons. We mimicked element mobilisation during early podzolisation by irrigating the AE horizon of a Dystric Arenosol with acetic acid at different flow velocities and applying flow interruptions to study rate-limited release in experiments with soil cylinders. We used eluates in batch experiments with goethite and Al-saturated montmorillonite to investigate DOM reactivity towards minerals. Both the flow velocity and flow interruptions affected element release, pointing to chemical non-equilibrium of release and to particles, containing Fe and OM mobilised at larger flow velocity, characteristic of heavy rain or snowmelt. Based on chemical extractions, the source of mobilised Al and Fe, the vast majority of which was complexed by DOM, was no oxide phase, but rather organic. Rate limitation also affected the composition of DOM released. Carboxyl and phenolic species were the most important species adsorbed by both minerals. However, DOM composition affected the extent of DOM adsorption on goethite more distinctly than that on montmorillonite. Our findings evidence that the intensity of soil percolation affects quantitative and qualitative element release during early podzolisation and adsorptive DOM retention in subsoil horizons. [ABSTRACT FROM AUTHOR]