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Very different soil types occur across a few tens of meters on dolostone, in a never glaciated karst landscape in the Lombard Pre-Alps (Selvino, Italy). This substrate is locally enriched in well-crystallized sand-grained quartz. The quartz content is responsible for the localized genesis of Podzols. Other soil types observed in the area include strongly rubified (Terra Rossa) horizons (paleosols), preserved in the most protected dolostone cracks. Non-rubified Luvisols and Cambisols were observed in karst dry valleys and dolines while Rendzic Leptosols/ Phaeozems were common on the steepest slopes. Such a variety of soils was explained assuming different parent materials (dolostone, silica-rich dolostone, with different amounts of aeolian inputs, ascertained using textural properties, mineralogy, micromorphology, total element composition, mass balance calculations, rare earth elements, and stable elements. Many soils were highly polycyclic, with different layers associated to different parent materials and characterized by different pedogenic processes evidencing different ages. We were thus able to distinguish the horizons mainly developed from the dissolution of the dolostone from those formed in Pleistocene loess. The geochemistry of all surface soil horizons, including Podzols and Rendzic Leptosols/ Phaeozems, apparently formed from pure or quartz-rich dolostone dissolution, has been influenced by recent aeolian additions (likely Saharan dust), with deeply modified effects according to different pedogenetic processes acting locally. Saharan dust, in fact, significantly increased metal and rare earth elements contents compared to the substrate, also in the youngest and least weathered soil types.

In tropical coastal forest ecosystems, human activities spread rapidly. It is, therefore, necessary to define soil quality. For this, the determination of the natural content of trace metals is an essential step. This study aims to understand the distribution of trace metals in the main soils of tropical coastal rainforest ecosystems: Ferralsols, Acrisols, and Podzols, in Bahia state, Brazil. After morphological, chemical, and physical characterization and classification of the soils, the concentration of trace metals was investigated both in soil profiles and in surface composite samples (national guideline recommendation), in five locations for each soil class. The soils were classified as Geric Ferralsol, Haplic Acrisol, Chromic Acrisol, and Ortsteinic Carbic Albic Endogleyic Podzol. Concentrations of metals differed significantly between soil classes. Even under tropical rainforest climate during soil formation, the parent rock material still influences geochemistry. Al, Fe, Mo, Ni, V, and Zn accumulate in Ferralsols, while Ba, Co, Cr, Cu, and Mn accumulate in Acrisols. In the Podzols, metals highly accumulate in B spodic horizon. The data highlights that composite sampling strictly based on soil layers and not horizons (as the national guideline recommends) can cause significant misinterpretations. Instead, the multivariate regression models provided consistent data, accurately predicting the pseudo-total concentrations of trace metals in individual soil samples. The regression method is fast and low cost and provides a reliable geochemical baseline for the definition of reference values.

Soil micromorphology is an excellent tool for relating quantitative laboratory data to soil development in complex pedogenic settings. This study utilizes micromorphology, scanning electron microscopy, bulk soil geochemistry, clay mineralogy, and particle-size analysis to reconstruct the depositional and pedogenic history of the Serpentine Hot Springs fluted point site on the Seward Peninsula, Alaska. Sediment deposition occurred via colluviation, which dominated during the late glacial period and early- to middle-Holocene, and aeolian processes, which dominated during the Younger Dryas (YD) and late Holocene. Two buried soils are present: one dating to the Holocene Thermal Maximum (HTM) and the other dating just before the Neoglacial period. Pedofeatures fall into four categories: 1) cryogenic features; 2) clay illuviation features; 3) podzolization/redox features; and 4) anthropogenic features. The spatial relationships among these features provides insight into the pedogenic history of the soil. The HTM soil is characterized by clay illuviation, suggesting warm, mildly acidic, well-drained soil conditions. The pre-Neoglacial soil is characterized by incipient placic horizon development and podzolization, indicative of moist, acidic, variably drained conditions. Cryogenic features associated with late Holocene Neoglaciation dominate the modern soil. Despite cryogenic activity and the presence of permafrost, the cultural stratigraphy of the site remains intact.

In the Laarder Wasmeren area in the western Netherlands, Late Pleistocene cover sands and overlying early Holocene drift sands show various paleosols, which can be characterized as more or less incipient podzols. We dated those soils and sands by radiocarbon analysis and OSL, and we used biostratigraphical dating based on the known chronology of the vegetation history. Apart from Usselo soils of Allerod age, we found early Holocene soils - showing Usselo soil characteristics but with relatively advanced podzolisation - covered by Early Holocene-early Middle Holocene drift sands. We discuss their age and origin, and reflect on the role of fires and ecosystem degradation in the early development of heathland, podzols and drift sands in the Netherlands, prior to any Neolithic farming. We hypothesize about the possible role of Mesolithic man, stimulating habitats for Corylus avellana by burning pine forest, in the longer term inducing the observed ecosystem degradation (transformation of forest into open short vegetation, acidification and concurrent podzolisation, wind erosion). This hypothesis is in line with studies in adjacent NW-European countries, which are reviewed, and an alternative for the theory of Vera (2000), who assumed that open forests and short vegetation resulted from grazing pressure by large herbivores.

Although many published studies have evaluated soil organic carbon (SOC) stocks in forest soils, none have yet focused on primary (i.e., unlogged) spruce (Picea spp.) forests on volcanic rocks. Previous research in the Calimani volcanic mountain range, Romania, revealed a close relationship between soil morphology and the canopy disturbance history of a primary spruce (Picea abies L. Karst.) forest in the area. Here, six representative soil profiles were chosen from a large pedological study to test the hypothesis that the different disturbance regimes of the study plots had significant effects on SOC stocks. We used a combination of traditional soil core and excavation methods, modified for soil sampling and SOC stock estimations by horizons. In addition, chemical soil properties such as pH and the contents of Al, Fe, and Si in selected extracts (oxalate-extracted Alo, Feo, and Sio, pyrophosphate-extracted Alp and Fep) were determined to detect diagnostic properties of the soils. Total SOC stocks in the organic horizons plus mineral soil to the 0.5 m depth ranged from 18.2 to 32.0 kg C m−2. In the 0–0.5 m depth, the SOC stocks were significantly positively correlated with the severity of the maximum-recorded canopy disturbance. The SOC contents in mineral soil down to the 1.0 m depth were positively correlated with the contents of Alp + Fep, especially in the subsoil horizons. A strong positive correlation was found between pHKCl, Sio contents, Alp − Alo contents, and the Alo/Feo ratio. The soils were classified as Podzols and Andosols. Our results indicate that in primary spruce-dominated forests on volcanic rocks, the regime of high-severity natural canopy disturbances may have positive effects on SOC accumulation in the mineral soil. The Alo/Feo ratio may be a potentially useful proxy for the relative degree of leaching and podzolization in these soils.

Post-disturbance pedogenetic pathways were characterized in three landscapes representing different degrees of weathering and leaching. Tree uprooting has been the main form of disturbance in all three landscapes. We hypothesized that the pedogenetic effect of trees due to uprooting is mainly governed by the regional degree of pedogenesis, which in turn affects soil and landscape evolution. The three regions were characterized by a chronosequence of treethrow pit-mound pairs, from fresh to almost leveled forms. Two sequences originated from the Czech Republic, one on Haplic Cambisols and one on Entic Podzols. The third and the oldest chronosequence, in Michigan, USA, was on Albic Podzols (dating back to 4080 BCE). We analyzed 38 chemical and physical soil properties for 700 samples from 42 pit-mound pairs in these regions. Ordination and regression techniques allowed us to evaluate the effect of sample depth, microsite (pit, mound, and undisturbed control position), and age of the soils formed after uprooting. Depth was the most significant variable in all regions (p

Morphology of podzol profiles can be used to improve our understanding of soil formation and degradation processes. The morphology of a podzol chronosequence was studied for a 1800 m long cliff perpendicular to the coastline at the southern coast of the Island Ilha Comprida (Sao Paulo, Brazil). The large variation in hydrological conditions with time (surfaces with ages from 6000 to 300 yrs BP) and space (topography) allowed studying the relation between podzol morphology and drainage conditions, both during soil formation and degradation. On the oldest two surfaces, the podzols formed under poorly drained circumstances. Uplift during their formation resulted in (1) very deep Bh horizons and (2) degradation of the upper B horizon as a result of improved drainage. On the younger surface most podzols were poorly drained, but well-drained podzols and transitions occurred in beach ridges. In the cliffs on the southern coast of the island, improved drainage of the poorly drained podzols resulted in degradation of the B horizon. This degradation exhibits various forms, including (1) complete removal of the B horizon down to an underlying clay layer, (2) degradation of the B horizon along root channels with preferential vertical water transport, (3) degradation of the upper B horizon resulting in a diffuse EB transition, and (4) areas of organic matter (OM) depletion related to microbial activity, sometimes combined with burrowing. Type (2) degradation may result in a convoluted EB transition, the formation of islands of B horizon in the deepening E horizon, and formation of E horizon tongues into the Bh. Recent (post degradation) OM bands were found in E and B horizons. A thorough study of podzol morphology can be used to reconstruct several stages of their formation and degradation in relation to drainage conditions.

Podzols developed on glacial and periglacial features provide the opportunity to reconstruct permafrost past limits and related paleoclimatic variations using micromorphological analysis. Analyzing 10 thin sections on 8 soils classified as Podzol in two study areas in the Central Italian Alps (Stelvio Pass area and Val Cantone area), we have been able to find different microstructures or pedofeatures (i.e., granular, platy, subangular blocky microstructures, silt cappings on coarse mineral grains) induced by processes related to permafrost conditions like gelifluction and ice lenses segregation. The type and the frequency of these micropedological traits allowed us to determine the lowest limit of past permafrost at 2228 m a.s.l. in Stelvio Pass area and 2347 m a.s.l. in Val Cantone area, respectively ca. 400 m and 330 m lower than today. Moreover, the analysis of paleoprecipitation and paleotemperature derived from various proxy data and the age of soil pedogenesis allowed us to identify four different phases of podzolization dated to: 13.5–11.5 ka (I phase), 11–9.7 ka (II phase), 9.3–8 ka (III phase), and 7.7–7.3 ka (IV phase). Reconstructed paleoprecipitation and paleotemperature of the four phases of podzolization also allowed us to determine that in Val Cantone there were two different permafrost aggradation periods that were synchronous to podzolization while in Stelvio Pass area one additional permafrost aggradation period that occurred at 7.7–7.3 ka.

Although eluvial (E) horizons of podzols typically form on sandy soils, they can also form in acidic clayey soils. Two non-exclusive hypotheses for E-horizon formation in clayey soils are podzolization and the reductive dissolution of iron (Fe). To analyze the effects of redox reactions on Fe solubilization in montane soils in regions with heavy snowfall, we measured the redox potential (Eh), pH, and Fe2+ concentration in soil solutions sampled from the Midagahara peatland of Mt. Tateyama and Mt. Naeba. We also conducted continual in situ Eh monitoring of soils under snow cover in a beech forest on Mt. Naeba. In the Midagahara peatland, Eh decreased with increasing clay content and was lowest in E horizons. A mineral stability diagram of the soil solution data, in which (pH + 3pe) was expressed as a function of log [Fe2+], suggests that ferrihydrite dissolution from the E horizons and precipitation of the other Fe oxides (lepidocrocite or goethite) in the B horizons are ongoing processes. A combination of low pH and reducing conditions in clayey soils can increase the loss of Fe oxides to form impermeable E horizons. Continual monitoring of Eh in the soil of Mt. Naeba revealed a sharp drop in Eh under heavy snow cover during winter. The reducing conditions in winter, along with consistently low pH, are favorable for the formation of E horizons in clayey soils, which lead to poor drainage and summer flooding. The combination of clayey E horizons and flooding with snowmelt are required for peat accumulation in the Midagahara peatland.

Over recent decades, andic soils have been increasingly found in non-volcanic mountain ecosystems (NVME) in many parts of the world. In Italy, this type of soil has proved to be greatly affected by aeolian deposits and to be widely distributed geographically. However, there are still many open questions, especially regarding the genesis of these soils. This paper focuses on five representative pedons taken from NVME. Soil forming processes and relationships between soil and underlying bedrock were investigated by using an integrated approach including geochemical, magnetic, mineralogical, micromorphological and particle size distribution (PSD) analysis. The 5 pedons showed andic character and similar morphology and micromorphology (e.g. silt illuviation, pedorelicts), as well as large differences in terms of soil reaction and clay mineralogy. The analysis of the vertical distribution of C, Al and Fe extracted in pyrophosphate along with related geochemical indices (e.g. C p /Al p ) enabled us to indicate andosolization as the main process of soil formation and to exclude podzolization. With respect to the soil-bedrock relationship, 2 soils showed great similarity to the underlying bedrock along with a clear aeolian particle size distribution footprint, whereas, in the remaining 3 soils, there was a clear soil-bedrock discontinuity and an evident volcanic fingerprint. Some of the soil-bedrock differences related to the geographical settings and latitude.

Soil surveys for improving carbon (C) stock estimates frequently involve soil sampling by pre-determined regular depth-intervals, in order to enable more convenient computation of soil organic carbon (SOC) stocks. As a result, soil horizons are often neglected in these surveys, although they represent distinct components of the soil profile. When soil-horizon depths and thicknesses vary considerably within the same site, soil sampling by horizon with accompanying depth measurements may be more suitable. The main objective in this study was to investigate the potential differences in current SOC stocks in different afforested mineral soils, with varying horizon depths and thicknesses, and that were sampled by soil horizon, by using the trapezoidal SOC stock computing approach, and comparing it to the spline approach. An adaptation of the trapezoidal rule computation approach, enabling relatively simple crude estimations of the fixed depth-interval SOC stocks from horizon data, was developed. Estimations of SOC stocks for 18 sites located on three different afforested mineral soils (Gleys, Podzols and Cambisols, aged ≥ 20 years) were done for 0–30 cm, 30–60 cm and 0–60 cm fixed depth-intervals, excluding surface organic layers. The results indicate that the trapezoidal approach is likely to provide cruder estimates of SOC stocks than the spline approach, although no statistically significant differences were observed between the fixed depth-interval SOC stocks (for 0–30 cm and 30–60 cm) when computed by the two methods. Both methods showed a significant effect of horizon and soil group on SOC stocks. The soil below the 30 cm depth was estimated to store over 22% of the total SOC stocks to 60 cm depth. Gleys showed significantly greater mineral SOC stocks than Podzols, with differences mainly evident in the upper 30 cm, which was observed regardless of the computing methodology used (trapezoidal or spline). The adapted trapezoidal rule computing approach is hoped to facilitate the use of soil-horizon sampling in studies on SOC stocks.

Up till now, the effect of topography on soils has usually been studied in mountainous areas, and any reference to relatively small-scale lowland landforms such as inland dunes has not been thus far recognized in any great detail. We investigated the effect of land relief on morphology and the properties of soils in a comparative study covering two ecosystem types (a production forest and a naturally revegetated deforested area) at the Torun artillery training ground, which is situated in Northern Poland. The objectives of this study were to: 1) compare the morphology and properties of soils with regard to topography on inland dunes at the Torun military area and to 2) show the modifying impact of deforestation on the effect of land relief on dune soils. In each investigated ecosystem variant, the pedological studies were conducted in two representative catenas; each of them was formed by soils situated in three topographical positions (north-facing slope, south-facing slope, and intra-dune depression). To indicate how the investigated pedons are ordered by soil properties, we applied the principal component analysis (PCA) in the research. Our study showed that regardless of ecosystem type, pedons taken from depressions clearly differed from soils located on both slope aspects, as the soils taken from lower areas form “hot spots” of distinctly higher moisture and fertility in landscapes which are normally dry and poor in nutrients, which is typical of inland dunes. Soils from north-facing slopes, in comparison to soils from south-facing slopes, were characterized by lower temperatures and pH values, higher moisture and stocks of nutrients in O horizons, as well as being more podzolized. However, in the mineral soil layer of 0–100 cm stocks of nutrients were higher in soils from south-facing slopes, which was explained by their lower leaching intensity by acid solutions. The magnitude of the impact of deforestation on the properties of dune soils was found to be strictly related to position in relief. In general, deforestation caused an increase of the differences between soils of the three topographical positions studied; however, this primarily resulted from the strongest influence of forest removal stated for south-facing slopes, while soils located both on north-facing slopes and in depressions were relatively unchanged by deforestation. The topographically-induced differentiation of soils on inland dunes shown in this study can be applied by practices (e.g. foresters, restoration ecologists) in activities to increase the biodiversity of inland dune ecosystems as well as in land restoration (e.g. in dune fixation by vegetation).

The overall impact of individual environmental factors on the content of soil organic carbon (SOC) is well known, but the simultaneous impacts of natural and anthropogenic factors on the amount and diversity of SOC pools in mountain areas are still insufficiently recognized. This study has three objectives: (1) to determine SOC pools in the mountain toposequence in relation to the climate-elevation gradient and vertical vegetation zonality, largely as a result of interference caused by human activity; (2) to predict the fluctuations of SOC pools in mountain soils affected by changes in land use/forest management and expected climate warming; and (3) to verify whether the humus form is a predictor of SOC pools in mountain soil. A spatial, climate-/altitude-dependent trend of SOC pools is clearly marked on the northern slopes of the Karkonosze Mountains, SW Poland. These SOC pools gradually increase up to the altitude of ca. 1000 m a.s.l. and then decrease in the uppermost forest and subalpine zones. The SOC pools are also strongly related to land use/vegetation (arable soils

There are various hypotheses on the relative importance of the individual soil-forming factors of Jenny’s (1941) functional-factorial approach. The quantitative influence of each soil-forming factor on the expression and rates of soil-forming processes, and in particular the influence of the different factors in combination, have not yet been fully explored. The aim of this study was thus to quantify the influence of the soil-forming factors on the rates of podzolization, using data from 48 studies of soil chronosequences developed in sandy parent materials, located in the humid mid and high latitudes. These studies contained altogether 259 soil profiles of known age, for which we tested existing hypotheses on the influence of different soil-forming factors. The formation of an E horizon and its increase in thickness over time is one of the characteristic features of Podzol formation. As it is one of the few features that was described in all 48 studies, we used it as an indicator of progressive podzolization. Through statistical analysis, we investigated how E horizon thickness is affected by latitude, longitude, mean annual precipitation, mean annual temperature, range between minimum and maximum monthly temperature, annual number of days with frost, vegetation class, sand content, clay content, and soil age. Because E horizon thickness exhibited a zero-inflated (semi-)continuous distribution, we opted for a zero-altered gamma (ZAG) model, consisting of a Bernoulli and a Gamma part. The Bernoulli part shows how the probability of the presence of an E horizon changes with soil age and environmental conditions. The Gamma part of the ZAG model allows for capturing the effects of the covariates on E horizon thickness. Our results indicate that vegetation is the most important factor for both (1) the age at which podzolization starts (used indicator: first occurrence of an E horizon), and (2) the rate of podzolization thereafter (used measure: increase of E horizon thickness with soil age). Climatic factors such as mean annual precipitation and range of temperature play subordinate roles. They can be important in determining the time to initiation of podzolization, but are less important for the rates of podzolization. Within this set of sandy soils, we did not identify a significant influence of sand content, neither on the start nor the rates of podzolization.

This paper investigates three techniques that are commonly used to generate estimates of base cation (BC) weathering rates, i.e. the profile mass balance (PEDON), the watershed input-output budget (WATERSHED) and the PROFILE model (MODEL). These methods were compared for their relative performance in estimating BC weathering rates for 21 watersheds located in southern Quebec that vary with respect to hydro-climatic conditions, soil properties and forest cover. Average total BC weathering rates for the 21 watersheds were 0.41 ± 0.09 (± SE), 1.20 ± 0.17 and 1.71 ± 0.22 kmol c ha − 1 yr − 1 for PEDON, WATERSHED and MODEL, respectively. Passing and Bablok regression analysis demonstrated good agreement between WATERSHED and MODEL {regression formula: WATERSHED = − 0.08 + 0.74 MODEL, with 95% CI for intercept [− 1.13; 0.25] and for slope [0.40; 1.43]}, while poorer agreements were observed between these two methods and PEDON. Contrary to the WATERSHED and the MODEL methods, BC weathering rates obtained with PEDON were not significantly associated with the spatial variation of the soil calcite content and of the size of the soil exchangeable BC pools. We hypothesized that in the calcite-containing watersheds, the performance of PEDON was negatively impacted by environmental conditions that favored the partial dissolution and leaching of the calcite contained in the initial parent material, including in the material situated at the base of the profile (C horizon).

Phosphorous (P) is a limiting nutrient in subtropical and tropical mountain forests, where placic podzolization further restricts mobilization and the transformation of P fractionation. We examined how the distribution of different forms of phosphorus varied with increasing placic podzolization along a toposequence of seven pedons in subalpine forest soils in Taiwan. We used a variation of the Hedley procedure for the chemical sequential extraction of P and electron-probe micro-analysis (EPMA) to determine the micro-distribution and associations of P with other elements in selected illuvial horizons. The fractionation and P:Ti ratios indicated that P is not greatly depleted during the development of placic conditions. It is instead increasingly sequestered in sesquioxides and their organic complexes in the illuvial B horizons and in the accreting peaty surface layers. The EPMA micro-mapping in the Bsm horizons revealed that P was mainly associated with illuviated iron but not with aluminum. Forests on these soils must cope with a combination of an apparently adequate P supply and an increasingly stagnic moisture regime. When placic conditions develop in the soil, P appears to be increasingly sequestered in the sesquioxides and their complexes with illuvial humus in the B horizons and in the accreting organic epipedon.

The Fraser Island and the Cooloola dune fields are dominated by giant (>20 m deep) podzols, with numerous buried and well-preserved soil B horizons. Due to their cohesive structure and composition, these horizons can provide extensive information on the past weathering and environmental events that contributed to their formation. Previous work has attributed differences in the consistency and appearance of these B horizons to their mode of formation and past environmental setting. However, the role of post-erosional weathering (weathering after the removal of the overlying A and E horizons in response to climate change), such as fire, in altering these properties has not yet been explored. This laboratory study investigated the effects of simulated fire conditions on B horizon samples from Fraser Island and the Cooloola coast, and how fire may affect their efficacy as weathering and soil formation proxies. Fire simulations were found to alter the mineralogy and geochemistry of the B horizons. More than 94% of soil C in all samples was lost through volatilisation upon heating to 500 °C. Key mineral transformations included the dehydroxylation of gibbsite, kaolinite and lepidocrocite, and the formation of hematite when samples were heated to 500 °C and above. Mineral transformations and soil C loss during heating were reflected in the extractable Al, Fe and Si concentrations, indicating decreased Al, Fe, Si-organic complexes and increased poorly crystalline fractions due to additions from newly-formed dehydroxylated minerals. Results indicate that fires have the ability to affect both the geochemistry and mineralogy of B horizons, and therefore the present study recommends preliminary work should be carried out to determine if soils have been fire affected, before measuring for and relying on B horizon properties as markers for past soil formation conditions.

A study of the literature dealing with micromorphology of Belgian soils and palaeosoils is presented. Most soils in Belgium developed in Quaternary covers, sandy in the north, becoming more silty towards the south, and mixed with more or less important amounts of substrate material. In addition, azonal soils occur in the recent dunes, the marine Polders and the alluvial areas. The main pedogenic micromorphological characteristics are bioturbation, clay illuviation features in the more silty materials, and spodic features in the more sandy materials. Glauconite plays an important role in pedogenesis. Throughout most profiles, features related to a sub-recent pedogenic environment are recognised, pointing to polygenetic soil formation. Impact of periglacial conditions is often visible. Bog ores in alluvial plains have a complex mineralogical composition and microfabric. Buried palaeosoils and soil sediments are discussed separately according to their age whereas polygenetic soils are treated together with the recent soils according to their geographic position. For some areas, e.g., the Polders, the sandy area of Flanders and the Pays de Gaume in the southernmost part of Belgium, only little micromorphological information is available. Most soils studied were situated under natural vegetation; studies of cultivated soils are rather rare.

The Karkonosze National Park (south-western Poland) represent central European medium-elevation mountains. At the end of the twentieth century, an ecological disaster was observed in this nature reserve, resulting in the defoliation of large areas of spruce forest. One of the considered reasons for this phenomenon was contamination with heavy metals. The aim of this study was to determine the origin of lead (lithogenic versus several specific anthropogenic sources) occurring in the soils of the highest located parts of the Karkonosze Mts. Lead concentrations and its isotope ratios were investigated in nine Podzol profiles located in the subalpine zone (1200–1400 m a.s.L.) of the Karkonosze Mts. Concentrations of total lead and its isotopes were measured in particular genetic horizons; then lead isotope ratios were calculated. On the basis of lead isotope signatures known from literature data, different anthropogenic sources of this element have been assessed (emissions from coal combustion, mining, metallurgy, and fuel combustion). The results obtained revealed the highest Pb concentrations (121.0–353.0 mg kg−1) in the surface horizons. The podzolization process, differentiating soil profiles into eluvial (Es) and illuvial (Bh and Bs) horizons, has contributed to different concentration of lead through the profile. The concentrations of this element in eluvial, illuvial Bh, and parent material horizons were 15.5–28.4 mg kg−1, 25.8–55.6 mg kg−1, and 8.7–29.6 mg kg−1, respectively. The Pb isotope composition determined in the ectohumus horizons and eluvial horizons showed that about 86–95% of lead existing in these surface horizons originated from emissions resulting from the burning of coal exploited in Poland and the Czech Republic. The Pb isotope signatures of lead present in the illuvial horizon (Bs) and parent material (C) pointed to the lithogenic origin of this element. The results obtained indicated that higher-elevation areas of the Karkonosze National Park have been contaminated with lead from long distance emissions. Pollution with lead has been limited only to ectohumus and eluvial horizons, although the soil-forming process contributed to translocation of lithogenic lead down the soil profile to the illuvial Bh horizon.

Soil is a non-renewable environment in which, depending on the prevailing O2 conditions, two opposite processes – methanogenesis and methanotrophy - may take place. The rates of the processes may result in soil acting as a sink or a source of methane (CH4). Due to agricultural practices, heavy metals may accumulate affecting soil microbial processes. We tested the effect of cadmium (Cd) contamination on CH4 emission and uptake in three mineral soils (Eutric Cambisol, Haplic Podzol, Mollic Gleysol). Additionally, in the methanotrophy study, different soil moisture levels (pF 0; 2.2; 3.2) were studied. Based on the European annual and maximum limits, soils were polluted with cadmium in four doses (per dry soil mass): 0.048 mg Cd kg−1 (and its five-fold higher value) and 3.00 mg Cd kg−1 (and its five-fold higher value). The results showed that all tested soils produced and consumed CH4. Methane production rates were not significantly changed by the presence of the cadmium (except annual five-fold Cd dose in Podzol). In methanotrophy study, soil moisture was stronger regulator of CH4 oxidation (p

Soil organic matter (SOM) in high-latitude soils is assumed to be highly vulnerable to climate changes. Relative little information exists from soils of mountain ecosystems which might respond differently to permafrost melt than in flat terrain due to a better drainage. In this study, we measured SOM composition of six typical soils along an altitudinal gradient of the remote Subpolar Urals, reaching from alpine tundra to the forest zone. The SOM characteristics was estimated by applying 13 C nuclear magnetic resonance ( 13 C NMR) spectroscopy, electron paramagnetic resonance (ESR), elemental analysis and amino acid composition of humic acid (HA) extracts from soils. Result showed that SOM stocks ranged between 8 and 13 kg C m − 2 but reached up to 40 kg C m − 2 in a Stagnic Podzol in the alpine tundra. In the mineral soil, 13 C NMR indicated that the contribution of alkyl-C was 60% in the forest and 50% in the tundra, while aromaticity was 5% in the tundra, but 19% in the forest. This shows that SOM of mineral soils in alpine tundra was more aliphatic but less aromatic than in the Podzols of the forested zone. In contrast to mineral soils, SOM characteristic in organic layers was very similar among all soil types despite different vegetation types. Consequently, we suggest that the large difference in SOM quality in the mineral soil between tundra and forest can primarily be attributed to abiotic soil conditions in the deeper soil with a stronger waterlogging and a lower permafrost depth in the tundra soils. The low status of oxidative SOM degradation in the mineral soil of the tundra is also an indication that SOM of tundra is highly vulnerable to an improved aeration associated with permafrost melt in drained mountain soils.

The objective of this study was to provide a general concept of post-agrogenic self-restoration of vegetation, soils, and carbon stocks in different climatic zones of European Russia based on comparative analysis of our previous studies (Kalinina et al., 2009, 2010, 2011, 2013, 2014). The focus was on post-agrogenic plant succession, pedogenesis, carbon stocks and different carbon pools of Podzols and Albeluvisols of the taiga, Chernozems of the semi-humid steppe, and Calcisols–Solonetzes of the semi-arid steppe of Russia. During self-restoration, vegetation and soils developed towards their natural conditions. Former homogenous plow horizons developed a vertical stratification in terms of the morphological and chemical properties typical of the undisturbed soils, promoting pedodiversity. With the exception of the post-agrogenic Chernozems, the plow boundary was present during the studied period of self-restoration (42–170 years). The trend towards natural soils was also observed in every chronosequence in terms of increasing soil organic carbon (SOC) dynamics, indicating a net carbon sink function during self-restoration. Accelerated SOC gains occurred when forests established in the taiga and steppe species appeared in the Chernozem and Calcisol sequences. SOC gains occurred in the taiga mostly within the organic surface layer whereas in the steppe areas within the mineral topsoil of 0–0.2 m. The investigation of different carbon pools showed a significant organic carbon (OC) enrichment of the density fractions 1.8 g cm− 3 (sand coarse/medium silt, fine silt, clay) following the increase of total SOC during self-restoration. In the taiga, SOC restoration time was almost identical with the duration of natural plant succession of about 150 years; in the steppe areas, SOC restoration took about 100 years and was longer than plant succession. Although self-restoration developed towards natural conditions, a full recovery was hardly ever reached, revealing that self-restoration is a long or infinitely long-term process.

Podzols developed within so-called cover beds were examined on a slope built of Cretaceous sandstones in SW-Poland. Their typical feature is an easily recognizable stratification of regolith, evidenced in the dichotomy of soil texture and dense subsoil. Heterogeneity of soil profiles is manifested in vertically differentiated sequence: (1) dense, skeletal and massive layer, comprising usually Bs and BC horizons, sometimes Bhs/Bh horizons with strong platy structure is overlain by (2) the uppermost, relatively young layer, consisting of loose sandy material, bearing single coarse fragments of a less weathered sandstone, hosting AE, E and partially Bh horizons. This remarkable layering of slope sediments caused a distinctive lithological discontinuity at the boundary of E and B horizons, evidenced by the differences in: (i) rock fragments' content, (ii) degree of rock clast weathering, (iii) distribution of highly resistant minerals, and (iv) fluctuation of silt and sand fractions within profiles. Lithological discontinuity influences both the lateral podzolization, and the thickness and depth of albic and spodic horizons along the slope catena. Regarding the temporal order, the lowermost layer was influenced by periglacial conditions at before the Boreal; presumably as the surface layer (high score of pollen grains). The age of surficial sandy layer (based on pollen record) could be established at Subatlantic and correlated with forest cutting and intensive surface erosion (charcoal dating: 960 +/− 30 cal BP). Neither layers that originated from the eolian processes were distinguished nor any admixture of allochthonous material was found, therefore “typical” middle and upper periglacial cover-beds are not present in this sequence. In any case, Podzols that were formed from the slope sediments in the Stolowe Mountains are polygenetic and of the Holocene age.

Podzolation is the dominant soil forming process in chemical poor sandy soils. It is well studied how iron concentrations of podzols are effected by translocation of active iron from eluvial to illuvial horizons and leaching to the aquifer. Iron stocks of Podzols, in contrasts, have not been widely studied for comparison purposes of individual soil horizons or between soils. In this study we provide an analysis of the iron stocks for two buried Podzols developed in Late-Glacial aeolian coversands. Chemical analyses of the active and immobile iron fractions in each of the horizons in both profiles show that more iron has been involved in the podzolation process, than the amount which can be derived by chemical weathering of minerals in the overlying soil horizons. This deficit in endogenic iron therefore requires exogenic enrichment to explain the observed iron concentrations during podzolation. The contribution of exogenic iron was studied using micrometeorites as a proxy for atmospheric deposition. These particles of cosmic origins are part of a continuous flux of iron-rich materials into the Earth's atmosphere and they are deposited over time on every square meter of land surface. Their extraction from ectorganic F horizon of initial Podzols helped illustrate that atmospheric deposition in the form of aerosol and aeolian (e.g. Sahara) dust, micrometeorites and other hydrolysable particles are a relevant iron contribution in soil development. The requisite active iron for podzolation can therefore be derived from chemical weathering of atmospheric iron sources in the acidic soil environment.

Forest harvest can disrupt biogeochemical cycles with consequences for regenerating forest nutrition and drainage water quality. Few studies have examined harvest impacts on soil chemistry in conifer forests which have not been significantly affected by acid deposition, as found on the Canadian West Coast. This study investigates the effects of conventional clear-cutting on soil chemistry in Podzols of Roberts Creek Study Forest (southwestern Canada). We measured forest floor composition, soil pH and salt-extractable ions concentrations in undisturbed forested stands (control plots), stands harvested 2 to 5 years prior to sampling (cleared plots) and stands harvested 8 to 15 years prior to sampling (regenerating plots). We focused on the effects of forest harvest both on mean (differences in average values) and dispersion parameters (differences in variance between treatments). We found that forest floors of harvested plots had lower phosphorus and potassium concentrations than control plots. In the mineral subsoil, exchangeable K was however higher in harvested than in control plots. This suggests that some of the K lost from the forest floor was preferentially retained in mineral horizons, possibly due to sorption to poorly crystalline and free aluminum and iron mineral phases. The subsoil of harvested plots was slightly more acidic than control plots. In contrast to classic studies of forest harvest impacts conducted in the U.S. Northwest, we did not measure pronounced acidification, a loss of base cations or an increase in exchangeable Al, most likely due to the much lower prior acid deposition load at our sites. The most notable harvest effect was a large increase in the variability of inorganic N concentration. This suggests an increase in micro-heterogeneity of post-harvest nutrient availability which has implications for the nutrition of regenerating vegetation, nutrient leaching potential as well as our ability to detect harvest-induced changes.

Soil richness was examined across the Wisconsin ecological tension zone, which constitutes a transition between the central hardwood forest and prairie biomes to the south and the northern mixed hardwood and conifer forest biome to the north. There were greater numbers (normalized by county area) of soil orders, suborders, and great groups in counties within the transition zone than in those outside the zone. A zone of soils containing glossic horizons extends 75 km to the north of the Wisconsin transition zone separates Alfisols (dominantly Hapludalfs) and Mollisols in the south from Spodosols and Glossudalfs in the north; this zone may represent the mid-Holocene position of the tension zone. Soil endemism is a concept whereby soils are restricted to a limited geographic area based on a unique set of soil-forming factors. In this study, endemic soils were identified on the basis of having a centralized distribution, lacking competing soil series, and being unique to Wisconsin and adjoining states. Although the transition zone contains 13% of the state's area, it has 40% of the endemic soils. Endemic soils in Wisconsin occur in 7 orders, 14 suborders, 29 great groups, 83 subgroups, and 138 families; they include 159 soil series that cover 1.44 million ha (19% of state land area). The predominant soil properties related to soil endemism include (i) the presence of a glossic horizon (34% of endemic soils), (ii) aquic conditions or oxyaquic subgroups (28%), and (iii) bisequal profiles (20%). There are 102 vascular plant species endemic to Wisconsin, the distribution of which appears to be related more to the landform than to soil taxa.

Evidence of slope-scale element translocation (lateral podzolization) has been documented in sandy areas of Northern Poland. Accumulative soils enriched with organic matter, iron, aluminum, and manganese (Entic Podzols) have been found at the bottom of closed, small depressions in inland-dune fields and undulated surfaces of glaciofluvial terraces. Together with the surrounding weakly or moderately developed podzolic soils (Albic Arenosols, Haplic Podzols) Entic Podzols form regular toposequences, and seem to be geochemically linked. In the light of chemical, micromorphological and SEM-EDS analyses, the whole solum of the soils under study exhibit diagnostic features of the illuvial spodic horizon; however, they do not have an eluvial albic horizon. Landscape position and features of the studied soils suggest inter-pedon translocation of organic matter, iron and aluminum as the concept of Entic Podzol genesis. Furthermore, high values of Fe d /Fe t and Fe o /Fe d ratios in their solum can be interpreted as evidence of allochtonous character of iron accumulation. The results of this study show that the lateral podzolization process can be common even along slopes built from loose, permeable sandy deposits, where one would not expect any effective intra-layer solution flow. Organic matter and compounds illuviated to the Bhs horizon are the probable factors limiting percolation and modifying the direction of solutions movement. On slopes of more complex morphology, small closed depressions act as geochemical traps, where compounds leached from the upper slope soils can accumulate. Radiocarbon dating carried out on a buried Entic Podzol found in one of the profiles shows that the process has continued for more than 1200 years.

The spatial pattern of soils and soil properties in soil landscapes is considered here as a function of (1) systematic variation along catenas or associated with spatial patterns of soil-forming factors; and (2) local pseudo-random variations associated with local disturbances or small, unobserved variations in soil-forming factors. The problem is approached at two study sites in the U.S. Atlantic Coastal Plain using algebraic graph theory and the spectral radius of the soil adjacency matrix as a measure of complexity. The matrix is constructed based on the observed spatial contiguity of soil taxa, and soil factor sequences (SFS) are defined for each site based on systematic soil variation associated with variations in parent material, topography, sandy surface thicknesses, and secondary podzolization. The spectral radii of the networks described by the adjacency graphs are compared to those associated with the maximum for a graph of the same size, and the maximum associated with control entirely by variations in soil forming factors. At the Clayroot study site, which is entirely cropland, complexity of the adjacency matrix is less than Λ, the maximum that could be accounted for by the four identified SFS, due to redundant information in the SFS. The Littlefield site, by contrast, has a spectral radius greater than Λ. Here, where about half the site is forested, the contingent variation is likely associated with effects of individual trees on soil morphology. The utility of the adjacency analysis is in identifying whether soil heterogeneity is likely associated with SFS or with contingent factors not captured in SFS.

Fragipans are dense subsurface soil layers that severely restrict water flow and root penetration. They are considered a pedogenic horizon, but their exact genesis is not well understood. In Soil Taxonomy (2010) a fragipan is defined as a layer that is at least 15 cm thick, contains a coarse structure, and is reversibly cemented. We examined 362 pedons with fragipans in the Natural Resources Conservation Service (NRCS) SSURGO database and 36 case studies in the USA from the literature. Soils with fragipans are classified primarily at the great-group but also at the subgroup level. Fragipans occur in four orders (Alfisols, Ultisols, Inceptisols, Spodosols), 10 suborders, 23 great groups, and 57 subgroups. From the NRCS database, fragipan soils have silty or loamy particle-size classes (95% of total soil series), an udic or aquic soil-moisture regime (98%), a mesic soil-temperature regime (60%), and a mixed mineralogy class (75% of total soil series). Although they occur in 28 states in the USA, the most extensive areas of soils with fragipans occur in the southern Mississippi River valley and the central and southern Appalachian Mountains. Soils with fragipans are most common east of the 97°W meridian and in forested areas where precipitation exceeds evaporation. These soils are derived from silt-rich materials, especially loess and low-lime tills (61% of total soil series) and occur primarily in lower, moderately well-drained topographic positions. The genesis of fragipans involves wetting and drying, possibly influenced by the presence of lithologic discontinuities, which lead to hydro-consolidation that causes close-packing of grains and reduces porosity. Although silica may bind clays and Fe oxides and bridge skeletal grains, this property is not recognized in the definition of the fragipan. In the conterminous USA soil mapping units containing soils with fragipans occupy 970,000 km 2 (12% of the land area).

Pleistocene periglacial cover-beds have been considered to be the proper parent material of soils in the medium mountains of the Central Europe and in other areas influenced by the periglacial conditions. The concept highlights an importance of solifluction and cryoturbation phenomena, and an addition of aeolian silt (loess) in the formation of cover-beds. Significant loess admixture may, however, hinder podzolization process. The objective of the present study was to recognize the stratification of slope materials in the upper zone (1000–1200 m ASL) of the Sudeten Mts. (SW Poland) and its relation to the morphology and properties of Podzols. Mineralogical and submicromorphological analyzes confirmed autochthonous origin of the parent materials and excluded loess admixture. Macro- and micro-observations proved periglacial formation of deeper beds, while the pollen analysis confirmed the Holocene age of an uppermost sand layer. Finally, four-partial mineral sequences were distinguished in soil profiles: (1) an underlying granite regolith (not always present within the standard soil pit), (2) a basal periglacial layer formed by solifluction, (3) a cryoturbated transitional zone instead of typical intermediate periglacial layer, (4) an uppermost sandy (or a sandy–silty) layer instead of the upper periglacial layer. Modification of periglacial cover-bed series by replacing of the silty “upper periglacial layer” with sandy Holocene cover allowed Podzol formation under favorable climate conditions. The same palynological and micromorphological observations confirmed polygenetic nature of Podzols. The present-day Bh horizon is in fact a humus layer of a late Pleistocene–early Holocene brown earth buried under a sandy cover. An albic horizon thickness and its lower boundary are therefore related to the lithological discontinuity in the cover-bed series.

The Haast chronosequence on the west coast of the South Island of New Zealand consists of a series of coastal dune ridges formed by periodic earthquake disturbance over the last 6500 years. It approximates an ideal chronosequence, because soils are under the same climate and vegetation, have similar topography, and are developed in the same parent material. We assessed soil development and the changes in nutrients at eleven sites along the sequence to determine rates of nutrient transformations and the potential for limitation of biological activity by nitrogen and phosphorus availability. Soils develop rapidly to podzols (Spodosols) under the super-humid climate, involving acidification and depletion of base cations in the first few hundred years, development of a bleached eluvial horizon under a thick organic horizon within 2000 years, and formation of a continuous cemented iron pan within 4000 years. Soil phosphorus concentrations decline markedly in the first few hundred years in both the organic and upper mineral soil horizons, with rapid depletion of primary mineral phosphate and the accumulation of organic phosphorus to ~ 80% of the total phosphorus in the upper mineral soil. These changes lead to an increasing degree of phosphorus limitation along the sequence, as indicated by an increase in C:P and N:P ratios and a decline in available phosphate. The rates of soil development and phosphorus depletion are more rapid than at the nearby Franz Josef post-glacial chronosequence, where glacial moraine derived from graywacke contains a relatively high phosphorus concentration and weathers into fine-textured soils. The Haast chronosequence therefore provides an important additional example of soil development linked to long-term depletion of soil phosphorus under a perudic moisture regime.

Soil hydraulic properties evolve over time as a result of soil formation processes. We investigated the rate and circumstances of change in soil hydraulic properties as a result of soil and landscape evolution that took place over a period of a few decades to several thousands of years. To this end, a sediment-soil sequence in which different sandy landscapes and associated soils are preserved was studied with respect to its geomorphological and pedohydrological characteristics. Three stages of soil development corresponding to specific landscapes were observed within a 2-m deep profile: 1) a stabilisation surface within an active drift sand landscape, 2) an A-horizon that developed on a stabilised drift sand landscape and 3) a pronounced podzol that developed in a stabilised landscape from the last glacial. Measurement of soil physical properties was conducted including grain size analysis, organic carbon content, soil water retention characteristic and hydraulic conductivity using constant head and air permeability analyses. Age control of soil horizons and vegetation history were obtained from optically stimulated luminescence (OSL) dating, radiocarbon (14C) dating, pollen analysis and historical archives. The results suggest a strong relationship between landscape evolution, soil development and hydraulic properties. Small changes in hydraulic properties may already be observed on a decadal and centennial scale, while long-term podzolisation processes may decrease the hydraulic conductivity of parent material up to three orders of magnitude in several thousands of years. It is concluded that combination of geomorphological and pedohydrological analyses of sediment-soil archives may provide a unique means to gain insight into the rate and extent of past changes in soil hydraulic properties and the consequences of future hydrological changes as a result of these evolving properties.

A study was conducted along the Kelantan–Terengganu Coastal Plains, Peninsular Malaysia to explain the occurrence of sandy beach ridges and to determine the physico-chemical properties of the soils formed on them. Two or occasionally three series of sandy ridges running parallel to the shoreline occur in the area. These ridges are believed to have been formed by the continuous action of the sea waves following changes in the sea level during the Holocene, the oldest ridge being the one farthest away from the shoreline. In between these ridges occurs a slight depression, usually occupied by soils under submerged condition. The soils on the ridges are subjected to the processes of soil formation, mainly podzolization. There is no horizon differentiation in the soils on the ridge nearest to the shoreline. However, soils on the older ridges contain spodic horizon, occurring at varying depths. Drainage and the depth below which this spodic horizon occurs are the deciding factors for determining soil type (series). Physically, the soils are sandy containing > 95% sand, with the drainage varying from moderately well to excessively-drained for the soils on the ridges. Under this condition, the mineralogy of the clay and silt fractions is dominated by quartz; some feldspars, mica, kaolinite, gibbsite and anatase are also present. Sandy nature of the soils on beach ridges, extreme leaching, low cation exchange capacity and low exchangeable bases leads to their low productivity.