Histic Gleysol Research Articles

Soil cover transformation after the laying of a high-voltage power line

Today the rate of anthropogenic transformations of the soil cover significantly exceeds the rate of its natural restoration. According to a modern digital soil map at a scale of 1 : 200,000 in the Leningrad Region anthropogenically modified subtypes of natural soils, which were formed as a result of human economic activity, predominate. The article considers anthropogenic changes in soils and soil cover of the territory of the high-voltage power line. The study area of 100×500 meters is located in the Tikhvinsky district between the settlements of Kalivets and Novaya Ust-Kapsha. The landscape of the territory belongs to the lake-glacial plain, the soil-forming rocks are lake-glacial sands and sandy loam. Natural soils that are not affected by technological works are found only in the forest, outside the clearing laid during the construction of the power line. These are Albic Podzol, Entic Podzol, Histic Albic Podzol, Histic Entic Podzol and Histic Gleysol. It was revealed that in the study area, the horizons of the original natural soils are partially or completely cut off, turbated, compacted, which led to the formation of their anthropogenically transformed subtypes: over-compacted, abraded, turbid and stratified. Sometimes soil material is exposed to the surface and moved over the study area by tens of meters. After the construction of the high-voltage line, new formations appeared in the soil cover, such as Podzol Nudispodic, buried soils and several types of non-soil formations. It is revealed that each technological operation (logging, installation of power transmission line supports, organization of places for technological operations and the creation of temporary roads) is characterized by its own special disturbances in the soil cover. Thus, after the construction of the power line, there were no natural soils with an undisturbed structure in the soil cover. In addition to the fundamental transformation of the soil cover at the site, natural vegetation was reduced, the mesorelief was partially disrupted and the microrelief was almost completely changed. All these anthropogenic transformations will affect the quality of the ecological functions of the soil cover. During the further operation of power transmission lines, such as clearing a cut-out clearing, updating fire-prevention mineralized strips, maintaining the power grid, disturbances of the soil cover will be periodically repeated, preventing the ecosystem from returning to its original state.

SOIL RESPIRATION AS MICROBIAL RESPONSE TO THE ENDOGEN INPUT OF BIO-SYNTHESIZED ORGANIC MATTER AND ITS IMPLICATION IN CARBON SEQUESTRATION

Active C, as a measure of the level of chemical oxidation of organic matter, reflects the carbon available to microorganisms. Soil respiration, as a direct way to estimate edaphic microbial activity, could be a measure of the fluctuations of carbon stocks in soils. To determine the ability of soil respiration to evaluate such fluctuations we used soils with an increased content of organic carbon, constant optimal conditions, to eliminate the disturbing factors, analyzed in a short period of time. The influence of the specific decomposition rates of these soils was assessed by both spot determinations of soil respiration and analyzing the flux of CO2 from ex situ soil samples, under standard experimental conditions, to highlight carbon storage in such soils. Reference data can be accumulated through the analysis of these parameters, which compared with the results of quantitative/qualitative determinations regarding the changes in the content of microbial biomass, the content of fulvic sub-fractions, the fluorescence of dissolved organic material and the evolution of the content of siderophores, could be considered, by their own evolutions, as arguments in sustaining the use of respiration in the efficient estimation of carbon storage evolution in the soils. The analyses of these parameters were carried out in two phases, for comparing initial and final data of experiment (after 30 days). The soils had different levels of the respiration potential between phases. The level of soil respiration was reduced in time between 4.27-14.60%, in each soil. The CO2 flux showed, in time, a continuous decreasing trend in both soils. In the case of Mollic Histic Gleysol (Salinic), the coefficient of determination has the value R2=0.92 for the flux determined in the final phase. The levels of microbial biomass of both soils were increased significantly at the end of the experiment. In the case of Mollic Histic Gleysol (Salinic), microbial biomass increased from 456±23.12 μgC∙g-1 to 514±24.57 μgC∙g-1 soil. The fulvic sub-fractions A-D of both soils revealed significant accumulates of soluble organic compounds, with different molecular weights and complexity levels, after 30 days of incubations in standard conditions. The fluorescent components present in the water-extractable organic matter were highlighted by imagistic method. The highest degree of storages of newly bio-synthesized compounds of carbon was registered in organic matter of Mollic Histic Gleysol (Salinic). The intensity of siderophores biosynthesis increased over time, starting from an initial lower presence in the Mollic Gleysol (Salinic) (with Ø 11 mm halo), which were followed by an increasing of siderophores content and availability of iron, at the end of the experimental period. Accumulations of siderophores in the Mollic Histic Gleysol (Salinic) determined a Ø 31 mm halo diameter.

Почвы юго-западного побережья острова Западный Шпицберген

A few soil types were studied at the south-west coast of West Spitsbergen Island during 2004–2018. The article discusses the morphological features and properties of the most common soil types in the surveyed area, including Folic Sceletic Umbrisols, Sceletic Umbrisols of the polygonal complexes, Histic Gleysols and Folic Gleysols of tussock bog, and Sceletic Dystric Regosols.

Накопичення 137Cs у суміші лучних трав на торфово-болотних ґрунтах зони Полісся у Рівненській області

The role and effectiveness of the combined action of various types of mineral fertilizers on the productivity of the agrocenosis and the accumulation of radionuclides by the phytomass of perennial grasses on peat-bog soil (Histic Gleysols) have been investigated. The research was carried out during 2011-2013. In a temporary field experiment with seeded perennial grasses (Dáctylis glomeráta, Bromopsis inermis, Phleum pratense) used for livestock feed. The aim of the research is to identify the features of the effect of radiological load on the quality of agricultural products in fertilized and non-fertilized areas by measuring the specific activity of radioactive 137Cs in the dry phytomass of collected herbs, the density of soil contamination and calculating the coefficients of the transfer of radionuclides from soil to pasture fodder. The activity of 137Cs in plants was determined by gamma spectrometer. The introduction of increased doses of potash (K120) and phosphorus fertilizers together with potash (P60 K120) was effective in reducing the activity of radiocaesium in the dry mass of feed. Over the three years of research on the variant with potash fertilizers, a decrease in 137Cs activity in the feed by an average of 2.9 times was recorded, and at the site of the combined application of potash and phosphate fertilizers – by 2.7 times compared with the control variant of the experiment (without fertilizers).

Features of soils and soil formation of natural monument «Park «Sergievka»» (Saint Petersburg, Russia)

Parks maintain crucial ecological functions and provide different benefits for city dwellers. These facts made studying of park ecosystems important task. Soil cover and patterns of its formation were studied in natural monument “Park “Sergievka” (Saint Petersburg). The structure and composition of the soil cover of the park depend mainly on relief, groundwater level and features of soil-forming materials. The soil cover of the park “Sergievka” is characterized by taxonomic diversity, complexity and heterogeneity. Natural soils occupy 75% of the park area. Gleysols and Fluvisols dominated on the modern marine terrace, Umbric and Histic Gleysols are typical for the first terrace, and Retisols are the most abundant soils of the second terrace. Urbic Technosols were found near buildings, ponds and along the highway. Terric Anthrosols occur on the Lower Meadow in front of the Palace. Despite the presence of artefacts and higher humus content, anthropogenic soils have acidic reaction and redoximorphic features typical for native soils of the park territory. The results of the study indicate the dominance of natural soil formation processes in the park due to absence of measures aimed at maintaining the effect of earlier work on soil drainage and cultivation.

Accelerated soil development due to seasonal water-saturation under hydric conditions

Pedogenesis is considered a long-term environmental process; however, it can be accelerated by periodic water saturation (hydric conditions). The exact nature and effectiveness of hydric conditions in the intensification of soil development are not clear yet. Our understanding of the timescales of the mineralogical changes occurring in soils is limited; however, the timeframe of soil organic matter accumulation is broadly known. Here, we described soil development over a period of 50 years.The studied soils Calcaric Mollic Gleysol (Endoarenic, Epiloamic, Hyperhumic) and a Calcaric Calcic Histic Gleysol (Endoarenic, Epiloamic) are located in a swampy area in Hungary, Central Europe. The start of the soil formation process is well documented here; the parent material was deposited during a major flood event in 1963. Therefore, the examined soil profile represents development over the last 50 years. We also studied the parent material of an adjacent dune as a reference. We used a CN elemental analyser to determine soil organic carbon and total bound nitrogen content. Selective extractions were also used to determine amorphous and crystalline Fe and Mn content alongside X-ray phase analysis (XRD) and transmission electron microscopy (TEM) for mineralogical analysis, X-ray fluorescence spectroscopy (XRF) for elemental analysis, and laser diffraction for particle size analysis of the bulk soil samples. Simple chemical tests were also performed in the field. Redox potential (Eh) and pH were measured by a field monitoring station.Fifty years under hydric conditions resulted in rapid vertical differentiation within the soil profile including remarkable soil organic matter enrichment in the topsoil, and the formation of smectite and Fe accumulation in the zone of groundwater fluctuation. A high proportion of amorphous and colloidal phases indicated that very intense processes had taken place in the zone of the most intensive redox oscillation. The presence of more crystalline goethite in the bulk soil reflects frequent Eh changes, associated with chemical or microbial processes, while the presence of amorphous ferrihydrite indicates the effect of plant roots. Permanently reductive subsoil conditions also facilitated intense carbonate precipitation. These findings demonstrate that soil formation can proceed faster than previously assumed under hydric conditions.

Correspondence Between Vegetation Patterns and Soils in Wet and Wet-mesic Grasslands of Hanság and Tóköz (Hungary)

Our research focused on the causes responsible for the fine mosaic pattern of plant associations on wet and wet-mesic meadows. The study area is located in the Little Hungarian Plain, including the former swamp basins of Hanság and Tóköz in Hungary. The vegetation survey data were evaluated by statistical methods (TWINSPAN method), and vegetation maps of the areas were prepared. Topsoil samples near the relevés were gathered for further laboratory tests. Soil profiles were opened by a Pürckhauer soil sampler for on-site description of the soil horizons and classification. Surface models provided a base for the preparation of contour maps that could be compared with the vegetation pattern. We found that of the two dominant vegetation types, mesotrophic wet meadows were associated with Mollic Gleysols, while non-tussock sedge beds were associated with Histic Gleysols. At the transitions of the two soil classes, the subgroup of non-tussock sedge beds is the dominant type. The soil class only determined the plant association on a habitat level, but it could not reason the fine pattern of the plant communities on the same soil class. Canonical correspondence analysis (CCA) was performed to investigate the relationship between the distribution of dominant species and soil parameters. Several soil parameters combined have a significant effect on the distribution of dominant species. In conclusion, we found that the formation of association types strongly depends on the soil characteristics of the area, and that it is closely related to it. However, in the formation of the fine mosaic pattern, the driving ecological factors are the microrelief and the length of the saturated or flooded soil conditions.

Cryogenic soils near the Yeletsky settlement, northeast of the Komi Republic

The subject of this research is the soils and soil-geochemical catenae in the area of Yeletsky settlement, located in the northeast of the Komi Republic. Catena were deposited on the mound covered with moss-shrub tundra transect from the interfluve of Usa and Yelets Rivers to a lacustrine depression, complicated by arching permafrost mounds. Within the district of research, the authors laid five soil incisions (EL20-P1, EL20-P2, EL20-P3, EL20-P4 and EL20-P5) that formed a soil-geochemical catena along the slope. Complex land cover found at the periphery. The explored soils were formed on silty loams with permafrost horizon at a depth of 0.5-0.7 m and belong to Cryosols, Turbic Cryosols and Histic Gleysols. Cryosols in the upper part of catena show specific cryogenic granular structure due to lack of soil moisture content. The soils on the slope and in the depression are more saturated with water; therefore, structureless Turbic Cryosols and Histic Gleysols are formed. In the soil horizons, the values of pH and electrical conductivity were measured, the content of organic carbon and soil texture were studied. An increase in soil acidity on organogenic zones by 4.3 - 5.7 was noticed; in underlying horizons the pH values reach 6.9.

Mineral matter composition of drained floodplain soils in north-eastern Poland

Abstract Soils in two river valleys (Rozoga and Omulew) in north-eastern Poland were investigated. The valleys are located on a sandy outwash plain formed during the Vistulian (Weichelian) Glaciation. The soils are drained, used as meadows and classified as Fluvic Umbric Gleysol, Fluvic Mollic Gleysol, and Eutric Fluvic Histic Gleysol (IUSS Working Group WRB 2015). The aim of the study was to identify the composition of mineral matter and to determine the types of clay minerals and intermediate stages of clay minerals by means of the X-ray diffraction (XRD). The studied floodplain soils are rich in organic matter and contain considerable mineral alluvial admixtures. The content of clay fraction (< 2.0 μm) is low (0.02–5.61% of total mineral matter). Higher content of clay fraction was noted in soils with elevated content of organic matter, which can be evidence of simultaneous accumulation of both components. In deeper depressions occurring in river valleys (oxbow lakes), a specific deposit termed silty telmatic mud (16–24% TOC, 50–75% silt, 3.1–5.6% clay fraction content) was accumulated. On the other hand, in shallow depressions, a muddy deposit was accumulated (5.7–7.7% TOC, sandy texture). The main identified clay minerals were smectite, vermiculite, illite and kaolinite as well as variety of mixed-layer clays. Alluvial clay admixture in studied soil formations showed mineralogical similarity to typical floodplain mineral soils (Fluvisols). Mineral fraction of studied soils is mostly of allochthonous origin.

Distributions of Heavy Metals and Benzo[a]pyrene in Oligotrophic Peat Soils and Peat Gleyzems of Northeastern Sakhalin

The contents and profile distributions of Cr, Ni, Cu, Zn, Cd, Hg, Pb, and benzo[a]pyrene in oligotrophic peat soils, oligotrophic peat gley soils (Dystric Fibric Histosols), humus-impregnated peat gleyzems (Dystric Histic Gleysols), and mucky gleyzems (Dystric Gleysols) have been analyzed with consideration for their degree of oligotrophicity and anthropogenic loads. Horizons with the accumulation (O, Tpyr, TT) and removal (Ghi,e) of heavy metals have been revealed. The increase in the content of heavy metals and benzo[a]pyrene in the upper layer of oligotrophic peat soils under technogenic fallouts in the impact zone of flare and motor transport has been considered. Statistical parameters of the spatial variation of parameters in organic and gley horizons have been calculated. The variation coefficients of pollutant elements (Pb and Zn) in the surface horizons of soils increase to 100–125%. Positive correlations revealed between the content of some heavy metals in litter indicate their bioaccumulation and possible joint input with aerotechnogenic fallouts. No correlations are found between the contents of benzo[a]pyrene and heavy metals, but a reliable negative correlation with the ash content is noted in the peat horizon.

Use of arable land with agroecological assessment of soils

Growing crop production with ignoring the quality of arable land leads to lower crop yields and unreasonable costs. There are areas of waterlogged, marshy, eroded soils or soil with low humus content and low available form for plant of nutrients in intensive use of land, that is leased or owned by modern agricultural companys. These lands have different area and configuration of soil contours and it is the cause of complicated planning of the fields’ boundaries. The purpose of representing data in this article is the justification of the rational use of arable land on condition detailed analysis of soil properties. Because the land management is the basis for optimization of agricultural production in a certain area. In order to obtain indicative results, the territory with complex structure of soil cover and with soils, which differ greatly in their physical and chemical properties and conditions of soil formation, was chosen as the object of research. Soil conditions were analyzed by natural indicators such us groundwater levels, granulometric composition of soil, nutrients concentration that are available for plants, acidity of soils. The explored area has flat relief with moderate climate and insufficient humidification in separate periods. Soils’ parent material: alluvial deposits, loess loam, deluvial deposits. There are 11 groups of soils on the research area of 1272.4789 ha. Among them Haplic Chernozem, Albic Luvisol, Gleyic Chernozem, Mollic Gleysol, Luvic Greyic Phaeozem, Endogleyic Arenosol and Histic Gleysol. The Gleysols occupy a large area of surveyed land (106 hectares). These soils have a very poor water-air mode and suffer from drought or waterlogging in some periods. In order to achieve the purpose of the work an existing methodology for the soils grouping into classes for the suitability of growing agricultural crops was used. Also the scale of soil evaluation for the Ruzhinsky agricultural region was applied. The article represents data of soil classification into classes of suitability by ten classification items. It is established that not the whole area of arable land is suitable for growing wheat. The estimated yield of winter wheat was calculated on the basis of soil's properties. Winter wheat is the demanding plant to soil and climate condition. This is the cause there are low productivity of this plant on clay soil types and soils that have sandy granulometric composition. The estimated yield of winter wheat on Histic Gleysol and Mollic Gleysol is 6.8 centner/ha and on Endogleyic Arenosol is 12.5 centner/ha. Inclusion such tapys of soils in fields area leads to a decrease the yield of winter wheat crops. This is difficult for land use in case low fertility soils are situated in higher quality soils’ area. This situation is inherent territory of Polisya and south part of Ukrainian Lisostep zone. As a result of researchi it was realized that Haplic Gleysol occupy small areas (between 0.1-0.3 ha). These soils are located near Endogleyic Arenosol that don’t suffer from excessive moisture and need another approach of land use. The importance of taking into account the properties of soils is proved. The approach of land use of arable land is proposed. Keywords . S uitability of soils, groups of soils, wheat crop, land use .

Soil mineral N dynamics and N 2 O emissions following grassland renewal

Abstract Managed grasslands are periodically renewed in north-western Europe, primarily in response to a decline in yield and nutritive value or sward damage. Grassland conversion to arable land is also a common agricultural practice on intensively used grassland sites. However, depending on the soil and its management, grassland break-up (i.e. the destruction of the grass sward and soil disturbance) is associated with the mineralisation of soil organic nitrogen (N) and the decomposition of stubbles and roots from the old grass sward, with both leading to enhanced nitrous oxide (N2O) emissions and nitrate (NO3−) leaching. Two sites were set up to investigate the effects of different grassland renewal techniques (keeping and improving the old sward, chemical sward killing and chemical killing of the sward followed by ploughing) with grassland conversion to maize cropping and permanent grassland as the reference treatments. The sites (Histic Gleysol and a Plaggic Anthrosol) differed in their organic matter content and groundwater level. N2O fluxes were measured weekly using static closed chambers for a period of two years. The relationship between N2O fluxes and explanatory/controlling variables was investigated using generalised additive models (GAM). The potential NO3− losses via NO3− leaching were quantified by taking weekly measurements of the soil mineral N (Nmin) from the topsoil layer (0–30 cm) and from depth profiles (0–90 cm) in the autumn (pre-winter) and spring (post-winter). The aboveground biomass in the different treatments was also measured. Grassland renewal was not a significant source of direct N2O emissions at either experimental site during the two years of the study. There was only a short two-month period during which there were significantly increased N2O fluxes (up to a maximum of 1.6 kg N2O ha−1 day−1 in the Histic Gleysol) and treatment differences. N fertilisation (as reflected in the Nmin content in soil), soil moisture, and microbial and plant respiratory activity were identified as important drivers of N2O emission. The destruction of the old grass sward (i.e. chemical killing by herbicide application and ploughing and conversion to maize cropping) resulted in an increased net N release of Nmin during the first year, which indicated losses via indirect N2O emission and a higher risk of NO3− leaching, especially on the sandy Plaggic Anthrosol. No yield effects were found after grassland renewal at either site. With respect to N2O mitigation and the prevention of NO3− leaching, it is recommended that the new grass sward should be rapidly established as a sink for Nmin and that the amount of available mineralised N following grassland renewal is taken into account when applying N fertiliser, as mineralisation following sward destruction provides high amounts of plant-available N.

Fluxes of N2 and N2O and contributing processes in summer after grassland renewal and grassland conversion to maize cropping on a Plaggic Anthrosol and a Histic Gleysol

Grassland renewal and grassland conversion to arable land are common agricultural practices on intensively used grassland sites, especially in north-western Europe. However, grassland ploughing can cause a flush of soil organic nitrogen (N) mineralisation due to soil disturbance during tillage and decomposition of stubble and roots from the old grass sward. This is known to result in enhanced nitrous oxide (N2O) emissions, but information about the underlying microbial processes, especially the role of N2O reduction to N2 via denitrification, is scarce. Therefore we applied the 15N gas flux method in situ to grassland recently ploughed under for maize cropping, renewed grassland and permanent grassland on a Histic Gleysol and a Plaggic Anthrosol which differed in organic matter content and drainage. We used needle injection of 15N-labelled KNO3− at three different depths in the soil to achieve homogeneous label distribution. Fluxes of N2O and N2, mineral N concentration and 15N enrichment of these were measured for 44 days after label addition. Overall, no differences in N2O and N2 emissions were found between grassland conversion/renewal and permanent grassland. N2 emissions increased up to 9115 g N ha−1 day−1 on a single sampling day following grassland conversion to maize cropping on the Histic Gleysol, leading to a great contribution of denitrification when N2O/(N2O + N2) ratio was low. However, heterogeneity of 15N label distribution proved to be a major difficulty in the water-saturated Histic Gleysol and caused potential uncertainty in identification of various production pathways. Lower gaseous losses and higher nitrification potential were detected in the Plaggic Anthrosol, indicating a higher threat of possible leaching of excess mineral N following grassland conversion/renewal.

Vertical electrical sounding of soils and permafrost of marine terraces of Gronfjord (Svalbard archipelago)

Vertical electrical resistivity sounding (VERS) of soil-permafrost strata has been performed during the field work within the sea terraces of Gronfjord (Svalbard archipelago, West Spitsbergen island). Vertical electrical resistivity sounding of soil-permafrost strata was performed by portable device LandMapper. Then these data have been analyzed via ZondIP software (1d model). Apparent electrical resistivity values on the soil-permafrost strata usually change rapidly. It was established that studied soils with different origin and morphological properties are referred to 2 trunks, 2 orders, 4 types and 7 subtypes. Histic Gleysols, Cryosols, Gleysols and their subtypes have been investigated within the key plots (Grendasselva, Aldegonda rivers and catena on the sea terrace in surroundings of Barentsburg aerodrome). Several trends in profile distribution of electrical resistivity values have been distinguished. The main is connected with monotonous increasing of electrical resistivity values with a depth. Values of apparent electrical resistivity increase rapidly on the border of active layer-permafrost layer. The contrasts in profile distribution of electrical resistivity values are caused mainly by differences in water content, texture class and degree of strata heterogeneity (due to cryogenic processes). The depths of active layer-permafrost boundary have been distinguished using ZondIP software. Regional differences in this indicator may be explained not only by local differences in thermal regime of soil and permafrost layers, but also by different character of anthropogenic influence on key plots. Vertical electrical resistivity sounding method provides significant information for understanding soil electrical properties without any mechanical disturbances of soil cover. The data obtained is clearly coincided with field work data on soil morphology.

Human-induced development of mollic and umbric horizons in drained and farmed swampy alluvial soils

River regulation since the 17th century, large-scale drainage, and intensive farming have seriously transformed soils in the river valleys of Poland. Flood suppression and groundwater lowering have created oxidizing conditions in topsoil and allowed biological activity and plant rooting, which has retarded original stratification of the alluvial substratum. However, ploughing has led to the development of thick humus horizons. In particular, soils with organic topsoil horizons have been changed, i.e. they have lost their initial swampy nature and have undergone an anthropogenic transformation to mineral soils. Despite the long-term agricultural land use, it is still possible to recognize the peaty character of organic matter in some soils and this allows reconstruction of their origin. This study investigated a sequence of soils in the valley of the river Barycz: (i) occasionally flooded, very moist Fluvic Histic Gleysols, with a Murshic organic layer, (ii) weakly drained soils with a high groundwater table, deeply ploughed, where the sandy plough layer contains easily recognizable peat-derived organic material, weakly bound to the mineral fraction (Fluvic Anthromollic Gleysols), and (iii) deeply drained soils, deeply ploughed, where organic carbon content in the plough layer is below 10%, but peat-derived particles of organic matter are still recognizable and are weakly bound to the mineral fractions [(Endogleyic Phaeozems (Anthric) or Endogleyic Umbrisols (Anthric)]. None of the thick plough layers, although intentionally created by humans by mixing the organic layer with underlying sandy material, fulfill the requirements of the anthropogenic diagnostic horizons. Therefore, two new qualifiers are proposed to the WRB classification in relation to the recent addition of the “Murshic” qualifier, namely “Anmooric” and “Atric”, to allow accurately naming the postswampy soils at subsequent stages of their transformation.

Fabric and properties of mineral soils underlying a shallow peat mantle in Estonia

The morphology and chemical characteristics of mineral soils underlying modern peaty (histic) and shallow peat soils (or histosols) are analyzed in pedoecological conditions of Estonia. The underlying shallow peat mantle gley soils have been formed on different geological origin (glaciolacustrine, glacial, glaciofluvial, marine) parent materials. The peat mantle overlying gley soils has accumulated in the process of landscape paludification during the post glacial period. Using the Estonian Soil Classification (ESC), the peat layer thickness of peaty soils is 10–30 cm and of shallow peat soils, 30–100 cm. The studied peaty soils may be characterized as polygenetic soils. Depending on parent material properties (calcareousness, acidity, texture) and feeding water the peaty soils are divided into two types specified by ESC as peaty gley soils and peaty podzols, and by WRB as Histic Gleysols and Histic Podzols. The mineral soils underlying peat soils may be defined as paleosols. The development of such soils has proceeded according to the chronosequence: gley soils or protosols → peaty soils → fen soils → transitional bog soils → bog soils, whereas mineral paleosols may be found under fen, transitional bog and bog soils. The peat soils studied in this research work, classified by ESC as drained shallow transitional (mesotrophic) bog soils and by WRB as Drainic Dystric Ombric Hemic Fibric Histosols, are located on the edges of bog areas and are fed mostly by mesotrophic surface seepage water. In comparative analysis of three soil groups (peaty gley soils, peaty podzols and shallow peat soils) (i) their location on the landscape, the geological origin of their parent materials and morphology of the mineral layers are characterized; (ii) the vertical distribution of organic carbon and total nitrogen contents, and different characteristics of soil acidity are analyzed, and (iii) their catenal position or associated soils are characterized. In the case of peaty soils, the three types of mineral soil profiles (eluvial, eluvio-accumulative and accumulative) which underlie the peat cover were elucidated. Under thicker peat layers, i.e. under shallow peat soils, mostly humus accumulative profiles were found. In all analyzed sites, in the course of progressive paludification (among this peatification) the peaty soils have been formed from gley soils. The formation of the peaty soil stage was followed by the fen soil stage. Depending on the feeding water, some of these soils developed in the direction of bog soils, with an intermediary transitional bog stage. Artificial drainage is of great importance in the development of peat cover, which influences first the decomposition of top layer peat.

Sheep excreta cause no positive priming of peat-derived CO2 and N2O emissions

Large areas of peatlands in Germany and the Netherlands are affected by drainage and high nitrogen deposition. Sheep grazing is a common extensive management activity on drained peatlands, in particular on nature protection areas. However, input of easily mineralisable material such as sheep excrements could enhance degradation of soil organic carbon (Corg), thereby increasing the effect of these ecosystems on national GHG budgets. Thus, a microcosm experiment on the influence of sheep excreta on GHG emissions from a histic Gleysol with strongly degraded peat was set up. The 15N and 13C stable isotope tracer technique was used to partition sources of CO2 and N2O. Labeled sheep faeces and urine were obtained by feeding enriched material. Undisturbed soil columns were treated with surface application of urine, faeces or mixtures of both in different label combinations to distinguish between direct effects and possible priming effects. Incubation was done under stable temperature and precipitation conditions. Fluxes as well as 15N and 13C enrichment of N2O and CO2, respectively, were measured for three weeks. Addition of sheep excreta increased emission of total CO2 in proportion to the added carbon amounts. There was no CO2 priming in the peat. No effect on CH4 and N2O was observed under the aerobic experimental conditions. The N2O–N source shifted from peat to excreta, which indicates negative priming, but priming was not significant. The results indicate that sheep excreta do not significantly increase GHG emissions from degraded peat soils. Considering the degraded peatland preserving benefits, sheep grazing on peatlands affected by drainage and high nitrogen deposition should be further promoted.

High CO<sub>2</sub> fluxes from grassland on histic Gleysol along soil carbon and drainage gradients

Abstract. Drained organic soils are anthropogenic emission hotspots of greenhouse gases (GHGs). Most studies have focused on deep peat soils and on peats with high organic carbon content. In contrast, histic Gleysols are characterized by shallow peat layers, which are left over from peat cutting activities or by peat mixed with mineral soil. It is unknown whether they emit less GHGs than deep Histosols when drained. We present the annual carbon and GHG balance of grasslands for six sites on nutrient-poor histic Gleysols with a shallow (30 cm) histic horizon or mixed with mineral soil in Northern Germany (soil organic carbon concentration (Corg) from 9 to 52%). The net GHG balance, corrected for carbon export by harvest, was around 4 t CO2–C–eq ha−1 yr−1 on soils with peat layer and little drainage (mean annual water table < 20 cm below surface). The net GHG balance reached 7–9 t CO2–C–eq ha−1 yr−1 on soils with sand mixed into the peat layer and water tables between 14 cm and 39 cm below surface. GHG emissions from drained histic Gleysols (i) were as high as those from deep Histosols, (ii) increase linearly from shallow to deeper drainage, (iii) but are not affected by Corg content of the histic horizon. Ecosystem respiration (Reco) was linearly correlated with water table level even if it was below the histic horizon. The Reco/GPP ratio was 1.5 at all sites, so that we ruled out a major influence of the inter-site variability in vegetation composition on annual net ecosystem exchange (NEE). The IPCC definition of organic soils includes shallow histic topsoil, unlike most national and international definitions of Histosols. Our study confirms that this broader definition is appropriate considering anthropogenic GHG emissions from drained organic soils. Countries currently apply soil maps in national GHG inventories which are likely not to include histic Gleysols. The land area with GHG emission hotspots due to drainage is likely to be much higher than anticipated. Deeply drained histic Gleysols are GHG hotspots that have so far been neglected or underestimated. Peat mixing with sand does not mitigate GHG emissions. Our study implies that rewetting organic soils, including histic Gleysols, has a much higher relevance for GHG mitigation strategies than currently recognized.

Soil variability through spatial scales in a permanently disturbed natural spruce-fir-beech forest

Soil variability was assessed in a 74.2-ha area within the Žofinský prales natural forest. Parameters evaluated for 1765 soil profiles inside 353 graticule plots were as follows: (1) thickness of organic horizons, (2) thickness and form of mineral horizons, (3) humus form (HF), (4) soil taxonomic unit (STU) and (5) anomalies. In addition, soil reaction (pHKCl) and oxidizable carbon content (Cox) were measured in the laboratory for 734 samples from the upper mineral (A) and lower mineral (B) horizons. The most frequently occurring humus form was mor followed by moder, hydromor and peaty T-horizon. Entic Podzols, Dystric Cambisols, Haplic Cambisols, Albic Podzols, Histic (or Haplic) Gleysols, Endogleyic Stagnosols, Fibric or Hemic or Sapric Histosols and Stagnic Gleysols were all present at the site despite its homogeneous geological bedrock. Overall coefficient of variance (CV) was lower in terrestrial soils compared with (semi-)hydromorphic soils. Overall variance decreased in both soil groups with increasing depth, as did CV differences between the fine (up to 10 m) and the locality scales. The lowest CV values occurred for Cox and pHKCl. The CV values differed between STUs as well. Compared to lower horizons, variograms of upper horizons showed greater autocorrelation at the intermediate spatial scale (10–320 m)—ranging from 50 to 150 m. Semivariance values, however, reached 70–80% of sill already at a distance of 10 m. The most significant factor of variability at all studied spatial scales is presumably the soil disturbance regime, followed by terrain micro-topography and the effect of tree species.

Formation of the chemical composition of Histosols and histic soils in the forest lands of Estonia

The formation and vertical distribution of the chemical properties of fen (group I, five research areas) and transitional bog (group II, eight research areas) Histosols, and situated depressions of mineral landscape Histic Gleysols (group III, six research areas) and Histic Podzols (group IV, seven research areas) soil covers were studied. As a benchmark in the comparative analysis of Histosols, we used the 20 cm epipedon peat layers of eutrophic moderately acid (I) and mesotrophic very strongly acid (II) types. The thickness of histic soil epipedon peat varied from 10 to 30 cm and was classified as slightly acid peaty mull (IIIa) or strongly acid peaty moder (IIIb), and as very strongly acid peaty mor (IV). In forming the epipedon of the forest floor, aqua regia (mixture of hydrochloridic and nitric acids, 3:1)-extractable Fe, Cr, Al, Pb and Ni accumulated to a great extent (accumulation coefficient>2.5), and S, Na and Hg accumulated to a medium extent (accumulation coefficient 1.2–2.0); the amounts of Zn, K and Mn decreased to a great extent (accumulation coefficient<0.5), and those of Mg and P to a medium extent (accumulation coefficient 0.6–0.8); levels of Ca, Cu and Cd remained practically unchanged. Comparison of Histosol subsoil and substratum peats with a Histosol epipedon demonstrates considerable accumulation of Mn, Pb, Cd, Zn, Hg and Na in the thin (20 cm) superficial peat layer of mires.