Displays

The study was set up to characterize upland soils of Koko/Besse Local Government Area  in North western Nigeria for sustainable intensification of cropped land. Soil units were identified using flexible grid method. Based on the geology, morphology and  physical  properties the soil units were identified provisional  Soil map was produced in a GIS environment using combination of DEM and field boundary parameters. The major pedogenic processes included ferruginisation, lessivage,  and mineralization. All these processes combined to form ferrallitic soils with  low organic matter content. The soil units on sand stone were generally low in  Cation Exchange Capacity (CEC) (0.88-3.82cmol/kg) while the soils formed from metamorphic rock had low to high CEC (2.92-12.44) The Phosphorus distribution was generally low (0.71–6.96 mg/kg) while Nitrogen content was less than or equal to 0.07%in all the units Soil organic carbon ranged from 0.21-0.95%.  The major pedogenetic processes included, cummilization and  gleization at the lower slopes while ferrolyses and lessivage and ferruginisation with formation of iron stone rubbles and plinthite was dominant at upper slope position of the soils formed from sand stone. While mineralization, salinisation and lessivage were dominant processes with basement complex. The soil units were classified using USDA classification system. The soils on sand stone include  Plinthustults, Kandiustults, Dystrochrept. Natrustalf and Kandiustalf dominated areas underlain by micaceous ferromagnessiun rock. Based on the characterization, sustainable land use will involve use of fortified organic fertilizers, green manure, leguminous cover crops and erosion control measures such as vetiver grass strips

How to cite: Ande, O., Are, K., Adeyolanu, O., Oke, A., Ojo, O., Denton, O., Oluwatosin, G., Taiwo, O., Lucas, A., and Adediran, J.: Mapping and Classification of upland soils formed from sand stone and micaceous schist in Koko/Besse Area in North western Nigeria., EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-8786, https://doi.org/10.5194/egusphere-egu2020-8786, 2020.

Abstract

Knowledge about the genesis and evolution of black soils in the Eastern Mediterranean is vital for sustainable land management as well as for revealing the current and past climate conditions that were decisive for their evolution and development. Hence, it is important to study this type of soil as it only occurs very rarely in the semi-arid region. Answers on the conditions of formation and type of paleoclimate that prevailed during its development can be found in the surrounding environment. In this study, the black soils that currently occur in the Eastern Mediterranean were analyzed in different bioclimatic zones and were found to genetically belong to two soil types: 1-Calcareous black soil (ProperRendzina-Typic Rendolls), 2-Hydromorphic black soil (Haploxerolls). The impact of the relief was obvious on both thickness of the solum and the mollic horizon. Proper Rendzina (Typic Rendolls) occurs on toe slopes and feet slopes, Para-Rendzina (Lithic Rendolls) on shoulders and Chernozems on a flat plain. Regarding the Rendzina, the color reflects the origin of the prevailing parent material from which they are derived: Proper Rendzina forms on limestone, chalk, sandstone, conglomerates, and claystone; Reddish Rendzina on Dolomite and hard limestone, and Grayish Rendzina on Serpentine. It was also found that the Hydromorphic black soils (Haploxerolls, Calcic Chernozems) only occur on calcic marl and lacustrine deposits under saturation conditions and bad drainage in the depressions that formed by the Dead Sea faults. The soil has a thick dark mollic horizon with a high content of organic matter.

Keywords: semi-arid, black soil, Rendzina, Chernozems, eastern Mediterranean.

How to cite: Hag Mohamed Husein, H., Sahwan, W., Lucke, B., and Bäumler, R.: Genesis and Evolution of Black Soil in the Eastern Mediterranean, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-370, https://doi.org/10.5194/egusphere-egu2020-370, 2020.

Soil formation is controlled by climate, vegetation, organisms, topography, parent material and time. There are various hypotheses on the relative importance of these individual soil-forming factors. 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 sufficiently analyzed. The aim of this study was to quantify the influence of the soil-forming factors on the rates of podzolization. For this purpose, we compiled published data from 46 soil chronosequence studies in a database. These studies contained altogether 231 soil profiles of known age, on 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 46 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 (pioneer, deciduous and coniferous), sand content, clay content, and soil age.

Since 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 soil age at which podzolization starts (used indicator: first occurrence of an E horizon), and (2) the rates 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 are important for the soil age at which podzolization starts but less important for the rates of podzolization. We did not identify a significant influence of sand content, neither on the start nor the rates of podzolization. Thus, this statistical assessment of global data provides new insights into the relative importance of the individual soil-forming factors on the onset and temporal course of podzolization.

How to cite: Zwanzig, L., Zwanzig, M., and Sauer, D.: Outcomes of a quantitative analysis of 46 soil chronosequence studies: Vegetation plays the key role for rates of podzolization in most environments., EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-3154, https://doi.org/10.5194/egusphere-egu2020-3154, 2020.

On an unglaciated karst landscape in the Lombard Pre-Alps (Salmezza, Bergamo, Italy), an extremely high pedodiversity occurs across a few hectares on Norian dolostone. The rock is locally enriched in well crystallized sand-grained quartz. The climate of the area is suboceanic, with >1500 mm of annual rainfall, and an average temperature around 6-8°C. Rendzic Leptosols and Phaeozems are developed on the steepest slopes, Podzols, Cambisols and Luvisols on flatter areas, while Rhodic Luvisols/Alisols (Terra-Rossa soils) are found in doline cracks and crevices. The sand-grained quartz content of the parent rock seems to be the main soil differentiating factor: where it is abundant (ca. 10-20% in volume), it is responsible for the genesis of Podzols.

We sampled and analyzed 9 soil profiles from the Salmezza area, thus characterizing all pedogenic processes active in the area. In particular, we analyzed standard soil chemical properties (pH, organic carbon, base status and Cation Exchange Capacity, dithionite and oxalate-extractable Fe and Al); we performed a total elemental analysis on most samples and on substrate samples, in order to calculate mass balance and element loss and enrichment; we observed thin sections and performed XRD analysis in powder samples and on the clay fraction of most pedogenic horizons as well.

The parent material is a rather pure dolostone, composed of dolomite, locally enriched in quartz. No other minerals have been observed. Very little amounts of Fe, Al and other elements are thus included in the parent rock (almost completely composed of Ca, Mg and Si), often very close to the analytical detection limit. Ca and Mg were almost completely lost during most soil forming processes in this temperate humid climate, while the enrichment in Si, Fe, Al varies broadly amidst the different soils, thanks to different pedogenic processes. Fe and Al, in particular, were up to 120 times more concentrated in Bt and Bhs horizons than in the parent rock. The ratios between stable elements in rocks and soils verifies important inputs of aeolian materials. The values are, however, different also amidst different soils, so an univocal origin of aeolian materials cannot be hypothesized. The mineralogy of the clay fraction is also strongly modified by pedogenesis, so that each soil type is characterized by a different mineralogical assemblage, making it difficult to detect signatures of specific aeolian origins as well.

How to cite: D'Amico, M., Casati, E., Barcella, M., and Previtali, F.: Aeolian inputs as parent materials for Podzols and terra-rossa soils in a dolomitic landscape in the Italian Alps (Salmezza, BG, Italy), EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-20494, https://doi.org/10.5194/egusphere-egu2020-20494, 2020.

Microorganisms can modify the composition of their lipid membrane in response to variations in environmental parameters. This is the case for bacterial lipids such as glycerol dialkyl tetraethers (GDGT) and 3-hydroxy fatty acids (3-OH FAs), both used for temperature and pH reconstructions in terrestrial paleoenvironmental studies. However, a major concern with these proxies is that their structure may be influenced by other environmental parameters than temperature or pH. The present study aimed at identifying and quantifying the influence of environmental parameters such as soil moisture, vegetation types and soil types on bacterial GDGTs and 3-OH FAs. These lipids were analyzed in 49 soil samples collected between 200 m and 3,000 m altitude in the French Alps. The soils cover a wide range of temperature (0 °C to 15 °C) and pH (3 to 8) and are representative of the diversity of soils and vegetation encountered along the investigated altitudinal transects. Using this new well-documented and unique dataset, the GDGT-pH correlation was confirmed, but the one between 3-OH FAs and pH was lower than in previous studies. For the temperature, correlations were lower than in previous studies for the GDGTs and absent for the 3-OH FAs. These observations could be explained thanks to different statistical analyses. Redundancy analysis (RDA) showed that pH is the main driver of the variability of 3-OH FAs and GDGTs, explaining 20.5 % and 56 % of the distribution of these bacterial lipids, respectively, followed by the altitude (8 % influence on the distribution of 3-OH FAs, and 11 % on GDGTs) and granulometry (5 % impact on 3-OH FAs and 7.5 % on GDGTs). Taken together, these results highlight the major influence of the vegetation cover and soil types on the distribution of bacterial lipids. Indeed, we quantified and explained for the first time the impact of the different environmental factors (temperature, vegetation, soil type…) on the distribution of bacterial lipids. This novel comprehension of the impacts of environmental parameters will allow to refine the use of proxies based on these compounds. These results pave the way for new types of applications of GDGTs and 3-OH FAs as environmental proxies in paleosoils, peat or lacustrine sediments.

How to cite: Véquaud, P., Derenne, S., Collin, S., Anquetil, C., Poulenard, J., Sabatier, P., and Huguet, A.: Influence of environmental parameters on bacterial lipids in soils from the French Alps: implications for paleo-reconstructions, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-501, https://doi.org/10.5194/egusphere-egu2020-501, 2020.

In hilly and mountainous landscapes, the bedrock is actively converted to a continuous soil mantle. The bedrock-soil interface lowers spatially at the soil production rate, and the soil acts as a layer removing sediment produced locally and transported from upslope. Forested soils of a hummocky ground moraine landscape in Northern Germany exhibit strongly varying soil thicknesses with very shallow soils on crest positions and buried soils at the footslope. We explored the explanatory power of both ¹⁰Be forms (in situ and meteoric) for forest soils on a hillslope to shed light into the complex mass redistribution. Our main research questions were: how do meteoric and in-situ ¹⁰Be compare to each other? What do they really indicate in terms of soil processes (erosion, sedimentation, reworking)? By using both types of ¹⁰Be, the dynamics of soils and related mass transports should be better traceable. Both ¹⁰Be forms were measured along three profiles at different slope positions: Hydro1 (summit), Hydro3 (shoulder), Hydro4 (backslope). Furthermore, a buried horizon was found in the profile Hydro4 at 160 cm depth and ¹⁴C-dated. The distribution pattern of meteoric ¹⁰Be of Hydro4 shows an inverse exponential depth profile, and an almost uniform content of in-situ ¹⁰Be along the profile. Meteoric ¹⁰Be indicates on the one hand that a new soil was put on top of an older, now buried soil. On the other hand, meteoric ¹⁰Be is involved in pedogenetic processes and clearly exhibits clay eluviation in the topsoil and clay illuviation in the subsoil. The uniform content of the in situ ¹⁰Be shows soil mixing that must have occurred during erosion and sedimentation. The¹⁴C dated buried soil horizon indicates a deposition of eroded soil material about 7 ka BP. Consequently, an increase in the in-situ ¹⁰Be content towards the surface should be expect which however was not the case. The reason for this is so far unknown. Radiocarbon dating and ¹⁰Be data demonstrate that strong events of soil mass redistribution in Melzower Forest are mainly a result of ancient natural events. Further measurements of fallout radionuclides (^239+240Pu) showed no erosion for the last few decades in the same catchment.

How to cite: Calitri, F., Egli, M., Sommer, M., Tikhomirov, D., and Christl, M.: Complex soil mass redistribution along a catena using meteoric and in-situ 10Be as tracers, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-15848, https://doi.org/10.5194/egusphere-egu2020-15848, 2020.

Terraces and lynchets are not only ubiquitous worldwide and within Europe but can provide increasingly important Ecosystem Services (ESs), which may be able to mitigate aspects of climate change. They are also probably a major cause of non-linearity between climate and erosion rates in agricultural systems as noted from alluvial and colluvial studies. In this paper we review the theoretical background of terraces and lynchets, present a modified classification, and show how new techniques are transforming the study of these widespread and often ancient anthropogenic landforms. Indeed the problems of dating terraces and also the time-consuming nature and costly surveys has held back the archaeological study of terraces until now. The applicable suite of techniques available now includes the creation of Digital Terrain Models (DTMs) from Structure from Motion (SfM) photogrammetry, Airborne and Terrestrial Laser Scanning (ALS-TLS); the use of OSL and pOSL, pXRF, FTIR, phytoliths, calcium oxalates from plants and potentially sedaDNA. Examples will be drawn from a recently started ERC project (TerrACE; ERC-2017-ADG: 787790, 2018-2023; https://www.terrace.no/) which is working at over 10 sites in Europe ranging from Norway to Greece.

This paper explains the development of a new holistic approach to terrace archaeology driven by a modern conceptualisation of human-landscape relationships, and facilitated by new scientific developments. We explain the rationale for our choice of case study areas, for example, the range of bio-climatic zones. In addition, this multi-regional approach allows us to address contingent regional and local historical/socioeconomic processes; from demographic fluctuations to the development of specific forms of agricultural techniques. Examples of DTM creation, field analyses and selected results will be given from Martleburg in Belgium and sites in Italy. We will then move on to explain how this combination of a comprehensive suite of modern field and laboratory methods and an interpretive strategy informed by the environmental humanities will yield exciting and groundbreaking results.

How to cite: Fallu, D., Brown, T., Walsh, K., Cucchiaro, S., Tarolli, P., Zhao, P., van Oost, K., Snape, L., Lang, A., Albert, R.-M., Alsos, I., and Waddington, C.: Ending the Cinderella Status of Terraces and Lynchets in Europe, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-7116, https://doi.org/10.5194/egusphere-egu2020-7116, 2020.

Pliocene has a key role in assessing future climate impact and specifically, the mid-Piacenzian is considered the most recent period in Earth’s history in which temperatures reached values similar to those predicted for the end of the 21st century, about 2°–3°C warmer globally on average than today. Palaeopedology offers a great potential for elucidating high resolution, deep time palaeoclimate records. Thus, we aimed to investigate palaeosols as suitable archives for reconstructing surface processes, paleo-ecosystem structures and local- to global-scale paleoclimate patterns in the Pliocene.

A favourable opportunity to study soils developed in the Early and in the Late Pliocene was provided on two alluvial sediments in Tuscany (Central Italy). Piacenzian palaeosol-stratigraphic sequences were compared with previously known Zanclean stratigraphic records. A multi-proxy approach, combining stratigraphic and paleopedological evidence, was adopted to produce more robust palaeoenvironmental insights. Field observations were related with quantitative techniques based on geochemical and isotopic analysis, to evaluate pedogenic processes, past-climate and palaeovegetation.

Pedological evidence of two contrasting environments were present at the two sequences. Strong redoximorphic features such as low-grade plinthite were observed in the Zanclean-age soil, suggesting that these soils evolved in humid palaeoclimate in a time span of a few thousand years. On the other hand, the Piacenzian-age soils of central Tuscany represented rhythmic and short intervals of pedogenesis, connected with sea level highstands. The best developed palaeosols show very well-expressed Calcic horizon. Pedogenic carbonates are typically associated with well-drained soil profiles in sub-humid, semi-arid and arid climates characterized by relatively low rainfall and high evapotranspiration. This suggest that Mediterranean-type rainfall patterns may have prevailed in the warmest intervals of Late Pliocene. The studied Piacenzian soils with carbonates were weak- to moderated-developed based on the characteristics of carbonate accumulation that are II and III stage moving from the ancient to the recent ones, suggesting a range of development from 10³ to 10⁴ years.

The estimates of the mean annual precipitation (MAP), based on weathering indices (CIA-K) and geochemical climofunctions, further allowed us to solidly inferred that substantial differences in climate conditions leaded to the divergent pedogenesis pathways, even considering the large difference in time as a factor (about one order of magnitude) between the two outcrops.

How to cite: Andreetta, A., Benvenuti, M., and Carnicelli, S.: Palaeoenvironmental insights into Pliocene palaeosols of Tuscany (Italy)., EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-12908, https://doi.org/10.5194/egusphere-egu2020-12908, 2020.

Environmental and time-scale reconstructions of deep sedimentary sequences are based on a wide variety of markers to highlight and characterise environmental variations within a homogeneous sedimentary setting. Moreover, in the lack of reliable age constrain, it is often the only way to highlight timelines and correlations between sequences collected in different places. Within this set of potential markers, palaeosols developed on terrestrial sedimentary beds during biostasy conditions stand out. These evidences are often useful for both their visibility within a core and their strong environmental implications. In continental basins characterized by glacial contributions, they also represent potential time information linked to the fluctuation of glacial and interglacial periods. However, the interpretation of sedimentary markers in cores using visual identification to the naked eye can possibly lead to the wrong conclusions: this method for palaeosol identification is not straightforward and prone to the production of false positives. We conducted detailed micromorphological investigations on a series of markers in a core from the central-northern portion of the Po Plain foreland basin, proximal to the Southern Italian Alps which fed the basin during the Pleistocene.

Seventeen sedimentary anomalies were identified during the visual description on the basis of colours and textures as potential palaeosols and were sampled to be studied in thin section. The study allowed to recognise evidences of soil-forming processes, which could characterise the past pedogenesis as well as their environment. From micromorphological analysis, only 4 samples showed visible signs of pedogenesis or post depositional weathering caused by proximity to the surface. Observed elements range from pedoplasmation to pedogenetic features related to redoximorphic processes and clay illuviation, thus allowing to interpreted them as truncated palaeosols. Conversely, 6 samples showed forms of transport of soil material, either sedimentary or in solution, but did not represent soils formed in situ; these can be interpreted as pedorelicts. Of the remaining samples, 5 were calcrete potentially related to groundwaters, and 2 represented accumulations of Fe/Mn oxides in wetland conditions (“bog iron”). These results suggest a reconsideration of the role of palaeosols as stratigraphic markers in the study of subsurface sedimentary sequences. Precise identification and microstructure characterization are necessary to avoid possible misinterpretations and correlations among cores.

How to cite: Mariani, G. S., Muttoni, G., Norini, G., Aghib, F. S., De Franco, R., Piccin, A., and Zerboni, A.: When appearances lie: micropedology of palaeosol markers in a Pleistocene sedimentary record from central Po Plain, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-18674, https://doi.org/10.5194/egusphere-egu2020-18674, 2020.

Here we investigate the timing of the last glacial loess - Holocene soil transition recorded in loess-paleosol sequences across the Chinese Loess Plateau, the SE European loess belt and the Central Great Plains, Nebraska, USA by applying comparative luminescence dating techniques on quartz and feldspars. Equivalent dose measurements were carried out using the single-aliquot regenerative-dose (SAR) protocol on silt (4–11 μm) and sand-sized (63–90 μm and coarser fraction when available) quartz. Feldspar infrared stimulated luminescence (IRSL) emitted by 4–11 μm polymineral grains was measured using the post IR-IRSL₂₉₀ technique.

The paleoenvironmental transition from the last glacial loess to the current interglacial soil was characterized using magnetic susceptibility and its frequency dependence. Based on the OSL ages and the threshold of the magnetic signal enhancement the onset of soil formation started around Termination 1 (~17 ka in the North Atlantic) as observed in radiocarbon-dated regional benthic δ¹⁸O stacks (Stern and Lisiecki, 2014) but before the stratigraphic Pleistocene/Holocene transition dated at 11.7 ka in ice core records (Svensson et al., 2008).

No major hiatuses in ages are identified in the investigated sites. A change in the sedimentation rate is generally observed at the Pleistocene-Holocene transition and no significant sedimentation change during the Holocene. Sedimentation rates of around 6 cm/ka are determined for the Holocene soil in most of the sites investigated.

The magnetic susceptibility indicates a gradual increase in pedogenesis after Termination 1 (∼17 ka in the North Atlantic). Based on this, we infer that the upbuilding soil formation prevailed over topdown soil formation during the Pleistocene-Holocene transition in the investigated sites (Roberts, 2008).

References

Roberts, H.M., 2008. The development and application of luminescence dating to loess deposits: a perspective on the past, present and future. Boreas 37, 483-507.

Svensson, A., Andersen, K.K., Bigler, M., Clausen, H.B., Dahl-Jensen, D., Davies, S.M., Johnsen, S.J., Muscheler, R., Parrenin, F., Rasmussen, S.O., Röthlisberger, R., Seierstad, I., Steffensen, J.P., Vinther, B.M., 2008.A 60 000 year Greenland stratigraphic ice core chronology. Climate of the Past 4, 47-57.

Stern, J.V., Lisiecki, L.E., 2014. Termination 1 timing in radiocarbon-dated regional benthic δ18O stacks. Paleoceanography 29, 1127-1142.

This project has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme ERC-2015-STG (grant agreement No [678106]).

How to cite: Constantin, D., Sacaciu, S.-M., Tecsa, V., Avram, A., Begy, R., Kelemen, S., Veres, D., Panaiotu, C., Zhou, L., Mason, J., Marković, S., Hambach, U., Gerasimenko, N., and Timar-Gabor, A.: Luminescence age constraints on the Pleistocene-Holocene transition recorded in loess sequences, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-16957, https://doi.org/10.5194/egusphere-egu2020-16957, 2020.

Over the last interglacial/glacial cycle climate variability and forcing in the northern hemisphere is best documented in high resolution from marine and ice core records. The response of land surface processes to climate over this period, however, remains poorly defined. Understanding landscape response to climate change is nevertheless of critical importance not only because as humans we live on and interact with the land, but also in order to identify potential feedbacks and forcings between land and atmosphere which cannot be ascertained from marine and ice core records. In this context, Loess-Palaeosol-Sequences (LPS) are outstanding terrestrial archives allowing detailed reconstruction of palaeoclimate and palaeo­environ­mental changes. However, regarding their complexity, LPS represent polygenetic and multiphase archives over different spatial and temporal scales. Consequently, a solid understanding of geomorphological and pedogenic processes involved in LPS formation, and the interplay with changes in ecological conditions, must be considered before LPS can be correlated with other archives.

Against this background, extensive fieldwork has been carried out at the Schwalbenberg site near Remagen (Middle Rhine valley, Germany) combining geophysical exploration with Direct Push borehole geophysical measurements and sediment coring. We will present a first comprehensive data set for the Schwalbenberg key area based on a transect from up- to downslope. The integration of grain size, organic carbon and weathering indices from long sediment cores (up to 30 m) and profile sections contribute to a better understanding of processes involved in the Schwalbenberg LPS formation. These data combined with age constraints based on radiocarbon and luminescence dating lead to a first robust chronostratigraphic model of the Last Interglacial/Glacial Cycle suggesting the Schwalbenberg LPS to be a terrestrial archive of palaeoclimate variations in phase with northern hemispheric ice and marine records.

How to cite: Fischer, P., Jöris, O., Vött, A., Fitzsimmons, K., Vinnepand, M., Hambach, U., Prud'homme, C., Schulte, P., Lehmkuhl, F., Zeeden, C., and Schirmer, W.: A New Continuous Terrestrial Archive of Environmental Change during the Last Interglacial/Glacial Cycle – The Loess-Palaeosol-Sequences of the Schwalbenberg (Middle Rhine Valley, Germany), EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-11167, https://doi.org/10.5194/egusphere-egu2020-11167, 2020.

Soils and sediments serve as complementary sources of detailed information on paleofires in various ecosystems. Despite the abundance of charcoal material entrapped in soils they remain relatively less studied pyrogenic archives in comparison to the sedimentary paleofire records (e.g. lacustrine and peat deposits), and that is especially the case for the most territory of Russia. We report here on the numerous soil archives of the Holocene forest fires at the Kola Peninsula (66.347°N, 37.948°E) and the north of Arkhangelsk region (64.747°N, 43.387°E) in Russia. Series of buried Podzols (up to ten successive profiles) separated by the distinct charcoal layers were revealed in specific geomorphological traps like the thermokarst depressions inherited from the early stages of moraine sediments formation (Kola Peninsula), as well as in active and paleokarst sinkholes in carbonate and sulfate rocks (Arkhangelsk region). The maximum temporal depth of archives was estimated as 10261±40 cal yr BP for the key site in Arkhangelsk region, with up to 12 major pyrogenic events recorded at the local scale. Soil formation at the inter-pyrogenic stages maintained a uniform direction for at least 10 thousand years and profiles of Podzols were regularly replicated at all the key sites. We employ here a combination of soil morphological hierarchical analysis, study of geomorphological processes leading to the burial of pyrogenic carbon, 14C dating of charcoal and TOC derived from the soil organic matter, carbon and nitrogen isotope ratio mass spectrometry and anthracomass concentrations analysis to extract a set of paleoenvironmental information from these soil archives. The study of complementary pyrogenic archives in the three-component system of the karst landscape (including bottom and slopes of the funnels, as well as the flat elevated areas between them) helped to mitigate overestimation or underestimation of the anthracomass concentration and allowed to acquire a detailed dataset on paleopyrogenic events at the local scale. This study is supported by the Russian Foundation for Basic Research, Project No. 19-29-05238.

How to cite: Mergelov, N., Petrov, D., Dolgikh, A., and Zazovskaya, E.: Soil record of the Holocene paleofires at the north of European Russia, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-19814, https://doi.org/10.5194/egusphere-egu2020-19814, 2020.

Ruins and archaeological structures in the southern Levant are often covered by initial soils that developed on debris. The fine grain size fractions of these soils may stem from aeolian sediments, and the ruins could serve as effective dust traps. The physical parameters and chemical composition of archaeological soils in hilltop ruins, cleanout spoils of cisterns, and ancient runoff-collecting terraces were determined in the Petra region in southern Jordan and the northern Negev in Israel. Different types of ruins could not be distinguished with regard to substrate composition. This indicates a predominance of aeolian processes for primary sedimentation, while fluvial processes only re-distribute aeolian material. In the Petra region, a significant local contribution from associated weathered rocks could be observed. Compared to modern settled dust, archaeological soils in southern Jordan are enriched with various major and trace elements associated with clays and oxide coatings of fine silt particles. In-situ weathering seems minimal, but preferential fixation of silt and clay by surface crusts (similar to desert pavements), and a role of moisture in sedimentation processes lead to increased sedimentation of calcareous silt. Contribution of rocks is negligible in the Negev due to greater rock hardness and abundant biological crusts sealing surfaces. Archaeological soils in the Negev and current settled dust consist of complex mixtures of local and remote sources, including significant portions of recycled material from paleosols. Archaeological soils in the southern Levant are archives of Holocene dust sources and aeolian sedimentation processes, with accretion rates exceeding those of Pleistocene hilltop loess in the Negev. Comparison with Pleistocene paleosols suggests that dust sources did not change significantly, but disappearance of snow could have reduced dust accumulation during the Holocene.

How to cite: Lucke, B., Sandler, A., Vanselow, K. A., Bruins, H., Abu-Jaber, N., and Bäumler, R.: Soils in archaeological structures of the southern Levant: archives of Holocene dust dynamics, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-270, https://doi.org/10.5194/egusphere-egu2020-270, 2020.

The sugar industry has been widespread in the world for centuries, accumulating huge amounts of production waste. The development of modern technologies for sugar beet processing has led to the abandonment of dumps and sumps; not all of them were remediated later. In Russia, the industrial production of sugar from sugar beets was established in the early 19th century. For the first time, soils and landscapes formed on abandoned sites of sugar production waste in the Chernozem zone of Russia were studied. The distribution and chronological sequence of abandoned sites were identified using space images and field observation. Sugar production wastes discharged into sumps and landfills contained mainly carbonic lime (СаСО3), caustic lime Ca(OH)₂ and organic material, and an admixture of nitrogen, phosphorus potassium and sulfur (about 1-3%). It was revealed that in about 50 years, alkaline soil- geochemical landscapes were formed, which are unusual in the study area. Series of ponds temporarily filled with rainwater – former waste sumps – are covered with dense reed beds (Phragmítes austrális); there, strongly alkaline (pH ≥9), rich in organic matter and bioturbated soils with a thickness of up to 50-60 cm are formed. They can be attributed to Garbic Technosols (Carbonic), but their classification position in WRB needs to be clarified. Reed has spread widely in the surrounding water bodies and rivers; newly formed landscapes enrich waters with nutrients, contributing to their eutrophication. Soil mantle is also complicated by Technosols of industrial sites of sugar factories, soils in the remediated and no-remediated landfills, and soils irrigated with sugar mills' wastewater. All these soils are repositories of large volumes of organic carbon. The study of newly formed soils and landscapes, overgrowing of dumps and sumps is extremely important both for nature conservation and for understanding the seasonal patterns of carbon dioxide emissions from accumulations of organic substances. Integrated soil-geochemical and geobotanical studies of areas affected by the sugar industry can be pioneers, among other things, to expand the horizons of soil and geobotanical classification.

The work was financially supported by the Russian Foundation for Basic Research, project № 19-29-05025-mk.

How to cite: Gracheva, R., Zamotaev, I., Konoplyanikova, Y., Telnova, N., and Belonovskaya, E.: Soils and landscapes as legacies of the sugar industry land use, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-17507, https://doi.org/10.5194/egusphere-egu2020-17507, 2020.

The possibility of an adequate use of data and maps from historical soil surveys depends, to a large measure, on their harmonisation. Legacy data originating from a large-scale national mapping campaign, “Systematic soil survey of agricultural soils in Czechoslovakia (SSS, 1961–1971)”, were harmonised and converted according to the World Reference Base 2014 (WRB). Applying three different methods of taxonomic distance computation and quantitative analysis and reclassification of the selected soil properties, the conversion of so-called Basic soil representatives (BSR) – mapping soil units providing information about soil (type, subtype, variety) and lithology (parent material, texture, soil depth, skeleton content) – to their counterparts in the WRB has been effectuated. The results proved the good potential of the used methods for soil data harmonisation. The values of taxonomic distance correspond to the different concepts and settings of the soil classes in the harmonized soil classifications. Classes with specific and narrowly defined diagnostics, often with one or few strong and distinctive features, show close distances with their counterparts, and, often, have only one relevant counterpart. On the contrary, soils with variable soil properties were approximating several related units. The additional information on the soil skeleton content, texture, depth and parent material showed the potential in the specification of some units, though the harmonisation of the soil texture turned out to be problematic due to the different categorisation of soil particles. The resulting soil classes have been presented for each polygon (so-called soil district) as i) one to one conversion, when each BSR is converted to one, most probable, WRB soil class (Reference soil group, RSG) and ii) soil association corresponding to the three closest RSGs. The validation of the results in the study region showed an average overall accuracy for a one-to-one (59.4 %) conversion and a very good accuracy (83.8 %) for the polygons presented as soil associations. The conversion accuracy differed significantly in the individual soil units, and ranged from 92 % in Fluvizems to 0 % in Technosols and Histosols. The extreme cases of a complete mis-classification can be attributed to inconsistencies originating in the historical database and maps. The study showed the potential of modern quantitative methods in the legacy data harmonisation and also the necessity of a critical approach to historical databases and maps.

Supported by the Ministry of Agriculture of the Czech Republic, Project No. QK1820389.

How to cite: Zádorová, T., Skála, J., Penížek, V., Žížala, D., and Vaněk, A.: Harmonisation of a large-scale historical database with the principles of the World Reference Base for Soil Resources, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-2622, https://doi.org/10.5194/egusphere-egu2020-2622, 2020.

On two accumulation levels, separated by an unevenness up to 2 m, two contrasted plant communities can be differentiated in subalpine stage of the Pyrenees: the dense tussock-forming grass Nardus stricta, at the upper level (L1), and the open chalk grasslands at the lower level (L2). In order to confirm the soil-relief-grasslands relationships, we analyzed and compared soil pedogenesis and properties in both accumulation levels. In addition, we classify the soils following WRB and ST systems and we discuss the finesse of both taxonomies in these high mountain environments. The work has been carried out at 1900 masl, in the Ordesa and Monte Perdido National Park (PNOMP), in the summer grasslands site of La Estiva (Fanlo, Central Pyrenees, NE Spain). Five soil pits were studied in every accumulation level (L1 and L2) for a side-by-side comparison.

            The study of soils in the two levels of accumulation reveals a series of differences in their genesis, properties and soil classification. The accumulation of organic matter and lixiviation are the dominant edafogenetic processes in L1, to which we must add the rejuvenation by gully erosion in L2. Soils at L1 and L2 shared many physical properties as a fine granulometry, with a homogeneous particle-size distribution with depth. In both levels, the soils lack carbonates, even though limestones are the parental material. The soils in L1 have a greater thickness and, thus, a higher water holding capacity than in L2. In relation to chemical properties, soils in L1 have a significantly lower pH, a lower base saturation, and lower available calcium content than in L2, reflecting a more intense leaching process, consistent with a longer period of slope stability. Over L1 with Nardus mat-grasslands, the main soil is classified as Orthoeutric Cambisols (Clayic, Humic), and the soil over L2, with chalk-grasslands, as Hypereutric Leptosols (Loamic, Ochric). Soil taxonomy System (USDA), giving more weight to the temperature regime, classify both soils as Haplocryept, at the level of great group, separating them at the subgroup level as Typic Haplocryept (L1) and Lithic Haplocryept (L2), according to the depth at which limestone appears (lithic contact). Definitely, the microtopograhy and geomorphologic context, is linked to the pedodiversity, which goes hand in hand with plant diversity in this subalpine environment.

How to cite: Badía-Villas, D., Buendía-García, L., Longares-Aladrén, L. A., Peña-Monné, J. L., and Martí-Dalmau, C.: Soils and relief relationships in subalpine grasslands in the Central Pyrenees (NE, Spain), EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-4178, https://doi.org/10.5194/egusphere-egu2020-4178, 2020.

Across the northcentral Appalachians, USA, high silt content soils are found as silty mantles or deep, high silt content pedons. The origin of such soils can be attributed to additions of wind-blown dust deposits (WBD) or local parent materials (i.e. shales or siltstone lithology). Previous research on silt soils originating specifically from WBD attributed to late marine isotope stage (MIS) 2 loess has often been isolated to drainageways receiving outwash from deglaciation. We hypothesize that thin (<25-50 cm) silty mantles, and some deep silt soils occurring farther from outwash systems, are also indicative of post MIS 2 WBD and their extent is widespread. To test this hypothesis, we evaluated over 900 pedons from an ~119,280 km² area of the northcentral Appalachians, USA to: (i) develop a particle size signature indicative of soils largely derived from WBD versus local parent materials, (ii) determine the potential depth of WBD additions to soils, and (iii) document the spatial extent of WBD versus deep, high-silt content soils across part of the region. Results suggest that silty mantles are prevalent across the study area and have a particle size signature indicative of loess and the mean depth of WBD additions to soils is ~50 cm.  Below 50 cm, local lithology or pedogenesis more influences particle size trends.  Pedon results were applied in a spatial modeling effort using the USA Soil Survey Geographic Database (SSURGO) to document the extent of silty mantles (over non-silt sourced parent materials) and deep, high silt content soils.  Model results indicate silty mantles are common on stable landscape positions or positions that accumulate sediments (depressions or valleys). Aspect dependent deposition appears tied to sources of WBD deposits, and deposits correspond strongly to regional studies of WBD deposits derived from loess. Last, proximity to topography, which can act as a trap for WBD, appears to be a key variable explaining silty mantle and deep, high-silt content soil occurrence. 

How to cite: Drohan, P., Raab, T., and Hirsch, F.: The presence of silty mantles in Northcentral Appalachian, USA soils and their relevance to pedology, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-5661, https://doi.org/10.5194/egusphere-egu2020-5661, 2020.

Podzols are considered to be the most common upland forest soil type in Finland. However, there have only been a few studies that have examined the degree of podsolization in Finnish soils. More detailed information about this dominating process in our soils can be utilized in other kinds of environmental research such as the impacts of climate change, carbon and nutrient cycling, and the degradation of soil and water systems.

We studied how the intensity of podsolization is related to Jenny’s classic five soil formation factors: climate, parent material, topography, biotic and time. The degree of podzolization of 86 soil profiles distributed over the whole of Finland was described using four podzolization indices: E-horizon thickness, B-horizon rubification, profile Al+Fe oxide eluviation-illuviation, and their sum (Podzolization Development Index, PDI). The soil profiles, selected out of over 600 soil profiles in a national database, met the World Reference Base for Soil Resources (WRB) criteria for them to be classified as Podzols. The relationship between the podzolization indices and a number of site and soil variables (continuous and categorical) describing Jenny’s soil formation factors were then evaluated. While podzolization intensity was found to be related to soil profile age, elevation, longitude, forest site type, aspect, Sphagnum moss cover and B-horizon texture, the individual relationships were weak. However, looking at the combined effect of all the variables using Partial Least Squares regression analysis, which is unaffected by multicollinearity among the predictor variables, nearly 70% of the measured PDI index could be explained.

How to cite: Törmänen, T., Lindroos, A.-J., Ilvesniemi, H., and Starr, M.: Development of Podzols in relation to Jenny's soil formation factors, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-21440, https://doi.org/10.5194/egusphere-egu2020-21440, 2020.

The distribution of forest patches in the foreststeppe of central Mongolia reflects the interplay of several environmental factors that together control the vegetation pattern of the landscape. Since the mean annual precipitation of this semiarid area rarely exceeds 300 mm, the existence of forest strongly depends on the hydrological properties of the system. Only north-facing slopes provide suitable conditions for the growth of larch trees (Larix sibirica Ledeb.) due to their reduced evapotranspiration. Plains and south-facing slopes are covered by open steppe.However, after disturbance of the forest patches by fire, the regrowth of larch trees does not proceed equally in all areas. During fieldworkat the northern edge of the Khangai Mountains, we identified areas that seemed to havesimilar site conditions but neverthelessshowed different regrowth of larch trees after fire, ranging from intensive regrowth to no regrowth at all.Thisobservation stimulated us to carry out a comprehensive study of soils, vegetation and landscape development in field campaigns in 2017 and 2018, followed by laboratory analyses of soil samples.Through this work, we aimed at identifying the role of soil hydrology for forest succession in this sensitive ecotone.

We described and sampled 57 soil profiles, including sites (i) under forest, (ii) under steppe, (iii) on sites with succession after forest fire, (iv) on sites without succession after forest fire. In the field, we carried out measurements of water conductivity (by use of a compact constant head permeameter). In the laboratory, we analyzed particle size distribution and carried outkfand pF measurements.

These analyses showed that the dominant grain size of the soils was sand, whereby soils with forest regrowth had slightly loamier texture than those without regrowth. We concluded that already slightly loamier texture may be important for water storage during dry periods and thus for forest regrowth.Soils with forest regrowth had higher hydraulic conductivity in the first 25 cm and lower conductivity below.Soils without forest regrowth showeda reverse depth pattern of hydraulic conductivity. We concluded that quick drainage through the upper horizons supports forest regrowth, as it reduces competition for water with grass roots in the upper part of the soil.Soils with forest regrowth hadgreater plant-available water capacity than those without regrowth. We conclude that under the given climatic conditions, storage of plant-available water is a key factor for regrowth / no regrowth of forest after disturbance.

How to cite: Schneider, F., Klinge, M., Brodthuhn, J., and Sauer, D.: Recovery of forest patches in central Mongolia after fire: Which role does soil hydrology play?, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-21125, https://doi.org/10.5194/egusphere-egu2020-21125, 2020.

The aim of this work was to obtain a deeper understanding of the factors triggering geomorphological processes in the semi-arid mountain forest-steppe of the Khangai Mountains in central northern Mongolia. We hypothesized that the pattern of geomorphological processes in this region is strongly influenced by (i) the spatial distribution of aeolian sediments and (ii) forest fires. We further assumed that the spatial and functional relationships between these two geomorphological factors lead to various types of sediment-soil archives of landscape evolution in different relief positions. These different types of archives should have recorded different pieces of information, which might be combined into a reconstruction of the landscape evolution in this area. We intended to use these different archives to reconstruct the Holocene landscape evolution, and in particular, to identify the roles of aeolian sediment distribution and forest fires on the geomorphological processes that took place over the Holocene.

The area is dominated by steppe vegetation. Only the north-facing slopes of the mountains, where reduced evapotranspiration leads to somewhat increased soil moisture, have forest. The bedrock on the slopes is overlain by Pleistocene periglacial slope deposits (PPSD), consisting of rock debris, which is mixed with fine sand in its upper part. These PPSD are widely covered by an aeolian sand sheet, which is usually more than one meter thick. IRSL ages indicate that the main deposition of these sediments took place 13-11 ka ago. Sediments at the toe slopes and on the valley bottom consist of layered, dark and lighter-colored, silty and sandy material with cryoturbation features. They apparently originate from soil material that has accumulated at the toe slopes and in the valleys by colluvial, fluvial and aeolian processes.

On the slopes under forest, charcoal commonly occurs in the upper 20 cm of the soils and provides calibrated ¹⁴C ages of up to 2 ka. Calibrated ¹⁴C ages of charcoal and soil organic carbon of the sediments at the toe slopes are generally older (up to 4.4 ka). This difference suggests that the charcoal produced by earlier forest fires, together with the sediment in which it is embedded, has been washed from the upper and mid slopes down to the toe slopes and valleys. Charcoal of later fires is at least partially still in the place of its origin, on the slopes.

Based on a set of 25 ¹⁴C and 24 IRSL ages, we distinguish three main periods, i.e., (1) a period of extensive aeolian transport and deposition during the late glacial period, 16-11 ka ago, (2) a period of geomorphological stability from early until mid-Holocene, and (3) a period of enhanced aeolian, colluvial, and alluvial processes since 4.5 ka. The abundance of charcoal, indicating frequent forest fires during the late Holocene, points to a severe change of environmental conditions and geomorphological dynamics. It is not yet clear whether this change is due to more arid climate or human activities. Therefore, our further research will focus on distinguishing natural and human influence on the landscape evolution in Mongolia since the mid-Holocene.

How to cite: Sauer, D., Klinge, M., Frechen, M., and Li, Y.: Archives of Holocene geomorphological development in the Khangai Mountains, Mongolia, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-13174, https://doi.org/10.5194/egusphere-egu2020-13174, 2020.

Loess deposits related to the lower course of the Ebro river occupy about 2,000 km², between the border of the Ebro depression and the Móra d’Ebre basin. They are the largest loess area in the Iberian Peninsula. The detailed study of these deposits has been intensified since the first decade of this century and now the first cartography of their spatial distribution is available. In parallel, the mineral composition, texture and physicochemical properties have been studied and the soils developed on them have been described and analyzed (mainly Calcic Haploxerept, Typic Xerorthent, Typic Calcixeroll). The most modern units have been dated with optically stimulated luminescence (OSL) and would have been deposited between 17 and 34 ky in relation to the Last Glacial Maximum and the oldest (few outcrops) would exceed 115 ky.

They form very discontinuous covers with average thicknesses of about 3-4 m, preferably located on the sheltered slopes of the prevailing W-NW winds and subsequently accumulated in the valley bottoms of the network of rivers and tributaries of the Ebro River. Their generally coarse grain size, with the predominance of very fine sand (50-100 µm) followed by the coarse sand fraction (20-50 µm), classifies them as sandy loess, and this feature has been interpreted as an effect of the proximity of the source areas of the particles, which according to the literature would be less than one hundred km.

Their mineral composition reflects a clear dominance of quartz and calcite (plus dolomite) in similar proportions and feldspar, mica and opaques as secondary minerals. In many of the outcrops, gypsum (up to 20%, average: 3.1%) appears as a companion mineral, which is redistributed in the profiles, preferably in the lower half, as gypsum infillings and crystal intergrowths, up to 1 cm size). It also gives a different response regarding magnetic susceptibility.

The direction of the prevailing winds, the arrangement of the outcrops, the coarse texture and the mineral composition are key indications of the proximal origin of the aeolian materials. Among the candidate areas are the alluvial plains of the Ebro river, which at that time would suffer the deflation of the extensive T-2 terrace (about 8-10 km wide and 20-30 m above the current talweg) and the interfluvial areas with Tertiary outcrops containing gypsum. Heavy minerals could serve as tracers of the origin of river sediments and gypsum (non-existent in river sediments) could be used as a marker of sedimentary materials with Oligocene and Miocene gypsum of the Ebro Depression, which is absent in the Móra d'Ebre basin.

Gypsum loess appears frequently and preferentially on the outcrops of the Ebro Depression. However, in the Móra d’Ebre basin they are seldom, which would indicate the isolation and independence between the two units of accumulation of loess by the Catalan Precoastal Range that would act as a first order orographic barrier against clouds with aeolian dust from the Ebro Depression.

How to cite: Plata, J. M., Balasch, C., Rodriguez, R., Poch, R. M., and Boixadera, J.: Unraveling the origin of the loess of the lower ebro river basin, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-7457, https://doi.org/10.5194/egusphere-egu2020-7457, 2020.

Diffuse Reflectance Spectroscopy (DRS) is a rapid method for analysing sediments and paleosols, which is a relatively new approach in Quaternary research. This method take into account the clay mineral content, the amount of Fe-bearing minerals and the grain size composition of samples at the same time.

Continuing our earlier research (Szeberényi et al. 2019), this paper reveals the relationship between the DRS curves of paleosols and their parent material. The basis of recent research was the most variable curve sections (between 400-1460 nm wavelength range) of entire measurement range (between 240-2000 nm). The goal of the actual study was to quantify the significant differences between original reflectance curves of paleosols and their parent materials in the case of different quaternary sediment successsions.

Different Quaternary sediment samples were chosen for characterization and comparison their reflectance curves, hereby detection and quantify the most important spectral properties of different paleosols and parent materials. Samples of different sediment types and paleosol variants were investigated from a loess-paleosol sequence at Malá nad Hronom (Slovakia) and a fluvial-aeolian sediment complex at Pilismarót (Hungary).

Five investigated curve sections were separated as the best indicators of reflectance properties of DRS curves. To compaire of spectral properties of samples was used the length of investigated curve sections. It could be explain by ΔR% value, which was shown the difference of reflectance intensity between end points of investigated curve sections.

This investigation showed the quantifiable differences between the units of pleistocene sediment successions, based on the reflectance properties. The influence of pedogenic processes were good detectable. Significant discrepancies were observed between reflectance curves of well-developed paleosols and parent material samples in the VIS-NIR range. Only in the visible range were observed differences between the weak developed paleosol layers and their parent materials. It could be separated from each other the fine sand, the sandy silt and the loess materials based on the intensity of entire reflectance curves.

How to cite: Szeberényi, J., Barta, G., Novothny, Á., Csonka, D., Viczián, I., Horváth, E., and Végh, T.: Investigation of spectral properties of different Quaternary paleosols and parent materials, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-7170, https://doi.org/10.5194/egusphere-egu2020-7170, 2020.

Granulometric composition and magnetic susceptibility are important indicators of the genesis of paleosols, loesses and other newest sediments. Along with other characteristics, they make it possible to reconstruct evolution, surrounding landscapes and climatic changes in the past. The stratotypic section "Alexandrovsky quarry" (natural monument in Kursk, 51°35′31″N, 36°3′21″E) reveals the most complete structure of the Late Pleistocene for the periglacial zone of the East European Plain. Soil-sediment stratum with a thickness of more than 10 m represents the filling of a small buried valley. The formation of the stratum took place practically without interruptions during the last 130 thousand years. It includes two interglacial paleosols: Holocene (Marine Isotope Stage 1) and Ryshkovo (MIS 5е); four interstadial paleosols: Kukuevka (MIS 5с), Streletsa (MIS 5а), Alexandrovka (MIS 3.1), Bryansk (MIS 3.2), and also loess, pedo-sediment and other deposits that have periodically experienced exposuring to cryogenesis [Sycheva, 2012]. The particle size distribution and the magnitude of the magnetic susceptibility reflect the complex history of the stratum formation and reveal detailed climate changes in the Late Pleistocene. The particle size distribution was determined with fractionation method by Kaczynski and by instrumental laser-diffractometry method on a "Malvern Mastersizer 3000" particle size analyzer. The magnetic susceptibility was determined by a SatisGeo KM-7m field capameter with triplicate measurements for every 6 cm.
A change in the granulometric composition from Ryshkovo (MIS 5e) medium loamy deposits to heavy loamy soils and loess belonging to MIS 3.1 was established. The largest value of the clay fraction (<0.001 mm) is characteristic of the MIS 3 paleosols. Significant values of this fraction are also characteristic of the humus horizons of paleosols and Bt horizon Ryshkovo paleosol (MIS 5e). The lowest clay content is observed in loess, especially in their upper parts and in the eluvial horizon of the Rushkovo paleosol (MIS 5е). The data gained by instrumental method of particle size determination is different from such as data gained by the Kaczynski method for the upper heavy loam stratum (MIS 3-1). The predominant fraction is fine dust, in contrast to the lower sediments MIS 5-4, where the coarse silt fraction prevails. Whereas according to data gained by Kaczynski method, the coarse silt fraction prevails in the entire studied thickness of the loess-soil sequence.
Magnetic susceptibility (MS) depends on the content of superparamagnetic mineral in each of the samples and represents levels of pedogenesis in loess deposits. The highest MS values are characteristic of the humus horizon of the interglacial Ryshkovo paleosol (MIS 5e). Followed by Ah horizon of the Streletsa paleosol (MIS 5a) and underlying loess. Smaller values are characteristic of the Kukuevka (MIS 5c) paleosol. But they are more eroded and represented by transitional AB horizons. Loess is characterized by the lowest values of magnetic susceptibility.
The study was funded by RFBR according to the research project № 19-29-05024.

How to cite: Zakharov, A., Sycheva, S., and Panin, P.: Granulometric composition and magnetic susceptibility of the Late Pleistocene loess-soil sequence of the stratotype section (Alexandrovsky quarry, Kursk, Russia), EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-11396, https://doi.org/10.5194/egusphere-egu2020-11396, 2020.

A catena of the Holocene soils and interstadial Bryansk paleosol has been studied within a small closed depression in the Kazatskaya Steppe on the Central Russian Upland. This depression is located on the territory of the Central Chernozem Biospheric Reserve named after V.V. Alekhin, Kursk oblast, Russia and presumably originated from suffosion processes. The main objective of the work is to find out how the Bryansk paleosol (final phase of MIS 3) changes under the influence of not only the cryogenesis of the Valdai glaciation maximum (MIS 2), but also Holocene soil formation (MIS 1) under different conditions of the modern microrelief within the studied catena. We studied the macro- and micromorphological characteristics, certain physical and chemical properties of the Bryansk paleosol on one hand and those of the superimposed Holocene soil on another, taking into consideration various conditions of the present-day microrelief. The studied catena is a typical component of the landscape and soil cover structure for watersheds of the Central Russian Upland. On the micro-elevation rising 80 cm above the micro-depression bottom, theHaplic Chernozems are developed, on the slope – the Luvic Chernozems, and at the bottom – theStagnic Chernozems. The change of the "normal" profile of paleosol of warm interstadial in final phase of MIS 3 started already in the last stages of its formation. The Bryansk soil is heavily deformed by cryogenic processes during the Valday glaciation maximum (the Vladimir cryogenic horizon, MIS 2). The secondary diagenesis of the Bryansk paleosol is related to the Holocene soil-forming processes. The Holocene soils are superimposed on the Middle Valday Bryansk paleosol, transforming it in different ways in different sectors of catena. On micro-elevation the Holocene diagenesis is minimal and consists in fragmentation by mesofauna, additional penetration of carbonates in the upper horizon of the paleosol. The micromorphological analysis showed that the fragmentation of soil mass by mezofauna is very significant, humus is abundant in the form of brown spots (organo-mineral complexes), and calcite is completely immersed into the clay fine material. The largest in size but rare grains of sparite have an unusual shape and probably biogenic origin. At the bottom of the micro-depression the Bryansk paleosol is the most transformed, and the entire profile of the Bryansk soil turned into illuvial horizon of the Holocene meadow-chernozem soil. At the micro-level of observation the clay fine material of the Bryansk soil is strongly consolidated (close c/f related distribution), has signs of anisotropy: circular, grano- and crosstriated b-fabric, the mineral grains are almost invisible and have the dimension of fine dust, very thin Fe- clay coatings in the pores, Fe spots are scattered over the fine clay material, and very characteristic of the presence of many black and sometimes transparent with a black border cube-shaped minerals (whewellite, weddellite?) which fill plant residues in the pores. This work was supported by the Russian Foundation for Basic Research; project N 19-29-05024 mk.

How to cite: Sycheva, S. and Khokhlova, O.: The diagenesis of the Bryansk paleosol (MIS 3) in a suffusion micro-depression at the center of the Russian Upland, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-1897, https://doi.org/10.5194/egusphere-egu2020-1897, 2020.

The loess-paleosols sections (LPS) situated on flat interfluves integrally reflect the zonal characteristics of paleolandscapes and climate change of large-scale rank such as interglacial-glaciation, megainterstadial-stadial. However, they do not reflect small-scale climatic fluctuations and the local diversity of paleoecological conditions. Geochemical combinations of soils and sediments along the slopes of the paleo-relief, i.e., paleo-catenas, make it possible to supplement the missing links of the paleogeographic history and to detail the paleogeographic events.

In support of this idea, we show the results of study of paleo-catenas of the Ryshkovo pedo-litho-complex formed in the Mikulino interglacial (MIS 5e) and presented in the Alexandrov quarry near the city of Kursk, the Central Russian Upland. The Ryshkovo paleocatenas are analyzed along the slopes of the northern and southern expositions in the paleo-balka’s upper course. The variability of the Ryshkovo paleosols fits into the framework of one genetic soil type. Its closest analogue is sod-podzolic soil of mixed forests (Luvic Retisols). The main differences between the soils developed in the paleo-catenas are related to the degree of detail of the evolutionary development record due to various combinations of soil forming and denudation-sedimentation processes. Paleo-catena 1 along the slope facing to south is distinguished by the simplicity of soil profiles. Paleo-catena 2 of the northern exposition slope is more diverse in the completeness of the structure of paleosol profiles. It is complicated by micro-catena along a buried coastal ravine. Based on the study of the Ryshkovo paleo-catenas, the following stages of soil development in the Mikulino interglacial (130-117 ka BP) are reconstructed: 1) the lower meadow soil (the first soil stage) is read throughout the paleo-catena 2, i.e., in the bottom and on the paleo-balka slope; 2) the formation of bottom and coastal ravines, their subsequent filling with material of a humus horizon, carried away from the slopes during the climatic cooling within the interglacial (the first morpholithogenic stage); 3) the formation of the of sod-podzolic soil profile (the second soil stage) is recorded in the fillings of the coastal ravine; 4) subsequent erosion and accumulation of humus material in the bottom of the balka and ravine (the second morpholithogenic stage); 5) sod-podzolic soil (the third soil stage) is detected throughout the catena; 6) stressful restructuring of the paleoecological situation before burial is recorded in traces of a strong fire and a post-fire storm erosion at the end of the interglacial period when the climate became cooler (the third morpholithogenic stage). Thus, in the catena along the northern exposition slope and especially in the bottoms of the ravine and the main channel of the balka, the detailed change in the stages of development of local landscapes is reflected: three soil-forming stages separated by two erosion stages, and the most intense final (third) erosion stage. A complex combination of soil and relief-forming processes is reflected in the physicochemical properties of the Ryshkovo pedo-litho-complex, especially in its upper humus-accumulative and eluvial parts. This work was supported by the Russian Foundation for Basic Research; project N 19-29-05024 mk.

How to cite: Pushkina, P. and Sycheva, S.: Paleo-catenas of the Ryshkovsky pedo-litho-complex (130-117 KA BP) of the Central Russian Upland, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-7240, https://doi.org/10.5194/egusphere-egu2020-7240, 2020.

The effects of historical charcoal production on forest soil properties are increasingly well studied on sites in Europe and the northern USA. The most obvious effect of this past forest use practice is the addition of large quantities of charcoal into the soil at sites of former charcoal production. These so called relict charcoal hearth (RCH) sites are mapped in expansive numbers due to the rising availability of high-resolution LiDAR data. However, studies determining the impact of RCHs on more than a field plot scale are rare, so far. To transform results from specific RCH sites to a landscape scale, we sampled and measured 52 RCH sites on a 0.7 km² area in the Litchfield Hills in western Connecticut, USA.

In this study we combine field based measurements of RCH site stratigraphy and geometry, GIS-based spatial analysis of site locations, laboratory determination of soil organic and pyrogenic carbon and FTIR-based analysis of soil carbon. We aim at assessing the soil distribution and soil development in an RCH affected landscape, i.e. the distribution of three typical soils commonly found in these landscapes: natural forest soils, technogenic soils of RCH platforms and soils buried below technogenic soils. Furthermore, we determine the distribution of organic and pyrogenic carbon in these soils and specifically the variation of carbon contents within the technogenic RCH soil stratigraphy.

Preliminary results suggest that RCH site occurrence does not depend on relief position, i.e. RCH site abundance is not correlated with slopes, plateau or flatland positions. However, RCHs with multiple layers of technogenic substrates are more abundant on slope positions. RCH soils have a significantly increased content in total carbon compared  to unaffected forest soils. Multi-layered RCHs have a heterogeneous vertical distribution of pyrogenic carbon and a possibly modern enrichment of organic matter in the surface soil. Wet chemical digestion of RCH soil samples coupled with FTIR analysis shows an increased presence of aromatic compounds and therefore pyrogenic carbon. However, the majority  of carbon in RCH soils seems to be of non-pyrogenic origin. As of now it is unclear, whether  the content of pyrogenic carbon is underestimated by analytical uncertainties or if pedogenic processes are responsible for an enrichment of labile- and semi-labile organic carbon in the charcoal-rich RCH soil.

How to cite: Bonhage, A., Hirsch, F., Raab, T., Schneider, A., Raab, A., and Ouimet, W.: A Field-, GIS- and FTIR based approach to assess the distribution and development of soils affected by historical charcoal production in western Connecticut, USA, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-3070, https://doi.org/10.5194/egusphere-egu2020-3070, 2020.

Throughout the northeastern United States and Europe, relic charcoal hearths (RCHs) are more regularly being discovered in proximity to furnaces used for iron or quick-lime production; charcoal was used as a primary fuel source in the furnaces.  RCHs have been found across parts of Europe and Connecticut, USA in different hillslope positions, on vary degrees of slope and aspect, all of which can be a factor affecting the shape of the RCH.  Their usage for charcoal production varied with time period furnaces were in operation with some hearths being used once and older ones (such as in Europe) being used multiple times. RCHs across the northcentral Appalachians, USA have been minimally investigated, thus determining where they occur on the landscape, their shape, and their morphologic positions will be useful in discerning their effect on surface hydrology and soil development. Our study focuses on developing a repeatable process for: finding RCHs, classifying the different shapes or styles of the hearths in relation to their geomorphic positions and quantifying how RCHs may alter surface hydrology.  

We used a combination of processed LiDAR to create hillshades of varying light angles and altitude, and slope gradient maps derived from the same LiDAR, to visually digitize > 6,100 hearths. A subset of the mapped hearths was ground-truthed for accuracy of the methodology. For our study, three areas in the mid-Appalachian region of Pennsylvania were chosen for study in order to reflect different historical time periods of construction and environments. A goal of our study is to determine the age of hearths. We hypothesize that using a calculated 3D distance to nearby furnaces, hearths closer to furnaces will be the oldest and have a higher likelihood of being used multiple times resulting in multiple layers of charcoal-enriched substrate. An initial analysis of RCHs indicates a relationship between slope gradient and hearth shape. Hearths constructed on flatter slope gradients are seemingly more circular in shape and have more equal axes whereas steep slopes have a more oval shape being elongated in one axis and shortened on the other.  Likewise, there may be a relationship between hillslope position and the shape of the RCHs such as more circular hearths are on or near flatter hillslope positions (such as on summits or shoulders) whereas oval shaped hearths are on steeper hillslope positions (like backslopes). We also modeled the effect of RCHs on hydrology.  Based on a combination of topographic wetness index data and geomorphology, hearths are not acting as sinks for surface flow but instead often cause water to flow around them leading to slightly drier conditions within RCHs. Future work will address site-specific monitoring of hearth temperature and moisture, and hearth carbon decomposition dynamics in relation to temp and moisture conditions.

How to cite: Bayuzick, S., Drohan, P., Raab, T., and Hirsch, F.: Relic charcoal hearth geomorphology and hydrology across the northcentral Appalachians, USA , EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-5744, https://doi.org/10.5194/egusphere-egu2020-5744, 2020.

The stratigraphy and properties of soils can be significantly altered by past land use, even in areas that have been continuously used for forestry. Soils on relict charcoal hearths (RCHs) are a widespread example of such a pedological legacy of past forest use. RCH soils occur in many forest areas and receive increasing attention as model sites to study long-term effects of soil amendment with biochars, however, their physical properties have hardly been studied. The objective of our study was to characterize the soil temperature and moisture regime of RCH soils through comparison to reference forest soils on sandy substrates in woodlands in Brandenburg, Germany. We combined laboratory analyses of bulk density, pore size distribution, thermal conductivity and saturated hydraulic conductivity with sensor-based monitoring of soil temperature, moisture contents and matric potentials. 

The results of laboratory analysis reveal high soil organic matter (SOM) contents, a low bulk density and high porosity of the RCH substrates. Associated with this RCH specific soil structure, RCHs exhibit clearly lower thermal conductivity. However, the higher total porosity of RCH substrates does not necessarily imply higher water retention and plant-available water contents in the RCH soils than in the topsoil horizons of undisturbed forest soils.  The monitoring results reveal distinct differences between the temperature regimes of the RCH and reference profiles, with the RCH soil exhibiting higher daily and seasonal temperature variations within the topmost horizon, but lower variations in deeper parts of the profiles. Soil moisture monitoring shows higher water contents in RCH soils under relatively wet conditions and lower water contents under dry conditions, and increased spatial variation in soil moisture in RCH soils. Overall, the results show increased spatial and temporal variability of soil temperature and moisture on RCHs, which implies an increased variability in ecological site conditions in historic charcoal production areas.

How to cite: Schneider, A., Hirsch, F., Bonhage, A., Raab, A., and Raab, T.: The temperature and moisture regime of charcoal-enriched land use legacy soils , EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-2339, https://doi.org/10.5194/egusphere-egu2020-2339, 2020.

Mountane and submontane hilly landscapes, mainly around the borders of the former Czech Kingdom were used for farming just rarely.  During the High Middle Ages these remote regions were colonized by mostly German speaking settlers invited by Bohemian King. Their villages were established and agricultural plots were divided into parallelly or fan-like ordered parcels, partially separated by agrarian walls. Parts of the historic settlements were continually used for agriculture for many centuries, sometimes with no problems with soil erosion. The traces of these landscape structures were best preserved around villages, which were not too suitable for farming and thus were not included into process of agriculture collectivization in the second half of the 20th Century. The historical landscape structures has thus preserved mainly in areas of high altitudes, steep slopes, low settlement density. Those areas with the traces, bearers of landscape memory, has been continually swallowed by forest and shrubs regrowth as noticeable in aerial images.

We mapped the preserved historical structures in the region of the Czechia based on the linear non-forest woody vegetation in current orthophotos and by use of topographic map and DTM based on LiDAR mapping. This examination showed a surprisingly large spatial extent of the historical landscape pattern, well framed bywoody vegetation. For our study, we used also old maps, archival aerial photographs and digital terrain models created from newly acquired airborne LiDAR imaging. We performed imaging of the wall structures by geophysical means (electromagnetic imaging EMI using a DEMP instrument). We focused particularly on terraced fields and agrarian walls.

The stone walls situated more-or-less perpendicular the slope gradient resulted in nearly terrace-like surface topography. Even in areas with a mean original slope higher than 10° the final slope of the fields decreased to a few degrees. Most agrarian walls were constructed from stones; their bases are usually a bit deeper than current terrain level at the wall foot according to the EMI images. Some walls are higher and wider than 1 m and their upper edge is buried by topsoil washed from upper parts of the fields. The topsoils on the fields have comparable grain size distribution in upslope, middle and downslope parts, showing the minimal net transfer of fine particles by erosion. No traces of deep erosion or soil degradation were observed, which could be attributed to the skeletal character of soils in well-preserved historical terrace fields.

We examined also local plant cover, which showed preservation of meadow species even after re-forestation of the former historical settlements and considerable differences in vegetation species composition of the agrarian wall and in surrounding agricultural parcels. Aconsiderable part of the still preserved historical agrarian, may play a positive future role in biodiversity of montane areas by presence of contrasting biotopes, e.g. including tree species more resistant to the global change than widespread spruce monocultures.

How to cite: Elznicová, J., Vardarman, J., Pacina, J., Machova, I., Stojdl, J., Riezner, J., and Matys Grygar, T.: Agrarian landforms in Czechia and their future value, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-10808, https://doi.org/10.5194/egusphere-egu2020-10808, 2020.

Intensive agricultural management can have significant impacts on soil properties. Such effects and their degree are often related to the history of land use and to the agronomic practices. When legacy soil data are missing, historical land use maps can help to describe how crop management might have changed the concentration of certain elements in soils. In this study, we prove how permanent crop management (vineyards and apple orchards) influenced heavy metal concentration in agricultural soils in South Tyrol, Italy. We selected areas where land-use change was unidirectional going from forests, grasslands and arable lands to apple orchards or vineyards. We hypothesize that the heavy metal accumulation in the soil starts when a parcel is converted to intensive permanent crops. This hypothesis allows us to see if there are any significant differences between parcels with a longer or shorter intensive agriculture history. We used approx. 6000 soil samples analyzed between 2006 and 2016 and coupled them with historical land use maps dating from the 1850s until today. Soils that have been cultivated as apple orchards or vineyards since the 1850s are characterized by higher concentrations of Cu. The oldest vineyards have much higher soil Cu concentrations than apple orchards of the same age with a median content of 342 mg kg^–1 and 212 mg kg^–1 of Cu respectively. Similar patterns, but with smaller extent can be described also for Zn concentration. Comparing the age of vineyards with today’s concentration we estimate an accumulation rate of 2.4 mg kg^–1 year^–1 of Cu. We conclude that historical land use maps are extremely helpful in understanding today’s soil characteristics especially with not degradable pollutants such as heavy metals. High concentrations of Cu in vineyards reveal the widespread and abundant use of this metal in viticulture for plant defense programs through time. The accumulation trend proves that further research and monitoring is needed to understand spatial and temporal pattern of Cu and Zn pollution in intensively managed permanent crops and to estimate their impact on taxonomical and functional fungal and bacterial diversity. These aspects are of pivotal role in determining the soil fertility levels of our cultivated soils.

How to cite: Genova, G., Niedrist, G., Della Chiesa, S., Tasser, E., Borruso, L., Cesco, S., and Mimmo, T.: Effects of land use history on heavy metals concentration in agricultural soils, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-20363, https://doi.org/10.5194/egusphere-egu2020-20363, 2020.