SSS3.5

Sphagnum moss and age-dated peat cores from bogs have long been used to study contemporary and past atmospheric deposition of trace elements (TEs). However, other components of bog ecosystems represent additional scientific opportunities. Snowpack sampling, for example, represents a chance to study winter deposition while providing the perfect matrix for ICP-MS analyses of TEs. The berries that grow in bogs, including blueberry (Vaccinium myrtilloides), cloudberry (Rubus chaemomorus), cranberry (Vaccinium oxycoccus) and lingonberry (Vaccinium vitisidaea), provide insight into the bioavailability of micronutrients (and contaminants) at the surface of the bog, as well as an index of dust deposition onto the fruits themselves. Labrador Tea (Rhododendron groenlandicum) provides similar information, but with greater relevance for Indigenous Peoples, as this is an important medicinal plant for them, along with the Pitcher Plant (Sarracenia purpurea). The acidic, organic-rich waters which represent > 90 % of the mass of these ecosystems, presents an even greater opportunity: the chance to quantify the extent to which aerosols and dusts dissolve, subsequent to deposition from the air. In this study, we present data for TEs in all of these media, with a view to exploring the broader potential of ombrotrophic peatlands as natural, holistic, integrated, long-term monitoring systems. The approach presented here not only addresses our need for information regarding  atmospheric deposition of environmental contaminants to terrestrial ecoystems, but also insight into their release, or potential release, to downstream aquatic ecosystems.

How to cite: Shotyk, W., Barraza, F., Belland, R., Butt, S., Chen, N., Devito, K., Cuss, C., Dennett, J., Frost, L., Grant-Weaver, I., Javed, M., Nielsen, S., Noernberg, T., and Oleksandrenko, A.: Ombrotrophic peatlands: natural, holistic, integrated, long-term monitoring systems for atmospheric deposition of environmental contaminants to terrestrial and aquatic ecosystems, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-1241, https://doi.org/10.5194/egusphere-egu21-1241, 2021.

Here we present a 4200-year-old high-resolution peat core reconstruction from southern Patagonia. Our detailed carbon isotope (δ13C) record and testate amoeba-inferred water table depth reconstruction point to a progressive wetting of the peatland surface from 4200 to 1500 cal. yr BP, followed by a dry event at 1200-800 cal. yr BP and drier conditions since then. Superimposed on this trend are centennial-scale dips in δ13C values and water table depths that we associate with warm/dry spells. We interpret these shifts, which are akin to positive phases of the Southern Annual Mode (SAM), as reflecting century-scale changes in the Southern Westerly Wind belt during the late Holocene. Other records from southern South America and Tasmania have revealed synchronous changes in local vegetation and fire activity, strengthening our hypothesis. We know that millennial-scale shifts in the Westerly winds influence ocean upwelling in the Southern Ocean, with effects on global atmospheric carbon dioxide (CO2) concentrations. Our study, along with a few others, may help elucidate whether centennial-scale SAM-like shifts could also modulate the global carbon cycle via CO2 degassing from the deep ocean. This is important because instrumental and reanalysis records indicate strengthening and poleward contraction indicate a positive phase of the SAM since the late twentieth century.

How to cite: Loisel, J. and Sarna, K.: Peat-based record from southern Patagonia shows centennial-scale variability since 4.2 ka, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-7993, https://doi.org/10.5194/egusphere-egu21-7993, 2021.

Open-pit mining for bitumen extraction generates considerable volumes of dust in northern Alberta. This area contains abundant peatlands, some of which are ombrotrophic bogs that are exclusively fed by atmospheric inputs. The most reactive mineral phases of dust deposited on these bogs can potentially dissolve in their surface waters because of the low pH and abundance of organic acids. Thus, peat bog surface waters could be used as unique monitors, to determine the chemical reactivity and dissolution characteristics of atmospheric dusts in industrial areas. The main goal of this study is to determine whether the elevated rates of dust deposition to peat bogs near bitumen mines have led to greater concentrations of trace elements (TEs) in the surface waters. To achieve this goal, it is essential to ensure that the TEs being measured in surface waters represent dust dissolution only and are not influenced by other element sources such as groundwaters or surface runoff.
Peat bog surface waters were collected in the autumn of 2019 from four peatlands near industry and a control site located more than 260 km upwind. Concentrations of TEs were determined in the dissolved fraction (i.e. filtered through a 0.45 μm membrane) using an ICP-MS. Surface waters near industry have elevated concentrations of Li, Fe, Mn, Ni, Y, selected REE (Tm, Dy, Yb, Sm) and Pb at 3 out of 4 sites, relative to the control location (UTK). Most of the elements are enriched 2x when compared to control site (UTK), but only Li, Mn, and Rb show enrichments >1Ox. At JPH4, the site closest to industry (12 km from the mid-point between the two central bitumen upgraders), a vegetation survey indicates that this peatland includes both ombrotrophic and minerotrophic zones, and this was confirmed by the pH and concentrations of major ions in the surface waters. At McK, the site next closest to industry (25 km), electrical conductivity as well as concentrations of chloride, Na, and K, all increase with distance toward the highway which is evidence of road salt runoff. Thus, at these two sites nearest industry, the TE concentrations in surface waters are supplied not only from airborne dusts, but contributions from groundwaters and road salt must also be considered. In contrast, the surface waters from the McM (49 km) and ANZ (69 km) sites are ombrotrophic, and elevated concentration of TEs in these samples can be attributed exclusively to dust dissolution.
The elevated concentrations of lithophile TEs in the dissolved fraction includes those which are
mobile in surficial environments (e.g. Li and Sr), but also those which are immobile (e.g. Y and the lanthanides). Elevated concentrations of the former are not surprising, but elevated concentrations of the latter are puzzling, given that they tend to be hosted within stable mineral phases that are resistant to chemical weathering. Size-resolved TE analyses of the dissolved fraction using AF4-ICP-MS will be used to distinguish between colloidal forms and ionic species, to differentiate inputs of nano-dusts from mineral dissolution in bog waters.

How to cite: Butt, S., Shotyk, W., Barraza, F., Chen, N., Cuss, C., Frost, L., Grant-Weaver, I., Javed, M., Noernberg, T., Oleksandrenko, A., and Pei, L.: Trace elements in peat bog surface waters as indicators of the dissolution of atmospheric dusts from open-pit bitumen mines, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-1430, https://doi.org/10.5194/egusphere-egu21-1430, 2021.

Black carbon (BC) and polycyclic aromatic hydrocarbons (PAHs) are potentially proxies of changes in natural and human activities during the past century. It is important to identify historical BC sources and differentiate human activities contribution to BC in the environment. In this study, a 30 cm peat profile from the Jiadengyu (JDY) peatland in Altay Mountain was dated by the ¹³⁷Cs and ²¹⁰Pb methods. BC, total PAHs content and δ¹³C_BC in JDY peat were tested. The results showed that the TOC, BC and PAHS contents in JDY peat core were 17.09 ~ 47.16%, 1.14 ~ 67.138 mg/g and 260.58 ~ 950.98 ng/g, respectively. The value of δ¹³C_BC ranged -31.5‰ ~ -27.43‰, with an average of -30.52‰. The range of total PAHs concentrations in JDY peat core were between 260.59 ng/g and 950.98 ng/g. The BC was significantly correlated with PAHs and regional population. The BC fluxes have slightly increased since 1900s with the increasing population and cultivate area, and more significantly in 1980s. The burning of biomass and yak dung, fossil fuels, and human activities (mining, coking coal) may have important effects on the BC emission of soil in the Altay region. The change of BC and δ¹³C_BC reflected the change of local energy structure. With the regional reclamation increasing and environment- friendly industry developing, the BC source of JDY peatland is mainly the result of the interaction between biomass combustion and fossil fuel combustion.

How to cite: Luo, N., Bao, K., Yu, R., Liu, X., Tuoliuhan, Y., and Wen, B.: Centennial records of PAHs and black carbon in Altay mountain peatlands, Xinjiang, China, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-1515, https://doi.org/10.5194/egusphere-egu21-1515, 2021.

The Athabasca Bituminous Sands (ABS) industry has dramatic benefits for the economy of Alberta, Canada. However, with increasing industrial operations, environmental concerns have grown regarding the contamination of air and water with trace elements (TEs). The ABS are composed of both minerals (ca. 85%) and bitumen (ca. 15%). While V, Ni, Mo, and Re are found primarily in bitumen, other potentially toxic TEs such as As, Cd, and Pb occur mostly in minerals. The mechanical processing of ABS by industry generates considerable volumes of dust particles from processes and sources such as open-pit mining, quarrying, road construction, petroleum coke transport and storage, and dry tailings. These dusts are dominated by coarse aerosols with short atmospheric residence times, consisting primarily of recalcitrant and sparingly reactive silicate minerals enriched in lithophile elements such as Al, Fe, and Mn. In contrast, high-temperature industrial processes such as the smelting and refining of metallic ores and coal combustion yield fine aerosols (< 2 µm) that can be transported for thousands of kilometers. These fine aerosols are respirable and mostly in the forms of oxides and hydroxides rich in TEs such as As, Cd, and Pb, posing a risk to all living organisms. Hence, it is important to differentiate between TEs in the two aerosol fractions.

Here, Sphagnum mosses collected from ombrotrophic (rain-fed) bogs within the ABS region are used as biomonitors of atmospheric deposition, and compared with mosses from a reference site 264 km to the southwest. The aim is to estimate the percentage of TEs in the fine versus coarse aerosol fractions by determining the abundance of TEs in the acid soluble ash (ASA) and acid insoluble ash (AIA) in Sphagnum. Trace element concentrations (total, in ASA and in AIA) were obtained using ICP-MS.

Concentrations of AIA and total concentrations of TEs increased towards industry, reflecting increasing dust deposition. Comparing the site nearest industry (JPH4) to the control site (UTK), the greatest differences in total concentrations were measured for lithophile elements such as Li, Be, and the lanthanides; V, Ni, and Mo were all 10x more abundant; the differences in chalcophile elements were much less apparent: Pb and Tl 6x, Ag 3x and Cu, Cd, and Zn < 2x. In AIA, Cs, Li, La, and Al were all more abundant at JPH4; Tl was slightly more abundant (3x); Ag, Cu, and Pb were all more abundant at UTK. In ASA, Th, Al, and the lanthanides were more abundant at JPH4; however, concentrations of Cd, Cu, Ag, Zn, Sb, and Tl were higher at UTK. In general, therefore, lithophile elements were more abundant in samples collected near industry, in total concentration as well as in the AIA and ASA fractions. However, chalcophile elements exhibited either insignificant differences, or were more abundant at the control site. Clearly, measuring only the total concentrations of TEs in moss from a dusty industrial region provides limited information about their associated health risks.

How to cite: Chen, N., Shotyk, W., Barraza, F., Belland, R., Javed, M. B., Cuss, C. W., and Grant-Weaver, I.: Distinguishing trace elements in acid soluble ash (ASA) and acid insoluble ash (AIA) of Sphagnum mosses within the Athabasca Bituminous Sands Region, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-3795, https://doi.org/10.5194/egusphere-egu21-3795, 2021.

Palsa peatlands are a significant carbon pool in Northern hemisphere which is subjected to change due to accelerated permafrost thaw and peat decomposition with progressing global warming. On the other hand, peat deposits of palsas serve as an important conduit of information about variability of environment conditions in the past millennia and respective vegetation changes. In our study we applied the multi-proxy record to distinguish variation in hydrothermal regimes of palsa peatland in Northern Siberia and to trace the likely diagenetic alteration of accumulated peat.

The study site is located 10 km North-East of Igarka settlement (67^o31’ N, 86^o38’E) within the area underlain discontinuous permafrost. The peat core was obtained in the central intact part of elevated (ca. > 3.5 m above surrounding hollows) dry hummock. The active layer, thawed seasonally layer, at the coring site was about 0.6 m. The entire depth of peat deposit was 8.6 m, but interrupted with several relatively thin (0.1-0.2 m) ice-rich lenses. Thawed and frozen peat samples of 0.5-5.0 cm thickness (mean = 2.8 cm) were collected at 2.5-12.0 cm step (mean =5.4 cm) depending on the amount of peat material. Collected samples (n = 160) after drying at 60^oC for 48 h were subjected to the analysis for C and N content, stable isotopic composition of C and N. These measurements will further accompany radiocarbon dating, loss on ignition, plant macrofossil and macro charcoal analyses.

The analyzed 8.6 m deep peat core demonstrated the large variation of C (17.3-54.7%) and N (0.37-3.26 %) contents as well as C:N ratios (14-134). The isotopic depth profile was in the range from -24.51 to -34.31 ‰ for d¹³C and from -1.77 to 6.96 ‰ for d¹⁵N. The highest enrichment in ¹⁵N (2.69±1.60 ‰ d¹⁵N) was found in seasonally thawed layer (≤0.6 m). A layer close to the bottom (6.9-8.3 m) contained peat the most depleted by ¹³C (<-30 ‰ d¹³C). Meanwhile, along the peat profile depth we detected significant fluctuations in these parameters suggesting the different periods with specific environmental conditions.

Further combined with radiocarbon dating and plant macrofossil analyses we will attempt to capture the changes occurred during the past epochs in an input matter (vegetation changes and/or its productivity), decomposition rates as well as hydrothermal regimes and permafrost processes like aggradation (e.g. hummock uplift and cryoturbation) and degradation (e.g. hummock collapse, shifts from minerotrophic to ombrotrohic conditions and vice versa).

This work was supported by the Russian Science Foundation, project № 20-17-00043.

How to cite: Anatoly, P., Elena, N., Dmitry, K., and Sergey, S.: Peat isotopic composition of a deep deposit of palsa mire for the reconstruction of environmental changes in permafrost domain of Northern Siberia, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-5395, https://doi.org/10.5194/egusphere-egu21-5395, 2021.

Montane bogs—peat-forming ecosystems located in high elevation and receiving their water supply mostly from meteoric waters—are unique archives of past environmental changes. Studying these ecosystems and their responses to recent climate warming will help improve our understanding of the sensitivity of high-elevation peatlands to regional climate dynamics. Here, we report a post-bomb radiocarbon-dated, high-resolution, and multi-proxy record in Laobaishan bog (LBS), a mountaintop bog from the Changbai Mountains Range in Northeast China. We analyzed plant macrofossils and testate amoebae of a 41-cm peat core dated between 1970 and 2009 to document the ecohydrological response of peatland to the anthropogenic warming in recent decades. We quantitatively reconstruct the surface wetness changes of LBS bog using the first axis of the detrended correspondence analysis (DCA) of plant macrofossil assemblages and depth to water table (DWT) inferred by transfer function of testate amoebae assemblages. We distinguished two hydroclimate stages: the moist stage before the 1990s and the rapidly drying stage since the 1990s. During the moist stage, plant macrofossils were characterized by the low abundance of Sphagnum capitifolium and Polytrichum strichum that prefer dry habitats, and testate amoebae assemblages were dominated by low abundance of dry-adapted Assulina muscorum and Corythion dubium. High score of first axis and low DWT also suggested a moist habitat at LBS. After the transition into the drying stage, the abundance of S. capitifolium and P. strichum increased and that of A. muscorum and C. dubium showed similar trend. Score of first axis and DWT reconstructions show that LBS have experienced rapid surface desiccation since the 1990s. Based on the high-resolution gridded reanalysis data, these ecohydrological changes occurred with a rapid increase in temperature (~1°C) but without notable change in total precipitation during the growing season (May–September) since the 1990s. Besides, backward trajectory analysis showed no apparent changes in atmospheric circulation pattern since the 1990s, supporting our interpretation that the ecohydrological changes in LBS bog were induced by climate warming. These results demonstrate that the plant communities, microbial assemblages, and peatland hydrology of montane peatland show a sensitive response to climate warming that might be in larger amplitude than the low-elevation areas.

How to cite: Yang, T., Zhao, H., Xia, Z., Yu, Z., Li, H., Bu, Z., and Wang, S.: Rapid Ecohydrological Response of a Mountaintop Peatland to Recent Climate Warming in Northeast China, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-15329, https://doi.org/10.5194/egusphere-egu21-15329, 2021.

Sphagnum mosses have been used in some of the earliest works in biomonitoring of atmospheric deposition of trace elements (TEs). Since their adoption into the field the Sphagnaceae have become one of the foremost biomonitors. When taken as contemporary samples, these mosses have allowed us to identify spatial variations as well as trends and major changes in atmospheric deposition due to changing policy, technology, industry, and land use. While long term monitoring programs, such as the European Moss Survey, allow us to track these changes through time, these ongoing studies only reach as far back as their start dates. In the case of the European Moss Survey this was 1990. The use of materials already collected and archived in herbaria provides a low-cost method for retrospective analysis of atmospheric deposition of TEs. The critical advantage of herbarium specimens over other historical monitoring method is their high temporal resolution, as their exact collection date is known. Once collected, stored, and protected from atmospheric dust, the concentrations of non-volatile TEs present remain effectively unchanged. The oldest herbarium records can predate industrialisation, but most have records from the beginning of industrialisation, with the frequency of collection increasing in the modern era. Using only the top 2 cm of herbarium specimens of Sphagnum mosses (S. fuscum, S. angustifolium, S. capillifolium, S. magellanicum) found in Canadian ombrotrophic bogs, we will be creating historical reconstructions of atmospheric deposition in northern Alberta since the 1940s and southern Ontario since 1860’s. The first objective is to determine how best to balance preservation of the limited herbarium material available while also using sufficient material to achieve suitable levels of analytical accuracy. As TE analyses using ICP-MS are destructive and some specimens have immeasurable value from a natural history perspective, as little material as possible should be taken for analysis. Grinding of the sample was avoided, to minimize sample loss and the risk of contamination. We compared the measured concentrations obtained with ICP-MS as a function of the mass of Sphagnum digested, using selected herbarium samples as well as two certified, Standard Reference Materials (NIST 1515 and HB36-M2). These analyses allow us to determine the optimal amount of material necessary to balance the analytical accuracy and preservation of material of 4 species of Sphagnum mosses from Alberta over the last 80 years. The results will be compared with the data already available for TE concentrations in age-dated peat cores from the same region.

How to cite: Frost, L., Belland, R., Grant-Weaver, I., and Shotyk, W.: Balancing preservation of material and the need for analytical accuracy: Mass requirements of Sphagnum moss from herbarium collections for trace element analysis, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-13836, https://doi.org/10.5194/egusphere-egu21-13836, 2021.

Although interest in peatland environments, especially in terms of their carbon storage, has gained momentum in response to a heightened awareness of the climate emergency; significant gaps remain in the geographical coverage of our knowledge of mires, including some major wetland systems. This paucity has implications, not only for our understanding of their development and functioning, but also for adequately predicting future changes and thus providing effective mire environmental management. Our INTERACT-supported study provides radiometrically dated, well-characterised millennial scale peat records from two contrasting undisturbed and impacted (ditched) ombrotrophic sites in the Great Vasyugan Mire (GVM) near Tomsk, Siberia and two additional mesotrophic sites to the east of the Ob river. In addition, the geochemical record was complemented by multiproxy palaeoecological characterisation (pollen, charcoal, stable isotopes, testate amoeba). We identified both natural (lithogenic) and anthropogenic geochemical signals recording human impacts with site specific variations. Elevated trace element concentrations in the peat profiles align with the region’s wider agricultural and economic development following the colonisation of Siberia by Russia (from ca. 1600 AD) when pollen assemblages indicate the decline of forest cover and an increase in human disturbance, including the use for fire. Trace element concentrations peak with the subsequent, post WWII industrialisation of regional centres in southern Siberia (after 1950 AD). On a global scale, our sites, together with evidence from the few other comparable studies in the region, suggest that the region’s peatlands are relatively uncontaminated by human activities with a mean lead (Pb) level of < 5 mg/kg. However, via lithogenic elements including Rb, Ti and Zr, we detected both a geochemical signal as a result of historical land cover changes enhancing mineral dust deposition following disturbance, as well as fossil fuel derived pollutants as relatively elevated, subsurface As and Pb concentrations of ca. 10 and 25 mg/kg respectively with the development of industry in the region. Nevertheless, the potential significance of local factors on the sites’ geochemical profile is also highlighted. For example, we identify the effects of past peat drainage for afforestation (ca. 1960s) and the scheme’s subsequent abandonment. Although the region’s mire systems are remote and vast, they appear to hold a legacy of human activity that can be detected as a geochemical signal supporting the inferences of other palaeoenvironmental proxies. Such geochemical peat core records, from Eurasia in particular, remain relatively scarce in the international scientific literature and therefore, as yet, inadequately characterised and quantified compared to other regions.

How to cite: Hutchinson, S., Diaconu, A., Kirpotin, S., and Feurdean, A.: Geochemical peat records from the Great Vasyugan Mire and Tomsk region, Siberia. Regional temporal trend of human impact over the last 500 years and local perturbations., EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-11669, https://doi.org/10.5194/egusphere-egu21-11669, 2021.

Northeast China—located near the northern limit of the influence by the East Asian summer monsoon—receives most moisture through the westerly airflow, but variations in moisture contributions from the Yellow Sea in the western Pacific Ocean determine its hydroclimate during summer monsoon season. The proportion of moisture from the Yellow Sea is strongly modulated by the location and intensity of the Western Pacific Subtropical High (WPSH). However, it is still unclear how sensitive regional hydroclimate to WPSH-modulated change in moisture sources and its impact on peatland carbon accumulation. Here, we used macrofossil data and paired δ¹³C and δ¹⁸O isotope analysis of Sphagnum moss cellulose from a well-dated bog from a steep mountain slope in the Greater Khingan Mountains (~47˚N) to reconstruct peatland moisture changes and elucidate past shifts in moisture sources. δ¹³C values reflect peatland surface moisture, as dry conditions with less water film effects would increase isotopic discrimination against ¹³C and result in lower δ¹³C values. Our results from a 250-year peat record show a decrease of ~3‰ in δ¹³C from -25 to -28‰—with corresponding increase in dry-adapted moss Polytrichum—suggesting a drying trend since about 1980 AD. Also, the down-core δ¹⁸O and δ¹³C data show a positive correlation (r = 0.65, p < 0.001), in contrast with evaporative enrichment of δ¹⁸O being the dominant effect. We argue that δ¹⁸O values reflect the input of moisture derived from the Yellow Sea—that has higher δ¹⁸O values than that from the westerlies—as modulated by the WPSH. When the WPSH extends westward, it blocks moisture transport from the Yellow Sea to North China, causing low δ¹⁸O values in summer precipitation, dry conditions, and negative shifts in δ¹³C, and vice versa. Furthermore, carbon accumulation rates show a major decrease after the 1980s—despite that more recent peat tends to have higher apparent accumulation rates—suggesting a sensitive response of this steep-slope mountain peatland to shift in regional hydroclimate in monsoon-margin region of Northeast China.

How to cite: Wang, Z. and Yu, Z.: Atmospheric circulation, hydroclimate change, and peat accumulation over the last 250 years inferred from a Sphagnum peatland in the southern Greater Khingan Mountains of Northeast China, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-10942, https://doi.org/10.5194/egusphere-egu21-10942, 2021.

Peat records of trace metals pollution history over thousands of years are not widely reported in northeastern Asia, although the mining/metallurgy have already started in the past 5000 years. Peat core was collected in September 2015, from the Nur Sphagnum bog, in Selenge province, in the NW part of the Kenthii Mountains, Mongolia. The Nur Sphagnum bog (49°39’N; 107°48’E; 1250 m.a.s.l.) is the largest wetland located in the mountain taiga forest of Mongolia in the northern part of the Hentei highlands. The mean January and July temperatures are -27.1°C and 18.3°C respectively, while mean annual precipitations are 288 mm. The peatland is composed of than 10 species of Sphagnum, while herb layer is dominated by Carex rostrata, and several species of Sphagnum. The dominant tree species are composed of Betulaplatyphylla, Pinussylvestris, Piceaobovata and Abiessibirica. As for the Nur bog, no research on elemental or isotopic geochemistry was undertaken currently. Our preliminary geochemical study established a baseline for typical heavy metal, Pb, 1.1 mg kg-1, which is reasonable to represent a pre-industrial background value in Mongolia, even in northeastern Asia. The average Pb content through the cores was 2.2 mg kg-1, which was significantly lower than the level in northeastern China and showed that the it was still typical area of pristine ecosystem in northern Mongolia. However, the elevation of Pb and Tl contents in the near surface layers was also observed, with an enrichment factor of 6, which suggested that the anthropogenic impact was approaching in this region and more attention should be paid to safeguard its nature heritage.

How to cite: Bao, K., Qiang, M., Zhao, K., Yan, Y., Ganzorig, U., and Batkhishig, O.: Mongolian peatland documents 5000-year pollution history and a baseline of Pb and Tl in northeastern Asia, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-9018, https://doi.org/10.5194/egusphere-egu21-9018, 2021.

A detailed pedocryostratigraphic scheme of the Late Pleistocene periglacial region of the East European Plain has been developed on the basis of study of the paleorelief, sediments, paleosols, and cryogenic horizons. OSL and ¹⁴C-dating of paleosols and sediments in Aleksandrov quarry and in other sections made it possible to substantiate this scheme and correlate it with analogous ones for different regions of Europe. The loess-paleosol sequence in Aleksandrov quarry (51º05'N, 36º08'E) does not have an analogous with respect to the completeness in the whole East European Plain. In the filling of paleobalka the Ryshkovo paleosol of the Mikulino interglacial (MIS 5e) is observed. Over this paleosol, the Valdai soil-sediment series (MIS 5d – MIS 2) is located. It includes four interstadial soils, two of them of the Early Valdai (Kukuevo and Streletsk ones), and two, sometimes three, of the Middle Valdai (Aleksandrov, Hydrouzel и Bryansk ones). The OSL date, 127 ± 8 ka BP, (beginning of MIS 5e) was obtained for a sample taken from the bottom of the Ryshkovo soil. The interglacial soil is overlain by the Seym layer formed mainly from destroyed and redeposited horizons of this soil. For the upper part of the Seym layer, OSL dates of 115 ± 7 ka BP and 112 ± 20 ka BP were obtained (MIS 5d). But the process of burial of Ryshkovo soil in the bottom of the paleobalka began at the end of the interglacial after a catastrophic forest fire. Large post-permafrost deformations - pseudomorphosis is confined to Selikhovodvor loess - MIS 4 (65 ± 8 ka BP). Two soils occurring between Seym and Selikhovodvor loesses: Kukuevo and Streletsk - Early Valdai (MIS 5c and MIS 5a). For Mlodat loess which separates those two soils (MIS 5b), OSL dates of 91 ± 1 and 89 ± 7 ka BP were obtained. For paleosols of Middle Valdai (MIS 3), ¹⁴C-dates were obtained: Aleksandrov (53.742 - 2.124 ka cal BP) and Bryansk soils (37.618 ± 0.668 ka cal BP). For Tuskar loess, which separates Alexandrov and Bryansk soils, OSL dates of 50 ± 3 and 51 ± 3 ka BP were obtained. The new stratigraphic scheme of Late Pleistocene agrees with the ideas of researchers from Eastern, Central, and Western Europe , which allows the following correlations. The identified paleosols correspond to the following intervals: Ryshkovo – Eemian interglacial (127-117 ka BP); Kukuevo to Amersfoort + Brørup – Saint-Germain 1 (105-95 ka BP); Streletsk – Odderade to Saint-Germain 2 (about 85-75 ka BP); Aleksandrov to Oerel (56-53 ka BP); Hydrouzel to Moershoofd – Poperinge (44-45 ka BP) and Hengelo (40-38 ka BP); and Bryansk (33-27 ka BP) to Stillfried B, Denekamp or Grand Bois interstadials. The reconstructed Late Pleistocene loess-paleosol sequence has the most similar structure with loess-paleosol sequences of Ukraine, with sequence Dolní Věstonice in Moravia (Czech Republik), Stillfried in Austria and Mainz-Weisenau in the Rhenish area (Germany), and other archives. This work was supported by RFBR, grant N19-29-05024 mk.

How to cite: Sycheva, S., Frechen, M., Terhorst, B., Sedov, S., and Khokhlova, O.: Stratigraphy and chronology of Late Pleistocene loess-paleosol sequence of the East European Plain and correlation with Late Pleistocene archives of Europe, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-650, https://doi.org/10.5194/egusphere-egu21-650, 2021.

Loess-palaeosol sequences are the most intensively studied terrestrial archives used for the reconstruction of late Pleistocene environmental and climatic changes in the Sea of Azov region, southwest Russia. Here we present a revised luminescence-based chronostratigraphy and a multi-proxy record of late Pleistocene environmental dynamics of the most complete and representative loess-palaeosol sequences (Beglitsa and Chumbur-Kosa sections) from the Azov Sea region. We propose a new chronostratigraphy following the Chinese and Danubean loess stratigraphy models that refines the subdivision of the last interglacial palaeosol (S1) in two Azov Sea sites, resolves the uncertainty of the stratigraphic position of the weakly developed paleosol (L1SSm) in Beglitsa section, and allows direct correlation of the Azov Sea sections with those in the Danube Basin and the Chinese Loess Plateau. More importantly, it adds important data to better constrain local and regional chronostratigraphic correlations, and facilitates the interpretation of climatic connections and possible forcing mechanisms responsible for the climatic trend among these regions. In addition, a general succession of environmental dynamics is reconstructed from these two vital sections, which is broadly consistent with other loess records in the Dnieper Lowland and Lower Danube Basin, demonstrating similar climatic trends in these regions at glacial-interglacial time scales. However, differences in details were also identified, especially for palaeosols developed during the last interglacial period, and the cause of these dissimilarities between loess records appears complex.

Furthermore, our results have important implications for the chronostratigraphic representativeness of Beglitsa as a key loess section and the reconstruction of the temporal and spatial evolution of late Pleistocene palaeoclimate in the Sea of Azov region.

How to cite: Chen, J.: Revised chronostratigraphy and palaeoenvironmental record of loess-palaeosol sequences in the Azov Sea region of Russia since the late Pleistocene, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-3207, https://doi.org/10.5194/egusphere-egu21-3207, 2021.

Here we investigate the timing of Pleistocene-Holocene climatic transition as reflected in nine luminescence dated loess-palaeosol sequences across the northern hemisphere, from the Chinese Loess Plateau, the southeastern European loess belt and the central Great Plains, Nebraska, USA.
First, logs of high-resolution magnetic susceptibility and its frequency dependence were used as palaeoclimatic proxies to define the environmental transition from the last glacial loess to the current interglacial soil. Second, the onset of increase in their values above typical loess values was used to assess the onset of, and developments during, the Pleistocene-Holocene climatic transition. The variability seen in the magnetic susceptibility records are interpreted based on high-resolution luminescence dating applied on multiple grain-sizes (4-11 µm, 63-90 µm, 90-125 µm) of quartz extracts from the same sample. In order to increase the overall precision of the luminescence based chronology we rely on weighted average ages. Based on these, Bayesian modeling allowed the determination of age-depth models and mean sedimentation rates for each investigated site.
The magnetic susceptibility signal shows a smooth and gradual increase for the majority of the sites from the typical low loess values to the interglacial ones. At all but one site, this increase, associated to the onset of the Pleistocene-Holocene boundary (ie., 11.7 ka) was dated to 14 ka or even earlier. Our results highlight the need of combining palaeoclimatic proxies (magnetic susceptibility) with absolute dating when placing the Pleistocene-Holocene climatic transition as reflected by the evolution of this proxy in order to avoid misinterpretations in loess-paleosol records caused by simple pattern correlation. These results indicate diverse environmental dynamics recorded in the different North Hemisphere loess regions during the major global climatic shift from the last glacial to the Holocene.
The detailed luminescence chronology coupled with magnetic susceptibility records indicate the formation of accretional Holocene soils in the sites investigated. Modeled accumulation rates for the Holocene soil are similar for European, Chinese and American loess sites investigated and vary from 0.02 m/ka to 0.09 m/ka.

How to cite: Constantin, D., Mason, J., Hambach, U., Veres, D., Panaiotu, C., Zeeden, C., Zhou, L., Marković, S., Gerasimenko, N., Avram, A., Tecsa, V., Sacaciu-Groza, S. M., del Valle Villalonga, L., Begy, R., and Timar-Gabor, A.: Accretional soil formation in northern hemisphere loess regions - evidence from OSL-dating of the P/H climatic transition from China, Europe and North America, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-2394, https://doi.org/10.5194/egusphere-egu21-2394, 2021.

In this work, the samples of red-coloured pedosediments were analyzed. They were found in two sections of the Lori Basin, Armenia - Kurtan-IV and Yagdan. Micromorphological analysis, the measurement of magnetic susceptibility, particle size distribution, CHN, determination of bulk, and biomorphic composition was made. Based on the results of previous studies, the age of the deposits overlying these sections was known. The pedosediment from the Kurtan-IV section is overlain by a mixture of sand and volcanic ash, which is dated at about 1.4 Ma (Calabrian). The pedosediment from the Yagdan section is overlain by 2-2.5 Ma basaltic lava (Gelasian). As a result of our research, it was revealed that both pedosediments were formed in conditions differ from current ones and have differences between themselves also. The pedosediment from the Yagdan section was formed during the dominance of the subtropical climate. It was revealed the presence of manganese-ferruginous and clayey films, a low index of carbonization and salinity, and a relatively high index of weathering. Pedo-sediments from the Yagdan section can be classified as Cambisols with vitric, argic, chromic qualifiers. By the time the later section Kurtan-IV was formed, the climate became cooler, which was reconstructed by the appearance of phytoliths of coniferous plants. Pedosediment from the Kurtan-IV section can be classified as Stagnic Luvisols. The later factors influencing the preservation of pedosediments and changes in their composition and properties were identified. Thus, the upper horizon of the Yagdan section sharply differs from the underlying ones in increased weathering and oxidation, and these properties are retained up to the third layer. It has increased indicators of magnetic susceptibility and the content of copper elements, cobalt, nickel, vanadium, chromium, which were brought in by basalt lava. The pedosediment from the Kurtan-IV section was overlain by lacustrine deposits, which led to a decrease in the magnetic susceptibility and an increase in the SiO₂ content and carbonation index. This work was supported by RFBR, grant N19-29-05024 mk.

How to cite: Revunova, A. and Khokhlova, O.: Red-coloured pedosediments of the Lori Basin, Armenia, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-14619, https://doi.org/10.5194/egusphere-egu21-14619, 2021.

In the framework of climate change research, alpine soils may provide excellent paleoenvironmental information, thus representing a powerful tool for paleoclimate reconstruction. However, since Pleistocene glaciations and erosion-related processes erased most of the pre-existing landforms and soils, reconstructing soil and landscape development in high-mountain areas can be a difficult task.

This study was performed in the periglacial environment of the Stolenberg Plateau (LTER site Istituto Mosso), located on the watershed between Valsesia and Lys Valley, at the foot of the southern slope of the Monte Rosa Massif (Western Italian Alps, elevation: ca. 3030 m a.s.l.). The plateau is covered by thick periglacial blockfields and blockstreams, with a plant cover that reaches no more than 3-5% of the surface.

These periglacial landforms unexpectedly revealed well-developed soils below the superficial coarse deposits. In particular, below the stone layer, thick (between 30 and 65 cm) umbric horizons were observed, under which discontinuous cambic Bw ones were developed. In contrast, the surrounding snowbed communities (Salicetum herbaceae) were characterized by Regosols or Cambisols with 10-15 cm thick A horizons and weak signs of cryoturbation.

Despite the sparce plant cover, the organic carbon (C) stocks were surprisingly high (above 5 kg*m^-2), comparable to vegetated and even forest soils at lower elevation. In addition, geophysical investigations showed that these soils are widespread under the stony cover, with a thickness ranging between 20 and 90 cm.

Radiocarbon dating (¹⁴C) indicated that these soils are paleosols, probably originated during the main warming phases/interstadials occurred between the end of Last Glacial Maximum and the beginning of the Neoglacial. In particular, the ages of the oldest samples were 20.5-20 ka cal. BP (values obtained from two independent and blind datings performed in different moments), others were dated ca. 17.5, 13, 8.5, 6.5, 5.7 ka cal. BP, while the youngest ages were 4.4-4.1 ka cal. BP.

These dates, particularly the oldest ones, show that the Stolenberg Plateau was presumably free of ice at the beginning of the Early Lateglacial, and its summer temperatures were already compatible with some kind of vegetation development. The origin of these unexpected high-elevation soils, below blockstreams and blockfields, is of great relevance for unraveling the climatic history in the Western Alps. The results, including the soil characteristics, the geomorphological framework and the specific local landform setting, aspect, and position, suggest that the plateau may have been a Nunatak, which acted as a refugium for alpine vegetation during the last glacial pulses, serving as a hot-spot for the rapid reoccupation of deglaciated high-elevation landscapes.

How to cite: Pintaldi, E., D'Amico, M. E., Colombo, N., Giardino, M., and Freppaz, M.: Hidden paleosols at high elevation in the Alps (Stolenberg Plateau - NW Italy): evidence for a Lateglacial Nunatak?, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-5354, https://doi.org/10.5194/egusphere-egu21-5354, 2021.

Hyperarid (< 80 mm yr^-1) soils in hot deserts are characterized by accumulations of soluble salts (gypsum and halite) in diagnostic horizons as a result of limited moisture availability. In most desert terrains, the source for pedogenic gypsum and halite is atmospheric dust and rainwater. The interplay between climatic properties such as frequency and intensity of rain events, rainfall composition, dust flux, and evaporation rates, govern the depth and concentration of these salts. Better understanding of these relationships can improve our estimation of regional paleoenvironmental and paleoclimate conditions. Up to date, only empirical correlations between annual rainfall and pedogenic salt horizons are available.

The goals of this study are to: 1) quantify rates of pedogenic gypsum accumulation with time and the role of controlling climatic conditions that govern its accumulation, 2) estimate the most likely climatic scenarios that led to the formation of the diagnostic gypsic horizon developed in late Pleistocene (~ 60 ka) abandoned alluvial fan surfaces in the hyperarid Negev desert,  southern Israel. To achieve these goals, we constructed a compartment model that simulates gypsum accumulation in soil and tests its sensitivity to various changes in the long-term climate properties. The model predicts gypsum content and depth of accumulation in the soil profile over thousands of years and more. The input parameters are stochastically simulated rainstorms, evaporation, dust flux, and sulfate concentration in rainwater, at daily time steps. The model was tested and calibrated using data of Holocene (< 11 ka) soil profiles developed on stable alluvial fans in the hyperarid Negev. With the assumption that the climate during the Holocene was not much different than today (i.e., mean annual rainfall < 50 mm). Sensitivity analyses indicate that gypsum accumulation is highly sensitive to mean annual rainfall and sulfate concentration in rainwater. Synthetic gypsum profiles were calculated using different climate scenarios and compared to late Pleistocene soils. Our results suggest that: (a) gypsum accumulation in late Pleistocene soils cannot occur simply by extending current climate conditions for a much longer duration. (b) The plausible climate scenarios for the late Pleistocene must include additional rain input (1.5 – 2.0 times than mean annual rainfall today) and increased sulfate concentration in rainwater (2.0 – 2.5 times than today) to successfully reconstruct the observed accumulated gypsum in mature (60 – 12 Ka) soil profiles.

How to cite: Siman-Tov, L., Crouvi, O., Morin, E., Amit, R., Enzel, Y., Marra, F., J. Reznik, I., and Rosenzweig, R.: Evaluating climate effects over long-term salts accumulation in hyperarid soils using stochastic modeling, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-2296, https://doi.org/10.5194/egusphere-egu21-2296, 2021.

Soil carbon isotopes (δ¹³C) provide reliable insights at the long-term scale for the study of soil carbon turnover and topsoil δ¹³C could well reflect organic matter input from the current vegetation. Qinghai-Tibet Plateau (QTP) is called “the third pole of the earth” because of its high elevation, and it is one of the most sensitive and critical regions to global climate change worldwide. Previous studies focused on variability of soil δ¹³C at in-site scale. However, a knowledge gap still exists in the spatial pattern of topsoil δ¹³C in QTP. In this study, we first established a database of topsoil δ¹³C with 396 observations from published literature and applied a Random Forest (RF) algorithm (a machine learning approach) to predict the spatial pattern of topsoil δ¹³C using environmental variables. Results showed that topsoil δ¹³C significantly varied across different ecosystem types (p < 0.05).  Topsoil δ¹³C was -26.3 ± 1.60 ‰ for forest, 24.3 ± 2.00 ‰ for shrubland, -23.9 ± 1.84 ‰ for grassland, -18.9 ± 2.37 ‰ for desert, respectively. RF could well predict the spatial variability of topsoil δ¹³C with a model efficiency (pseudo R²) of 0.65 and root mean square error of 1.42. The gridded product of topsoil δ¹³C and topsoil β (indicating the decomposition rate of soil organic carbon, calculated by δ¹³C divided by logarithmically converted SOC) with a spatial resolution of 1000 m were developed. Strong spatial variability of topsoil δ¹³C was observed, which increased gradually from the southeast to the northwest in QTP. Furthermore, a large variation was found in β, ranging from -7.87 to -81.8, with a decreasing trend from southeast to northwest, indicating that carbon turnover rate was faster in northwest QTP compared to that of southeast. This study was the first attempt to develop a fine resolution product of topsoil δ¹³C for QTP using a machine learning approach, which could provide an independent benchmark for biogeochemical models to study soil carbon turnover and terrestrial carbon-climate feedbacks under ongoing climate change.

How to cite: Lai, Y., Li, S., Tang, X., Luo, X., Liu, L., Shi, Y., and Yu, P.: Spatial variability of topsoil δ13C across Qinghai-Tibet Plateau, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-5768, https://doi.org/10.5194/egusphere-egu21-5768, 2021.

Geomorphometric information can be exploited to study the most extensive and common landforms that humans have ever produced: agricultural terraces. An understanding of these historical ecosystems can only be determined through in-depth knowledge of their origin, evolution, and current state in the landscape. These factors can ultimately assist in the future preservation of such landforms in a world increasingly affected by anthropogenic activities. High-resolution topographic (HRT) techniques allow the mapping and characterization of geomorphological features with wide-ranging perspectives at multiple scales. From HRT surveys, it is possible to produce high-resolution Digital Terrain Models (DTMs) to extract important geomorphometric parameters such as topographic curvature, to identify terrace edges, even if abandoned or covered by uncontrolled vegetation. By using riser bases as well as terrace edges (riser tops) and through the computation of minimum curvature, it is possible to obtain environmentally useful information on these agricultural systems such as terrace soil thickness and volumes. The quantification of terrace volumes can provide new benchmarks for soil erosion models, new perspectives for land and stakeholders for terrace management in terms of natural hazard and offer a measure of the effect of these agricultural systems on soil organic carbon (SOC) sequestration. This work aims to realize and test an innovative and rapid methodological workflow to estimate the minimum anthropogenic reworked and moved soil of terrace systems in different landscapes. This aspect of new technology and its application to terrace soil-systems has not been fully explored in the literature. We start with remote terrace mapping at a large scale (using Airborne Laser Scanning) and then utilize more detailed HRT surveys (i.e., Structure from Motion and Terrestrial Laser Scanning) to extract geomorphological features, from which the original theoretical slope-surface of terrace systems were derived. These last elements were compared with in-field sedimentological recording obtained from the excavations across the study sites to assess the nature of sub-surface topographies. The results of this work have produced accurate DTMs of Difference (DoD) for three terrace sites in central Europe in Italy and Belgium. The utilization of ground-truthing through field excavation and sampling has confirmed the reliability of the methodology used across a range of sites with very specific terrace morphologies, and in each case has confirmed the nature of the reconstructed, theoretical original slope. Differences between actual and theoretical terraces from DTM and excavation evidence have been used to estimate the minimum soil volumes and masses used to remould slopes. Moreover, geomorphometric analysis through indices such as sediment connectivity permitted also to quantify the volume of sediment transported downstream, with the associated and mobilized C, after a collapsed terrace. The quantification of terrace soil volumes provides extremely useful standards for further multi-disciplinary analysis on the terrace sediments themselves, aiding physical geographers, geoarchaeologists, palaeo-environmentalists, and landscape historians in the understanding of terrace systems and the impact of agricultural processes on the landscape.

How to cite: Cucchiaro, S., Paliaga, G., Fallu, D. J., Pears, B. R., Walsh, K., Zhao, P., Van Oost, K., Snape, L., Lang, A., Brown, A. G., and Tarolli, P.: A geomorphometric approach to estimate soil volumes stored in agricultural terrace systems, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-1772, https://doi.org/10.5194/egusphere-egu21-1772, 2021.

The activities of ancient population strongly affected the development of landscapes and soils in Western Siberia during the late Holocene. It should be noted that studies devoted to the processes of natural and anthropogenic evolution within this vast territory are extremely irregular. Thus, the significant proportion of the materials on the dynamic of Siberian landscapes in the Holocene, related to the studies of various natural archives and archeological monuments, falls on the southern part of region. On the one hand, this situation is due to the relatively recent development of Western Siberia in relation to the development of hydrocarbon deposits, on the other hand, on the peculiarities of the relief and landscapes prevailing in the central and northern parts of the West Siberian Plain. A significant part of the territory under consideration is characterized by low, poorly dissected relief, which largely contributes to its bogging and widespread distribution of organogenic peat soils. It is not surprising that the deposits of lakes and peat bogs are the main natural archives that provide information on the dynamics of the natural environment within the central parts of Western Siberia and, first of all, the taiga zone, while the potential of mineral soils and sediments from this point of view is insignificant, compared to other regions. At the same time the boreal zone of Western Siberia is very large and includes regions with more complex geomorphological conditions.

To assess the possibility of using buried soils and colluvial layers in the middle taiga of Western Siberia for reconstruction of the Holocene landscape’s dynamics, we carried out research on two key sites with rather contrast relief and high frequency of archeological sites: in the middle Yugan River Basin and in the North of the Kondinskaya Lowland. Buried soils and colluvial sediments in a number of sections characterizing foots of the steep slopes on the border with peat bogs were selected as objects for our study. Based on the obtained radiocarbon dates it is possible to preliminarily identify several stages of the activation of erosional processes. For the north of the Kondinskaya lowland three remarkable phases of erosional activity were identified, while for the Yugan River Basin the number of phases was larger - 6. It is interesting to note that the obtained results make it possible to correlate these two regions. The presence of a larger number of recorded erosion-pyrogenic events for the Yugan River basin reflects a longer permanent human presence in the area under consideration, which is also consistent with archaeological data.

The study was funded by the Ministry of Science and Higher Education of the Russian Federation and was performed as a part of project FEWZ-2020-0007 “Fundamentals of the natural environment history of the south of Western Siberia and Turgay in the Cenozoic: sequence sedimentology, abiotic geological events and the evolution of the Paleobiosphere“. The studies were carried out using the equipment of the Center for Collective Use "Bioinert Systems of the Cryosphere", Tyumen Scientific Center, SB RAS and RFBR, project number 20-04-00836.

How to cite: Kurasova, A., Konstantinov, A., Loiko, S., and Kulizhskiy, S.: Evaluating the potential of buried soils and colluvial layers for tracking natural and human-induced transformation of landscapes in the middle taiga of Western Siberia, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-16454, https://doi.org/10.5194/egusphere-egu21-16454, 2021.

Changes in land use represent, after fossil-fuel combustion, the greatest cause of greenhouse-gases emission into the atmosphere. Coastal wetlands, also referred as coastal blue carbon ecosystems (e.g. salt marshes, mangrove forests, seagrass meadows, swamps), represent one of the most powerful C sinks among the Earth’s ecosystems, being capable to sequester organic carbon (OC) at rates ca. 30-50 times higher than terrestrial forests. Historically, land reclamation for agriculture, farming and urban expansion, severely impacted coastal wetlands, causing their loss and degradation. Wetlands drainage lead to the oxidation of organic matter previously stored under anaerobic conditions and the release of CO₂ into the atmosphere. Only recently the critical role of blue carbon ecosystems in climate-change mitigation has been recognised, highlighting the importance of protecting and studying these precious environments.

In this work, changes in land use in the last two centuries are reconstructed through comparison with historical maps. At the beginning of the 19^th century Napoleon Bonaparte requested the development of high-quality maps of occupied territories. Among these, the so-called ‘Carta del Ferrarese’ (CdF), completed between 1812 and 1814, is composed of 38 sheets and represents, to a scale of 1:15.000, 240.000 hectares of the Po lowlands, roughly corresponding to the present-day Ferrara district. The CdF, archived at the Kriegsarchiv in Vienna, is an extraordinary example among historical maps for its high quality and accuracy, which constitute a two-centuries-old reliable paleo-landscape picture.

Within the Historical Land Use Change research project, leaded by the Emilia-Romagna Statistical and GIS Service, the CdF was scanned, accurately georeferenced and orthorectified, showing a surprising generalized match with recent maps. More than 31.000 polygons were digitized in a GIS environment and interpreted on the basis of the European Corine Land Cover codes, properly modified for the land uses at the time.

Comparison with the recent land use analysis, carried out in 2014, highlights changes in land use, mainly related to land reclamation. Salt marshes and swamps, originally extended for 100.000 hectares, were reduced of about 85%, starting from 1861. Major phases of land reclamation occurred in 1870s and 1960s. Geochemical analyses on shallow samples (depth < 50 cm), depict OC content of artificially drained soils < 5% of the total volume. Soil texture testifies to the almost complete mineralization of OC after reclamation. Only recently drained soils show higher OC content, in the range of 10-15%.

How to cite: Meli, M. and Bruno, L.: Changes in land use in the last two centuries in the Po lowlands (northern Italy), EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-9780, https://doi.org/10.5194/egusphere-egu21-9780, 2021.

In 2018, the Voorthuizen-Wikselaarseweg archaeological site was excavated. This settlement dates back to Roman and Medieval times and is located in the central part of the Netherlands: the so-called Gelderse Vallei, an area build-up of fluvioperiglacial and eolian sands. Questions related to the anthropogenic influence of settlers on the surrounding landscape, as well as the specification of the ancient agricultural activity, were among the main research tasks posed to this archaeological study. Despite the fact that modern geoarchaeology offers a variety of methods of researching archaeological sites, in practice, the vast majority of archaeological work in the Netherlands is limited to the use of palynological and macrobotanical analyzes and radiocarbon dating. The choice of research methods in relation to the sandy cultural layer is especially narrow as it is assumed to bear worse conditions of preservation of traces of anthropogenic activity.

For the investigation of the sandy cultural layer of Voorthuizen, a method of microbiomorphic (phytolith) analysis was proposed. The information that is given by this method is different from that provided by palynological study (though they strongly complement each other). While pollen provides a general insight into the plant growth in the region around the settlement, phytoliths (silica copies of plant cells)  present data on the plant species grown, eaten, and used on the settlement itself. This information is contained in the old living layer, as well as in the pits (working places and waste pits), postholes, ditches etc. The combination of phytoliths and other microbiomorphs (e.g. detritus, diatoms, etc.) essentially broadens the range of palaeoecological information.

In Voorthuizen 34 samples have been collected and processed according to standard sample treatment technique (Golyeva, 2008). All samples were found to be suitable for analysis, with a sufficient number of microbiomorphs.

The results of the study not only allow to clarify significantly the archaeological interpretation of the site but also provides new information on the anthropogenic impact on the landscape. Microbiomorphic analysis manifests the genesis of the cultural layer and the several phases and types of anthropogenic use of the territory. The research also demonstrates the applicability of the microbiomorhic (phytolith) analysis in the case of sandy archaeological layers.

References:

Golyeva А. А., Microbiomorphic complexes of natural and anthropogenic landscapes. Genesis, geography, informative capacity (LKI, Moscow, 2008) (in Russian).

How to cite: Druzhinina, O., van den Berghe, K., and Golyeva, A.: Application of the microbiomorphic (phytolith) analysis in the geoarchaeological study of the land-use at the Voorthuizen-Wikselaarseweg archaeological site (Netherlands), EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-9043, https://doi.org/10.5194/egusphere-egu21-9043, 2021.

Reflectance spectroscopy is widely used to rapidly and quantitatively determine soil properties. This study introduces a method to identify archaeological soils, which are soils influenced by ancient anthropogenic activities, from the surrounding landscape using a portable VIS-NIR reflectance spectrometer. To identify spectral features of archaeological soils, the method statistically calculates the difference between an archaeological soil spectrum and a non-archaeological soil spectrum. Such difference is quantified by an R-value. Any soil spectra with R-values larger than 1 are more likely to be anthropogenically-affected soils.

Previously, the method was successfully applied to several archaeological sites in Italy and Hungary showing clear differences between the archaeological and non-archaeological soils. In this study, we will investigate the R-values for soils from prehistoric settlement sites in Sintanjin, Korea, and compare these to the results from Italy and Hungary. Both in-situ and topsoil spectral measurements were gathered using a portable ASD spectrometer. In this site, soils from kitchen areas showed R-values between 2.5 and 4.2, while soils from graves ranged from 1 to 1.4. The results indicate that the R-values vary a lot depending on the type of archaeological remains and a more detailed investigation of the method to various archaeological remains is essential to improve the method. One of our interesting results is that the method can be applied to soil spectra gathered with low-resolution spectrometers which leads to the possibility of applying continuous 2D spectral imaging applications.

How to cite: Choi, Y. J. and Yu, B.: Detection of archaeological soils through portable VIS-NIR spectrometer, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-13745, https://doi.org/10.5194/egusphere-egu21-13745, 2021.

Growing infrastructure development in Israel has increased the number of rescue excavations involving multi-layer archaeological sites and "megasites" in landscapes ranging from dunes to clay-rich soils and yielding prehistoric to early modern finds. The limited time and resources allocated for the excavations requires rapid on-site scientific data, which are used for research during and after excavation, prioritizing artefact treatment, sediment analysis, and absolute and relative dating.

Lateral and vertical pulsed-photon (portable) OSL (PPSL) profiling of sections of anthropogenically-altered sediments containing feldspar or quartz, provide rapid and partial answers for interpreting depositional processes. These answers allow researchers to discriminate between natural and human-intervened sedimentation, identify relative age and laterally synchronize between similar sediment units, which, in turn, often help to orient the excavation goals. The potential for inhomogeneity of archaeological sediments in some cases constrain the comparability of results and call for complementary analysis of the measured sediments in order to define their inter-compatibility. Independent mineralogical and chemical and textural properties of the sediments affect the inherent luminescence signals and should therefore be analyzed.

Here we present a PPSL profiling approach combining tailored sedimentological analyses to validate sample comparability in different sedimentological and archaeological settings. The analyses include gamma and FTIR spectroscopy, portable XRF geochemistry, carbon content, particle-size distribution and colorimetry. The complementary data are intended to improve PPSL protocols by characterizing the context inhomogeneity and helping to prioritize samples for OSL dating

How to cite: Roskin, J., Ackermann, O., and Asscher, Y.: Lateral and vertical pulsed-photon portable luminescence (PPSL) profiling of anthropogenically-altered sediments in rescue excavations of different landscapes, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-9335, https://doi.org/10.5194/egusphere-egu21-9335, 2021.

Anthropogenic soils and soil-sedimentary systems (cultural layer, occupation deposit) in settlement archaeological settings are highly valuable and underappreciated archives of past environments, land-use activities, and life cycles within past residential areas. This study is aimed to reconstruct fire history for the early medieval town of Dzhankent located in Eastern Aral region, Kazakstan as based on the C14 dated stratigraphy, morphology and micromorphology, data on charcoal morphology, C:N and C13 isotope records.  

Several sections of cultural layers were studied within excavated areas. Stratigraphic units were thoroughly C14 dated (58 dates). Most 14C dates are between the 7th and 10th centuries, and most of the dates have overlapping intervals of calibrated age although clear up-section trends from older to younger ages may be seen. This demonstrates the slow, progressive accumulation of occupation deposits. The analysed excavation sections are very well stratified. Stratigraphic units based on char-enriched marker beds could sometimes be traced for long distances. Char enriched layers contain enormous quantities of both grass and wood charcoals. Thin, about 1 m long lenses of ash and charcoals of poor and unified taxonomic variety are thought to be fireplaces. Extended thick char-enriched layers (about 10 meters long and 0,1 m thick), well stratified at macro-, and micro-levels, with sub-parallel oriented charcoals of highly variable taxonomic compositions considered to be traces of big fires. Three fire events were detected based on the stratigraphy, morphology, charcoal amounts, C, N and C13 isotope depth variability.  

Filed studies and were funded by DFG project 389351859. The analytical part was supported by RFBR 19-29-05238, and DFG 389351859.

How to cite: Bronnikova, M., Shumilovskikh, L., Karpova, Y., Panin, A., Arzhantseva, I., and Härke, H.: Stratigraphy of habitation deposits and fire history of the early medieval town Dzhankent (Kazakhstan, Eastern Aral region) , EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-16537, https://doi.org/10.5194/egusphere-egu21-16537, 2021.

Across much of the Mid-Atlantic United States and Europe, relict charcoal hearths (RCHs) are a common landscape feature once used as a primary fuel source for iron smelting and quick-lime production. We investigated a landscape surrounding the Monroe Furnace in central Pennsylvania, which was in operation for around 17 years until 1846. This preliminary investigation explores landscape patterns of hearth placement in relation to the furnace and landscape position and resulting potential effect on soil moisture. We mapped RCHs using LiDAR derived hillshade models of varying aspects, elevation, and slope. We classified the different shapes of RCHs in relation to their geomorphic positions and modeled both a topographic and soil wetness index for selected hearths and off-hearth locations nearby. Two hearths were sampled in the field and their morphology and soil properties investigated.

Hearths that were constructed on flatter slope gradients are seemingly more circular in shape and have more equal axes whereas steep slopes have a more oval shape elongated in one axis with the slope direction. More circular hearths are on or near flatter hillslope positions (such as on summits or shoulders) whereas eye-like shaped hearths are on steeper hillslope positions (like backslopes).  Based on initial topographic wetness index data, hearths are not acting as sinks for flow but instead often cause water to flow around them leading to drier conditions within RCHs.

Trenches alongside the slope orthogonal direction of the two sampled RCHs show a single layered stratigraphy, i.e. both sides had only one continuous technogenic, charcoal rich layer. The downslope half of both sites had generally higher contents of macroscopic charcoal pieces as well as buried colluvial- and buried fossilized A-horizons underlying the charcoal rich layer. Both sites are not perfectly levelled, but slightly sloped. Buried B- and colluvial horizons show signs of heat induced reddening of iron oxides on the top few centimeters. Preliminary results suggest significant differences in soil chemical and physical properties of the technogenic layer in comparison to the adjacent forest soils.

How to cite: Bonhage, A., Bayuzick, S., Drohan, P., Hirsch, F., and Raab, T.: Relict charcoal hearth landscape and soil profile characteristics surrounding a mid-19th century Appalachian iron furnace, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-5691, https://doi.org/10.5194/egusphere-egu21-5691, 2021.

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 the 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 and quantifying how RCHs may alter surface hydrology.  

We used a combination of processed LiDAR data to create hillshades, and slope gradients to visualize RCHs.  A total of 6,758 hearths have been digitized across three study areas that reflect different historical time periods of construction and environments. We hypothesize that the construction of RCHs can alter the surface hydrology of their surrounding environments. To fully quantify the landscape-level effects of RCHs, a subset of the total was created to fully digitize the RCHs’ area.  The RCH was broken into their rim and platform components.  A topographic wetness index (TWI), and SAGA wetness index (SWI) was created for two study areas in order to quantify surface hydrology effects.  We found that RCH platforms have a significantly higher TWI and SWI than the rim counterparts indicating that the platform is wetter than the RCH outer rims.  Geomorphic position was found to not effect wetness.  Using field measured volumetric water content, we found that as distance from the center of the hearth increases, the drier the soil becomes. Using a combination of GIS flow path analysis, and RCH geometry, standardized ellipses using the axis of local RCHs and the mean area of the total RCHs were created to understand the upslope (control) and downslope (experiment) effects of hearths on the surface hydrology.  Preliminary analysis indicates that downslope positions from RCHs are drier than upslope positions and that there is a significant difference in the relationship between slope position and distance from an RCH and the corresponding TWI and SWI values. Future research will address the effect of slope position and distance to quantify the effect of RHCs on surface hydrology. Furthermore, the soil chemical changes from RCH creation and the increase moisture may increase the habitat for rare species of both plants and animals that otherwise would not be present.  Understanding the extent of the impact human activity can have on various ecosystems can help forest managers, conservationists, pedologists, and climatologists better adapt their management or research pursuits within a specific environment to prepare for future changes, natural or anthropogenic.

How to cite: Bayuzick, S., Drohan, P., Raab, T., Hirsch, F., Bonhage, A., McDill, M., and Diefenbach, D.: Relic charcoal hearths geomorphology and hydrology in mid-Appalachian region of Pennsylvania, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-6243, https://doi.org/10.5194/egusphere-egu21-6243, 2021.