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Historic charcoal hearth remains provide a unique archive of the long term interaction between biochar, soil development and plant growth. Charcoal as raw material was crucial for production of iron in iron works and hence numerous charcoal hearths can be found in the forests near historic iron works in Europe as well as the Eastern United States. Charcoal hearths are round to elliptical forms often around 10 m in diameter, and consist of several decimeter thick layers that contain charcoal fragments, ash, and burnt soil. We studied the soil chemistry of 24 charcoal hearths and compared them to the surrounding ‘natural’ soils in the northern Appalachians of northwestern Connecticut. The thickness of the topsoils on the charcoal hearths and their carbon content are remarkably higher than in the surrounding topsoils. The presence of residual products from charcoal production classifies the soils as Anthropic Udorthents (US Soil Taxonomy) or Spolic Technosols (Humic) according to the World Reference Base for Soil Resources. The widespread occurrence of charcoal hearth remains and their high spatial density in different ecosystems underlines their importance for further pedological research.
Historical charcoal production can have significant effects on soil properties. We studied soils at former charcoal production sites (relict charcoal hearths, RCHs) and compared these soils with undisturbed soil next to the charcoal hearths and four typical soils on similar parent material located at distances between 10 and 70 km from the RCHs. In a landscape typical of the northern German lowland, we found Podsolige Braunerde [WRB: Brunic Arenosols (Protospodic)] outside of the RCHs and soils with a clearly different stratigraphy within the RCHs. The main feature of the soils at both of the studied RCHs is a heterogeneous, charcoal-bearing deposit that is ~30 cm thick. No indications of translocation or mineral transformation processes, which form distinct soil horizons after the deposition of anthropogenic material on the RCHs, are present. Except for the differences in color and total carbon content, the soil chemistry of the RCHs hardly differs from that of the soil outside of the charcoal hearth sites. The soil colors and magnetic susceptibility values strongly suggest that the RCH substrates and the underlying topsoil were affected by thermally induced transformation of iron (hydr-)oxides. Although the charring procedure normally requires ~2 weeks, the heating effect only reaches to a maximum depth of 8 cm into the buried soil below the charcoal hearths. The presence of reddish soil and an abrupt increase in magnetic susceptibility in the upper 2 cm of the soil below the charcoal hearths indicate the heat-induced transformation of iron (hydr-)oxides into maghemite. Brighter soil color and an increase in soil organic matter (SOM) in the lower parts of the buried topsoil demonstrate the combustion of SOM up to 5 cm depth below the RCH. According to the German Guidelines for Soil Mapping, the soils in the RCHs are classified as Regosols above Braunerde [WRB: Spolic Technosols (Arenic)]. However, because the anthropogenic features of these soil sediments are disregarded in the German Guidelines for Soil Mapping, we suggest adapting the “M” horizon to permit a jM horizon. Thus, the soils in the RCHs could be classified as Kolluviale Braunerde.
Relict charcoal hearths (RCHs) are sites of former charcoal production that are an increasingly well documented anthropogenic feature in forests of the temperate climate zone. However, the type and extent of a possible legacy effect from RCHs on soil physical and chemical properties is still largely unknown. In the Litchfield Hills in west Connecticut, RCH sites are located mainly on slopes and therefore differ in their architecture from lowland sites found in Europe. One of the striking characteristics of a RCH site regardless of its architecture is the enrichment of the soil with charcoal in varying particle sizes. In this study, we use chemical digestion coupled with a PLSR-model to quantify organic carbon and pyrogenic carbon in RCH substrate by MIR-DRIFT measurements. Furthermore, we analyse the quality of carbon compounds by MIR-DRIFT measurements on multiple grain size fractions to assess the post-burn enrichment of soil organic matter. Preliminary results show a markedly increase in organic and pyrogenic carbon in RCH substrates in relation to the natural forest soil. Also, our first results suggest that the enrichment of organic carbon is favoured on RCHsites. However, the causality between the enrichment of soil organic matter and site features remains open. Experiments using chemical extraction techniques on our samples hint at an increase of labile organic compounds and/or microbial biomass. This legacy effect of RCHs is however evident and further studies need to focus on how to address them.
Do small landforms have large effects? A review on the legacies of pre-industrial charcoal burning
(2022)
Relict charcoal hearths (RCHs) are small, anthropogenic landforms resulting from past charcoal burning and reaching significant land coverage in pre-industrial mining areas. We review three coupled legacies linked by RCH development: (i) a landscape-scale geomorphic effect, (ii) a unique soil fingerprint, and (iii) an evolving novel ecosystem. The history and technique of charcoal production are described to clarify legacy effects. Applying a recently presented morpho-genetic catalogue is useful for classified mapping of RCH findings. The RCH numbers and calculated RCH densities per study region vary greatly and impose uncertainties due to insufficient methods causing over- or underestimations. Areas with high RCH densities between 50 and 500 RCH/km2 seem reasonable. Machine learning-based remote sensing techniques are promising approaches with which to better assess the full scale of charcoal burning legacies. RCH soil properties feature dark charcoal-rich technogenic substrate layers classified as Auh horizons according to the World Reference Base with significantly increased C contents. These Auh horizons can also exhibit specific physical and chemical properties, such as relatively low bulk density, high porosity, high plant available water content, low thermal conductivity and differences in cation exchange capacity or nutrient status. However, relevant studies are rare, and thus, the effects may differ by study region. Regarding vegetation, there seem to be four main effects: changes in forest structure, species composition, recruitment pattern and productivity. The number of studies on this issue is, however, also very limited. Even fewer studies have examined the soil fauna in RCHs; thus, the reported effects cannot be used to draw general conclusions. Notably, RCH research has made considerable progress in the last five years, especially in the Light Detection and Ranging-based mapping of these small landforms and identification of RCH-specific soil properties, but ecological legacies are not well understood; thus, more interdisciplinary and integrative studies are needed.
Seit 2010 untersucht eine interdisziplinäre Forschergruppe der BTU, des BLDAM und des LBGR die Landnutzungsgeschichte sowie die natürliche und anthropogen induzierte Landschaftsentwicklung in der Niederlausitz, Brandenburg. Systematische archäologische Grabungen des BLDAM im Vorfeld der laufenden Tagebaue sind eine wichtige Grundlage für geopedologische Untersuchungen. Die Arbeiten hatten zunächst ihren räumlichen Schwerpunkt in den Braunkohletagebauen nordöstlich von Cottbus (Tgb. Cottbus Nord, Tgb. Jänschwalde) und wurden dann ausgedehnt auf weitere Forstflächen nördlich von Peitz. Wir geben einen Überblick über die wichtigsten Erkenntnisse der letzten Jahre, präsentieren aktuelle Ergebnisse und zeigen zukünftige Forschungsfelder auf.
Im Tagebau Jänschwalde sind zwischenzeitlich mehr als 1000 Relikte von Holzkohlmeilern (HKM) als Zeugen einer intensiven historischen Holznutzung archäologisch dokumentiert. Mit Stand Januar 2016 liegen Dendroalter von 64 HKM vor. Die Alter schwanken zwischen dem ausgehenden 16. Jahrhundert und der Mitte des 19. Jahrhunderts, was in etwa dem Betriebszeitraum des Hüttenwerks in Peitz entspricht. Die Mehrzahl der Meiler datiert auf den Beginn des 18. Jahrhunderts. Weitere Hinterlassenschaften der historischen Landnutzung sind u.a. Wölbäcker und begrabene Ackerböden. Fossile Böden und ehemalige Landoberflächen sind stellenweise mit äolischen Sedimenten überdeckt. 14C- und OSL-Datierungen an diesen Böden und Sedimenten lassen auf eine Intensivierung der äolischen Aktivität zur slawischen Zeit und im Deutschen Mittelalter schließen. Einige Relikte von HKM sind mit Sand überweht worden, und an einer Stelle konnte das Alter dieser äolischen Sedimentation mittels Dendrodatierung des begrabenen Meilers auf1850 oder jünger bestimmt werden. Allerdings stellt dies die Ausnahme dar. Der weitaus größere Teil der HKM-Relikte liegt direkt an der Oberfläche und ist nicht begraben, was auf eine sehr geringe Winderosion in der Neuzeit schließen lässt. Seit 2015 konnte im Rahmen des DFG-Projekts „Räumliche und zeitliche Dimension der historischen Köhlerei im Tauerschen Forst (Niederlausitz, Brandenburg). Ein Beitrag zur Kulturlandschaftsentwicklung des Norddeutschen Tieflands“ (Az RA 1129/3-1; RA 931/6-1) ein weiteres Gebiet mit hoher HKM-Dichte untersucht werden. Erste Auswertungen der LiDAR-Daten ergeben eine Anzahl von 4449 ehemaligen Meilerstandorten im Tauerschen Forst. 26 Meilerstellen sind beprobt, die Dendroalter hierzu sind in Bearbeitung. Ebenfalls in jüngerer Zeit fanden Untersuchungen zur Verbreitung von HKM-Relikten für das gesamte Land Brandenburg statt. Mit Hilfe eines binären Modells wurden Gebiete mit hoher Wahrscheinlichkeit von HKM-Standorten detektiert. Im Rahmen des im November 2016 beginnenden DFG-Projekts „Die historische Köhlerei in Brandenburg - Analyse der räumlichen Dimension und der Effekte auf bodenhydraulische Eigenschaften“ (SCHN 1349/1-1) sollen nun neben der Verbreitung der historischen Köhlerei auch bodenrelevante Auswirkungen beschrieben und bewertet werden.
Various sources provide information about land use history and landscape transformation. For a variety of reasons, the quality of information differs and is often discontinuous or incomplete. In this interdisciplinary study we take advantage of comprehensive archaeological data gathered by large-scale excavations that were necessary because of opencast lignite mining in Lusatia, Brandenburg, Germany. By using a GIS we integrate these archaeological findings with results from archival and literature studies, from historical maps, from landforms and soils as well as from analyses of shaded-relief maps derived from up-to-date LiDAR data. The long-term aim is to develop a palaeoenvironmental model and thus to reconstruct landscape changes caused by human activities. The focus of the study is the Peitz ironwork in SE Brandenburg, which was a large consumer of commodities for about 300 years. During the time it operated, extensive transformations are supposed to have affected the landscape in the vicinity because of wood consumption and especially charcoal production. Digital datasets about forested areas for different timespans reconstructed from historical maps were made available. In combination with dendrochronological dating of charred trees, the spatiotemporal dimension of charcoal kilns was determined. Also, sites of former bog iron ore mining could be identified. Moreover, the different sources contain further information about other forms of land uses such as agriculture, pastoralism and even viticulture. In conclusion we can highlight that the mosaic of past land use systems is different from the modern structure but that major changes in the forests have been retained.
Recent findings of several thousand relict charcoal hearths (RCHs) in the Tauer Forest (Brandenburg, Germany) raise questions about the legacy effects of historical charcoal production on soil properties. RCH sites are characterized by the admixture of charcoal fragments to the natural forest soil, constituting an anthropogenic addition of carbon. Dendrochronological dating of large charcoal pieces has identified RCH ages ranging from 1709 AD to 1823 AD for a subarea in the Tauer Forest, which allows for assessing century old effects of charcoal application on forest soils. We measured the geometry and soil organic matter (SOM) content of 20 RCH sites in a selected part of the forest. The results provide a basis for estimating RCH SOM stocks on a 40-ha forest plot with 120 RCH sites. We also assessed the accuracy of RCH mapping based on digital elevation models (DEMs) with results from a ground survey. Over 50 % of sites were not detected by the DEM-based mapping. In the range of statistical uncertainties, RCHs add between 18 % and 32 % of SOM to the stock of the natural forest soil in the study area. This equals an additional 4.9 – 8.9 Mg of carbon per hectare of forest soil. These substantial amounts of SOM are so far not recognized by any survey or forest soil SOM inventories. Considering recent studies, which uncovered tens- and hundreds- of thousands of RCHs throughout Europe and the USA, we conclude that further knowledge of RCH SOM is important for quantifying anthropogenic SOM stocks on a global scale.
Historical charcoal production has long been an unconsidered type of forest utilization in lowland areas. The archaeological discovery of a large charcoal burning area in the forefield of the active opencast lignite mine J€anschwalde in SE Brandenburg (North German Lowlands) has highlighted the need for multidisciplinary research in the study of the dimensions of historical charcoal burning. The charcoal produced in our study area, the former royal forest district Tauer, provided energy for the nearby Peitz ironworks during its operation from the mid-16th to the mid-19th century. Here, we aimed to record the amount, size and distribution of relict charcoal hearths (RCHs) to examine their context with respect to the ironworks and to better understand the potential impacts on late Quaternary landscape change. The applied methods combined archaeological research with shaded-relief mapping of RCHs. To evaluate the detection success of RCHs in the shaded-relief maps (SRMs), we compared the results with the results from specific archaeological surveys and conventional forest site mapping. Furthermore, we analyzed our dataset with descriptive, comparable and spatial statistics. Additionally, dendrochronological dating of charcoal fragments from selected RCHs was used to investigate the temporal relationships among the RCHs. Approximately 6000 circular RCHs were manually digitally identified in the SRMs of the 109-km2 evaluable area. However, ground truthing showed that the shaded-relief maps could not completely capture all RCHs in our study area due to local conditions. At the regional scale, two focus areas with high RCH site densities were found. Statistical analysis revealed that the diameters of the RCHs range widely from 4 to 30.5 m. Spatial statistics were applied to the RCH diameters to aggregate areas with larger or smaller RCHs. At the small scale, no systematic arrangement of RCHs was obvious in the SRMs. Dendrochronological dating of selected RCHs lying close together could not detect significant spatiotemporal relationships or patterns. The dating results also showed that some areas have been preferentially used for charcoal production for over 300 years. Due to the homogeneity of the physiogeographical location factors, we assume that these factors are not superficially responsible for site selection. Instead, economic location factors and contemporary regulations are more likely responsible for the distribution of RCHs.
An initiative for a morphologic‐genetic catalog of relict charcoal hearths from Central Europe
(2020)
Human land use often leads to distinct modifications of soils within small, clearly delimited areas. Legacy effects of past land use are also abundant in recent forest areas, but are hardly considered in ecosystem assessment and soil mapping. The soils on relict charcoal hearths (RCHs) are a widespread example for such land use legacy soils in forests. Soils on RCHs differ clearly from surrounding forest soils in their stratigraphy and properties, and are most prominently characterized by a technogenic substrate layer with high contents of charcoal and thus soil organic matter (SOM). Although RCH soils can clearly contribute to the SOM stocks of forest soils, their relevance on the landscape scale has hardly been quantified. In this paper we analyze and discuss the distribution and effects of RCH soils across scales for forests in the state of Brandenburg, Germany, with a focus on SOM stocks. Our analysis is based on a large-scale mapping of RCHs from digital elevation models (DEMs), combined with a linear regression model of SOM stocks in RCH soils. The spatial distribution of RCH soils in the study region has a scale dependent heterogeneity. The large-scale variation in site densities is related to the concentration of charcoal production to specific forest areas while the small-scale variation is related to the irregular distribution of single RCHs within the charcoal production fields. Up to 1.5 % of the surface are covered by RCH soils in the forest areas within the study region. The results also show that RCHs can significantly contribute to the SOM stocks of forests, even where they cover only a small fraction of the soil surface, with up to 18 % additional SOM for forest areas. Because of the heterogeneous distribution of RCHs, the SOM stock additions depend on the scale of observation. Our results suggest that RCH SOM additions can be overestimated when sites in small areas (< 1 km²) are analyzed; and that characteristic spatial concentration patterns of RCHs are even observable when values are aggregated to large areas (25 km² and more). Aggregating effects to irregularly-sized forest administrative units resulted in maps that well represent the spatial distribution of RCH soils and SOM. The study highlights that considering land use legacy effects can be relevant for the results of soil mapping and inventories; and that prospecting and mapping land use legacies from DEMs can contribute to improving such approaches.
Charcoal-rich Technosols on century-old relict charcoal hearths (RCHs) are the subject of ongoing research regarding potential legacy effects that result from historic charcoal production and subsequent charcoal amendments on forest soil properties and forest ecosystems today. RCHs consist mostly of Auh horizons that are substantially enriched in soil organic carbon (SOC), of which the largest part seems to be of pyrogenic origin (PyC). However, the reported range of SOC and PyC contents in RCH soil also suggests that they are enriched in nonpyrogenic SOC. RCH soils are discussed as potential benchmarks for the long-term influence of biochar amendment and the post-wildfire influences on soil properties. In this study, we utilised a large soil sample dataset (n = 1245) from 52 RCH sites in north-western Connecticut, USA, to quantify SOC contents by total element analysis. The contents of condensed highly aromatic carbon as a proxy for black carbon (BC) were predicted by using a modified benzene polycarboxylated acid (BPCA) marker method in combination with diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy-based partial least square regression (r2 = 0.89). A high vertical spatial sampling resolution allowed the identification of soil organic matter (SOM) enrichment and translocation processes. The results show an average 75% and 1862% increase in TOC and BPCA-derived carbon, respectively, for technogenic Auh horizons compared to reference soils. In addition to an increase in aromatic properties, increased carboxylic properties of the RCH SOC suggest self-humification effects of degrading charcoal and thereby the continuing formation of leachable aromatic carbon compounds, which could have effects on pedogenic processes in buried soils. Indeed, we show BPCA-derived carbon concentrations in intermediate technogenic Cu horizons and buried top/subsoils that suggest vertical translocation of highly aromatic carbon originating in RCH Auh horizons. Topmost Auh horizons showed a gradual decrease in total organic carbon (TOC) contents with increasing depth, suggesting accumulation of recent, non-pyrogenic SOM. Lower aliphatic absorptions in RCH soil spectra suggest different SOM turnover dynamics compared to reference soils. Furthermore, studied RCH soils featured additional TOC enrichment, which cannot be fully explained now.
In Central Europe, Late Quaternary landscapes experienced multiple phases of geomorphologic activity. In this study,we used a combined geomorphological, pedological, sedimentological and palynological approach to characterize landscape development after the Last Glacial Maximum (LGM) near Lake Wygonin in Northern Poland. The pedostratigraphical findings from soil pits and drillings were extrapolated using ground-penetrating radar (GPR) and electric resistivity tomography (ERT). During the Pomeranian phase, glacial and fluvioglacial processes dominated the landscape near Lake Wygonin. At the end of the glacial period, periglacial processes became relevant and caused the formation of ventifacts and coversands containing coated sand grains. At approximately 15,290–14,800 cal yr BP, a small pond formed in a kettle hole (profile BWI2). The lacustrine sediments lack eolian sand components and therefore indicate the decline of eolian processes during that time. The increase of Juniperus and rock-rose (Helianthemum) in the pollen diagram is a prominent marker of the Younger Dryas. At the end of the Younger Dryas, a partial reshaping of the landscape is indicated by abundant charcoal fragments in disturbed lake sediments. No geomorphologic activity since the beginning of the Holocene is documented in the terrestrial and wetland archives. The anthropogenic impact is reflected in the pollen diagram by the occurrence of rye pollen grains (Secale cereale) and translocated soil sediments dated to 1560–1410 cal yr BP, proving agricultural use of the immediate vicinity. With the onset of land use, gully incision and the accumulation of colluvial fans reshaped the landscape locally. Since 540–460 cal yr BP, further gully incision in the steep forest tracks has been associated with the intensification of forestry. Outside of the gully catchments, the weakly podzolized Rubic Brunic Arenosols show no features of Holocene soil erosion.
The spatial variability of soil physical properties on the landscape scale is often increased by anthropogenic land occupation, not only by current land use but also through the legacies of past land use systems. The remains of historic charcoal hearts are an example for such a disturbance of the soil landscape by former forestry. Such relict charcoal hearths (RCH) exhibit a clearly altered soil stratigraphy, most prominently characterized by a technogenic substrate layer on the soil surface, and their soil physical properties can considerably differ from those of surrounding forest soils. The aim of our study is to characterize the soil water and temperature regime on RHC in a pre-industrial charcoal production area in Brandenburg, Germany, as compared with the surrounding sandy forest soils. Soil properties were analyzed in profiles on and around hearth sites and are monitored in a sensor transect equipped with soil
moisture sensors and pF-meters. Results of soil sample analyses show differences in density and porosity between the RCH soils and surrounding forest soils, not only in the technogenic layer but also in the buried soil layers on hearth sites. The soil water characteristic curves determined in the laboratory indicate a modified pore size distribution and lower plant available water contents in the RCH soils. Preliminary results of the ongoing soil water monitoring, however, show increased soil wetness in the RCH soils, along with lower soil moisture tensions. Furthermore, the measurements show higher variations of soil temperature in RCH soils. The results affirm that the legacies of historic charcoal production can increase the spatial variability of soil physical properties and therefore also of ecological site conditions in forest areas. The results of soil moisture monitoring suggest that a determination of soil physical parameters in the laboratory is not sufficient to characterize the spatio-temporal variations of the soil water regime.
Occurrence, soil parameters and genesis of Rhodic Arenosols (‘Fuchserden’) in northeastern Germany
(2018)
In der Niederlausitz finden sich - meist unter Kiefern- und Eichenforsten versteckt - zahlreiche Relikte der historischen Landnutzung, die bisher kaum bekannt sind. Zu den auffälligsten Formen zählen Wölbäcker und Plätze ehemaliger Kohlemeiler. In einigen Regionen der Niederlausitz ist die Verbreitung der Landnutzungsrelikte so groß bzw. ihre Dichte so hoch, dass sie prägend für die Bodenlandschaft werden. Dieser Beitrag zeigt an repräsentativen Beispielen die charakteristischen Merkmale und Eigenschaften der Böden auf Wölbäckern und Relikten von Holzkohlenmeilern (HKM).
Mapping and visualizing the position of archaeological remains in the surface relief provides important basic information for archaeological survey design and interpretation. Geomorphological processes in (pre)history can have resulted in a modification of the local relief around archaeological sites, especially in areas that are prone to sediment erosion and relocation, so that models of past surfaces are necessary for a correct interpretation of
archaeological survey results. In this study, we combined terrestrial survey and remote sensing methods to reconstruct
the palaeorelief around two archaeological excavation sites in an inland dune area in southern Brandenburg, Germany. Remains from two Mesolithic hunter-gatherer camps were documented in archaeological excavations and found to be associated with a buried soil horizon. To gather information on the relief of the buried soil surface, we used a combination of sedimentological and pedological profile description of archaeological survey trenches and geophysical prospection with Ground-Penetrating Radar; supplemented by microdrone photography and photogrammetry, GPS surveys and analysis of LIDAR-based elevation models. A digital elevation model of the buried surface was created by combining point data from these sources. The buried surface morphology and the position of the archeological remains within the reconstructed landscape were analyzed in GIS. The comparison of the generated paleosurface model with the recent surface elevation model shows that sand remobilization resulted in
a considerable reshaping of the relief. Analysis of the buried surface model further shows that the relief position
of the two archaeological sites in the study area was considerably more prominent in relation to the corresponding
buried soil surface than in relation to the recent surface morphology. Results affirm the importance of considering
Holocene relief modifications in archaeological surveys.
We used a GIS analysis of environmental and historical data to identify potential areas of extensive charcoal
production in Brandenburg. The analysis was based on three assumptions (i to iii). Large charcoal kiln fields can be found in areas that i) are close to historical industrial sites, ii) are close to bog iron ore deposits, and iii) have
been continuously covered by forest during the last centuries. Information on theses parameters was gathered in an archive and literature study and from historical and recent maps. Areas with a high probability of kiln site occurrence were then determined using a simple binary additive model. In the last step, shaded-relief maps (SRMs) were visually checked for clearly visible kiln sites and soil
properties were analysed in the determined areas. In total, eight areas with a high probability of kiln site occurrence are identified for the state of Brandenburg. By visual interpretation of SRMs, high kiln site densities in these areas are confirmed. The analysis of soil maps shows that kiln fields are predominantly located on sandy soils with a low yield potential. Although further parameters and study areas need to be considered in the model in order to explain the spatial distribution patterns of charcoal production, the results indicate correlations between the location of bog iron ore deposits, historic ironworks and charcoal kiln fields.
In the sandy deposits from the Late Pleistocene in the Northern European lowlands, the local appearance of red
subsoils emerges the question of their formation and palaeoenvironmental significance. According to the WRB
this soil is classified as Rhodic Arenosols, but in the German Guidelines for Soil Mapping this soil is still unconsidered because the age and genesis is unclear. Due to the intense red subsoil, the working title of this soil is
‘Fuchserde’. Whereas rubefication is a characteristic feature of soils in regions with warm and dry summers like in the Mediterranean, the occurrence of red subsoil horizons containing hematite in soils in northeastern Germany is not an indicator for tropic or Mediterranean climate conditions. Already the appearance of Fuchserden on sandy
deposits from the last glaciation objects earlier theories that consider these soils as a relictic soil formation from
the last interglacial or even the Palaeogene or Neogene. To characterize the genesis of the Fuchserden, we focused
on four different study sites in northeastern Germany. We present our findings from soil micromorphology and the
identification of the iron(hydr)oxides by FTIR. Our results give new insights on the development of the Fuchserden
and the importance of lateral input of iron for their genesis.
The usage of non-reversible ploughs, mainly during the Middle Ages and until historic times, led to the formation
of ridge and furrow systems. Due to improvements of agricultural techniques, these historic agricultural sites were often abandoned and are now marginal land. The parallel ridges and furrows are usually, if not destroyed by later
conventional ploughing, preserved in present-day forests. In northeastern Germany ridge and furrow systems are normally several decameters long and up to ten meters wide. The height difference between ridge top and furrow bottom is up to 50 centimeters and is expected to cause significant contrasts of soil properties and vegetation. Furthermore, due to the abandonment of sites with ridges and furrows, soils on these sites are unique archives for studies on fertilization, soil carbon dynamics and soil development. Therefore, we are characterizing soil physics (bulk density, saturated soil hydraulic conductivity, texture) and soil chemistry (soil acidity, carbon and nitrogen content) on a type location of historic ridges and furrows about 100 km northwest of Berlin.
Charcoal hearths are a unique archive for the long term interaction between biochar, soil development and plant
growth. Charcoal as raw material was crucial for the production of iron in iron works and hence numerous charcoal
hearths can be found in the forests near historic iron works in Europe as well as the Eastern United States. Charcoal
hearths are round to elliptical forms often around 10 m in diameter, and consisting of a several decimeter thick layer containing charcoal fragments, ash, and burnt soil. We studied the soil chemistry of 24 charcoal hearths and
compared them to the surrounding ‘natural’ soils in Litchfield County, Connecticut. The thickness of the organic
rich horizons on the charcoal hearths and their carbon content is remarkably higher than in the surrounding topsoils. The wide distribution of charcoal hearths, their usually high quantity, and their occurrence in different ecosystems underlines their importance for further pedological research.
Seit dem Neolithikum wirkt sich die Nutzung der Landschaft auf unterschiedliche Weise auf Relief, Böden, Gewässer, Flora, Fauna und Klima aus. Insbesondere die Folgen land- und forstwirtschaftlicher Wirtschaftsweisen waren dafür ausschlaggebend. Grundsätzlich reagieren Ökosysteme auf anthropogene Eingriffe, wie die Umwandlung von Wald in andere Nutzungsformen, mit einer schrittweisen Degradation sowie reversiblen oder irreversiblen Veränderungen. Beispiele sind Bodenerosion und eine veränderte Artenzusammensetzung. Die Abschätzung des Ausmaßes im globalen Maßstab gestaltet sich generell schwierig. Für die Geoarchäologie bedeutsam sind daher hauptsächlich lokale Spuren früherer Bewirtschaftung und Formen im Kleinrelief, die sich im Gelände wiederfinden lassen und als Geoarchive fungieren. Denn sie geben Aufschluss über (prä-)historische Bewirtschaftungsformen. So zeugen Wölbäcker, Hochbeete, Plaggenesche und die Relikte der historischen Teichwirtschaft, Moorkultivierung und Köhlerei von früheren Formen der Land- und Forstwirtschaft.
Archaeological excavations have revealed more than thousand charcoal kiln remains (CKRs) in the prefield of
the active opencast lignite mine Jänschwalde, situated about 150 km SE of Berlin (SE Brandenburg, Germany).
The charcoal was mainly produced for the ironwork Peitz nearby, which operated from the 16th to the mid-19th
centuries. In a first approach, to estimate the dimension of the charcoal production, CKRs were mapped on
shaded-relief maps (SRMs) derived from high-resolution LiDAR data (Raab et al. 2015). Subsequently, for a selected test area, identified CKRs on the SRMs were compared with archaeologically excavated CKRs in the
field. This survey showed a considerably number of falsely detected sites. Therefore, the data was critically
re-evaluated using additional relief visualisations. Further, we extended the CKR mapping to areas which are not
archaeologically investigated. The study area, the former royal forest district Tauer, consists of two separate areas: the Tauersche Heide (c. 96 km2 area) N of Peitz and the area Jänschwalde (c. 32 km2 area) NE of Peitz. The study area is characterized by a flat topography. Different former and current anthropogenic uses (e.g., military training, solar power plant, forestry measures) have affected the study area, resulting in extensive disturbances of the terrain surface. The revised CKR abundance in the study area Jänschwalde was considerably smaller than the numbers produced by our first approach. Further, the CKR mapping revealed, that a total record of the CKRs is not possible for various reasons. Despite these limitations, a solid database can be provided for a much larger area than before. Basic statistic parameters of the CKR diameters and all comparative statistical tests were calculated using SPSS. To detect underlying spatial relationships in the CKR site distribution, we applied the Getis-Ord Gi* statistic, a method to test for local spatial autocorrelation between neighbouring sites. The test is available as part of the ArcGis 10.1 spatial statistics toolbox. The outcomes are discussed in consideration of our archaeological, archival and dendrochronological research results.
Geoecological legacies of pre-industrial charcoal burning – Research questions and approaches
(2019)
Der Einfluss von Relikten der historischen Köhlerei auf Bodentemperatur und –wärmeleitfähigkeit
(2019)
Die Beimengung von Holzkohle in Böden kann deutlichen Einfluss auf die physikalischen Bodeneigenschaften haben. Solche Effekte treten nicht nur in gezielt mit Holzkohle („biochar“) angereicherten Ackerböden auf, sondern auch auf den Standorten historischer Holzkohlemeiler (HKM), die in vielen Waldgebieten in großer Zahl vorkommen. Die prägendste Eigenschaft solcher Böden auf HKM ist eine technogene, kohlereiche Substratschicht, die über dem natürlich entwickelten Bodenprofil abgelagert ist. In jüngster Zeitwurden in mehreren Studien ein von den umliegenden Waldböden abweichendes Vegetationswachstum und eine abweichende C-Dynamik auf HKM festgestellt. Welche Bodeneigenschaften der HKM solche Unterschiede bewirken, ist aber noch unklar. Ein möglicher, bisher kaum untersuchter Einflussfaktor ist die Bodentemperatur. Ziel dieser Studie war es, den Einfluss von Holzkohlebeimengungen auf die Wärmeleitfähigkeit und das Bodentemperaturregime von HKM-Böden zu charakterisieren. Untersucht wurden HKM auf sandigem Substrat in der Lausitz (Brandenburg). An zwei Standorten wurden Profile auf HKM und benachbarten Waldböden für ein Monitoring der Bodentemperatur über jeweils ein Jahr instrumentiert, die Wärmeleitfähigkeit von HKM-Schicht, Ah-, fAh-und Bv-Horizont wurde im Labor bestimmt. In einem Laborexperiment wurde zusätzlich die Wärmeleitfähigkeit von künstlich hergestellten Proben aus sandigem Substrat und Holzkohlefragmenten in unterschiedlichen Mischungsverhältnissen untersucht. Die Ergebnisse zeigen eine deutlich verringerte Wärmeleitfähigkeit des kohlereichen Substrats. Damit verbunden zeigen sich im Monitoring geringere Schwankungen der Bodentemperatur auf den HKM in tiefen Bereichen des Profils, in den obersten Dezimetern wurden hingegen stärkere Schwankungen der Bodentemperatur festgestellt. Insgesamt zeigt sich damit ein noch über die technogene Substratschicht hinaus wirksamer Einfluss der typischen Eigenschaften des kohlereichen HKM-Substrats auf die Bodentemperatur.
Aged biochar enriched substrate increases SOM stocks of forest soils in the North German Lowland
(2019)
Recentfindings of more than 4000 relict charcoal hearths (RCH) in the forest district Tauer (Brandenburg, Germany) raise the question to what extent soil properties are controlled by a legacy effect of historical charcoal burning. RCH sites are characterized bya substantial admixture of charcoal fragments of varying particle sizes constituting an anthropogenic addition of carbon to the natural forest soil. Ages of about 250 years proven by dendrochronological dating of larger charcoal pieces on RCHs allow for assessing long-term effects of biochar application on forest soils. In this study, we measured the geometry and SOM content of 20 RCH sites in a selected part of the forest district. The results are the basis for a projection of RCH SOM stocks on a 40 ha forest plot with 120 RCH sites. In the range of statistical uncertainties it is shown that RCHs add between 13 % and 32 % of SOM to the SOM stock of the natural forest soil in the studied plot. These substantial amounts of SOM are so far not recognized by any soil survey or forest soil inventories of SOM and SOC stocks. In light of an increasing amount of studies that detect RCH sites in forests of Europe and the USA in the range of tens-and even hundreds of thousands, the question has to be asked how to address this legacy effect in ongoing scientific discussions about soil carbon stocks, carbon sequestration and the long-term effects of biochar application into soils.
The North European lowland has been formed by glacial and periglacial processes in the Late Pleistocene. Multiple reshaping since the Late Glacial considerably changed the landscape up to and including especially historic times. Sediment sequences and (fossilized) soils can improve our understanding of Late Quaternary landscape development, but mapping of buried soils and surfaces is often limited to single outcrops. Ongoing archaeological rescue excavations in the pre-field of the open-cast mine Cottbus-Nord (northeastern Germany) with dense excavation trenches in an about 10 ha dune and drift sand area reveal multilayered sediment sequences with fossilized soils and sediments from the Late Pleistocene to the Late Holocene. Archaeological findings ranging from Mesolithic flint stones to an about 200 year old ceramics in eolian sediments covering plow horizons and wheel tracks suggest that eolian relocation of sandy material was intensive about 200 years ago. Still unpublished OSL dating underline the intense eolian activity. Recent studies showed that between the 15Th to the 19Th century an iron smelter 5 km to the west of our study site was supplied with charcoal, which was produced in a forest 5 km east to our study
site. Our current findings about Late Holocene eolian activity raise the question if this eolian reshaping of the landscape is connected with the operation of the iron smelter either directly by transport or bog iron ore winning or indirectly by population pressure caused by the prospering iron smelter. Our ongoing research indicates, that already for historic land-use off-site effects causing further landscape changes have to be considered.
South Brandenburg is the central part of the North European Lowland (NEL) extending as a plain landscape from
the North and Baltic Sea to the foothills of the Central European Highlands and reaching from the Netherlands to Poland. Since many decades lignite opencast mines have been operating in this region which is known as the Lusatian mining district. The total land demand in Lusatia is about 852 square kilometres and mining will continue
for many more years or even decades. Large-scale outcrops resulting from these mining activities are excellent archives to study the younger Earth’s history. The scope of our research in open cast mines is to reconstruct the
Late Quaternary landscape development and to distinguishing natural from anthropogenic forcing and processes. In more detail, the aims are to identify and to quantify the impact of past land uses, i.e. changes of vegetation, landforms and soils induced by agriculture and/or forestry. Here, we are presenting latest results from our research and review important findings giving novel insights into man-induced environmental changes in Lusatia within the past thousands years and thus improving the general understanding of Late Quaternary landscape dynamics.