Forschungszentrum Landschaftsentwicklung und Bergbaulandschaften (FZLB)
Analysing the spatial distribution of anthropogenic relief structures can contribute to the understanding of past landuse systems. With automated mapping routines, small relief forms can be detected efficiently from high-resolution digital terrain models (DTMs). In this study, we describe an approach for the automated mapping of charcoal kiln sites from an airborne laser-scanning DTM. The study site is located north of Cottbus, Germany, where an exceptionally large historic charcoal production field has been documented in previous archaeological surveys. The goal of this study was to implement, evaluate and improve an automated GIS-based routine for mapping these features based on the template-matching principle. In addition to the DTM, different morphometric variables were evaluated for their suitability to detect kiln sites. The mapping results were validated against a comprehensive database of kiln sites recorded from archaeological excavations and via manual digitization. The effects of irregular kiln-site geometry and DTM noise were evaluated using synthetic DTMs. The results of the synthetic DTM mapping show that the template-matching results differed depending on the morphometric variable used for the mapping process. In accordance with this observation, a validation of the mapping procedure for the field site suggests that feature mapping can be improved. In particular, the number of false detections can be reduced using a combination of morphometric variables. For the validation area, the kiln sites with diameters of at least 10m were mapped using the automated routine, with detection rates that were close to those of manual digitization. Therefore, the described method can considerably facilitate the mapping and distribution analysis of kiln sites or similar small relief forms that are prominent in a specific landscape.
In pre-industrial times, charcoal burning was a common source of energy across Europe. Charcoal production and its related consequences for the upland environment are well known due to historical and palaeoenvironmental research. In recent years, awareness has grown regarding the use of woods in the lowlands for charcoal production. In the last 20 years, a large charcoal-burning field in Lower Lusatia (Brandenburg, North German Lowlands) was discovered by systematic archaeological excavations of the opencast mine of Jänschwalde. However, the excavations are limited to the mine, which only covers a portion of the Jänschwalder Heide and the surrounding forests.
In this paper, we present the results of our study regarding the spatial extension and timing of charcoal production in the Jänschwalder Heide and its surrounding areas. We applied a combined approach using archaeological research results, GIS-analyses of shaded-relief maps (SRMs) and tree-ring dating of selected charcoal kiln remains. Approximately 900 excavated charcoal kiln ground plans were analysed, which provided a solid data basis for our GIS analyses. For an extensive evaluation, we enlarged our study area beyond the limits of the lignite mine. We identified and digitised the remains of the charcoal kilns by creating SRMs from digital elevation models (DEMs) that were based on high-resolution airborne laser scanning data (ALS). The data from the excavated and digitised charcoal kiln remains were analysed in terms of their sizes and spatial distributions. In addition, the dendrochronological ages of 16 selected charcoal kiln remains were determined.
This study shows that charcoal production was more extensive than initially proven by archaeological excavations. The remains of more than 5000 charcoal kilns were detected on the SRMs across an area that was twice as large as the excavated charcoal-burning field. In the Jänschwalder Heide, considerably more charcoal kiln relicts exist compared with the surrounding communal areas. Furthermore, the charcoal kiln remains in the Jänschwalder Heide have larger diameters, suggesting large-scale charcoal production for supplying energy to the nearby ironworks at Peitz. However, the charcoal production on the communal land was most likely for local crafts. The ages of the charcoal kiln remains indicated that charcoal production occurred between the 17th and 19th centuries, corresponding with the main period of charcoal burning. Overall, our study suggested that charcoal production sites are underestimated in the modern landscapes of the North German Lowlands.
We hypothesized that at the very beginning of terrestrial ecosystem development, airborne testate amoebae play a pivotal role in facilitating organismic colonization and related soil processes. We, therefore, analyzed size and quantity of airborne testate amoebae and immigration and colonization success of airborne testate amoebae on a new land surface (experimental site “Chicken Creek”, artificial post-mining water catchment). Within an altogether 91-day exposure of 70 adhesive traps, 12 species of testate amoebae were identified to be of airborne origin. Phryganella acropodia (51% of all individuals found, diameter about 35–45 μm) and Centropyxis sphagnicola (23% of all individuals found, longest axis about 55–68 μm), occurred most frequently in the adhesive traps. We extrapolated an aerial amoeba deposition of 61 individuals d−1 m−2 (living and dead individuals combined). Although it would be necessary to have a longer sequence (some additional years), our analysis of the “target substrate” of aerial immigration (catchment site) may point to a shift from a stochastic (variable) beginning of community assembly to a more deterministic (stable) course. This shift was assigned to an age of seven years of initial soil development. Although experienced specialists are necessary to conduct these time-consuming studies, the presented data suggest that terrestrial amoebae are suitable indicators for initial ecosystem development and utilization.