Time filter

Source Type

Nielsen A.B.,University of Gottingen | Nielsen A.B.,Lund University | Giesecke T.,University of Gottingen | Theuerkauf M.,Institute For Botanik Und Landschaftsokologie | And 17 more authors.
Quaternary Science Reviews

By applying the recently developed model REVEALS (Regional Estimates of VEgetation Abundance from Large Sites) (Sugita, 2007) to pollen data from a large number of sites across Northern Germany and Denmark, we construct maps of regional patterns in landscape openness and in cover abundance of key plant taxa in the cultural landscape of north-central Europe for selected time slices in the Holocene. The results indicate that the pattern of landscape openness across the regions of northern Germany and Denmark prior to the introduction of agriculture was affected by soil conditions and degree of continentality. The 8.2 ka climate event did not lead to a general decrease in tree cover, although some changes in species composition were observed. The early phases of agriculture also had little effect on landscape openness at the regional scale, but later human impact lead to large scale deforestation and development of arable areas, grasslands and of heathlands in the north-western part of the region. The timing and degree of deforestation, and the weight between arable and grazing areas varied in space, partly due to differences in natural conditions, partly due to differences in cultural impact. © 2012 Elsevier Ltd. Source

Enters D.,University of Bremen | Enters D.,University of Savoy | Enters D.,Lower Saxony Institute for Historical Coastal Research | Kirilova E.,University Utrecht | And 6 more authors.
Journal of Paleolimnology

Lacustrine sediments in north-eastern Germany have rarely been used as archives to address the effects of climate change and human impact on both lake ecosystem and landscape evolution for this region. Sacrower See, a hardwater lake located in Brandenburg, provides a unique sediment record covering the past 13,000 years which was used to reconstruct climatic and anthropogenic forcing on lacustrine sedimentation. Time control is provided by 12 AMS 14C dates of terrestrial plant remains, the Laacher See Tephra, and the onset of varve formation in AD 1870 (80 cal. BP). Geochemical (including XRF logging of major elements, CNS analyses as well as δ13Corg and δ15N measurements) and pollen analyses allowed detecting detailed environmental changes in the sediment record. During the Younger Dryas cold phase increased soil erosion and hypolimnetic oxygen depletion enhanced the nutrient supply to the lake water causing eutrophic conditions. The beginning of the Holocene is characterized by large changes in C/N ratios, total sulphur, δ13C of bulk organic matter as well as in K, Si, and Ti, reflecting the response of the lake's catchment to climatic warming. Reforestation reduced the influx of detrital particles and terrestrial organic matter. The first, rather weak evidence of human impact is documented only in the pollen record at 5,500 cal. BP. However, until 3,200 cal. BP sedimentological and geochemical parameters indicate relatively stable environmental conditions. During periods of intense human impact at around 3,200, 2,800, and 900 cal. BP peaks in Ti and K represent phases of increased soil erosion due to forest clearing during the Bronze Age, Iron Age, and Medieval Times, respectively. In general, greater variation is observed in most variables during these perturbations, indicating less stable environmental conditions. The steady rise of biogenic silica accumulation rates during the Holocene reflects an increasing productivity of Sacrower See until diatoms were outcompeted by other algae during the last centuries. The applied multi-proxy approach fosters the interpretation of the sediment record to reveal a consistent picture of environmental change including environmental factors controlling lake ontogeny and the effects of human impact. © 2009 Springer Science+Business Media B.V. Source

Theuerkauf M.,University of Greifswald | Bos J.A.A.,Landscape Archaeology Team | Jahns S.,Brandenburgisches Landesamt fur Denkmalpflege und Archaologisches Landesmuseum | Janke W.,Karl Liebknecht Ring 23 | And 3 more authors.
Quaternary Science Reviews

The warming at the Younger Dryas-Holocene transition (~11,600cal.BP) triggered the rearrangement of vegetation across Europe. To better understand that response, we analysed both an extended fossil pollen data set and robust present-day site parameters from NE Germany in a data model comparison approach. This approach allowed to quantify past plant abundances in sub-regional landscape patterns, as defined by soil types and relief. Betula was the first tree taxon to expand from scattered stands that already existed during the Younger Dryas. The major tree taxa Betula and Pinus fully established after 200-400 years as largely separated stands of Pinus on well drained sandy and Betula on fertile morainic soils. Corylus started to spread after 11,200cal.BP, yet the final expansion was delayed until ~10,800cal.BP. Corylus established on gleyic soils, from which it largely expelled Betula. Throughout the first two millennia of the Holocene, open grasslands existed on fine grained soils, where seasonal dryness prevented the establishment of deciduous trees. © 2014 Elsevier Ltd. Source

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. © 2014 Elsevier Ltd and INQUA. Source

Discover hidden collaborations