Historical Spruce Abundance in Central Europe: A Combined Dendrochronological and Palynological Approach

Spruce is the most cultivated tree species in modern forestry in Central Europe, since it has the ability to grow on many soil types with profitable biomass accumulation. However, even-aged and uniform spruce forests are affected by recurring droughts and associated biotic stressors leading to large-scale diebacks across Central Europe causing controversies among foresters and nature conservationists. We investigate the role of spruce in historical woodlands by using 15666 spruce timbers from historical buildings and on the basis of pollen-based land cover estimates using the REVEALS model from 157 pollen sites in southern Central Europe. Start and end dates of the spruce timber samples and their dendrological characteristics (age, growth rates and stem diameters) were used to obtain information on past forest structures. Tree rings and REVEALS estimates are combined at a spatial scale of 1° × 1° resolution, grouped in four sub-regions, and a temporal resolution of 100-year time windows starting from 1150 to 1850 CE. We found that spruce dominates the species assemblage of construction timber with almost 41% and that the harvest age varies little through time, whereas a declining trend in growth rates and stem diameters are observed toward times before modern forestry. Temporal and regional differences in spruce abundance and building activity were found highlighting periods of (i) land abandonment and forest expansion in the 14th century, (ii) increased wood consumption during the 16th century due to population increase and beginning industrial developments, (iii) a forest recovery during and after the Thirty years' war, and (iv) afforestation efforts from the 1650s onwards. Furthermore, this study shows that spruce was constantly present in the study area in most studied sub-regions for the last 800 years. We demonstrate the need of combining tree-ring and pollen data to identify spatiotemporal patterns in spruce abundance and utilization.publishedVersio

Missing link in Late Antiquity? A critical examination of Hollstein's Central European Oak Chronology

In 1980 Ernst Hollstein published his Central European Oak Chronology, which covers a period from 724 BCE to 1974 CE. Besides a later correction of the end date of the sampling site chronologies Kirnsulzbach (Germany) and Gustavsburg (Germany) this master chronology has since not been changed and still remains one of the most important bases for dendrochronological dating in western Germany. It stands out in so far as it provides comprehensive graphical findspot series for each individual sampled site and year to year growth values for eight regional sub-chronologies in addition to the combined Central European reference curve. Particularly due to the fact of Hollstein's chronology being publicly available, it has frequently been criticized for its insufficient data to bridge the Late Antiquity between 350 and 400 CE with only three sampling sites (tomb near Beerlegem, Belgium; tomb inside of Cologne Cathedral, Germany; subfossil trees near Broichweiden, Germany) and that these site chronologies cover those decades with inadequate correlation coefficients. With regard to recent statistical threshold values for crossdating, Hollstein's Late Antiquity bridging needs to be reconsidered. Therefore, in a combined effort, the dendrochronological laboratories at Rheinisches Landesmuseum Trier (RLM), the University of Cologne and Albert-Ludwigs-University Freiburg re-evaluated Hollstein's findings for Late Antiquity by including the respective dendrochronological examinations conducted in Rhineland-Palatinate, North Rhine-Westphalia and north-eastern France during the past 40 years. A total of 62 site chronologies were compiled to establish a new Late Antiquity chronology. Thirteen of these site chronologies could be used to support Hollstein's original bridging series between 350 and 400 CE while the mean series for Broichweiden had to be corrected from end date 365 to 503 CE. Furthermore, this new bridging chronology could be validated by comparing it to an independent chronology from southern Germany. This study thus proves that the integrity of Hollstein's Central European Oak Chronology is not compromised by a flawed Late Antiquity bridging and that therefore dating based on the Roman part of this chronology can still be considered as absolute

Regional patterns of Late Medieval and Early Modern European building activity revealed by felling dates

Although variations in building activity are a useful indicator of societal well-being and demographic development, historical datasets for larger regions and longer periods are still rare. Here, we present 54,045 annually precise dendrochronological felling dates from historical construction timber from across most of Europe between 1250 and 1699 CE to infer variations in building activity. We use geostatistical techniques to compare spatiotemporal dynamics in past European building activity against independent demographic, economic, social and climatic data. We show that the felling dates capture major geographical patterns of demographic trends, especially in regions with dense data coverage. A particularly strong negative association is found between grain prices and the number of felling dates. In addition, a significant positive association is found between the number of felling dates and mining activity. These strong associations, with well-known macro-economic indicators from pre-industrial Europe, corroborate the use of felling dates as an independent source for exploring large-scale fluctuations of societal well-being and demographic development. Three prominent examples are the building boom in the Hanseatic League region of northeastern Germany during the 13th century, the onset of the Late Medieval Crisis in much of Europe c. 1300, and the cessation of building activity in large parts of central Europe during armed conflicts such as the Thirty Years’ War (1618–1648 CE). Despite new insights gained from our European-wide felling date inventory, further studies are needed to investigate changes in construction activity of high versus low status buildings, and of urban versus rural buildings, and to compare those results with a variety of historical documentary sources and natural proxy archives