scholarly journals Tree-Ring Dating and Radiocarbon Calibration in South-Central Europe

Radiocarbon ◽  
1980 ◽  
Vol 22 (2) ◽  
pp. 219-226 ◽  
Author(s):  
Bernd Becker

Radiocarbon variations between 3900 and 2800 bc have been established in La Jolla and Groningen using oak tree rings from a 2350-year floating oak series. Comparison of these variations with the bristlecone pine 14C variations provides precise ages for tree-ring dates of Neolithic settlements of Switzerland and Germany over a period of 1400 years. 14C variations measured in Heidelberg in absolutely dated oak-ring series from ad 250 to 720 show trends similar to those of long-term growth variation of oaks during the same period of time. The influence of the climatic regime on oak growth of this period is discussed.

Radiocarbon ◽  
1983 ◽  
Vol 25 (2) ◽  
pp. 197-203 ◽  
Author(s):  
Bernd Becker

The Hohenheim Tree-Ring Laboratory has extended the Holocene oak tree-ring chronology back to prehistoric times by analyses of subfossil tree trunks from gravel deposits along the rivers of central Europe. Hundreds of subfossil oaks can be collected each year because of widespread gravel quarrying. Despite this nearly continuous source of samples (at present, 2200 trees are analyzed), even within these deposits some limitations do exist in linking together a Holocene tree-ring sequence.


Radiocarbon ◽  
1986 ◽  
Vol 28 (2B) ◽  
pp. 954-960 ◽  
Author(s):  
Bernd Kromer ◽  
Monika Rhein ◽  
Michael Bruns ◽  
Hildegard Schoch-Fischer ◽  
Karl Otto Münnich ◽  
...  

14C calibration curves derived from South German oak tree-ring series are presented. They cover the interval between 4400 and 7200 BC complementing existing data sets and extending them to older periods. The atmospheric 14C level before 6200 BC no longer follows the long-term sinusoidal trend fitted to the bristlecone data. This observation is supported by a tentative match of the Main 9 series.


Radiocarbon ◽  
1993 ◽  
Vol 35 (1) ◽  
pp. 125-135 ◽  
Author(s):  
Bernd Kromer ◽  
Bernd Becker

Radiocarbon calibration data derived from German oak chronologies, ranging back to 7200 BC, have been published in the previous Calibration Issue (Stuiver & Kra 1986). In recent years, the German oak chronology has been extended to 7938 BC (Becker, this issue). For earlier intervals, tree-ring chronologies must be based on pine, because oak re-emigrated to central Europe at the Preboreal/Boreal transition, at about 8000 BC. We have established a 1784-yr pine chronology centered in the Preboreal, and have linked it tentatively to the absolutely dated oak master. We present here calibration data based on this link, for the age range, 7145–9439 BC.


2016 ◽  
Vol 8 (1) ◽  
Author(s):  
Asok K. Sen ◽  
Zoltán Kern

AbstractThis study investigates the low-frequency (interannual and longer period) variability in three hydroclimatic records from east Central Europe. Two of these records consist of climate proxies derived from oak-tree rings in Bakta forest, and Balaton Highlands in Hungary, for the time interval 1783-2003. The third record consists of homogenized instrumental precipitation data from Budapest, Hungary, from 1842 to 2003. Using wavelet analysis, the three time series are analyzed and compared with one another. It is found that all three time series exhibit strong interannual variability at the 2-4 years timescales, and these variations occur intermittently throughout the length of each record. Significant variability is also observed in all the records at decadal timescales, but these variations persist for only two to three cycles. Wavelet coherence among the various time series is used to explore their time-varying correlation. The results reveal significant coherence at the 2-4 years band. At these timescales, the climatic variations are correlated to the tree-ring signal over different time intervals with changing phase. Increased (decreased) contribution of large-scale stratiform precipitation offers a potential explanation for enhanced (faded) coherence at the interannual timescale. Strong coherence was also observed occasionally at decadal timescales, however these coherences did not appear uniformly. These results reinforce the earlier assertion that neither the strength nor the rank of the similarity of the local hydroclimate signals is stable throughout the past two centuries.


Author(s):  
Hans Pretzsch

AbstractForest tree growth is primarily explained, modelled, and predicted depending on current age or size, environmental conditions, and competitive status in the stand. The accumulated size is commonly used as a proxy for a tree's past development. However, recent studies suggest that antecedent conditions may impact present growth by epigenetic, transcriptional, proteomic, or metabolic changes alongside physiological and structural properties. Here, I analysed the ecological memory effect embedded in the xylem as a tree-ring structure. I used 35 mature Norway spruces (Picea abies (L.) H. Karst.) and 36 European beeches (Fagus sylvatica L.) of the Kranzberg Forest water retention experiment KROOF in South Germany to scrutinise how their past development determines the growth of control plots and plots with 5-year water retention. I hypothesised that the current size and growing conditions determine tree growth and drought stress resistance. Metrics quantifying the trees’ recent and past growth, and correlation and linear mixed models with random effects revealed the following ecological memory effects. (1) For both species, the progressive growth course, low inter-annual growth variation in the long term, and low growth deflections in the recent past increased the growth resistance to drought. (2) The correlation between the past growth metrics and current stress reactions revealed that legacy effects could reach back 5–30 years; I found short- and long-term ecological memory. (3) Parameters of model prediction of the basic model with only size as a predictor of tree growth could be improved. The results suggest differences in the internal stem structure and ring pattern cause-specific differences in the trees' functioning and growth. I conclude that a long-term progressive increase and low variation in ring width may improve water conduction and reduce embolism in both species. Annual growth variation and low growth events in the recent past may have primed the morphology and allocation of the Norway spruce to better resist drought. The strong reduction in current growth, drought resistance by irregular growth, and past growth disturbances reveal a memory effect embedded in the tree ring pattern, suggesting further exploration and consideration in tree monitoring, growth modelling, and silvicultural prescriptions.


Radiocarbon ◽  
2004 ◽  
Vol 46 (3) ◽  
pp. 1111-1122 ◽  
Author(s):  
Michael Friedrich ◽  
Sabine Remmele ◽  
Bernd Kromer ◽  
Jutta Hofmann ◽  
Marco Spurk ◽  
...  

The combined oak and pine tree-ring chronologies of Hohenheim University are the backbone of the Holocene radiocarbon calibration for central Europe. Here, we present the revised Holocene oak chronology (HOC) and the Preboreal pine chronology (PPC) with respect to revisions, critical links, and extensions. Since 1998, the HOC has been strengthened by new trees starting at 10,429 BP (8480 BC). Oaks affected by cockchafer have been identified and discarded from the chronology. The formerly floating PPC has been cross-matched dendrochronologically to the absolutely dated oak chronology, which revealed a difference of only 8 yr to the published 14C wiggle-match position used for IntCal98. The 2 parts of the PPC, which were linked tentatively at 11,250 BP, have been revised and strengthened by new trees, which enabled us to link both parts of the PPC dendrochronologically. Including the 8-yr shift of the oak-pine link, the older part of the PPC (pre-11,250 BP) needs to be shifted 70 yr to older ages with respect to the published data (Spurk 1998). The southern German part of the PPC now covers 2103 yr from 11,993–9891 BP (10,044–7942 BC). In addition, the PPC was extended significantly by new pine chronologies from other regions. A pine chronology from Avenches and Zürich, Switzerland, and another from the Younger Dryas forest of Cottbus, eastern Germany, could be crossdated and dendrochronologically matched to the PPC. The absolutely dated tree-ring chronology now extends back to 12,410 cal BP (10,461 BC). Therefore, the tree-ring-based 14C calibration now reaches back into the Central Younger Dryas. With respect to the Younger Dryas-Preboreal transition identified in the ring width of our pines at 11,590 BP, the absolute tree-ring chronology now covers the entire Holocene and 820 yr of the Younger Dryas.


Radiocarbon ◽  
1985 ◽  
Vol 27 (1) ◽  
pp. 20-32 ◽  
Author(s):  
T W Linick ◽  
H E Suess ◽  
Bernd Becker
Keyword(s):  
Oak Tree ◽  

Radiocarbon measurements made by the La Jolla laboratory on tree-ring samples from South German oak chronologies are presented. Several previously separate tree-ring series have been reduced to one absolutely dendro-dated chronology spanning the period from 4066 BC to the present and one still-floating chronology which spans the approximate period 7225 to 4125 BC. Previous estimates of the dendro-years made by the authors are compared with the dendro-years now assigned.


2017 ◽  
Author(s):  
Alfonso Fernández ◽  
Ariel Muñoz ◽  
Álvaro González-Reyes ◽  
Isabella Aguilera-Betti ◽  
Isadora Toledo ◽  
...  

Abstract. Streamflow in South-Central Chile (SCC, ∼35° S–42° S) is vital for agriculture, forestry production, hydroelectricity, and human consumption. Recent drought episodes have generated hydrological deficits with damaging effects on these activities. This region is projected to undergo major reductions in water availability, concomitant with projected increases in water demand. However, the lack of long-term records hampers the development of accurate estimations of natural variability and trends. In order to provide more information on long-term streamflow variability and trends in SCC, here we report findings of an analysis of instrumental records and a 296-year tree-ring reconstruction of the summer streamflow of the Río Imperial (∼37°40' S–38°50' S). This is the first reconstruction in Chile targeted at this season. Results from the instrumental streamflow record (∼1940 onwards) indicated that the hydrological regime is fundamentally pluvial with a small snowmelt contribution during spring, and evidenced a decreasing trend, both for the summer and the full annual record. The reconstruction showed that streamflow below the average characterized the post-1980 period, with more frequent, but not more intense, drought episodes. We additionally found that the recent positive phase of the Southern Anular Mode has significantly influenced streamflow. These findings agree with previous studies, suggesting a robust regional signal and a shift to a new hydrological scenario. In this paper, we also discuss the implications of these results for water managers and stakeholders; we provide rationale and examples that support need for the incorporation of tree-ring reconstructions into water resources management.


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