TY  - GEN
A1  - Pauly, Maren
A1  - Helle, Gerhard
A1  - Miramont, Cécile
A1  - Büntgen, Ulf
A1  - Treydte, Kerstin
A1  - Reinig, Frederick
A1  - Guibal, Frédéric
A1  - Sivan, Olivier
A1  - Heinrich, Ingo
A1  - Riedel, Frank
A1  - Kromer, Bernd
A1  - Balanzategui, Daniel
A1  - Wacker, Lukas
A1  - Sookdeo, Adam Sookdeo
A1  - Brauer, Achim
T1  - Subfossil trees suggest enhanced Mediterranean hydroclimate variability at the onset of the Younger Dryas
T2  - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2  - Nearly 13,000 years ago, the warming trend into the Holocene was sharply interrupted by a reversal to near glacial conditions. Climatic causes and ecological consequences of the Younger Dryas (YD) have been extensively studied, however proxy archives from the Mediterranean basin capturing this period are scarce and do not provide annual resolution. Here, we report a hydroclimatic reconstruction from stable isotopes (delta O-18, delta C-13) in subfossil pines from southern France. Growing before and during the transition period into the YD (12 900-12 600 cal BP), the trees provide an annually resolved, continuous sequence of atmospheric change. Isotopic signature of tree sourcewater (delta O-18(sw)) and estimates of relative air humidity were reconstructed as a proxy for variations in air mass origin and precipitation regime. We find a distinct increase in inter-annual variability of sourcewater isotopes (delta O-18(sw)), with three major downturn phases of increasing magnitude beginning at 12 740 cal BP. The observed variation most likely results from an amplified intensity of North Atlantic (low delta O-18(sw)) versus Mediterranean (high delta O-18(sw)) precipitation. This marked pattern of climate variability is not seen in records from higher latitudes and is likely a consequence of atmospheric circulation oscillations at the margin of the southward moving polar front.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1135 
KW  - annually laminated sediments
KW  - lake Meerfelder Maar
KW  - isotopic composition
KW  - oxygen isotope
KW  - climate
KW  - cellulose
KW  - radiocarbon
KW  - temperature
KW  - record
KW  - model
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-459169
SN  - 1866-8372
IS  - 1135
ER  - 
TY  - GEN
A1  - Siegmund, Jonatan Frederik
A1  - Sanders, Tanja G. M.
A1  - Heinrich, Ingo
A1  - Maaten, Ernst van der
A1  - Simard, Sonia
A1  - Helle, Gerhard
A1  - Donner, Reik Volker
T1  - Meteorological drivers of extremes in daily stem radius variations of beech, oak, and pine in Northeastern Germany
BT  - an event coincidence analysis
T2  - Frontiers in plant science
N2  - Observed recent and expected future increases in frequency and intensity of climatic extremes in central Europe may pose critical challenges for domestic tree species. Continuous dendrometer recordings provide a valuable source of information on tree stem radius variations, offering the possibility to study a tree's response to environmental influences at a high temporal resolution. In this study, we analyze stem radius variations (SRV) of three domestic tree species (beech, oak, and pine) from 2012 to 2014. We use the novel statistical approach of event coincidence analysis (ECA) to investigate the simultaneous occurrence of extreme daily weather conditions and extreme SRVs, where extremes are defined with respect to the common values at a given phase of the annual growth period. Besides defining extreme events based on individual meteorological variables, we additionally introduce conditional and joint ECA as new multivariate extensions of the original methodology and apply them for testing 105 different combinations of variables regarding their impact on SRV extremes. Our results reveal a strong susceptibility of all three species to the extremes of several meteorological variables. Yet, the inter-species differences regarding their response to the meteorological extremes are comparatively low. The obtained results provide a thorough extension of previous correlation-based studies by emphasizing on the timings of climatic extremes only. We suggest that the employed methodological approach should be further promoted in forest research regarding the investigation of tree responses to changing environmental conditions.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 456 
KW  - dendrometer measurements
KW  - event coincidence analysis
KW  - climate extremes
KW  - growth response
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-407943
ER  -