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Age, growth and architecture of monumental angiosperm trees assessed by AMS radiocarbon investigation and climate research performed by stable isotope analysis of wood samples collected from such trees
Investigarea vârstei și arhitecturii unor arbori angiospermi monumentali prin datare cu radiocarbon, respectiv studiul climatic al mostrelor recoltate din acești arbori prin analiză de izotopi stabili
Articles

1. S. Woodborne, G. Hall, C.J. Jones, N. Loader, A.Pătruţ, R.T. Pătruţ, I. Robertson, S.R.Winkler, C. Winterbach, A 250-year isotopic proxy rainfall from southern Botswana, Studia UBB Chemia, 2018, LXIII, 1, 109-123. doi: 10.24193/subbchem.2018.1.09

ABSTRACT: Climate records along aridity gradients where manifestations of climate change are most profound are important for testing climate models. The Kalahari Transect spans such a gradient, but instrumental records of climate parameters are limited in the sparsely populated region. We analysed the δ13C and δ18O record from a Vachellia erioloba (E.Mey) tree from the southern Kalahari Desert in Botswana to explore its potential as a climate proxy archive. Radiocarbon dates show that the record spans the period 1758-2013 CE. Both the δ13C and δ18O records correlate with local rainfall. The isotope proxies show a weak positive correlation with sea-surface temperature reconstruction from the southwestern Indian Ocean, and a stronger correlation with the El Niño Southern Oscillation index. This appears to contradict previous evidence that higher sea-surface temperatures are associated with reduced summer rainfall over the southern African interior. Instead of eastward shifts in the temperate tropical trough synoptic system during elevated southwestern Indian Ocean temperature anomalies, the evidence supports a westwards shift. The result demonstrates the potential of Vachellia erioloba as a climate proxy archive that may yield past climate variability from the arid regions of southern Africa.

 

2. A. Pătruţ, S. Woodborne, R.T. Patrut, L. Rakosy, D.A. Lowy, G. Hall, K.F. von Reden, The demise of the largest and oldest African baobabs, Nature Plants, 2018, 4, 423-426. doi: 10.1038/s41477-018-0170-5

ABSTRACT: The African baobab is the biggest and longest living angiosperm tree. By using radiocarbon dating we identified the stable architectures that enable baobabs to reach large sizes and old ages. We report that 9 of the 13 oldest and 5 of the 6 largest individuals have died or at least their oldest parts/stems have collapsed and died over the past 12 years; the cause of the mortalities is still unclear.

 

3. A. Pătruţ, R.T. Pătruţ, L. Rakosy, I.A. Raţiu, D.A. Lowy, J. Bodis, K.F. von Reden, Radiocarbon dating of the old ash of Aiton, Romania, Studia UBB Chemia, 2018, LXIII, 3, 41-48. doi: 10.24193/subbchem.2018.3.03

ABSTRACT: The article reports the AMS (accelerator mass spectrometry) radiocarbon investigation results of the old common ash of Aiton. Five wood samples were collected from the trunk of the tree. The deepest ends of the samples were analysed by AMS radiocarbon. We found radiocarbon dates between 165 ± 20 BP and 240 ± 18 BP, which correspond to calibrated ages of 230 – 360 years. These results, combined with a ring counting estimate, indicate an age of 330 ± 30 years for the ash of Aiton. By this value, the ash of Aiton becomes the oldest known common ash with accurate dating results.

 

4. A. Pătruţ, N. Robu, V. Savu, R.T. Pătruţ, L. Rakosy, I.A. Raţiu, D.Lowy, D. Mărgineanu, K.F. von Reden, Radiocarbon investigation of the pedunculate oak of Botoşana, Studia UBB Chemia, 2018, LXIII, 4, 7-14. doi: 10.24193/subbchem.2018.4.01

ABSTRACT: The article discloses the AMS (accelerator mass spectrometry) radiocarbon dating results of the pedunculate oak of Botoşana. Four wood samples were extracted from its trunk. Five segments extracted from these samples were analyzed by AMS radiocarbon. Their radiocarbon dates were found to be between 161 ± 21 BP and 260 ± 20 BP. These values correspond to calibrated ages of 235 – 365 years. The dating results extrapolated to the geomentric center of the trunk indicate an age of 645 ± 50 years for the oak of Botoşana.

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