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

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.

5. A. Pătruţ, R.T. Pătruţ, L. Rakosy, D.A. Lowy, D. Mărgineanu, K.F. von Reden, Radiocarbon investigation of the superlative African baobabs from Savé Valley Conservancy, Zimbabwe, Studia UBB Chemia, 2019, LXIV, 2 (Tom II), 7-14. > doi: 10.24193/subbchem.2019.2.35.
ABSTRACT: The article reports the radiocarbon investigation results of the superlative African baobabs from Savé Valley, Zimbabwe. Several wood samples collected from these baobabs were analysed by AMS (accelerator mass spectrometry) radiocarbon dating. The radiocarbon dates of the oldest samples were 1529 ± 14 BP for Matendere Big baobab, 1179 ± 19 BP for Chishakwe Big tree and 1096 ± 35 BP for Mokore Giant baobab. The corresponding calibrated ages are 1430 ± 15, 1090 ± 40 and 1020 ± 25 calendar yr. The oldest tree from Savé Valley, which we described previously, is the Humani Bedford Old baobab. The radiocarbon date of its oldest sample, 1655 ± 14 BP, corresponds to a calibrated age of 1580 ± 30 calendar yr.

6. A. Pătruţ, S. Woodborne, R.T. Pătruţ, G. Hall, L. Rakosy, C. Winterbach, K.F. von Reden, Age, growth and death of a national icon: the historic Chapman baobab of Botswana, Forests, 2019. 10, (11), 983; doi: 10.3390/f10110983.
ABSTRACT: The year 2016 witnessed the fall of a symbol of the botanical world: the historic Chapman baobab of Botswana. The article presents the results of our investigation of the standing and fallen tree. The Chapman baobab had an open-ring shaped structure composed of six partially fused stems. Several wood samples collected from the stems prior and after their collapse were analysed by using radiocarbon dating. The radiocarbon date of the oldest sample was 1381 ± 22 BP, which corresponds to a calibrated age of 1345 (+10, -15) calendar years. The dating results show that the six stems of Chapman baobab belonged to three different generations, which were 1350-1400, 800-1000 and 500-600 years old. The growth rate variation of the largest and oldest stem is presented and correlated with the climate evolution in the area over the past 1000 years. The factors that determined the sudden fall and death of the Chapman baobab are also presented and discussed.

7. A. Pătruţ, A. Garg, S. Woodborne, R.T. Pătruţ, L. Rakosy, I.A. Raţiu, D.A. Lowy, Radiocarbon dating of two old sacred baobabs from India, PLOS One, 2019. doi: 10.1371/journal.pone.0227352.
ABSTRACT: The article presents the radiocarbon investigation of the baobab of Jhunsi, Allahabad and the Parijaat tree at Kintoor, two old African baobabs from northern India. Several wood samples extracted from these baobabs were analysed by using AMS radiocarbon dating. The radiocarbon date of the oldest samples were 779 ± 41 BP for the baobab of Jhunsi and 793 ± 37 BP for the baobab of Kintoor. The corresponding calibrated ages are 770 ± 25 and 775 ± 25 calendar years. These values indicate that both trees are around 800 years old and become the oldest dated African baobabs outside Africa.

8. R.T. Pătruţ, A. Pătruţ, J.M. Leong Pock-Tsy, S. Woodborne, L. Rakosy, P. Danthu, I.A. Ratiu, J. Bodis, K. von Reden, Radiocarbon investigation of a superlative Grandidier baobab, the Big Reniala of Isosa, Studia UBB Chemia, 2019, LXIV, 4, 131-139. doi: 10.24193/subbchem.2019.4.10.
ABSTRACT: The article discloses the AMS (accelerator mass spectrometry) radiocarbon dating results of the Big Reniala of Isosa, which is a massive Grandidier baobab (Adansonia grandidieri Baill.) of Madagascar. The investigation of this baobab shows that it consists of 5 perfecly fused stems and exhibits a cluser structure. The calculated wood volume of the tree is 540 m³, which makes the Big Reniala of Isosa the largest individual of all Adansonia species and also the biggest known angiosperm in terms of volume. Several samples were collected from the outer part of the stems. The oldest dated sample had a radiocarbon date of 934 ± 24 BP, which corresponds to a calibrated age of 845 ± 25 years. This value indicates that the big Reniala of Isosa is 1000 ± 100 years old.