AMS RADIOCARBON INVESTIGATION OF THE LARGE AFRICAN BAOBABS OF OUTAPI, NAMIBIA

Prof. Adrian Patrut1,2, Dr. Roxana T. Patrut3, Prof. Laszlo Rakosy3, Dr. Demetra Rakosy4, Dr. Ileana-Andreea Ratiu1,2, Dr. Karl von Reden5

1Babeş-Bolyai University, Faculty of Chemstry and Chemical Engineering, Cluj-Napoca, Romania, 2Babeş-Bolyai University, Raluca Ripan Institute for Research in Chemistry, Cluj-Napoca, Romania, 3Babeş-Bolyai University, Faculty of Biology and Geology, Cluj-Napoca, Romania, 4AG Spatial Interaction Centre, Centre for Integrative Biodiversity Research, Leipzig, Germany, 5NOSAMS Facility, Woods Hole Oceanographic Institution, Woods Hole, U.S.A.

The iconic African baobab (Adansonia digitata L.) is endemic to the arid savanna of mainland Africa. In 2005, we initiated an extended research project to clarify several controversial aspects regarding the age, growth and architecture of the African baobab.
Namibia is one of the African countries with the highest number of baobabs, which have different local abundance and distribution in its 12 regions. The highest number and density of baobabs can be found in the Omusati region (26,573 km2), in the north-central part of Namibia. According to a survey, the mean density of baobabs in Omusati is 6.7 trees/ha, which corresponds to a total number of 17.8 million individuals.
Our research in Omusati identified a number of 11 superlative baobabs, with a circumference of over 20 m, out of which 6 are located in and around Outapi, 3 in Onesi and one each in Tsandi and Okahao. The high density of baobabs and the high number of superlative individuals is also due to the large areas with sandy soils, rich in sodium and calcium.
Outapi, located close to the border with Angola, which is the capital of the Omusati region, hosts 6 superlative baobabs in an area of less than 10 km2. The most famous is the Ombalantu baobab, which is part of a national heritage site. Here we present the investigation and the radiocarbon dating results of the 4 largest and oldest baobabs of Outapi, i.e., the Big Baobab of Outapi (girth 31.01 m), the historic Amadhila baobab of Anamulenge (25.33 m), the historic Ombalantu baobab (24.60 m) and the Market Toilet tree (23.05 m). All these superlative baobabs exhibit a closed ring-shaped structure with a false cavity inside. They are all multi-stemmed, with several normal and false stems. The false stems, which emerge from an adjacent normal stem, act as anchors in sandy soils. Thus, the Big Baobab consists of 8 stems, the Amadhila baobab has 11 stems, the Market Toilet tree is composed of 4 stems and the Ombalantu baobab is constructed of 7 stems. These stems may have different ages and belong to several generations. The oldest dated sample had a radiocarbon date of 820 ± 17 BP corresponding to a calibrated age of 780 ± 10 calendar years. It was extracted from the damaged false cavity of the Big Baobab of Outapi. According to the radiocarbon results, the four baobabs exhibit ages between 600 and 850 years. Unfortunately, the historic Amadhila baobab of Anamulenge collapsed and died in April 2021.
Certain wood samples which are radiocarbon dated will be investigated by stable isotope analysis for a climate reconstruction in the area over the past 600-750 years.
The research was funded by the Romanian Ministry of National Education CNCS-UEFISCDI under grant PN-III-P4-ID-PCE-2020-2567, No. 145/2021.


Biography:

Personal data:
First name and surname: ADRIAN IOAN PATRUT
Degree: Ph.D. in Chemistry
Profession: Professor of Nuclear and Inorganic Chemistry, Faculty of Chemistry and Chemical Engineering, Babes-Bolyai University, Cluj-Napoca, Romania.
Professional Competences:
-Metal-oxygen clusters; Polyoxometalates with giant molecules; Descriptive inorganic, coordination and supramolecular chemistry.
-Nuclear chemistry; Radiocarbon dating; Stable isotope analysis.
-Climate changes and modifications.
-Dating of giant trees; Architecture of monumental trees.
Scientific Activity:
– 7 scientific books.
– over 80 scientific articles.
– over 50 scientific communications and presentations at international conferences.
– 8 multiannual research projects (23 years) as PI (principal investigator, project manager).

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Date

Nov 08 - 19 2021