AMS Radiocarbon Dating of Large Za Baobabs (Adansonia za) of Madagascar

Abstract

The article reports the radiocarbon investigation of Anzapalivoro, the largest za baobab (Adansonia za) specimen of Madagascar and of another za, namely the Big cistern baobab. Several wood samples collected from the large inner cavity and from the outer part/exterior of the tree were investigated by AMS (accelerator mass spectrometry) radiocarbon dating. For samples collected from the cavity walls, the age values increase with the distance into the wood up to a point of maximum age, after which the values decrease toward the outer part. This anomaly of age sequences indicates that the inner cavity of Anzapalivoro is a false cavity, practically an empty space between several fused stems disposed in a ring-shaped structure. The radiocarbon date of the oldest sample was 780 ± 30 bp, which corresponds to a calibrated age of around 735 yr. Dating results indicate that Anzapalivoro has a closed ring-shaped structure, which consists of 5 fused stems that close a false cavity. The oldest part of the biggest za baobab has a calculated age of 900 years. We also disclose results of the investigation of a second za baobab, the Big cistern baobab, which was hollowed out for water storage. This specimen, which consists of 4 fused stems, was found to be around 260 years old.

Radiocarbon investigation of a superlative grandidier baobab, the big reniala of Isosa

“…(Za baobab) and Adansonia grandidieri Baill. (Grandidier baobab), which grow in the west and south [5,[16][17][18][19].…”

“…Sample ages and errors were rounded to the nearest 5 yr. This approach was used for selecting calibrated age ranges and single values for sample ages in all our previous articles on AMS radiocarbon dating of large and old angiosperm trees, especially of baobabs [6][7][8][9][10][11][12][13][14][15][17][18][19]. Dating results of samples (segments).…”

Radiocarbon investigation of the superlative african baobabs from Savé valley conservancy, Zimbabwe

“…This research is based on our new approach, which is not limited to fallen specimens, but allows to investigate and date live individuals, as well. Our approach consists of AMS (accelerator mass spectrometry) radiocarbon dating of tiny wood samples collected especially from inner cavities, deep incisions/entrances in the stems, fractured stems and from the outer part/exterior of large baobabs [6][7][8][9][10][11][12].…”

The Growth Stop Phenomenon Of Baobabs (Adansonia Spp.) Identified By Radiocarbon Dating

“…One should mention that the identification of very complex architectures and the accurate dating of large and old baobabs are not possible by means of traditional dendrochronological methods, which are based on tree-ring investigation. The existence of growth rings in African baobabs has generated much controversy (Guy 1970;Patrut et al 2007Patrut et al , 2016Wickens and Lowe 2008). We used 14 C dating to determine age sequences along wood samples collected from different baobabs, which were compared against growth ring counts.…”

“…), and the Grandidier’s baobab or Reniala ( Adansonia grandidieri Baill.) (Baum 1996; Patrut et al 2015b, 2015c, 2016). We found that their characteristic features, as assessed by AMS 14 C dating, are similar to those of the African baobab.…”