Abstract:
The paper discloses the radiocarbon investigation results of
the Luna tree, a representative African baobab from Venetia Limpopo Nature
Reserve, South Africa. Several wood samples collected from deep incisions
in the trunk were investigated by AMS (accelerator mass spectrometry)
radiocarbon dating. The age sequence of segments extracted from the
oldest sample demonstrates that ages increase with the distance into the
wood up to a point of maximum age, after which ages decrease toward the
sample end. This anomaly is typical for multi-stemmed baobabs, having a
closed ring-shaped structure with a false cavity inside. Dating results reveal
that each of the two large fused units, which build the Luna tree, consist of
such a closed ring. The two closed rings include two interconnected false
inner cavities. False cavities are empty spaces between fused stems that
were never filled with wood. We named this baobab architecture, which has
a very high symmetry, double closed ring-shaped structure with two false
cavities. The new architecture, which is very uncommon, enables baobabs to
reach large sizes and very old ages. The radiocarbon date of the oldest
sample segment was 1507 ± 22 BP, which corresponds to a calibrated age of
1405 ± 20 yr. We estimate that the oldest part of Luna tree has an age of
1600 ± 100 yr. By these results, the Luna tree becomes the fourth oldest
African baobab with accurate dating results.
