Age determination of large live trees with inner cavities: radiocarbon dating of Platland tree, a giant African baobab
- 225 Downloads
For large trees without a continuous sequence of growth rings in their trunk, such as the African baobab (Adansonia digitata L.), the only accurate method for age determination is radiocarbon dating. As of today, this method was limited to dating samples collected from the remains of dead specimens.
Our research extends significantly the dating of such trees to large live specimens with inner cavities. The new approach is based on collecting samples from the cavities and their subsequent radiocarbon dating.
The giant two-stemmed Platland tree, also known as Sunland baobab, was investigated by using this new approach. AMS radiocarbon dates of the oldest sample segments originating from the two inner cavities indicate that the large stem I (364.5 m3) is 750 ± 75 years old, while the much smaller stem II (136.7 m3) has 1,060 ± 75 years. Results also show that stem I is still growing very fast, while the older stem II slowed down consistently its growth over the past 250 years. The complete mapping of Platland tree determined an overall wood volume of 501.2 m3.
Dating results demonstrate that the size–age relation cannot be used for estimating accurately the age of African baobabs.
KeywordsAdansonia digitata Radiocarbon dating Age determination Growth rate Accelerator mass spectrometry
This work was fully funded by the Romanian Authority CNCSIS-UEFISCDI under grant PN II-IDEI 2354, Nr. 1092. AMS radiocarbon dating at the NOSAMS Facility is supported by the U.S. National Science Foundation under Cooperative Agreement OCE-0753487. We would like to thank Heather and Doug van Heerden, the owners of Sunland Nursery, for granting permission for on-site investigation and also for sampling the Platland tree.
- Bronk Ramsey C (2009) Bayesian analysis of radiocarbon dates. Radiocarbon 51:337–360Google Scholar
- von Breitenbach F (1985) Aantekeninge oor die groeitempo van aangeplante kremeteartbome (Adansonia digitata) en opmerkinge ten opsigte van lewenstyd, groeifases en genetiese variasie van die spesie. J Dendrology 5:1–21Google Scholar
- Department of Water Affairs and Forestry (South Africa) (2008) List of champion trees. Available at http://www2.dwaf.gov.za
- Esterhuyse N, von Breitenbach J, Sőhnge H (2001) Remarkable trees of South Africa. Briza, Pretoria, pp 155–161Google Scholar
- Hartesveldt RJ, Harvey HT, Shellhammer HS (1975) The giant sequoias of the Sierra Nevada. National Park Service, Washington, pp 57–59Google Scholar
- McCormack FG, Hogg AG, Blackwell PG, Buck CE, Higham TFG, Reimer PJ (2004) SHCal04 Southern Hemisphere calibration, 0–11.0 cal kyr bp. Radiocarbon 46:1087–1092Google Scholar
- Olsson IU (1986) Radiometric Methods. In: Berglund B (ed) Handbook of Holocene palaeoecolgy and palaeohydrology. Wiley, Chichester, pp 273–312Google Scholar
- Patrut A, Mayne DH, von Reden KF, Lowy DA, Van Pelt R, McNichol AP, Roberts ML, Margineanu D (2010a) Fire history of a giant African baobab evidenced by radiocarbon dating. Radiocarbon 52:717–726Google Scholar
- Patrut A, Mayne DH, von Reden KF, Lowy DA, Venter S, McNichol AP, Roberts ML, Margineanu D (2010b) Age and growth rate dynamics of an old African baobab determined by radiocarbon dating. Radiocarbon 52:727–734Google Scholar
- Patrut A, von Reden KF, Lowy DA, Mayne DH, Elder KE, Roberts ML, McNichol AP (2010c) Comparative AMS radiocarbon dating of pretreated versus non-pretreated tropical wood samples. Nucl Instr Methods B 268:910–913Google Scholar
- Reimer PJ, Baillie MGL, Bard E, Bayliss A, Beck JW, Blackwell PG, Bronk RC, Buck CE, Burr GS, Edwards RL, Friedrich M, Grootes PM, Guilderson TP, Hajdas I, Heaton TJ, Hogg AG, Hughen KA, Kaiser KF, Kromer B, McCormac FG, Manning SW, Reimer RW, Richards DA, Southon JR, Talamo S, Turney CSM, van der Plicht J, Weyhenmeyer CE (2009) IntCal09 and Marine09 radiocarbon age calibration curves, 0–50,000 years cal bp. Radiocarbon 51:1111–1150Google Scholar
- Roberts ML, Burton JR, Elder KL, Longworth BE, McIntyre CP, von Reden KF, Han BX, Rosenheim BE, Jenkins WJ, Galutschek E, McNichol AP (2010) A high-performance 14C accelerator mass spectrometry system. Radiocarbon 52:228–235Google Scholar
- Woodborne S, Hall G, Basson S, Zambatis G, Zambatis N (2010) The death of a giant: on the age of baobabs. Savanna Network Meeting, SkukuzaGoogle Scholar
- Worbes M, Junk WJ (1999) How old are tropical trees? The persistence of a myth. IAWA J 20:255–260Google Scholar