Towards a Temperature Reconstruction for Southern Africa: Exploring the Climate Signal in Tree-Ring Density of Clanwilliam Cedar from South Africa
Abstract
High-resolution annual temperature proxies are largely lacking in Southern Africa, partly due to the scarcely available tree species that are suitable for dendrochronology. Clanwilliam cedar (Widdringtonia cedarbergensis) from Cape Province, South Africa, is a long-lived conifer with distinct tree rings and thus a strong dendroclimatic potential. However, the climatic signal in its tree-ring width (TRW) is weak and other tree-ring parameters need to be explored to extract climatic information from this proxy. Here we investigate the climatic signal of maximum latewood density (MXD) in 17 Clanwilliam cedar samples collected in 1978 (Dunwiddie & LaMarche, 1980). We use a non-destructive X-ray Computed Tomography facility to develop a MXD chronology that reliably extends back to 1825 CE. For the period 1930-1970, correlation between the MXD chronology and current June temperature is 0.37 (p<0.05). Clanwilliam cedar can live to be 356 years old and the current TRW chronology extends to 1564 CE. A full-length MXD chronology for this long-lived species could provide a high-resolution temperature reconstruction for southern Africa, a region where historical climate observations are limited and where societal vulnerability to future climate change is high.
References: Dunwiddie, P. W., & LaMarche, V. C. (1980). A climatically responsive tree-ring record from Widdringtonia cedarbergensis, Cape Province, South Africa. Nature, 286(5775), 796-797.- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFMPP43D1640D
- Keywords:
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- 4916 Corals;
- PALEOCEANOGRAPHY;
- 4920 Dendrochronology;
- PALEOCEANOGRAPHY;
- 4928 Global climate models;
- PALEOCEANOGRAPHY;
- 4932 Ice cores;
- PALEOCEANOGRAPHY