Hostname: page-component-78c5997874-xbtfd Total loading time: 0 Render date: 2024-11-05T04:31:10.516Z Has data issue: false hasContentIssue false

Rainfall Reconstruction Using Wood Charcoal from Two Archaeological Sites in South Africa

Published online by Cambridge University Press:  20 January 2017

ED C. February*
Affiliation:
Water Research Project, South African Museum, P.O. Box 61, Cape Town 8000, South Africa

Abstract

Major components of most southern African archaeological sites are stone, bone, and charcoal. A new technique for climate reconstruction utilizes measurements of vessel size and frequency in the cross-sectional xylem anatomy of archaeological charcoal from Collingham Shelter and Mhlwazini Cave in the Natal Drakensberg. Previous wood anatomical studies have shown that links exist among vessel diameter, vessel frequency and climate. The present study demonstrates that in relation to rainfall, vessel diameter in the species Protea caffra and Protea roupelliae correlated positively, whereas vessel frequency correlated negatively. In P. roupelliae, mean vessel diameter increases from 46 to 62 μm along a rainfall gradient ranging from 760 to 1665 mm. The significant correlations between rainfall and tangential vessel diameter for a charred sample of P. roupelliae suggest that such measures on an archaeological charcoal sample may be used to reconstruct rainfall patterns through time. Using nine assemblages of archaeological charcoal, generalized patterns of wetter and drier periods can be postulated. Comparison with contemporary values indicates that at 200 and 2400 yr B.P. the area near the archaeological sites was wetter than at present. A dry phase occurred between 1300 and 300 yr B.P. Values for the contemporary wood sample are the lowest observed, indicating that present conditions are much drier than those at any time within the last ca. 2000 yr. Dating resolution however, is insufficient to allow more-detailed interpretation of rainfall conditions over the past 2000 yr.

Type
Research Article
Copyright
University of Washington

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Baas, P. (1982). Systematic, phylogenetic and ecological wood anatomy— History and perspectives. In “New Perspectives in Wood Anatomy” (Baas, P., Ed.), pp. 2358. Martinus Nijhoff, The Hague.Google Scholar
Baas, P., and Schweingruber, E H. (1987). Ecological trends in the wood anatomy of trees, shrubs and climbers from Europe. IAWA Bulletin 8, 245274.Google Scholar
Baas, P. Werker, E., and Fahn, A. (1983). Some ecological trends in vessel characters. IAWA Bulletin 4, 141159.Google Scholar
Beall, F. C. Blankenhom, P. R., and Moore, G. R. (1974). Carbonised wood—Physical properties and use as an SEM preparation. Wood Science 6, 212.Google Scholar
Butzer, K. W. (1984). Late Quaternary environments in South Africa. In “Late Cainozoic Palaeoclimates of the Southern Hemisphere” (Vogel, J. C., Ed.), pp. 235264. A. A. Balkema, Rotterdam.Google Scholar
Butzer, K. W. Stuckenrath, R. Bruzewicz, A., and Helgren, D. M., (1978). Late Cenozoic palaeoclimates of the Gaap Escarpment, Kalahari margin, South Africa. Quaternary Research 10, 310339.Google Scholar
Carlquist, S. (1966). Wood Anatomy of Compositae: A summary, with comments on factors controlling wood evolution. ALISO 6, 2544.Google Scholar
Carlquist, S. (1975). “Ecological Strategies of Xylem Evolution.” Univ. of California Press, Berkeley.Google Scholar
Carlquist, S. (1977a). Ecological factors in wood evolution: A floristic approach. American Journal of Botany 64, 887896.Google Scholar
Carlquist, S. (1977b). Wood anatomy of Peneaceae (Myrtales): Comparative, phyJogenetic and ecoJogicaJ implications. Botanical Journal of the Linnaean Society 75, 211227.Google Scholar
Clark, R. L. (1982). Point count estimation of charcoal in pollen preparations and thin sections of sediments. Pollen et spores 24, 523530.Google Scholar
Cooke, H. J., and Verstappen, H. T,, (1984) The land forms of the western Makgadigadi basin in northern Botswana, with a consideration of the chronology of the evolution of Lake Palaeo-Makgadigadi, Zeitschrift fur Geomorphologie 28, 119.Google Scholar
Cousins, W. J. (1975). Optical microscopy of charcoal. Journal of Microscopy 105, 1518.Google Scholar
February, E. C. (1992). Archaeological charcoals as indicators of vegetation change and human fuel choice in the late Holocene at Elands Bay, western Cape Province, South Africa. Journal of Archaeological Science 19, 347354.Google Scholar
February, E. C. (in press). Palaeoenvironmental reconstruction using wood charcoal as a conservation management tool. South African Journal of Science. Google Scholar
Hall, M. (1976). Dendroclimatology, rainfall and human adaptation in the late Iron Age of Natal and Zululand. Annals of the Natal Museum 23, 693703.Google Scholar
IAWA Committee, Wheeler, E. A. Baas, P., and Gasson, P. E. (Eds.) (1989). IAWA list of microscopic features for hardwood identification. IAWA Bulletin 10, 219332.Google Scholar
Klein, R. G. (1980). Environmental and ecological implications of large mammals from Upper Pleistocene and Holocene sites in southern Africa. Annals of the South African Museum 81, 223283.Google Scholar
Lilly, M. A. (1977), “An Assessment of the Dendrochronological Potential of Indigenous Tree Species in South Africa.” Environmental Studies Occasional Paper 18, Department of Geographical and Environmental Studies. University of the Witwatersrand, Johannesburg.Google Scholar
Maggs, T. (1980). The Iron Age sequence south of the Vaal and Pongola Rivers: Some historical implications. Journal of African History 21, 115.Google Scholar
Mazel, A. D. (1990). Mhlwazini Cave: The excavation of Late Holocene deposits in the northern Natal Drakensberg, Natal, South Africa. Natal Museum Journal of Humanities 2, 95133.Google Scholar
Mazel, A. D. (1992). Collingham Shelter: The excavation of Late Holocene deposits Natal South Africa. Natal Museum Journal of Humanities 4, 151.Google Scholar
McGinnes, E. A. Jr., (1971). Some structural changes observed in the transformation of wood into charcoal. Wood and Fibre. Journal of the Society of Wood Science and Technology 3(2), 7783.Google Scholar
Smith, A. M. (1992). Holocene palaeoclimatic trends from palaeoflood analysis. Palaeogeography, Palaeoclimatology, Palaeoecology (Global and Planetary Change Section) 97, 235240.CrossRefGoogle Scholar
Salisbury, E. J., and Jane, F. W. (1940). Charcoals from Maiden Castle and their significance in relation to the vegetation and climatic conditions in prehistoric times. Journal of Ecology 28, 310325.Google Scholar
Schultze, R. E., and Maharaj, M. (1993). Unpublished temperature information. Department of Agricultural Engineering, University of Natal, Pietermaritzburg.Google Scholar
Tusenius, M. (1989). Charcoal analytical studies in the north-eastern Cape, South Africa. South African Archaeological Society Goodwin Series 6, 7783.Google Scholar
Tyson, P. D. (1986). “Climatic change and variability in southern Africa.” Oxford Univ. Press, Cape Town.Google Scholar
Tyson, P. D., and Lindsay, J. A. (1992). The Little Ice Age in southern Africa. Holocene 2, 271278.Google Scholar
Vogel, C. H. (1989). A documentary-derived climatic chronology for Southern Africa, 1820-1900. Climatic Change 14, 291307.CrossRefGoogle Scholar
Wilkins, A. P., and Papassotiriou, S. (1989). Wood anatomical variation of Acacia Melanoxylon in relation to latitude. I AW A Bulletin 10, 201207.Google Scholar
Zhang Xining, Deng Liang, , and Pieter Baas, . (1988). The ecological wood anatomy of the Lilacs (Syringa Oblata var. giraldii) on Mount Taibei in north-western China. IAWA Bulletin 9, 2430.Google Scholar
Zimmerman, M. H. (1978). Structural requirements for optimal conduction in tree stems. In “Tropical Trees as Living Systems” (Tomlinson, P. B. and Zimmerman, M. H., Eds.), pp. 517532. Cambridge Univ. Press, London, New York, and Melbourne.Google Scholar
Zimmerman, M. H. (1982). Functional Xylem Anatomy of angiosperm trees. In “New Perspectives in Wood Anatomy” (Baas, P., Ed.). Nijhoff/Junk, The Hague.Google Scholar
Zimmerman, M. H. (1983). “Xylem Structure and the Ascent of Sap.” Springer-Verlag, Berlin.Google Scholar