Abstract Seven cores were extracted from a river terrace swamp in the forested Kauaeranga valley, Coromandel Peninsula, New Zealand. High-resolution (c. 36-73 yr interval) pollen records were obtained from four of the cores and aged by radiocarbon dating and with stratigraphic reference to the 665 ± 15 14C yr BP Kaharoa Tephra. The records span the last c. 1800 yr and show that the vegetation consisted of lowland podocarp-hardwood forest before deforestation by burning occurred. The pattern of deforestation at Kauaeranga, indicated by the abrupt dominance of Pteridium with concurrent increased charcoal, is typical of pollen records associated with early Polynesian settlement in New Zealand. Peaks of Pteridium and charcoal were also found in sediments deposited after European settlement. Different cores show marked palynological and stratigraphic differences relative to the Kaharoa Tephra, most importantly with regard to the timing of deforestation. Deforestation occurred close to the Kaharoa, at a calculated age of c. 750 BP in one core but well above the Kaharoa (c. 480 BP) in another. The stratigraphic unconformities between cores are attributed to variable fluvial processes causing an uneven deposition of sediments within the swamp.
Keywords palynology; charcoal; Pteridium; deforestation; Kaharoa Tephra; Kauaeranga; Coromandel; New Zealand
R01021 Received 8 November 2002; accepted 17 June 2002; published 27 September
2002
©Journal of The Royal Society of New Zealand, Volume 32, Number
3, September 2002, pp 507-531
PDF file of entire paper: Print-quality (1508K) |screen-quality (326K)