- Kohika: The Archaeology of a Late Māori Lake Village in the Ngati Awa Rohe, Bay of Plenty, New Zealand
The Kohika volume explores the archaeology of a Māori lake village situated on the flood plain of the Rangitaiki and Tarawera Rivers, not far from where they jointly [End Page 118] flow into the ocean in the eastern Bay of Plenty, New Zealand. The village was abandoned in the seventeenth century A.D., following a flood that introduced quantities of pumiceous alluvium onto the site. A rising water table and subsequent buildup of peat preserved materials from this village. The site was discovered as a result of farm drainage, and the Whakatane and District Historical Society excavated there between 1974 and 1978. Subsequent excavations were carried out by Professor Geoffrey Irwin from the University of Auckland. This volume of papers edited by Irwin documents his research, together with specialist papers covering Māori traditional knowledge, geomorphology, vegetation change, faunal remains, coprolite analysis, obsidian sourcing, and stone, fiber, and wood technology. Given the range of topics covered, this is more than a site report. Despite the delay between excavations and field analyses (1975–1981) and publication (2004), this volume represents a very useful contribution to current archaeological problems in New Zealand. It throws further light on the nature and timing of Māori settlement in the Bay of Plenty toward the end of the prehistoric period. The volume is supported by color plates and excellent illustrations.
I will discuss the specialist papers first. Central to the current understanding of New Zealand archaeology in the northern North Island is the presence of Kaharoa tephra, which was distributed as air-fall from the Kaharoa eruption at Mount Tarawera and dated to c. A.D. 1350. This event is crucial to our understanding of anthropogenic changes in vegetation—particularly the shift from lowland rain forest to pyrogenic bracken fern—which have been dated relative to this tephra layer (Newnham et al. 1998). At present, all evidence for convincing anthropogenic impacts on the vegetation occurs at or just after the time of the Kaharoa eruption. At Kohika, the period before the Kaharoa eruption is dominated by forest vegetation on dunes and ridges and flax (Leptospermum and Coprosma) in the swamps. Evidence for major vegetation change to bracken fern (Pteridium esculentum) and shrubs occurs about 50 years after the Kaharoa eruption, at c. 600 B.P. Such anthropogenic changes to the vegetation provide indirect evidence for the early presence of humans in New Zealand (McGlone and Wilmshurst 1999). In these terms, the suggestion is that the eastern Bay of Plenty was settled by A.D. 1350–1400. The chapter on site chronology (Irwin and Jones) makes use of a Bayesian calibration to argue that direct evidence for human occupation of the site occurs in the interval A.D. 1610–1690 and lasts for only a short period of 70–80 years. Thus occupation of the Kohika site occurs about 250 years after the first paleoecological indications of a human presence.
The excavations at Kohika consisted of four adjacent but noncontinuous areas, with the Whakatane and District Historical Society excavations making a fifth area (termed Area HS). Recent excavations in New Zealand, such as Pouerua (Sutton et al. 2003), have demonstrated that excavations require a dual strategy: first, opening areas that are sufficiently large that they relate to the scale of later Māori settlements; and second, working in terms of detailed contexts that enable sequences of smaller events to be built up. Irwin's work at Kohika is a forceful demonstration of the usefulness of this approach, using stratigraphy and geomorphology to correlate excavation areas that are separated by distances of up to 40 m. This research reinforces the point that a taphonomic knowledge of how a site has emerged over even a short period of time is essential to an understanding of human behavior and human–landscape interactions there. The sequence of events in Area D is a case in point. In...