Coastal Restoration Trust of New Zealand

Coastal Dune Ecosystem Reference Database

Plant biogeography and the late Cenozoic history of New Zealand Journal Paper

McGlone, M.S.
Journal / Source
New Zealand Journal of Botany
New Zealand flora; plant biogeography: plant migration; evolution; endemism; vicariance; disjunction; Nothofagus; Agathis; Phyllocladus; Dracophyllum; Plate tectonics; Alpine Fault; Quaternary; Pleistocene: Miocene: Neogene
The Wairarapa region is a tectonic landscape at the southeastern corner of the North Island of New Zealand. Seismic events are an important key to its natural and cultural character. Archaeological sites and environmental events are dated by their stratigraphic relationship to earthquake-uplifted shorelines, and with dune-building phases and alluvial deposition episodes thought to be triggered by earthquakes. Two cultural periods are recognised: early and late. Early period sites are older than or contemporary with a period of seismic activity dated to about the late 15th Century AD. The inferred early settlement pattern was coastal. At the time of Maori settlement the coast was largely forested with extensive lagoons between uplifted beach ridges, and it had been stable for at least 800 years. Economic pursuits, in particular gardening, were related to the geological nature of the coast. Gardening was common where a hard rock platform and coastal sediments of greywacke or limestone resistant to wave erosion occurred in front of the coastal hills. It was virtually absent from parts of the coast where the coastal hills were easily eroded mudstones fronted by soft rocks and coastal sediments poorly resistant to wave erosion. Parts of the coast were abandoned following uplift of the coast that drained lagoons, silted up streams, and reactivated building of stream fans on the coastal platform. I suggest that tsunami inundation killed off the coastal forest that remained following Maori clearance by fire. During the late period the focus of occupation moved to the main Wairarapa Valley. Gardening was practised in the southern part of the valley and settlement sites tended to be concentrated on the eastern side of the valley. Forest clearance, however, seems to have focused for some reason on the extensive gravelly soils of the Waiohine fans that were deposited from the mountain ranges on the western side of the valley at the end of the last glaciation. Future research is proposed with the intention of clarifying aspects of the natural and cultural history of the region and their interrelationship. Of particular importance are: the direct dating of two earthquakes that have uplifted the coast between Flat Point and Cape Palliser twice since human settlement; and the field identification of at least two tsunamis that have struck the coast since human settlement. Both types of events would have had severe consequences for the human communities living on the coast that should be detectable in the archaeological record.