PALYNOLOGICAL AND SEDIMENTOLOGICAL EVIDENCE FOR A RADIOCARBON CHRONOLOGY OF ENVIRONMENTAL-CHANGE AND POLYNESIAN DEFORESTATION FROM LAKE TAUMATAWHANA, NORTHLAND, NEW-ZEALAND

We present pollen diagrams and sedimentological analyses from a lake s ite within an extensive dune system on the Aupouri Peninsula, Northlan d. Five thousand years ago, a regional Agathis australis-podocarp-broa dleaf forest dominated the vegetation, which manifested an increasing preponderance of conifer species. Climate was cooler and drier than at present. From ca. 3400 sp, warmth-loving species such as A. australis and drought-intolerant species, Dacrydium cupressinum and Ascarina lu cida, became common, implying a warm and moist climate. The pollen rec ord also suggests a windier climate. The most significant event in the record, however, occurred after ca. 900 sp (800 cal sp) when anthropo genic deforestation commenced. A dramatic decline in forest taxa follo wed, accompanied by the establishment of a Pteridium-esculentum-domina ted community. Fire almost certainly caused this, evidenced by a drama tic increase of charcoal. Sedimentological evidence for this site indi cates a relatively stable environment before humans arrived and an inc reasingly unstable environment with frequent erosional events after hu man contact.