A palaeo-environmental record of natural and human change from the Auckland Isthmus, New Zealand, during the Late Holocene

Abstract

A multi-proxy analysis of a sediment core from Waiatarua, Auckland Isthmus adds to an environmental history from the local wetland spanning the Late Glacial to modern times. Several distal tephra were recorded in the core: 8.5 ka Rotoma (reworked), 6.1 ka Tuhua (primary and reworked), most likely the 1.8 ka Taupo (the latter is previously unreported for the Auckland Isthmus) and one unidentified, possibly 665 yr B.P. Kaharoa.

Pollen and diatom analyses of the core shows that during the period c. 6000-c. 4800 yr B.P., the site was a lake fringed with Cyperaceae/Leptospermum swamp. The lake became progressively shallower after c. 4800 yr B.P., probably due to hydroseral infilling. Surrounding the lake was forest dominated by Dacrydium, Prumnopitys, Metrosideros and Nestegis. Transition to the Polynesian era appears unclear because the site probably endured a hiatus due to destruction of peat by burning in European times.

Keywords

Palynology, diatoms, tephra, Auckland, Holocene.