Abstract
Our understanding of when Polynesian colonists first arrived in New Zealand, how the landscape was altered, and the pace of anthropogenic modification has been primarily sourced from archaeological evidence and environmental histories collected from the South Island. Research from the South Island suggests that once humans arrived in New Zealand around 1300 AD they quickly and dramatically impacted the environment. Though more research has been undertaken on the North Island recently, the north remains under-researched compared to the south regarding these issues. The variety of subsistence practices available in this sub-tropical microclimate and the wetter, less combustible forests may have led to different land use practices and pace of landscape alteration compared to the drier, cooler climate of the South Island.
For this project two lacustrine systems proximal to archaeological sites in Northland, New Zealand were cored, and a multi-proxy approach was undertaken to create a high-resolution chronology of anthropogenic environmental change. The age-model was used to identify the timing of human arrival and develop a catchment specific environmental history to determine the speed and duration of land use in this area to compare to records from the south. Thorough testing was performed to identify reliable radiocarbon targets to provide confidence in the precision for the chronology. Elemental and isotopic carbon and nitrogen measurement, C:N ratios and X-ray fluorescence (XRF) measurements were performed on the lake sediments to create catchment specific proxy data. These data, supported by the age-depth model and pollen and charcoal records, were used to determine the pace and intensity of local land use through time.
The results of the research indicate that pollen concentrated from post-human impact sediment produced unreliably old 14C ages and could not be used to develop the lake chronologies through those time-depths. However, terrestrial macrofossils appear to have returned accurate ages for deposition and can be used in cultural landscapes to build chronologies. The age-depth model projects human arrival for the Far North District between 1164-1277cal AD, suggesting that this area was colonized early in New Zealand’s settlement history. The isotopic and elemental data for both lakes show evidence of human modification of the environment but raise the possibility that different processes were occurring in each lake. The pace of human modification of the landscape appears to be longer in duration compared to environmental records from the south but indicate that shortly after Polynesian arrival the study area was completely altered by anthropogenic modification.