| Popis: |
Analysis of high spatial resolution of nine pollen profiles (150 m–6·5 km apart) from Great Barrier Island shows that between 7500 and 600 calibrated year bp, the island had a low frequency of natural fires compared with elsewhere in the northern North Island. Except for one site which has locally sourced pre-Kaharoa charcoal, source of this charcoal in the Awana–Kaitoke area is uncertain. If local pre-Kaharoa burning did occur at other sites in this area, it was patchy, occurring at different times in different places, and was small-scale. Charcoal was first recorded c. 1700 year bp, then again after c. 1200 year bp. Pre-Kaharoa charcoal on Great Barrier may be interpreted as either an increased frequency of natural fires in the region due to climatic change to drier conditions, or small-scale, localized initial human impact, or some combination of these factors. Major post-Kaharoa burning in the Awana–Kaitoke area was also patchy, commencing at different times in different places. The presence of the Kaharoa Tephra on Great Barrier Island allows the commencement of major, sustained Polynesian deforestation at Awana–Kaitoke to be reliably dated to c. 600 year bp at some sites, and possibly up to 50 years later at other sites. |
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