Late Holocene forest disturbance in Gisborne, New Zealand: a comparison ofterrestrial and marine pollen records

A late Holococene (from c. 5500 yr B.P.) record of vegetation change is pre sented for the Gisborne region, based on pollen, charcoal, and tephra analy ses of a terrestrial and a marine core. Up until the time of anthropogenic deforestation about 650 yr B.P., well drained lowland areas were covered wi th a Prumnopitys taxifolia, and Dacrydium cupressinum-dominated podocarp/ha rdwood forest. The poorly drained Dacrycarpus dacrydioides-dominated alluvi al swamp forests were not as vulnerable to fire, and remained on the Gisbor ne Plains until European drainage and clearance began in the 19th century. In the last 5500 yr B.P., the lowland forests have been disturbed by at lea st five ashfalls originating from volcanic eruptions in the Central Volcani c Region. Where the terrestrial and marine cores overlap, comparisons of th e pollen records show the vegetation changes and taxa present to be compara ble. The fire record was not clear in the marine record, as the charcoal cu rve was diluted with high background levels of reworked charcoal. Sedimenta tion rates from the marine core indicate that erosion in the Waipaoa catchm ent has increased significantly since European clearance of soil-protecting remnant forest and fern/scrubland and its replacement with pasture.