Late-glacial and Holocene vegetation and environment of Campbell Island,far southern New Zealand

Campbell Island lies 600 km southeast of the New Zealand mainland. Scrub, grassland, rushes and large-leaved forb vegetation grow on the deep peats that cover nearly the entire island. Campbell Island was extensively glaciated at the height of the Last Glaciation and mean annual temperatures were about 5°C below present. Peat growth began c. 13 000 BP, and large-leaved forbs, rushes and other tundra plants grew under a cooler (—3°C) climate than now. Grassland largely replaced the large-leaved forbs at around 9500 BP as the climate warmed. Scrub and dwarf forest of Dracophyllum was uncommon until around 7000 BP and reached its greatest altitudinal and areal extent between then and 3000 BP. Warmer (+0.5°C), drier summer conditions during the mid- to late Holocene favoured this scrub expansion. In the late Holocene, Dracophyllum scrub was reduced in density and altitudinal range, probably by cooling temperatures and increased southwesterly winds. A warming of the island by 1 °C since the turn of the century may have encouraged Dracophyllum to spread into tussock and bog communities depleted by late nineteenth to early twentieth century fire and grazing.