Vegetation and climate history of the Longwood Range, South Island, New Zealand, 12 000 B. P. to the present

Abstract

Raised bogs on the crest and at the foot of the Longwood Range (altitude 700 m) in western Southland provide a pollen record of vegetation Change which spans the last 12 000 years. Before 12 000 yr B.P. coastal Southland was covered with a sparse grassland-shrubland. After 12 000 yr B.P. Coprosma-Myrsine shrub land spread, and a low Hoheria forest established on the Longwood Range in response to ameliorating climate. Throughout this period the climate remained cool, variable, and perhaps subject to frequent outbreaks of cold subpolar air. There was no significant spread of tall forest. At about 9400 yr B.P. Podocarpus spicatus-Dacrycarpus dacrydioides forest replaced the shrubland, and remained dominant until 7000 yr B.P. Climate during this interval was warmer than at present, but also slightly drier. Dacrydium cupressinum and Nothofagus menziesii began to spread from about 7000 yr B.P., a process that accelerated after 4000 yr B.P. and slowed or stopped by 2500 yr B.P. Changes since 7000 yr B.P. are largely attributed to a shift towards a wetter, cooler, and perhaps more stormy climate which was the consequence of an increased south-westerly airflow. POlynesian deforestation of the region began at about 900 yr B.P. but major destruction of the lowland forest and its replacement with fernshrubland occurred at about 700 yr B.P.

Keywords:

• vegetation history
• climate change
• pollen analysis
• late glacial
• Holocene
• Last Glaciation
• Quaternary
• Southland, New Zealand